* hurd/hurd/signal.h (struct hurd_sigstate): New member `preempters'. cvs/libc-960102

	(hurd_preempt_signals, hurd_unpreempt_signals): Decls removed.
	* hurd/hurd/sigpreempt.h: New file.
	* hurd/preempt-sig.c: Rewritten with new interface.
	* sysdeps/mach/hurd/jmp-unwind.c (_longjmp_unwind): Remove local signal
	preempters being unwound past.

	* db: New directory, 4.4 BSD db package incorporated from BSD db-1.85
	release.

	* sysdeps/unix/sysv/linux/sys/param.h: Several new macros for BSD
	compatibility.

49 files changed, 11649 insertions, 104 deletions

diff --git a/ChangeLog b/ChangeLog
index 5edb92e6ac..53f44887a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
 Tue Jan  2 00:50:10 1996  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>
 
+	* hurd/hurd/signal.h (struct hurd_sigstate): New member `preempters'.
+	(hurd_preempt_signals, hurd_unpreempt_signals): Decls removed.
+	* hurd/hurd/sigpreempt.h: New file.
+	* hurd/preempt-sig.c: Rewritten with new interface.
+	* sysdeps/mach/hurd/jmp-unwind.c (_longjmp_unwind): Remove local signal
+	preempters being unwound past.
+
+	* db: New directory, 4.4 BSD db package incorporated from BSD db-1.85
+	release.
+
+	* sysdeps/unix/sysv/linux/sys/param.h: Several new macros for BSD
+	compatibility.
+
 	* misc/queue.h: New file, incorporated from 4.4BSD.
 	* misc/Makefile (headers): Add queue.h.
 
diff --git a/NEWS b/NEWS
index a20648f6a9..c5b0d45c49 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,6 @@
-GNU C Library NEWS -- history of user-visible changes.  26 July 1995
+GNU C Library NEWS -- history of user-visible changes.  2 January 1996
 
-Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
 See the end for copying conditions.
 
 Please send GNU C library bug reports to bug-glibc@prep.ai.mit.edu.
@@ -32,6 +32,11 @@ Version 1.10
   new header file <link.h> gives access to the internals of the run-time
   dynamic linker, `ld.so'.
 
+* The C library now provides the run-time support code for profiling
+  executables compiled with `-pg'.  Programs can control the profiling code
+  through the interface in <sys/gmon.h>.  The profiling code was adapted
+  from 4.4 BSD-Lite.
+
 * The new functions `strtoq' and `strtouq' parse integer values from
   strings, like `strtol' and `strtoul', but they return `long long int' and
   `unsigned long long int' values, respectively (64-bit quantities).
@@ -48,7 +53,7 @@ Version 1.10
 * The new header <langinfo.h> defines an interface for accessing
   various locale-dependent data (using the locale chosen with `setlocale').
 
-* You can now use positional parameter specifications in format strings 
+* You can now use positional parameter specifications in format strings
   for the `printf' and `scanf' families of functions.  For example,
   `printf ("Number %2$d, Mr %1$s\n", "Jones", 6);'' prints
   ``Number 6, Mr Jones''.  This is mainly useful when providing different
@@ -75,7 +80,7 @@ Version 1.10
 * The new header file <fts.h> and suite of functions simplify programs that
   operate on directory trees.  This code comes from 4.4 BSD.
 
-* The resolver code has been updated from the BIND-4.9.3-BETA26 release.
+* The resolver code has been updated from the BIND 4.9.3 release.
 
 * The new function `malloc_find_object_address' finds the starting address
   of a malloc'd block, given any address within the block.  This can be
@@ -123,13 +128,45 @@ Version 1.10
 * Ulrich Drepper has contributed new, highly-optimized versions of several
   string functions for the i486/Pentium family of processors.
 
-* Ulrich Drepper has updated the Linux-specific code, based largely 
+* Ulrich Drepper has updated the Linux-specific code, based largely
   on work done in Hongjiu Lu's version of GNU libc for Linux.
   The GNU library now supports Linux versions 1.3.29 and later,
   using the ELF object file format (i[345]86-*-linux).
 
 * Ulrich Drepper has contributed a new set of message catalog functions to
   support multiple languages, for use with his new package GNU gettext.
+
+* New header file <values.h> gives SVID-compatible names for <limits.h>
+  constants.
+
+* Various new macros, declarations, and small header files for compatibility
+  with 4.4 BSD.
+
+* New function `group_member' is a convenient way to check if a process has
+  a given effective group ID.
+
+* When using GCC 2.7 and later, the socket functions are now declared in a
+  special way so that passing an argument of type `struct sockaddr_in *',
+  `struct sockaddr_ns *', or `struct sockaddr_un *' instead of the generic
+  `struct sockaddr *' type, does not generate a type-clash warning.
+
+* New function `error' declared in header file <error.h> is a convenient
+  function for printing error messages and optionally exitting; this is the
+  canonical function used in GNU programs.  The new functions `err', `warn',
+  and friends in header file <err.h> are the canonical 4.4 BSD interface for
+  doing the same thing.
+
+* The <glob.h> interface has several new flags from 4.4 BSD that extend the
+  POSIX.2 `glob' function to do ~ and {...} expansion.
+
+* New function `unsetenv' complements `setenv' for compatibility with 4.4 BSD.
+
+* New function `getsid' returns session ID number on systems that support it.
+
+* The 4.4 BSD `db' library has been incorporated into the GNU C library.
+  New header files <db.h> and <mpool.h> provide a rich set of functions for
+  several types of simple databases stored in memory and in files, and
+  <ndbm.h> is an old `ndbm'-compatbile interface using the `db' functions.
 
 Version 1.09
 
@@ -362,7 +399,7 @@ Version 1.04
   compiler, so the C library should now work with C++ code.
 
 * The header file <bstring.h> is gone.  <string.h> now declares bcopy,
-  bcmp, bzero, and ffs.  
+  bcmp, bzero, and ffs.
 
 * Mike Haertel (of GNU e?grep and malloc fame) has written a new sorting
   function which uses the `merge sort' algorithm, and is said to be
@@ -388,7 +425,7 @@ Version 1.04
 ----------------------------------------------------------------------
 Copyright information:
 
-Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1992, 93, 94, 95, 96 Free Software Foundation, Inc.
 
    Permission is granted to anyone to make or distribute verbatim copies
    of this document as received, in any medium, provided that the
diff --git a/db/Makefile b/db/Makefile
new file mode 100644
index 0000000000..c7a385a486
--- /dev/null
+++ b/db/Makefile
@@ -0,0 +1,28 @@
+# Makefile for 4.4BSD db code in GNU C library.
+# This code is taken verbatim from the BSD db 1.85 package.  Only this
+# Makefile and compat.h were written for GNU libc, and the header files
+# moved up to this directory.
+
+subdir = db
+
+dbdirs = btree db hash mpool recno
+vpath %.c $(dbdirs)
+
+routines := bt_close bt_conv bt_debug bt_delete bt_get bt_open bt_overflow \
+	    bt_page bt_put bt_search bt_seq bt_split bt_utils		   \
+	    db								   \
+	    hash hash_bigkey hash_buf hash_func hash_log2 hash_page	   \
+	    ndbm							   \
+	    mpool							   \
+	    rec_close rec_delete rec_get rec_open rec_put rec_search	   \
+	    rec_seq rec_utils
+
+headers		:= db.h mpool.h ndbm.h
+distribute	:= compat.h					\
+		   btree/btree.h btree/extern.h			\
+		   hash/extern.h hash/hash.h hash/page.h	\
+		   recno/extern.h recno/recno.h
+
+include ../Rules
+
+CPPFLAGS += -D__DBINTERFACE_PRIVATE
diff --git a/db/btree/bt_close.c b/db/btree/bt_close.c
new file mode 100644
index 0000000000..27f9ab660f
--- /dev/null
+++ b/db/btree/bt_close.c
@@ -0,0 +1,182 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_close.c	8.7 (Berkeley) 8/17/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int bt_meta __P((BTREE *));
+
+/*
+ * BT_CLOSE -- Close a btree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__bt_close(dbp)
+	DB *dbp;
+{
+	BTREE *t;
+	int fd;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Sync the tree. */
+	if (__bt_sync(dbp, 0) == RET_ERROR)
+		return (RET_ERROR);
+
+	/* Close the memory pool. */
+	if (mpool_close(t->bt_mp) == RET_ERROR)
+		return (RET_ERROR);
+
+	/* Free random memory. */
+	if (t->bt_cursor.key.data != NULL) {
+		free(t->bt_cursor.key.data);
+		t->bt_cursor.key.size = 0;
+		t->bt_cursor.key.data = NULL;
+	}
+	if (t->bt_rkey.data) {
+		free(t->bt_rkey.data);
+		t->bt_rkey.size = 0;
+		t->bt_rkey.data = NULL;
+	}
+	if (t->bt_rdata.data) {
+		free(t->bt_rdata.data);
+		t->bt_rdata.size = 0;
+		t->bt_rdata.data = NULL;
+	}
+
+	fd = t->bt_fd;
+	free(t);
+	free(dbp);
+	return (close(fd) ? RET_ERROR : RET_SUCCESS);
+}
+
+/*
+ * BT_SYNC -- sync the btree to disk.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__bt_sync(dbp, flags)
+	const DB *dbp;
+	u_int flags;
+{
+	BTREE *t;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Sync doesn't currently take any flags. */
+	if (flags != 0) {
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	if (F_ISSET(t, B_INMEM | B_RDONLY) || !F_ISSET(t, B_MODIFIED))
+		return (RET_SUCCESS);
+
+	if (F_ISSET(t, B_METADIRTY) && bt_meta(t) == RET_ERROR)
+		return (RET_ERROR);
+
+	if ((status = mpool_sync(t->bt_mp)) == RET_SUCCESS)
+		F_CLR(t, B_MODIFIED);
+
+	return (status);
+}
+
+/*
+ * BT_META -- write the tree meta data to disk.
+ *
+ * Parameters:
+ *	t:	tree
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+static int
+bt_meta(t)
+	BTREE *t;
+{
+	BTMETA m;
+	void *p;
+
+	if ((p = mpool_get(t->bt_mp, P_META, 0)) == NULL)
+		return (RET_ERROR);
+
+	/* Fill in metadata. */
+	m.magic = BTREEMAGIC;
+	m.version = BTREEVERSION;
+	m.psize = t->bt_psize;
+	m.free = t->bt_free;
+	m.nrecs = t->bt_nrecs;
+	m.flags = F_ISSET(t, SAVEMETA);
+
+	memmove(p, &m, sizeof(BTMETA));
+	mpool_put(t->bt_mp, p, MPOOL_DIRTY);
+	return (RET_SUCCESS);
+}
diff --git a/db/btree/bt_conv.c b/db/btree/bt_conv.c
new file mode 100644
index 0000000000..1cb208b14d
--- /dev/null
+++ b/db/btree/bt_conv.c
@@ -0,0 +1,221 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_conv.c	8.5 (Berkeley) 8/17/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+
+#include <db.h>
+#include "btree.h"
+
+static void mswap __P((PAGE *));
+
+/*
+ * __BT_BPGIN, __BT_BPGOUT --
+ *	Convert host-specific number layout to/from the host-independent
+ *	format stored on disk.
+ *
+ * Parameters:
+ *	t:	tree
+ *	pg:	page number
+ *	h:	page to convert
+ */
+void
+__bt_pgin(t, pg, pp)
+	void *t;
+	pgno_t pg;
+	void *pp;
+{
+	PAGE *h;
+	indx_t i, top;
+	u_char flags;
+	char *p;
+
+	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
+		return;
+	if (pg == P_META) {
+		mswap(pp);
+		return;
+	}
+
+	h = pp;
+	M_32_SWAP(h->pgno);
+	M_32_SWAP(h->prevpg);
+	M_32_SWAP(h->nextpg);
+	M_32_SWAP(h->flags);
+	M_16_SWAP(h->lower);
+	M_16_SWAP(h->upper);
+
+	top = NEXTINDEX(h);
+	if ((h->flags & P_TYPE) == P_BINTERNAL)
+		for (i = 0; i < top; i++) {
+			M_16_SWAP(h->linp[i]);
+			p = (char *)GETBINTERNAL(h, i);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			P_32_SWAP(p);
+			p += sizeof(pgno_t);
+			if (*(u_char *)p & P_BIGKEY) {
+				p += sizeof(u_char);
+				P_32_SWAP(p);
+				p += sizeof(pgno_t);
+				P_32_SWAP(p);
+			}
+		}
+	else if ((h->flags & P_TYPE) == P_BLEAF)
+		for (i = 0; i < top; i++) {
+			M_16_SWAP(h->linp[i]);
+			p = (char *)GETBLEAF(h, i);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			flags = *(u_char *)p;
+			if (flags & (P_BIGKEY | P_BIGDATA)) {
+				p += sizeof(u_char);
+				if (flags & P_BIGKEY) {
+					P_32_SWAP(p);
+					p += sizeof(pgno_t);
+					P_32_SWAP(p);
+				}
+				if (flags & P_BIGDATA) {
+					p += sizeof(u_int32_t);
+					P_32_SWAP(p);
+					p += sizeof(pgno_t);
+					P_32_SWAP(p);
+				}
+			}
+		}
+}
+
+void
+__bt_pgout(t, pg, pp)
+	void *t;
+	pgno_t pg;
+	void *pp;
+{
+	PAGE *h;
+	indx_t i, top;
+	u_char flags;
+	char *p;
+
+	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
+		return;
+	if (pg == P_META) {
+		mswap(pp);
+		return;
+	}
+
+	h = pp;
+	top = NEXTINDEX(h);
+	if ((h->flags & P_TYPE) == P_BINTERNAL)
+		for (i = 0; i < top; i++) {
+			p = (char *)GETBINTERNAL(h, i);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			P_32_SWAP(p);
+			p += sizeof(pgno_t);
+			if (*(u_char *)p & P_BIGKEY) {
+				p += sizeof(u_char);
+				P_32_SWAP(p);
+				p += sizeof(pgno_t);
+				P_32_SWAP(p);
+			}
+			M_16_SWAP(h->linp[i]);
+		}
+	else if ((h->flags & P_TYPE) == P_BLEAF)
+		for (i = 0; i < top; i++) {
+			p = (char *)GETBLEAF(h, i);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			P_32_SWAP(p);
+			p += sizeof(u_int32_t);
+			flags = *(u_char *)p;
+			if (flags & (P_BIGKEY | P_BIGDATA)) {
+				p += sizeof(u_char);
+				if (flags & P_BIGKEY) {
+					P_32_SWAP(p);
+					p += sizeof(pgno_t);
+					P_32_SWAP(p);
+				}
+				if (flags & P_BIGDATA) {
+					p += sizeof(u_int32_t);
+					P_32_SWAP(p);
+					p += sizeof(pgno_t);
+					P_32_SWAP(p);
+				}
+			}
+			M_16_SWAP(h->linp[i]);
+		}
+
+	M_32_SWAP(h->pgno);
+	M_32_SWAP(h->prevpg);
+	M_32_SWAP(h->nextpg);
+	M_32_SWAP(h->flags);
+	M_16_SWAP(h->lower);
+	M_16_SWAP(h->upper);
+}
+
+/*
+ * MSWAP -- Actually swap the bytes on the meta page.
+ *
+ * Parameters:
+ *	p:	page to convert
+ */
+static void
+mswap(pg)
+	PAGE *pg;
+{
+	char *p;
+
+	p = (char *)pg;
+	P_32_SWAP(p);		/* magic */
+	p += sizeof(u_int32_t);
+	P_32_SWAP(p);		/* version */
+	p += sizeof(u_int32_t);
+	P_32_SWAP(p);		/* psize */
+	p += sizeof(u_int32_t);
+	P_32_SWAP(p);		/* free */
+	p += sizeof(u_int32_t);
+	P_32_SWAP(p);		/* nrecs */
+	p += sizeof(u_int32_t);
+	P_32_SWAP(p);		/* flags */
+	p += sizeof(u_int32_t);
+}
diff --git a/db/btree/bt_debug.c b/db/btree/bt_debug.c
new file mode 100644
index 0000000000..3aefbe7622
--- /dev/null
+++ b/db/btree/bt_debug.c
@@ -0,0 +1,329 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_debug.c	8.5 (Berkeley) 8/17/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+#ifdef DEBUG
+/*
+ * BT_DUMP -- Dump the tree
+ *
+ * Parameters:
+ *	dbp:	pointer to the DB
+ */
+void
+__bt_dump(dbp)
+	DB *dbp;
+{
+	BTREE *t;
+	PAGE *h;
+	pgno_t i;
+	char *sep;
+
+	t = dbp->internal;
+	(void)fprintf(stderr, "%s: pgsz %d",
+	    F_ISSET(t, B_INMEM) ? "memory" : "disk", t->bt_psize);
+	if (F_ISSET(t, R_RECNO))
+		(void)fprintf(stderr, " keys %lu", t->bt_nrecs);
+#undef X
+#define	X(flag, name) \
+	if (F_ISSET(t, flag)) { \
+		(void)fprintf(stderr, "%s%s", sep, name); \
+		sep = ", "; \
+	}
+	if (t->flags != 0) {
+		sep = " flags (";
+		X(R_FIXLEN,	"FIXLEN");
+		X(B_INMEM,	"INMEM");
+		X(B_NODUPS,	"NODUPS");
+		X(B_RDONLY,	"RDONLY");
+		X(R_RECNO,	"RECNO");
+		X(B_METADIRTY,"METADIRTY");
+		(void)fprintf(stderr, ")\n");
+	}
+#undef X
+
+	for (i = P_ROOT; (h = mpool_get(t->bt_mp, i, 0)) != NULL; ++i) {
+		__bt_dpage(h);
+		(void)mpool_put(t->bt_mp, h, 0);
+	}
+}
+
+/*
+ * BT_DMPAGE -- Dump the meta page
+ *
+ * Parameters:
+ *	h:	pointer to the PAGE
+ */
+void
+__bt_dmpage(h)
+	PAGE *h;
+{
+	BTMETA *m;
+	char *sep;
+
+	m = (BTMETA *)h;
+	(void)fprintf(stderr, "magic %lx\n", m->magic);
+	(void)fprintf(stderr, "version %lu\n", m->version);
+	(void)fprintf(stderr, "psize %lu\n", m->psize);
+	(void)fprintf(stderr, "free %lu\n", m->free);
+	(void)fprintf(stderr, "nrecs %lu\n", m->nrecs);
+	(void)fprintf(stderr, "flags %lu", m->flags);
+#undef X
+#define	X(flag, name) \
+	if (m->flags & flag) { \
+		(void)fprintf(stderr, "%s%s", sep, name); \
+		sep = ", "; \
+	}
+	if (m->flags) {
+		sep = " (";
+		X(B_NODUPS,	"NODUPS");
+		X(R_RECNO,	"RECNO");
+		(void)fprintf(stderr, ")");
+	}
+}
+
+/*
+ * BT_DNPAGE -- Dump the page
+ *
+ * Parameters:
+ *	n:	page number to dump.
+ */
+void
+__bt_dnpage(dbp, pgno)
+	DB *dbp;
+	pgno_t pgno;
+{
+	BTREE *t;
+	PAGE *h;
+
+	t = dbp->internal;
+	if ((h = mpool_get(t->bt_mp, pgno, 0)) != NULL) {
+		__bt_dpage(h);
+		(void)mpool_put(t->bt_mp, h, 0);
+	}
+}
+
+/*
+ * BT_DPAGE -- Dump the page
+ *
+ * Parameters:
+ *	h:	pointer to the PAGE
+ */
+void
+__bt_dpage(h)
+	PAGE *h;
+{
+	BINTERNAL *bi;
+	BLEAF *bl;
+	RINTERNAL *ri;
+	RLEAF *rl;
+	indx_t cur, top;
+	char *sep;
+
+	(void)fprintf(stderr, "    page %d: (", h->pgno);
+#undef X
+#define	X(flag, name) \
+	if (h->flags & flag) { \
+		(void)fprintf(stderr, "%s%s", sep, name); \
+		sep = ", "; \
+	}
+	sep = "";
+	X(P_BINTERNAL,	"BINTERNAL")		/* types */
+	X(P_BLEAF,	"BLEAF")
+	X(P_RINTERNAL,	"RINTERNAL")		/* types */
+	X(P_RLEAF,	"RLEAF")
+	X(P_OVERFLOW,	"OVERFLOW")
+	X(P_PRESERVE,	"PRESERVE");
+	(void)fprintf(stderr, ")\n");
+#undef X
+
+	(void)fprintf(stderr, "\tprev %2d next %2d", h->prevpg, h->nextpg);
+	if (h->flags & P_OVERFLOW)
+		return;
+
+	top = NEXTINDEX(h);
+	(void)fprintf(stderr, " lower %3d upper %3d nextind %d\n",
+	    h->lower, h->upper, top);
+	for (cur = 0; cur < top; cur++) {
+		(void)fprintf(stderr, "\t[%03d] %4d ", cur, h->linp[cur]);
+		switch (h->flags & P_TYPE) {
+		case P_BINTERNAL:
+			bi = GETBINTERNAL(h, cur);
+			(void)fprintf(stderr,
+			    "size %03d pgno %03d", bi->ksize, bi->pgno);
+			if (bi->flags & P_BIGKEY)
+				(void)fprintf(stderr, " (indirect)");
+			else if (bi->ksize)
+				(void)fprintf(stderr,
+				    " {%.*s}", (int)bi->ksize, bi->bytes);
+			break;
+		case P_RINTERNAL:
+			ri = GETRINTERNAL(h, cur);
+			(void)fprintf(stderr, "entries %03d pgno %03d",
+				ri->nrecs, ri->pgno);
+			break;
+		case P_BLEAF:
+			bl = GETBLEAF(h, cur);
+			if (bl->flags & P_BIGKEY)
+				(void)fprintf(stderr,
+				    "big key page %lu size %u/",
+				    *(pgno_t *)bl->bytes,
+				    *(u_int32_t *)(bl->bytes + sizeof(pgno_t)));
+			else if (bl->ksize)
+				(void)fprintf(stderr, "%s/", bl->bytes);
+			if (bl->flags & P_BIGDATA)
+				(void)fprintf(stderr,
+				    "big data page %lu size %u",
+				    *(pgno_t *)(bl->bytes + bl->ksize),
+				    *(u_int32_t *)(bl->bytes + bl->ksize +
+				    sizeof(pgno_t)));
+			else if (bl->dsize)
+				(void)fprintf(stderr, "%.*s",
+				    (int)bl->dsize, bl->bytes + bl->ksize);
+			break;
+		case P_RLEAF:
+			rl = GETRLEAF(h, cur);
+			if (rl->flags & P_BIGDATA)
+				(void)fprintf(stderr,
+				    "big data page %lu size %u",
+				    *(pgno_t *)rl->bytes,
+				    *(u_int32_t *)(rl->bytes + sizeof(pgno_t)));
+			else if (rl->dsize)
+				(void)fprintf(stderr,
+				    "%.*s", (int)rl->dsize, rl->bytes);
+			break;
+		}
+		(void)fprintf(stderr, "\n");
+	}
+}
+#endif
+
+#ifdef STATISTICS
+/*
+ * BT_STAT -- Gather/print the tree statistics
+ *
+ * Parameters:
+ *	dbp:	pointer to the DB
+ */
+void
+__bt_stat(dbp)
+	DB *dbp;
+{
+	extern u_long bt_cache_hit, bt_cache_miss, bt_pfxsaved, bt_rootsplit;
+	extern u_long bt_sortsplit, bt_split;
+	BTREE *t;
+	PAGE *h;
+	pgno_t i, pcont, pinternal, pleaf;
+	u_long ifree, lfree, nkeys;
+	int levels;
+
+	t = dbp->internal;
+	pcont = pinternal = pleaf = 0;
+	nkeys = ifree = lfree = 0;
+	for (i = P_ROOT; (h = mpool_get(t->bt_mp, i, 0)) != NULL; ++i) {
+		switch (h->flags & P_TYPE) {
+		case P_BINTERNAL:
+		case P_RINTERNAL:
+			++pinternal;
+			ifree += h->upper - h->lower;
+			break;
+		case P_BLEAF:
+		case P_RLEAF:
+			++pleaf;
+			lfree += h->upper - h->lower;
+			nkeys += NEXTINDEX(h);
+			break;
+		case P_OVERFLOW:
+			++pcont;
+			break;
+		}
+		(void)mpool_put(t->bt_mp, h, 0);
+	}
+
+	/* Count the levels of the tree. */
+	for (i = P_ROOT, levels = 0 ;; ++levels) {
+		h = mpool_get(t->bt_mp, i, 0);
+		if (h->flags & (P_BLEAF|P_RLEAF)) {
+			if (levels == 0)
+				levels = 1;
+			(void)mpool_put(t->bt_mp, h, 0);
+			break;
+		}
+		i = F_ISSET(t, R_RECNO) ?
+		    GETRINTERNAL(h, 0)->pgno :
+		    GETBINTERNAL(h, 0)->pgno;
+		(void)mpool_put(t->bt_mp, h, 0);
+	}
+
+	(void)fprintf(stderr, "%d level%s with %ld keys",
+	    levels, levels == 1 ? "" : "s", nkeys);
+	if (F_ISSET(t, R_RECNO))
+		(void)fprintf(stderr, " (%ld header count)", t->bt_nrecs);
+	(void)fprintf(stderr,
+	    "\n%lu pages (leaf %ld, internal %ld, overflow %ld)\n",
+	    pinternal + pleaf + pcont, pleaf, pinternal, pcont);
+	(void)fprintf(stderr, "%ld cache hits, %ld cache misses\n",
+	    bt_cache_hit, bt_cache_miss);
+	(void)fprintf(stderr, "%ld splits (%ld root splits, %ld sort splits)\n",
+	    bt_split, bt_rootsplit, bt_sortsplit);
+	pleaf *= t->bt_psize - BTDATAOFF;
+	if (pleaf)
+		(void)fprintf(stderr,
+		    "%.0f%% leaf fill (%ld bytes used, %ld bytes free)\n",
+		    ((double)(pleaf - lfree) / pleaf) * 100,
+		    pleaf - lfree, lfree);
+	pinternal *= t->bt_psize - BTDATAOFF;
+	if (pinternal)
+		(void)fprintf(stderr,
+		    "%.0f%% internal fill (%ld bytes used, %ld bytes free\n",
+		    ((double)(pinternal - ifree) / pinternal) * 100,
+		    pinternal - ifree, ifree);
+	if (bt_pfxsaved)
+		(void)fprintf(stderr, "prefix checking removed %lu bytes.\n",
+		    bt_pfxsaved);
+}
+#endif
diff --git a/db/btree/bt_delete.c b/db/btree/bt_delete.c
new file mode 100644
index 0000000000..ece1ab656e
--- /dev/null
+++ b/db/btree/bt_delete.c
@@ -0,0 +1,657 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_delete.c	8.13 (Berkeley) 7/28/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int __bt_bdelete __P((BTREE *, const DBT *));
+static int __bt_curdel __P((BTREE *, const DBT *, PAGE *, u_int));
+static int __bt_pdelete __P((BTREE *, PAGE *));
+static int __bt_relink __P((BTREE *, PAGE *));
+static int __bt_stkacq __P((BTREE *, PAGE **, CURSOR *));
+
+/*
+ * __bt_delete
+ *	Delete the item(s) referenced by a key.
+ *
+ * Return RET_SPECIAL if the key is not found.
+ */
+int
+__bt_delete(dbp, key, flags)
+	const DB *dbp;
+	const DBT *key;
+	u_int flags;
+{
+	BTREE *t;
+	CURSOR *c;
+	PAGE *h;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Check for change to a read-only tree. */
+	if (F_ISSET(t, B_RDONLY)) {
+		errno = EPERM;
+		return (RET_ERROR);
+	}
+
+	switch (flags) {
+	case 0:
+		status = __bt_bdelete(t, key);
+		break;
+	case R_CURSOR:
+		/*
+		 * If flags is R_CURSOR, delete the cursor.  Must already
+		 * have started a scan and not have already deleted it.
+		 */
+		c = &t->bt_cursor;
+		if (F_ISSET(c, CURS_INIT)) {
+			if (F_ISSET(c, CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE))
+				return (RET_SPECIAL);
+			if ((h = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL)
+				return (RET_ERROR);
+
+			/*
+			 * If the page is about to be emptied, we'll need to
+			 * delete it, which means we have to acquire a stack.
+			 */
+			if (NEXTINDEX(h) == 1)
+				if (__bt_stkacq(t, &h, &t->bt_cursor))
+					return (RET_ERROR);
+
+			status = __bt_dleaf(t, NULL, h, c->pg.index);
+
+			if (NEXTINDEX(h) == 0 && status == RET_SUCCESS) {
+				if (__bt_pdelete(t, h))
+					return (RET_ERROR);
+			} else
+				mpool_put(t->bt_mp,
+				    h, status == RET_SUCCESS ? MPOOL_DIRTY : 0);
+			break;
+		}
+		/* FALLTHROUGH */
+	default:
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+	if (status == RET_SUCCESS)
+		F_SET(t, B_MODIFIED);
+	return (status);
+}
+
+/*
+ * __bt_stkacq --
+ *	Acquire a stack so we can delete a cursor entry.
+ *
+ * Parameters:
+ *	  t:	tree
+ *	 hp:	pointer to current, pinned PAGE pointer
+ *	  c:	pointer to the cursor
+ *
+ * Returns:
+ *	0 on success, 1 on failure
+ */
+static int
+__bt_stkacq(t, hp, c)
+	BTREE *t;
+	PAGE **hp;
+	CURSOR *c;
+{
+	BINTERNAL *bi;
+	EPG *e;
+	EPGNO *parent;
+	PAGE *h;
+	indx_t index;
+	pgno_t pgno;
+	recno_t nextpg, prevpg;
+	int exact, level;
+	
+	/*
+	 * Find the first occurrence of the key in the tree.  Toss the
+	 * currently locked page so we don't hit an already-locked page.
+	 */
+	h = *hp;
+	mpool_put(t->bt_mp, h, 0);
+	if ((e = __bt_search(t, &c->key, &exact)) == NULL)
+		return (1);
+	h = e->page;
+
+	/* See if we got it in one shot. */
+	if (h->pgno == c->pg.pgno)
+		goto ret;
+
+	/*
+	 * Move right, looking for the page.  At each move we have to move
+	 * up the stack until we don't have to move to the next page.  If
+	 * we have to change pages at an internal level, we have to fix the
+	 * stack back up.
+	 */
+	while (h->pgno != c->pg.pgno) {
+		if ((nextpg = h->nextpg) == P_INVALID)
+			break;
+		mpool_put(t->bt_mp, h, 0);
+
+		/* Move up the stack. */
+		for (level = 0; (parent = BT_POP(t)) != NULL; ++level) {
+			/* Get the parent page. */
+			if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
+				return (1);
+
+			/* Move to the next index. */
+			if (parent->index != NEXTINDEX(h) - 1) {
+				index = parent->index + 1;
+				BT_PUSH(t, h->pgno, index);
+				break;
+			}
+			mpool_put(t->bt_mp, h, 0);
+		}
+
+		/* Restore the stack. */
+		while (level--) {
+			/* Push the next level down onto the stack. */
+			bi = GETBINTERNAL(h, index);
+			pgno = bi->pgno;
+			BT_PUSH(t, pgno, 0);
+
+			/* Lose the currently pinned page. */
+			mpool_put(t->bt_mp, h, 0);
+
+			/* Get the next level down. */
+			if ((h = mpool_get(t->bt_mp, pgno, 0)) == NULL)
+				return (1);
+			index = 0;
+		}
+		mpool_put(t->bt_mp, h, 0);
+		if ((h = mpool_get(t->bt_mp, nextpg, 0)) == NULL)
+			return (1);
+	}
+
+	if (h->pgno == c->pg.pgno)
+		goto ret;
+
+	/* Reacquire the original stack. */
+	mpool_put(t->bt_mp, h, 0);
+	if ((e = __bt_search(t, &c->key, &exact)) == NULL)
+		return (1);
+	h = e->page;
+
+	/*
+	 * Move left, looking for the page.  At each move we have to move
+	 * up the stack until we don't have to change pages to move to the
+	 * next page.  If we have to change pages at an internal level, we
+	 * have to fix the stack back up.
+	 */
+	while (h->pgno != c->pg.pgno) {
+		if ((prevpg = h->prevpg) == P_INVALID)
+			break;
+		mpool_put(t->bt_mp, h, 0);
+
+		/* Move up the stack. */
+		for (level = 0; (parent = BT_POP(t)) != NULL; ++level) {
+			/* Get the parent page. */
+			if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
+				return (1);
+
+			/* Move to the next index. */
+			if (parent->index != 0) {
+				index = parent->index - 1;
+				BT_PUSH(t, h->pgno, index);
+				break;
+			}
+			mpool_put(t->bt_mp, h, 0);
+		}
+
+		/* Restore the stack. */
+		while (level--) {
+			/* Push the next level down onto the stack. */
+			bi = GETBINTERNAL(h, index);
+			pgno = bi->pgno;
+
+			/* Lose the currently pinned page. */
+			mpool_put(t->bt_mp, h, 0);
+
+			/* Get the next level down. */
+			if ((h = mpool_get(t->bt_mp, pgno, 0)) == NULL)
+				return (1);
+
+			index = NEXTINDEX(h) - 1;
+			BT_PUSH(t, pgno, index);
+		}
+		mpool_put(t->bt_mp, h, 0);
+		if ((h = mpool_get(t->bt_mp, prevpg, 0)) == NULL)
+			return (1);
+	}
+	
+
+ret:	mpool_put(t->bt_mp, h, 0);
+	return ((*hp = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL);
+}
+
+/*
+ * __bt_bdelete --
+ *	Delete all key/data pairs matching the specified key.
+ *
+ * Parameters:
+ *	  t:	tree
+ *	key:	key to delete
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
+ */
+static int
+__bt_bdelete(t, key)
+	BTREE *t;
+	const DBT *key;
+{
+	EPG *e;
+	PAGE *h;
+	int deleted, exact, redo;
+
+	deleted = 0;
+
+	/* Find any matching record; __bt_search pins the page. */
+loop:	if ((e = __bt_search(t, key, &exact)) == NULL)
+		return (deleted ? RET_SUCCESS : RET_ERROR);
+	if (!exact) {
+		mpool_put(t->bt_mp, e->page, 0);
+		return (deleted ? RET_SUCCESS : RET_SPECIAL);
+	}
+
+	/*
+	 * Delete forward, then delete backward, from the found key.  If
+	 * there are duplicates and we reach either side of the page, do
+	 * the key search again, so that we get them all.
+	 */
+	redo = 0;
+	h = e->page;
+	do {
+		if (__bt_dleaf(t, key, h, e->index)) {
+			mpool_put(t->bt_mp, h, 0);
+			return (RET_ERROR);
+		}
+		if (F_ISSET(t, B_NODUPS)) {
+			if (NEXTINDEX(h) == 0) {
+				if (__bt_pdelete(t, h))
+					return (RET_ERROR);
+			} else
+				mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+			return (RET_SUCCESS);
+		}
+		deleted = 1;
+	} while (e->index < NEXTINDEX(h) && __bt_cmp(t, key, e) == 0);
+
+	/* Check for right-hand edge of the page. */
+	if (e->index == NEXTINDEX(h))
+		redo = 1;
+
+	/* Delete from the key to the beginning of the page. */
+	while (e->index-- > 0) {
+		if (__bt_cmp(t, key, e) != 0)
+			break;
+		if (__bt_dleaf(t, key, h, e->index) == RET_ERROR) {
+			mpool_put(t->bt_mp, h, 0);
+			return (RET_ERROR);
+		}
+		if (e->index == 0)
+			redo = 1;
+	}
+
+	/* Check for an empty page. */
+	if (NEXTINDEX(h) == 0) {
+		if (__bt_pdelete(t, h))
+			return (RET_ERROR);
+		goto loop;
+	}
+
+	/* Put the page. */
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+	if (redo)
+		goto loop;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_pdelete --
+ *	Delete a single page from the tree.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	leaf page
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ *
+ * Side-effects:
+ *	mpool_put's the page
+ */
+static int
+__bt_pdelete(t, h)
+	BTREE *t;
+	PAGE *h;
+{
+	BINTERNAL *bi;
+	PAGE *pg;
+	EPGNO *parent;
+	indx_t cnt, index, *ip, offset;
+	u_int32_t nksize;
+	char *from;
+
+	/*
+	 * Walk the parent page stack -- a LIFO stack of the pages that were
+	 * traversed when we searched for the page where the delete occurred.
+	 * Each stack entry is a page number and a page index offset.  The
+	 * offset is for the page traversed on the search.  We've just deleted
+	 * a page, so we have to delete the key from the parent page.
+	 *
+	 * If the delete from the parent page makes it empty, this process may
+	 * continue all the way up the tree.  We stop if we reach the root page
+	 * (which is never deleted, it's just not worth the effort) or if the
+	 * delete does not empty the page.
+	 */
+	while ((parent = BT_POP(t)) != NULL) {
+		/* Get the parent page. */
+		if ((pg = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
+			return (RET_ERROR);
+		
+		index = parent->index;
+		bi = GETBINTERNAL(pg, index);
+
+		/* Free any overflow pages. */
+		if (bi->flags & P_BIGKEY &&
+		    __ovfl_delete(t, bi->bytes) == RET_ERROR) {
+			mpool_put(t->bt_mp, pg, 0);
+			return (RET_ERROR);
+		}
+
+		/*
+		 * Free the parent if it has only the one key and it's not the
+		 * root page. If it's the rootpage, turn it back into an empty
+		 * leaf page.
+		 */
+		if (NEXTINDEX(pg) == 1)
+			if (pg->pgno == P_ROOT) {
+				pg->lower = BTDATAOFF;
+				pg->upper = t->bt_psize;
+				pg->flags = P_BLEAF;
+			} else {
+				if (__bt_relink(t, pg) || __bt_free(t, pg))
+					return (RET_ERROR);
+				continue;
+			}
+		else {
+			/* Pack remaining key items at the end of the page. */
+			nksize = NBINTERNAL(bi->ksize);
+			from = (char *)pg + pg->upper;
+			memmove(from + nksize, from, (char *)bi - from);
+			pg->upper += nksize;
+
+			/* Adjust indices' offsets, shift the indices down. */
+			offset = pg->linp[index];
+			for (cnt = index, ip = &pg->linp[0]; cnt--; ++ip)
+				if (ip[0] < offset)
+					ip[0] += nksize;
+			for (cnt = NEXTINDEX(pg) - index; --cnt; ++ip)
+				ip[0] = ip[1] < offset ? ip[1] + nksize : ip[1];
+			pg->lower -= sizeof(indx_t);
+		}
+
+		mpool_put(t->bt_mp, pg, MPOOL_DIRTY);
+		break;
+	}
+
+	/* Free the leaf page, as long as it wasn't the root. */
+	if (h->pgno == P_ROOT) {
+		mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+		return (RET_SUCCESS);
+	}
+	return (__bt_relink(t, h) || __bt_free(t, h));
+}
+
+/*
+ * __bt_dleaf --
+ *	Delete a single record from a leaf page.
+ *
+ * Parameters:
+ *	t:	tree
+ *    key:	referenced key
+ *	h:	page
+ *	index:	index on page to delete
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__bt_dleaf(t, key, h, index)
+	BTREE *t;
+	const DBT *key;
+	PAGE *h;
+	u_int index;
+{
+	BLEAF *bl;
+	indx_t cnt, *ip, offset;
+	u_int32_t nbytes;
+	void *to;
+	char *from;
+
+	/* If this record is referenced by the cursor, delete the cursor. */
+	if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+	    !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
+	    t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index == index &&
+	    __bt_curdel(t, key, h, index))
+		return (RET_ERROR);
+
+	/* If the entry uses overflow pages, make them available for reuse. */
+	to = bl = GETBLEAF(h, index);
+	if (bl->flags & P_BIGKEY && __ovfl_delete(t, bl->bytes) == RET_ERROR)
+		return (RET_ERROR);
+	if (bl->flags & P_BIGDATA &&
+	    __ovfl_delete(t, bl->bytes + bl->ksize) == RET_ERROR)
+		return (RET_ERROR);
+
+	/* Pack the remaining key/data items at the end of the page. */
+	nbytes = NBLEAF(bl);
+	from = (char *)h + h->upper;
+	memmove(from + nbytes, from, (char *)to - from);
+	h->upper += nbytes;
+
+	/* Adjust the indices' offsets, shift the indices down. */
+	offset = h->linp[index];
+	for (cnt = index, ip = &h->linp[0]; cnt--; ++ip)
+		if (ip[0] < offset)
+			ip[0] += nbytes;
+	for (cnt = NEXTINDEX(h) - index; --cnt; ++ip)
+		ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
+	h->lower -= sizeof(indx_t);
+
+	/* If the cursor is on this page, adjust it as necessary. */
+	if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+	    !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
+	    t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index > index)
+		--t->bt_cursor.pg.index;
+
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_curdel --
+ *	Delete the cursor.
+ *
+ * Parameters:
+ *	t:	tree
+ *    key:	referenced key (or NULL)
+ *	h:	page
+ *  index:	index on page to delete
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+static int
+__bt_curdel(t, key, h, index)
+	BTREE *t;
+	const DBT *key;
+	PAGE *h;
+	u_int index;
+{
+	CURSOR *c;
+	EPG e;
+	PAGE *pg;
+	int curcopy, status;
+
+	/*
+	 * If there are duplicates, move forward or backward to one.
+	 * Otherwise, copy the key into the cursor area.
+	 */
+	c = &t->bt_cursor;
+	F_CLR(c, CURS_AFTER | CURS_BEFORE | CURS_ACQUIRE);
+
+	curcopy = 0;
+	if (!F_ISSET(t, B_NODUPS)) {
+		/*
+		 * We're going to have to do comparisons.  If we weren't
+		 * provided a copy of the key, i.e. the user is deleting
+		 * the current cursor position, get one.
+		 */
+		if (key == NULL) {
+			e.page = h;
+			e.index = index;
+			if ((status = __bt_ret(t, &e,
+			    &c->key, &c->key, NULL, NULL, 1)) != RET_SUCCESS)
+				return (status);
+			curcopy = 1;
+			key = &c->key;
+		}
+		/* Check previous key, if not at the beginning of the page. */
+		if (index > 0) { 
+			e.page = h;
+			e.index = index - 1;
+			if (__bt_cmp(t, key, &e) == 0) {
+				F_SET(c, CURS_BEFORE);
+				goto dup2;
+			}
+		}
+		/* Check next key, if not at the end of the page. */
+		if (index < NEXTINDEX(h) - 1) {
+			e.page = h;
+			e.index = index + 1;
+			if (__bt_cmp(t, key, &e) == 0) {
+				F_SET(c, CURS_AFTER);
+				goto dup2;
+			}
+		}
+		/* Check previous key if at the beginning of the page. */
+		if (index == 0 && h->prevpg != P_INVALID) {
+			if ((pg = mpool_get(t->bt_mp, h->prevpg, 0)) == NULL)
+				return (RET_ERROR);
+			e.page = pg;
+			e.index = NEXTINDEX(pg) - 1;
+			if (__bt_cmp(t, key, &e) == 0) {
+				F_SET(c, CURS_BEFORE);
+				goto dup1;
+			}
+			mpool_put(t->bt_mp, pg, 0);
+		}
+		/* Check next key if at the end of the page. */
+		if (index == NEXTINDEX(h) - 1 && h->nextpg != P_INVALID) {
+			if ((pg = mpool_get(t->bt_mp, h->nextpg, 0)) == NULL)
+				return (RET_ERROR);
+			e.page = pg;
+			e.index = 0;
+			if (__bt_cmp(t, key, &e) == 0) {
+				F_SET(c, CURS_AFTER);
+dup1:				mpool_put(t->bt_mp, pg, 0);
+dup2:				c->pg.pgno = e.page->pgno;
+				c->pg.index = e.index;
+				return (RET_SUCCESS);
+			}
+			mpool_put(t->bt_mp, pg, 0);
+		}
+	}
+	e.page = h;
+	e.index = index;
+	if (curcopy || (status =
+	    __bt_ret(t, &e, &c->key, &c->key, NULL, NULL, 1)) == RET_SUCCESS) {
+		F_SET(c, CURS_ACQUIRE);
+		return (RET_SUCCESS);
+	}
+	return (status);
+}
+
+/*
+ * __bt_relink --
+ *	Link around a deleted page.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	page to be deleted
+ */
+static int
+__bt_relink(t, h)
+	BTREE *t;
+	PAGE *h;
+{
+	PAGE *pg;
+
+	if (h->nextpg != P_INVALID) {
+		if ((pg = mpool_get(t->bt_mp, h->nextpg, 0)) == NULL)
+			return (RET_ERROR);
+		pg->prevpg = h->prevpg;
+		mpool_put(t->bt_mp, pg, MPOOL_DIRTY);
+	}
+	if (h->prevpg != P_INVALID) {
+		if ((pg = mpool_get(t->bt_mp, h->prevpg, 0)) == NULL)
+			return (RET_ERROR);
+		pg->nextpg = h->nextpg;
+		mpool_put(t->bt_mp, pg, MPOOL_DIRTY);
+	}
+	return (0);
+}
diff --git a/db/btree/bt_get.c b/db/btree/bt_get.c
new file mode 100644
index 0000000000..74824c73f4
--- /dev/null
+++ b/db/btree/bt_get.c
@@ -0,0 +1,105 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_get.c	8.6 (Berkeley) 7/20/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include <db.h>
+#include "btree.h"
+
+/*
+ * __BT_GET -- Get a record from the btree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key to find
+ *	data:	data to return
+ *	flag:	currently unused
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
+ */
+int
+__bt_get(dbp, key, data, flags)
+	const DB *dbp;
+	const DBT *key;
+	DBT *data;
+	u_int flags;
+{
+	BTREE *t;
+	EPG *e;
+	int exact, status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Get currently doesn't take any flags. */
+	if (flags) {
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	if ((e = __bt_search(t, key, &exact)) == NULL)
+		return (RET_ERROR);
+	if (!exact) {
+		mpool_put(t->bt_mp, e->page, 0);
+		return (RET_SPECIAL);
+	}
+
+	status = __bt_ret(t, e, NULL, NULL, data, &t->bt_rdata, 0);
+
+	/*
+	 * If the user is doing concurrent access, we copied the
+	 * key/data, toss the page.
+	 */
+	if (F_ISSET(t, B_DB_LOCK))
+		mpool_put(t->bt_mp, e->page, 0);
+	else
+		t->bt_pinned = e->page;
+	return (status);
+}
diff --git a/db/btree/bt_open.c b/db/btree/bt_open.c
new file mode 100644
index 0000000000..f052249777
--- /dev/null
+++ b/db/btree/bt_open.c
@@ -0,0 +1,444 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_open.c	8.10 (Berkeley) 8/17/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * Implementation of btree access method for 4.4BSD.
+ *
+ * The design here was originally based on that of the btree access method
+ * used in the Postgres database system at UC Berkeley.  This implementation
+ * is wholly independent of the Postgres code.
+ */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <db.h>
+#include "btree.h"
+
+#ifdef DEBUG
+#undef	MINPSIZE
+#define	MINPSIZE	128
+#endif
+
+static int byteorder __P((void));
+static int nroot __P((BTREE *));
+static int tmp __P((void));
+
+/*
+ * __BT_OPEN -- Open a btree.
+ *
+ * Creates and fills a DB struct, and calls the routine that actually
+ * opens the btree.
+ *
+ * Parameters:
+ *	fname:	filename (NULL for in-memory trees)
+ *	flags:	open flag bits
+ *	mode:	open permission bits
+ *	b:	BTREEINFO pointer
+ *
+ * Returns:
+ *	NULL on failure, pointer to DB on success.
+ *
+ */
+DB *
+__bt_open(fname, flags, mode, openinfo, dflags)
+	const char *fname;
+	int flags, mode, dflags;
+	const BTREEINFO *openinfo;
+{
+	struct stat sb;
+	BTMETA m;
+	BTREE *t;
+	BTREEINFO b;
+	DB *dbp;
+	pgno_t ncache;
+	ssize_t nr;
+	int machine_lorder;
+
+	t = NULL;
+
+	/*
+	 * Intention is to make sure all of the user's selections are okay
+	 * here and then use them without checking.  Can't be complete, since
+	 * we don't know the right page size, lorder or flags until the backing
+	 * file is opened.  Also, the file's page size can cause the cachesize
+	 * to change.
+	 */
+	machine_lorder = byteorder();
+	if (openinfo) {
+		b = *openinfo;
+
+		/* Flags: R_DUP. */
+		if (b.flags & ~(R_DUP))
+			goto einval;
+
+		/*
+		 * Page size must be indx_t aligned and >= MINPSIZE.  Default
+		 * page size is set farther on, based on the underlying file
+		 * transfer size.
+		 */
+		if (b.psize &&
+		    (b.psize < MINPSIZE || b.psize > MAX_PAGE_OFFSET + 1 ||
+		    b.psize & sizeof(indx_t) - 1))
+			goto einval;
+
+		/* Minimum number of keys per page; absolute minimum is 2. */
+		if (b.minkeypage) {
+			if (b.minkeypage < 2)
+				goto einval;
+		} else
+			b.minkeypage = DEFMINKEYPAGE;
+
+		/* If no comparison, use default comparison and prefix. */
+		if (b.compare == NULL) {
+			b.compare = __bt_defcmp;
+			if (b.prefix == NULL)
+				b.prefix = __bt_defpfx;
+		}
+
+		if (b.lorder == 0)
+			b.lorder = machine_lorder;
+	} else {
+		b.compare = __bt_defcmp;
+		b.cachesize = 0;
+		b.flags = 0;
+		b.lorder = machine_lorder;
+		b.minkeypage = DEFMINKEYPAGE;
+		b.prefix = __bt_defpfx;
+		b.psize = 0;
+	}
+
+	/* Check for the ubiquitous PDP-11. */
+	if (b.lorder != BIG_ENDIAN && b.lorder != LITTLE_ENDIAN)
+		goto einval;
+
+	/* Allocate and initialize DB and BTREE structures. */
+	if ((t = (BTREE *)malloc(sizeof(BTREE))) == NULL)
+		goto err;
+	memset(t, 0, sizeof(BTREE));
+	t->bt_fd = -1;			/* Don't close unopened fd on error. */
+	t->bt_lorder = b.lorder;
+	t->bt_order = NOT;
+	t->bt_cmp = b.compare;
+	t->bt_pfx = b.prefix;
+	t->bt_rfd = -1;
+
+	if ((t->bt_dbp = dbp = (DB *)malloc(sizeof(DB))) == NULL)
+		goto err;
+	memset(t->bt_dbp, 0, sizeof(DB));
+	if (t->bt_lorder != machine_lorder)
+		F_SET(t, B_NEEDSWAP);
+
+	dbp->type = DB_BTREE;
+	dbp->internal = t;
+	dbp->close = __bt_close;
+	dbp->del = __bt_delete;
+	dbp->fd = __bt_fd;
+	dbp->get = __bt_get;
+	dbp->put = __bt_put;
+	dbp->seq = __bt_seq;
+	dbp->sync = __bt_sync;
+
+	/*
+	 * If no file name was supplied, this is an in-memory btree and we
+	 * open a backing temporary file.  Otherwise, it's a disk-based tree.
+	 */
+	if (fname) {
+		switch (flags & O_ACCMODE) {
+		case O_RDONLY:
+			F_SET(t, B_RDONLY);
+			break;
+		case O_RDWR:
+			break;
+		case O_WRONLY:
+		default:
+			goto einval;
+		}
+		
+		if ((t->bt_fd = open(fname, flags, mode)) < 0)
+			goto err;
+
+	} else {
+		if ((flags & O_ACCMODE) != O_RDWR)
+			goto einval;
+		if ((t->bt_fd = tmp()) == -1)
+			goto err;
+		F_SET(t, B_INMEM);
+	}
+
+	if (fcntl(t->bt_fd, F_SETFD, 1) == -1)
+		goto err;
+
+	if (fstat(t->bt_fd, &sb))
+		goto err;
+	if (sb.st_size) {
+		if ((nr = read(t->bt_fd, &m, sizeof(BTMETA))) < 0)
+			goto err;
+		if (nr != sizeof(BTMETA))
+			goto eftype;
+
+		/*
+		 * Read in the meta-data.  This can change the notion of what
+		 * the lorder, page size and flags are, and, when the page size
+		 * changes, the cachesize value can change too.  If the user
+		 * specified the wrong byte order for an existing database, we
+		 * don't bother to return an error, we just clear the NEEDSWAP
+		 * bit.
+		 */
+		if (m.magic == BTREEMAGIC)
+			F_CLR(t, B_NEEDSWAP);
+		else {
+			F_SET(t, B_NEEDSWAP);
+			M_32_SWAP(m.magic);
+			M_32_SWAP(m.version);
+			M_32_SWAP(m.psize);
+			M_32_SWAP(m.free);
+			M_32_SWAP(m.nrecs);
+			M_32_SWAP(m.flags);
+		}
+		if (m.magic != BTREEMAGIC || m.version != BTREEVERSION)
+			goto eftype;
+		if (m.psize < MINPSIZE || m.psize > MAX_PAGE_OFFSET + 1 ||
+		    m.psize & sizeof(indx_t) - 1)
+			goto eftype;
+		if (m.flags & ~SAVEMETA)
+			goto eftype;
+		b.psize = m.psize;
+		F_SET(t, m.flags);
+		t->bt_free = m.free;
+		t->bt_nrecs = m.nrecs;
+	} else {
+		/*
+		 * Set the page size to the best value for I/O to this file.
+		 * Don't overflow the page offset type.
+		 */
+		if (b.psize == 0) {
+			b.psize = sb.st_blksize;
+			if (b.psize < MINPSIZE)
+				b.psize = MINPSIZE;
+			if (b.psize > MAX_PAGE_OFFSET + 1)
+				b.psize = MAX_PAGE_OFFSET + 1;
+		}
+
+		/* Set flag if duplicates permitted. */
+		if (!(b.flags & R_DUP))
+			F_SET(t, B_NODUPS);
+
+		t->bt_free = P_INVALID;
+		t->bt_nrecs = 0;
+		F_SET(t, B_METADIRTY);
+	}
+
+	t->bt_psize = b.psize;
+
+	/* Set the cache size; must be a multiple of the page size. */
+	if (b.cachesize && b.cachesize & b.psize - 1)
+		b.cachesize += (~b.cachesize & b.psize - 1) + 1;
+	if (b.cachesize < b.psize * MINCACHE)
+		b.cachesize = b.psize * MINCACHE;
+
+	/* Calculate number of pages to cache. */
+	ncache = (b.cachesize + t->bt_psize - 1) / t->bt_psize;
+
+	/*
+	 * The btree data structure requires that at least two keys can fit on
+	 * a page, but other than that there's no fixed requirement.  The user
+	 * specified a minimum number per page, and we translated that into the
+	 * number of bytes a key/data pair can use before being placed on an
+	 * overflow page.  This calculation includes the page header, the size
+	 * of the index referencing the leaf item and the size of the leaf item
+	 * structure.  Also, don't let the user specify a minkeypage such that
+	 * a key/data pair won't fit even if both key and data are on overflow
+	 * pages.
+	 */
+	t->bt_ovflsize = (t->bt_psize - BTDATAOFF) / b.minkeypage -
+	    (sizeof(indx_t) + NBLEAFDBT(0, 0));
+	if (t->bt_ovflsize < NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t))
+		t->bt_ovflsize =
+		    NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t);
+
+	/* Initialize the buffer pool. */
+	if ((t->bt_mp =
+	    mpool_open(NULL, t->bt_fd, t->bt_psize, ncache)) == NULL)
+		goto err;
+	if (!F_ISSET(t, B_INMEM))
+		mpool_filter(t->bt_mp, __bt_pgin, __bt_pgout, t);
+
+	/* Create a root page if new tree. */
+	if (nroot(t) == RET_ERROR)
+		goto err;
+
+	/* Global flags. */
+	if (dflags & DB_LOCK)
+		F_SET(t, B_DB_LOCK);
+	if (dflags & DB_SHMEM)
+		F_SET(t, B_DB_SHMEM);
+	if (dflags & DB_TXN)
+		F_SET(t, B_DB_TXN);
+
+	return (dbp);
+
+einval:	errno = EINVAL;
+	goto err;
+
+eftype:	errno = EFTYPE;
+	goto err;
+
+err:	if (t) {
+		if (t->bt_dbp)
+			free(t->bt_dbp);
+		if (t->bt_fd != -1)
+			(void)close(t->bt_fd);
+		free(t);
+	}
+	return (NULL);
+}
+
+/*
+ * NROOT -- Create the root of a new tree.
+ *
+ * Parameters:
+ *	t:	tree
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+static int
+nroot(t)
+	BTREE *t;
+{
+	PAGE *meta, *root;
+	pgno_t npg;
+
+	if ((meta = mpool_get(t->bt_mp, 0, 0)) != NULL) {
+		mpool_put(t->bt_mp, meta, 0);
+		return (RET_SUCCESS);
+	}
+	if (errno != EINVAL)		/* It's OK to not exist. */
+		return (RET_ERROR);
+	errno = 0;
+
+	if ((meta = mpool_new(t->bt_mp, &npg)) == NULL)
+		return (RET_ERROR);
+
+	if ((root = mpool_new(t->bt_mp, &npg)) == NULL)
+		return (RET_ERROR);
+
+	if (npg != P_ROOT)
+		return (RET_ERROR);
+	root->pgno = npg;
+	root->prevpg = root->nextpg = P_INVALID;
+	root->lower = BTDATAOFF;
+	root->upper = t->bt_psize;
+	root->flags = P_BLEAF;
+	memset(meta, 0, t->bt_psize);
+	mpool_put(t->bt_mp, meta, MPOOL_DIRTY);
+	mpool_put(t->bt_mp, root, MPOOL_DIRTY);
+	return (RET_SUCCESS);
+}
+
+static int
+tmp()
+{
+	sigset_t set, oset;
+	int fd;
+	char *envtmp;
+	char path[MAXPATHLEN];
+
+	envtmp = getenv("TMPDIR");
+	(void)snprintf(path,
+	    sizeof(path), "%s/bt.XXXXXX", envtmp ? envtmp : "/tmp");
+
+	(void)sigfillset(&set);
+	(void)sigprocmask(SIG_BLOCK, &set, &oset);
+	if ((fd = mkstemp(path)) != -1)
+		(void)unlink(path);
+	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
+	return(fd);
+}
+
+static int
+byteorder()
+{
+	u_int32_t x;
+	u_char *p;
+
+	x = 0x01020304;
+	p = (u_char *)&x;
+	switch (*p) {
+	case 1:
+		return (BIG_ENDIAN);
+	case 4:
+		return (LITTLE_ENDIAN);
+	default:
+		return (0);
+	}
+}
+
+int
+__bt_fd(dbp)
+        const DB *dbp;
+{
+	BTREE *t;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* In-memory database can't have a file descriptor. */
+	if (F_ISSET(t, B_INMEM)) {
+		errno = ENOENT;
+		return (-1);
+	}
+	return (t->bt_fd);
+}
diff --git a/db/btree/bt_overflow.c b/db/btree/bt_overflow.c
new file mode 100644
index 0000000000..b28b8e0471
--- /dev/null
+++ b/db/btree/bt_overflow.c
@@ -0,0 +1,228 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_overflow.c	8.5 (Berkeley) 7/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+/*
+ * Big key/data code.
+ *
+ * Big key and data entries are stored on linked lists of pages.  The initial
+ * reference is byte string stored with the key or data and is the page number
+ * and size.  The actual record is stored in a chain of pages linked by the
+ * nextpg field of the PAGE header.
+ *
+ * The first page of the chain has a special property.  If the record is used
+ * by an internal page, it cannot be deleted and the P_PRESERVE bit will be set
+ * in the header.
+ *
+ * XXX
+ * A single DBT is written to each chain, so a lot of space on the last page
+ * is wasted.  This is a fairly major bug for some data sets.
+ */
+
+/*
+ * __OVFL_GET -- Get an overflow key/data item.
+ *
+ * Parameters:
+ *	t:	tree
+ *	p:	pointer to { pgno_t, u_int32_t }
+ *	buf:	storage address
+ *	bufsz:	storage size
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__ovfl_get(t, p, ssz, buf, bufsz)
+	BTREE *t;
+	void *p;
+	size_t *ssz;
+	void **buf;
+	size_t *bufsz;
+{
+	PAGE *h;
+	pgno_t pg;
+	size_t nb, plen;
+	u_int32_t sz;
+
+	memmove(&pg, p, sizeof(pgno_t));
+	memmove(&sz, (char *)p + sizeof(pgno_t), sizeof(u_int32_t));
+	*ssz = sz;
+
+#ifdef DEBUG
+	if (pg == P_INVALID || sz == 0)
+		abort();
+#endif
+	/* Make the buffer bigger as necessary. */
+	if (*bufsz < sz) {
+		*buf = (char *)(*buf == NULL ? malloc(sz) : realloc(*buf, sz));
+		if (*buf == NULL)
+			return (RET_ERROR);
+		*bufsz = sz;
+	}
+
+	/*
+	 * Step through the linked list of pages, copying the data on each one
+	 * into the buffer.  Never copy more than the data's length.
+	 */
+	plen = t->bt_psize - BTDATAOFF;
+	for (p = *buf;; p = (char *)p + nb, pg = h->nextpg) {
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			return (RET_ERROR);
+
+		nb = MIN(sz, plen);
+		memmove(p, (char *)h + BTDATAOFF, nb);
+		mpool_put(t->bt_mp, h, 0);
+
+		if ((sz -= nb) == 0)
+			break;
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __OVFL_PUT -- Store an overflow key/data item.
+ *
+ * Parameters:
+ *	t:	tree
+ *	data:	DBT to store
+ *	pgno:	storage page number
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__ovfl_put(t, dbt, pg)
+	BTREE *t;
+	const DBT *dbt;
+	pgno_t *pg;
+{
+	PAGE *h, *last;
+	void *p;
+	pgno_t npg;
+	size_t nb, plen;
+	u_int32_t sz;
+
+	/*
+	 * Allocate pages and copy the key/data record into them.  Store the
+	 * number of the first page in the chain.
+	 */
+	plen = t->bt_psize - BTDATAOFF;
+	for (last = NULL, p = dbt->data, sz = dbt->size;;
+	    p = (char *)p + plen, last = h) {
+		if ((h = __bt_new(t, &npg)) == NULL)
+			return (RET_ERROR);
+
+		h->pgno = npg;
+		h->nextpg = h->prevpg = P_INVALID;
+		h->flags = P_OVERFLOW;
+		h->lower = h->upper = 0;
+
+		nb = MIN(sz, plen);
+		memmove((char *)h + BTDATAOFF, p, nb);
+
+		if (last) {
+			last->nextpg = h->pgno;
+			mpool_put(t->bt_mp, last, MPOOL_DIRTY);
+		} else
+			*pg = h->pgno;
+
+		if ((sz -= nb) == 0) {
+			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+			break;
+		}
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __OVFL_DELETE -- Delete an overflow chain.
+ *
+ * Parameters:
+ *	t:	tree
+ *	p:	pointer to { pgno_t, u_int32_t }
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__ovfl_delete(t, p)
+	BTREE *t;
+	void *p;
+{
+	PAGE *h;
+	pgno_t pg;
+	size_t plen;
+	u_int32_t sz;
+
+	memmove(&pg, p, sizeof(pgno_t));
+	memmove(&sz, (char *)p + sizeof(pgno_t), sizeof(u_int32_t));
+
+#ifdef DEBUG
+	if (pg == P_INVALID || sz == 0)
+		abort();
+#endif
+	if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+		return (RET_ERROR);
+
+	/* Don't delete chains used by internal pages. */
+	if (h->flags & P_PRESERVE) {
+		mpool_put(t->bt_mp, h, 0);
+		return (RET_SUCCESS);
+	}
+
+	/* Step through the chain, calling the free routine for each page. */
+	for (plen = t->bt_psize - BTDATAOFF;; sz -= plen) {
+		pg = h->nextpg;
+		__bt_free(t, h);
+		if (sz <= plen)
+			break;
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			return (RET_ERROR);
+	}
+	return (RET_SUCCESS);
+}
diff --git a/db/btree/bt_page.c b/db/btree/bt_page.c
new file mode 100644
index 0000000000..0d9d138d5c
--- /dev/null
+++ b/db/btree/bt_page.c
@@ -0,0 +1,98 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_page.c	8.3 (Berkeley) 7/14/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <stdio.h>
+
+#include <db.h>
+#include "btree.h"
+
+/*
+ * __bt_free --
+ *	Put a page on the freelist.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	page to free
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ *
+ * Side-effect:
+ *	mpool_put's the page.
+ */
+int
+__bt_free(t, h)
+	BTREE *t;
+	PAGE *h;
+{
+	/* Insert the page at the head of the free list. */
+	h->prevpg = P_INVALID;
+	h->nextpg = t->bt_free;
+	t->bt_free = h->pgno;
+
+	/* Make sure the page gets written back. */
+	return (mpool_put(t->bt_mp, h, MPOOL_DIRTY));
+}
+
+/*
+ * __bt_new --
+ *	Get a new page, preferably from the freelist.
+ *
+ * Parameters:
+ *	t:	tree
+ *	npg:	storage for page number.
+ *
+ * Returns:
+ *	Pointer to a page, NULL on error.
+ */
+PAGE *
+__bt_new(t, npg)
+	BTREE *t;
+	pgno_t *npg;
+{
+	PAGE *h;
+
+	if (t->bt_free != P_INVALID &&
+	    (h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) {
+		*npg = t->bt_free;
+		t->bt_free = h->nextpg;
+		return (h);
+	}
+	return (mpool_new(t->bt_mp, npg));
+}
diff --git a/db/btree/bt_put.c b/db/btree/bt_put.c
new file mode 100644
index 0000000000..952be09e55
--- /dev/null
+++ b/db/btree/bt_put.c
@@ -0,0 +1,320 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_put.c	8.8 (Berkeley) 7/26/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *));
+
+/*
+ * __BT_PUT -- Add a btree item to the tree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key
+ *	data:	data
+ *	flag:	R_NOOVERWRITE
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the
+ *	tree and R_NOOVERWRITE specified.
+ */
+int
+__bt_put(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key;
+	const DBT *data;
+	u_int flags;
+{
+	BTREE *t;
+	DBT tkey, tdata;
+	EPG *e;
+	PAGE *h;
+	indx_t index, nxtindex;
+	pgno_t pg;
+	u_int32_t nbytes;
+	int dflags, exact, status;
+	char *dest, db[NOVFLSIZE], kb[NOVFLSIZE];
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Check for change to a read-only tree. */
+	if (F_ISSET(t, B_RDONLY)) {
+		errno = EPERM;
+		return (RET_ERROR);
+	}
+
+	switch (flags) {
+	case 0:
+	case R_NOOVERWRITE:
+		break;
+	case R_CURSOR:
+		/*
+		 * If flags is R_CURSOR, put the cursor.  Must already
+		 * have started a scan and not have already deleted it.
+		 */
+		if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+		    !F_ISSET(&t->bt_cursor,
+		        CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE))
+			break;
+		/* FALLTHROUGH */
+	default:
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	/*
+	 * If the key/data pair won't fit on a page, store it on overflow
+	 * pages.  Only put the key on the overflow page if the pair are
+	 * still too big after moving the data to an overflow page.
+	 *
+	 * XXX
+	 * If the insert fails later on, the overflow pages aren't recovered.
+	 */
+	dflags = 0;
+	if (key->size + data->size > t->bt_ovflsize) {
+		if (key->size > t->bt_ovflsize) {
+storekey:		if (__ovfl_put(t, key, &pg) == RET_ERROR)
+				return (RET_ERROR);
+			tkey.data = kb;
+			tkey.size = NOVFLSIZE;
+			memmove(kb, &pg, sizeof(pgno_t));
+			memmove(kb + sizeof(pgno_t),
+			    &key->size, sizeof(u_int32_t));
+			dflags |= P_BIGKEY;
+			key = &tkey;
+		}
+		if (key->size + data->size > t->bt_ovflsize) {
+			if (__ovfl_put(t, data, &pg) == RET_ERROR)
+				return (RET_ERROR);
+			tdata.data = db;
+			tdata.size = NOVFLSIZE;
+			memmove(db, &pg, sizeof(pgno_t));
+			memmove(db + sizeof(pgno_t),
+			    &data->size, sizeof(u_int32_t));
+			dflags |= P_BIGDATA;
+			data = &tdata;
+		}
+		if (key->size + data->size > t->bt_ovflsize)
+			goto storekey;
+	}
+
+	/* Replace the cursor. */
+	if (flags == R_CURSOR) {
+		if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL)
+			return (RET_ERROR);
+		index = t->bt_cursor.pg.index;
+		goto delete;
+	}
+
+	/*
+	 * Find the key to delete, or, the location at which to insert.
+	 * Bt_fast and __bt_search both pin the returned page.
+	 */
+	if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL)
+		if ((e = __bt_search(t, key, &exact)) == NULL)
+			return (RET_ERROR);
+	h = e->page;
+	index = e->index;
+
+	/*
+	 * Add the key/data pair to the tree.  If an identical key is already
+	 * in the tree, and R_NOOVERWRITE is set, an error is returned.  If
+	 * R_NOOVERWRITE is not set, the key is either added (if duplicates are
+	 * permitted) or an error is returned.
+	 */
+	switch (flags) {
+	case R_NOOVERWRITE:
+		if (!exact)
+			break;
+		mpool_put(t->bt_mp, h, 0);
+		return (RET_SPECIAL);
+	default:
+		if (!exact || !F_ISSET(t, B_NODUPS))
+			break;
+		/*
+		 * !!!
+		 * Note, the delete may empty the page, so we need to put a
+		 * new entry into the page immediately.
+		 */
+delete:		if (__bt_dleaf(t, key, h, index) == RET_ERROR) {
+			mpool_put(t->bt_mp, h, 0);
+			return (RET_ERROR);
+		}
+		break;
+	}
+
+	/*
+	 * If not enough room, or the user has put a ceiling on the number of
+	 * keys permitted in the page, split the page.  The split code will
+	 * insert the key and data and unpin the current page.  If inserting
+	 * into the offset array, shift the pointers up.
+	 */
+	nbytes = NBLEAFDBT(key->size, data->size);
+	if (h->upper - h->lower < nbytes + sizeof(indx_t)) {
+		if ((status = __bt_split(t, h, key,
+		    data, dflags, nbytes, index)) != RET_SUCCESS)
+			return (status);
+		goto success;
+	}
+
+	if (index < (nxtindex = NEXTINDEX(h)))
+		memmove(h->linp + index + 1, h->linp + index,
+		    (nxtindex - index) * sizeof(indx_t));
+	h->lower += sizeof(indx_t);
+
+	h->linp[index] = h->upper -= nbytes;
+	dest = (char *)h + h->upper;
+	WR_BLEAF(dest, key, data, dflags);
+
+	/* If the cursor is on this page, adjust it as necessary. */
+	if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
+	    !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
+	    t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= index)
+		++t->bt_cursor.pg.index;
+
+	if (t->bt_order == NOT)
+		if (h->nextpg == P_INVALID) {
+			if (index == NEXTINDEX(h) - 1) {
+				t->bt_order = FORWARD;
+				t->bt_last.index = index;
+				t->bt_last.pgno = h->pgno;
+			}
+		} else if (h->prevpg == P_INVALID) {
+			if (index == 0) {
+				t->bt_order = BACK;
+				t->bt_last.index = 0;
+				t->bt_last.pgno = h->pgno;
+			}
+		}
+
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+success:
+	if (flags == R_SETCURSOR)
+		__bt_setcur(t, e->page->pgno, e->index);
+
+	F_SET(t, B_MODIFIED);
+	return (RET_SUCCESS);
+}
+
+#ifdef STATISTICS
+u_long bt_cache_hit, bt_cache_miss;
+#endif
+
+/*
+ * BT_FAST -- Do a quick check for sorted data.
+ *
+ * Parameters:
+ *	t:	tree
+ *	key:	key to insert
+ *
+ * Returns:
+ * 	EPG for new record or NULL if not found.
+ */
+static EPG *
+bt_fast(t, key, data, exactp)
+	BTREE *t;
+	const DBT *key, *data;
+	int *exactp;
+{
+	PAGE *h;
+	u_int32_t nbytes;
+	int cmp;
+
+	if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) {
+		t->bt_order = NOT;
+		return (NULL);
+	}
+	t->bt_cur.page = h;
+	t->bt_cur.index = t->bt_last.index;
+
+	/*
+	 * If won't fit in this page or have too many keys in this page,
+	 * have to search to get split stack.
+	 */
+	nbytes = NBLEAFDBT(key->size, data->size);
+	if (h->upper - h->lower < nbytes + sizeof(indx_t))
+		goto miss;
+
+	if (t->bt_order == FORWARD) {
+		if (t->bt_cur.page->nextpg != P_INVALID)
+			goto miss;
+		if (t->bt_cur.index != NEXTINDEX(h) - 1)
+			goto miss;
+		if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0)
+			goto miss;
+		t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index;
+	} else {
+		if (t->bt_cur.page->prevpg != P_INVALID)
+			goto miss;
+		if (t->bt_cur.index != 0)
+			goto miss;
+		if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0)
+			goto miss;
+		t->bt_last.index = 0;
+	}
+	*exactp = cmp == 0;
+#ifdef STATISTICS
+	++bt_cache_hit;
+#endif
+	return (&t->bt_cur);
+
+miss:
+#ifdef STATISTICS
+	++bt_cache_miss;
+#endif
+	t->bt_order = NOT;
+	mpool_put(t->bt_mp, h, 0);
+	return (NULL);
+}
diff --git a/db/btree/bt_search.c b/db/btree/bt_search.c
new file mode 100644
index 0000000000..485afcbbf0
--- /dev/null
+++ b/db/btree/bt_search.c
@@ -0,0 +1,213 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_search.c	8.8 (Berkeley) 7/31/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <stdio.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int __bt_snext __P((BTREE *, PAGE *, const DBT *, int *));
+static int __bt_sprev __P((BTREE *, PAGE *, const DBT *, int *));
+
+/*
+ * __bt_search --
+ *	Search a btree for a key.
+ *
+ * Parameters:
+ *	t:	tree to search
+ *	key:	key to find
+ *	exactp:	pointer to exact match flag
+ *
+ * Returns:
+ *	The EPG for matching record, if any, or the EPG for the location
+ *	of the key, if it were inserted into the tree, is entered into
+ *	the bt_cur field of the tree.  A pointer to the field is returned.
+ */
+EPG *
+__bt_search(t, key, exactp)
+	BTREE *t;
+	const DBT *key;
+	int *exactp;
+{
+	PAGE *h;
+	indx_t base, index, lim;
+	pgno_t pg;
+	int cmp;
+
+	BT_CLR(t);
+	for (pg = P_ROOT;;) {
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			return (NULL);
+
+		/* Do a binary search on the current page. */
+		t->bt_cur.page = h;
+		for (base = 0, lim = NEXTINDEX(h); lim; lim >>= 1) {
+			t->bt_cur.index = index = base + (lim >> 1);
+			if ((cmp = __bt_cmp(t, key, &t->bt_cur)) == 0) {
+				if (h->flags & P_BLEAF) {
+					*exactp = 1;
+					return (&t->bt_cur);
+				}
+				goto next;
+			}
+			if (cmp > 0) {
+				base = index + 1;
+				--lim;
+			}
+		}
+
+		/*
+		 * If it's a leaf page, we're almost done.  If no duplicates
+		 * are allowed, or we have an exact match, we're done.  Else,
+		 * it's possible that there were matching keys on this page,
+		 * which later deleted, and we're on a page with no matches
+		 * while there are matches on other pages.  If at the start or
+		 * end of a page, check the adjacent page.
+		 */
+		if (h->flags & P_BLEAF) {
+			if (!F_ISSET(t, B_NODUPS)) {
+				if (base == 0 &&
+				    h->prevpg != P_INVALID &&
+				    __bt_sprev(t, h, key, exactp))
+					return (&t->bt_cur);
+				if (base == NEXTINDEX(h) &&
+				    h->nextpg != P_INVALID &&
+				    __bt_snext(t, h, key, exactp))
+					return (&t->bt_cur);
+			}
+			*exactp = 0;
+			t->bt_cur.index = base;
+			return (&t->bt_cur);
+		}
+
+		/*
+		 * No match found.  Base is the smallest index greater than
+		 * key and may be zero or a last + 1 index.  If it's non-zero,
+		 * decrement by one, and record the internal page which should
+		 * be a parent page for the key.  If a split later occurs, the
+		 * inserted page will be to the right of the saved page.
+		 */
+		index = base ? base - 1 : base;
+
+next:		BT_PUSH(t, h->pgno, index);
+		pg = GETBINTERNAL(h, index)->pgno;
+		mpool_put(t->bt_mp, h, 0);
+	}
+}
+
+/*
+ * __bt_snext --
+ *	Check for an exact match after the key.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	current page
+ *	key:	key
+ *	exactp:	pointer to exact match flag
+ *
+ * Returns:
+ *	If an exact match found.
+ */
+static int
+__bt_snext(t, h, key, exactp)
+	BTREE *t;
+	PAGE *h;
+	const DBT *key;
+	int *exactp;
+{
+	EPG e;
+
+	/*
+	 * Get the next page.  The key is either an exact
+	 * match, or not as good as the one we already have.
+	 */
+	if ((e.page = mpool_get(t->bt_mp, h->nextpg, 0)) == NULL)
+		return (0);
+	e.index = 0;
+	if (__bt_cmp(t, key, &e) == 0) {
+		mpool_put(t->bt_mp, h, 0);
+		t->bt_cur = e;
+		*exactp = 1;
+		return (1);
+	}
+	mpool_put(t->bt_mp, e.page, 0);
+	return (0);
+}
+
+/*
+ * __bt_sprev --
+ *	Check for an exact match before the key.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	current page
+ *	key:	key
+ *	exactp:	pointer to exact match flag
+ *
+ * Returns:
+ *	If an exact match found.
+ */
+static int
+__bt_sprev(t, h, key, exactp)
+	BTREE *t;
+	PAGE *h;
+	const DBT *key;
+	int *exactp;
+{
+	EPG e;
+
+	/*
+	 * Get the previous page.  The key is either an exact
+	 * match, or not as good as the one we already have.
+	 */
+	if ((e.page = mpool_get(t->bt_mp, h->prevpg, 0)) == NULL)
+		return (0);
+	e.index = NEXTINDEX(e.page) - 1;
+	if (__bt_cmp(t, key, &e) == 0) {
+		mpool_put(t->bt_mp, h, 0);
+		t->bt_cur = e;
+		*exactp = 1;
+		return (1);
+	}
+	mpool_put(t->bt_mp, e.page, 0);
+	return (0);
+}
diff --git a/db/btree/bt_seq.c b/db/btree/bt_seq.c
new file mode 100644
index 0000000000..303b481903
--- /dev/null
+++ b/db/btree/bt_seq.c
@@ -0,0 +1,460 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_seq.c	8.7 (Berkeley) 7/20/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int __bt_first __P((BTREE *, const DBT *, EPG *, int *));
+static int __bt_seqadv __P((BTREE *, EPG *, int));
+static int __bt_seqset __P((BTREE *, EPG *, DBT *, int));
+
+/*
+ * Sequential scan support.
+ *
+ * The tree can be scanned sequentially, starting from either end of the
+ * tree or from any specific key.  A scan request before any scanning is
+ * done is initialized as starting from the least node.
+ */
+
+/*
+ * __bt_seq --
+ *	Btree sequential scan interface.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key for positioning and return value
+ *	data:	data return value
+ *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+int
+__bt_seq(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key, *data;
+	u_int flags;
+{
+	BTREE *t;
+	EPG e;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/*
+	 * If scan unitialized as yet, or starting at a specific record, set
+	 * the scan to a specific key.  Both __bt_seqset and __bt_seqadv pin
+	 * the page the cursor references if they're successful.
+	 */
+	switch (flags) {
+	case R_NEXT:
+	case R_PREV:
+		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
+			status = __bt_seqadv(t, &e, flags);
+			break;
+		}
+		/* FALLTHROUGH */
+	case R_FIRST:
+	case R_LAST:
+	case R_CURSOR:
+		status = __bt_seqset(t, &e, key, flags);
+		break;
+	default:
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	if (status == RET_SUCCESS) {
+		__bt_setcur(t, e.page->pgno, e.index);
+
+		status =
+		    __bt_ret(t, &e, key, &t->bt_rkey, data, &t->bt_rdata, 0);
+
+		/*
+		 * If the user is doing concurrent access, we copied the
+		 * key/data, toss the page.
+		 */
+		if (F_ISSET(t, B_DB_LOCK))
+			mpool_put(t->bt_mp, e.page, 0);
+		else
+			t->bt_pinned = e.page;
+	}
+	return (status);
+}
+
+/*
+ * __bt_seqset --
+ *	Set the sequential scan to a specific key.
+ *
+ * Parameters:
+ *	t:	tree
+ *	ep:	storage for returned key
+ *	key:	key for initial scan position
+ *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV
+ *
+ * Side effects:
+ *	Pins the page the cursor references.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+static int
+__bt_seqset(t, ep, key, flags)
+	BTREE *t;
+	EPG *ep;
+	DBT *key;
+	int flags;
+{
+	PAGE *h;
+	pgno_t pg;
+	int exact;
+
+	/*
+	 * Find the first, last or specific key in the tree and point the
+	 * cursor at it.  The cursor may not be moved until a new key has
+	 * been found.
+	 */
+	switch (flags) {
+	case R_CURSOR:				/* Keyed scan. */
+		/*
+		 * Find the first instance of the key or the smallest key
+		 * which is greater than or equal to the specified key.
+		 */
+		if (key->data == NULL || key->size == 0) {
+			errno = EINVAL;
+			return (RET_ERROR);
+		}
+		return (__bt_first(t, key, ep, &exact));
+	case R_FIRST:				/* First record. */
+	case R_NEXT:
+		/* Walk down the left-hand side of the tree. */
+		for (pg = P_ROOT;;) {
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+
+			/* Check for an empty tree. */
+			if (NEXTINDEX(h) == 0) {
+				mpool_put(t->bt_mp, h, 0);
+				return (RET_SPECIAL);
+			}
+
+			if (h->flags & (P_BLEAF | P_RLEAF))
+				break;
+			pg = GETBINTERNAL(h, 0)->pgno;
+			mpool_put(t->bt_mp, h, 0);
+		}
+		ep->page = h;
+		ep->index = 0;
+		break;
+	case R_LAST:				/* Last record. */
+	case R_PREV:
+		/* Walk down the right-hand side of the tree. */
+		for (pg = P_ROOT;;) {
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+
+			/* Check for an empty tree. */
+			if (NEXTINDEX(h) == 0) {
+				mpool_put(t->bt_mp, h, 0);
+				return (RET_SPECIAL);
+			}
+
+			if (h->flags & (P_BLEAF | P_RLEAF))
+				break;
+			pg = GETBINTERNAL(h, NEXTINDEX(h) - 1)->pgno;
+			mpool_put(t->bt_mp, h, 0);
+		}
+
+		ep->page = h;
+		ep->index = NEXTINDEX(h) - 1;
+		break;
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_seqadvance --
+ *	Advance the sequential scan.
+ *
+ * Parameters:
+ *	t:	tree
+ *	flags:	R_NEXT, R_PREV
+ *
+ * Side effects:
+ *	Pins the page the new key/data record is on.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+static int
+__bt_seqadv(t, ep, flags)
+	BTREE *t;
+	EPG *ep;
+	int flags;
+{
+	CURSOR *c;
+	PAGE *h;
+	indx_t index;
+	pgno_t pg;
+	int exact;
+
+	/*
+	 * There are a couple of states that we can be in.  The cursor has
+	 * been initialized by the time we get here, but that's all we know.
+	 */
+	c = &t->bt_cursor;
+
+	/*
+	 * The cursor was deleted where there weren't any duplicate records,
+	 * so the key was saved.  Find out where that key would go in the
+	 * current tree.  It doesn't matter if the returned key is an exact
+	 * match or not -- if it's an exact match, the record was added after
+	 * the delete so we can just return it.  If not, as long as there's
+	 * a record there, return it.
+	 */
+	if (F_ISSET(c, CURS_ACQUIRE))
+		return (__bt_first(t, &c->key, ep, &exact));
+
+	/* Get the page referenced by the cursor. */
+	if ((h = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL)
+		return (RET_ERROR);
+
+	/*
+ 	 * Find the next/previous record in the tree and point the cursor at
+	 * it.  The cursor may not be moved until a new key has been found.
+	 */
+	switch (flags) {
+	case R_NEXT:			/* Next record. */
+		/*
+		 * The cursor was deleted in duplicate records, and moved
+		 * forward to a record that has yet to be returned.  Clear
+		 * that flag, and return the record.
+		 */
+		if (F_ISSET(c, CURS_AFTER))
+			goto usecurrent;
+		index = c->pg.index;
+		if (++index == NEXTINDEX(h)) {
+			pg = h->nextpg;
+			mpool_put(t->bt_mp, h, 0);
+			if (pg == P_INVALID)
+				return (RET_SPECIAL);
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+			index = 0;
+		}
+		break;
+	case R_PREV:			/* Previous record. */
+		/*
+		 * The cursor was deleted in duplicate records, and moved
+		 * backward to a record that has yet to be returned.  Clear
+		 * that flag, and return the record.
+		 */
+		if (F_ISSET(c, CURS_BEFORE)) {
+usecurrent:		F_CLR(c, CURS_AFTER | CURS_BEFORE);
+			ep->page = h;
+			ep->index = c->pg.index;
+			return (RET_SUCCESS);
+		}
+		index = c->pg.index;
+		if (index == 0) {
+			pg = h->prevpg;
+			mpool_put(t->bt_mp, h, 0);
+			if (pg == P_INVALID)
+				return (RET_SPECIAL);
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+			index = NEXTINDEX(h) - 1;
+		} else
+			--index;
+		break;
+	}
+
+	ep->page = h;
+	ep->index = index;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_first --
+ *	Find the first entry.
+ *
+ * Parameters:
+ *	t:	the tree
+ *    key:	the key
+ *  erval:	return EPG
+ * exactp:	pointer to exact match flag
+ *
+ * Returns:
+ *	The first entry in the tree greater than or equal to key,
+ *	or RET_SPECIAL if no such key exists.
+ */
+static int
+__bt_first(t, key, erval, exactp)
+	BTREE *t;
+	const DBT *key;
+	EPG *erval;
+	int *exactp;
+{
+	PAGE *h;
+	EPG *ep, save;
+	pgno_t pg;
+
+	/*
+	 * Find any matching record; __bt_search pins the page.
+	 *
+	 * If it's an exact match and duplicates are possible, walk backwards
+	 * in the tree until we find the first one.  Otherwise, make sure it's
+	 * a valid key (__bt_search may return an index just past the end of a
+	 * page) and return it.
+	 */
+	if ((ep = __bt_search(t, key, exactp)) == NULL)
+		return (NULL);
+	if (*exactp) {
+		if (F_ISSET(t, B_NODUPS)) {
+			*erval = *ep;
+			return (RET_SUCCESS);
+		}
+			
+		/*
+		 * Walk backwards, as long as the entry matches and there are
+		 * keys left in the tree.  Save a copy of each match in case
+		 * we go too far.
+		 */
+		save = *ep;
+		h = ep->page;
+		do {
+			if (save.page->pgno != ep->page->pgno) {
+				mpool_put(t->bt_mp, save.page, 0);
+				save = *ep;
+			} else
+				save.index = ep->index;
+
+			/*
+			 * Don't unpin the page the last (or original) match
+			 * was on, but make sure it's unpinned if an error
+			 * occurs.
+			 */
+			if (ep->index == 0) {
+				if (h->prevpg == P_INVALID)
+					break;
+				if (h->pgno != save.page->pgno)
+					mpool_put(t->bt_mp, h, 0);
+				if ((h = mpool_get(t->bt_mp,
+				    h->prevpg, 0)) == NULL) {
+					if (h->pgno == save.page->pgno)
+						mpool_put(t->bt_mp,
+						    save.page, 0);
+					return (RET_ERROR);
+				}
+				ep->page = h;
+				ep->index = NEXTINDEX(h);
+			}
+			--ep->index;
+		} while (__bt_cmp(t, key, ep) == 0);
+
+		/*
+		 * Reach here with the last page that was looked at pinned,
+		 * which may or may not be the same as the last (or original)
+		 * match page.  If it's not useful, release it.
+		 */
+		if (h->pgno != save.page->pgno)
+			mpool_put(t->bt_mp, h, 0);
+
+		*erval = save;
+		return (RET_SUCCESS);
+	}
+
+	/* If at the end of a page, find the next entry. */
+	if (ep->index == NEXTINDEX(ep->page)) {
+		h = ep->page;
+		pg = h->nextpg;
+		mpool_put(t->bt_mp, h, 0);
+		if (pg == P_INVALID)
+			return (RET_SPECIAL);
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			return (RET_ERROR);
+		ep->index = 0;
+		ep->page = h;
+	}
+	*erval = *ep;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_setcur --
+ *	Set the cursor to an entry in the tree.
+ *
+ * Parameters:
+ *	t:	the tree
+ *   pgno:	page number
+ *  index:	page index
+ */
+void
+__bt_setcur(t, pgno, index)
+	BTREE *t;
+	pgno_t pgno;
+	u_int index;
+{
+	/* Lose any already deleted key. */
+	if (t->bt_cursor.key.data != NULL) {
+		free(t->bt_cursor.key.data);
+		t->bt_cursor.key.size = 0;
+		t->bt_cursor.key.data = NULL;
+	}
+	F_CLR(&t->bt_cursor, CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE);
+
+	/* Update the cursor. */
+	t->bt_cursor.pg.pgno = pgno;
+	t->bt_cursor.pg.index = index;
+	F_SET(&t->bt_cursor, CURS_INIT);
+}
diff --git a/db/btree/bt_split.c b/db/btree/bt_split.c
new file mode 100644
index 0000000000..1646d82159
--- /dev/null
+++ b/db/btree/bt_split.c
@@ -0,0 +1,827 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_split.c	8.9 (Berkeley) 7/26/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int	 bt_broot __P((BTREE *, PAGE *, PAGE *, PAGE *));
+static PAGE	*bt_page
+		    __P((BTREE *, PAGE *, PAGE **, PAGE **, indx_t *, size_t));
+static int	 bt_preserve __P((BTREE *, pgno_t));
+static PAGE	*bt_psplit
+		    __P((BTREE *, PAGE *, PAGE *, PAGE *, indx_t *, size_t));
+static PAGE	*bt_root
+		    __P((BTREE *, PAGE *, PAGE **, PAGE **, indx_t *, size_t));
+static int	 bt_rroot __P((BTREE *, PAGE *, PAGE *, PAGE *));
+static recno_t	 rec_total __P((PAGE *));
+
+#ifdef STATISTICS
+u_long	bt_rootsplit, bt_split, bt_sortsplit, bt_pfxsaved;
+#endif
+
+/*
+ * __BT_SPLIT -- Split the tree.
+ *
+ * Parameters:
+ *	t:	tree
+ *	sp:	page to split
+ *	key:	key to insert
+ *	data:	data to insert
+ *	flags:	BIGKEY/BIGDATA flags
+ *	ilen:	insert length
+ *	skip:	index to leave open
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__bt_split(t, sp, key, data, flags, ilen, argskip)
+	BTREE *t;
+	PAGE *sp;
+	const DBT *key, *data;
+	int flags;
+	size_t ilen;
+	u_int32_t argskip;
+{
+	BINTERNAL *bi;
+	BLEAF *bl, *tbl;
+	DBT a, b;
+	EPGNO *parent;
+	PAGE *h, *l, *r, *lchild, *rchild;
+	indx_t nxtindex;
+	u_int16_t skip;
+	u_int32_t n, nbytes, nksize;
+	int parentsplit;
+	char *dest;
+
+	/*
+	 * Split the page into two pages, l and r.  The split routines return
+	 * a pointer to the page into which the key should be inserted and with
+	 * skip set to the offset which should be used.  Additionally, l and r
+	 * are pinned.
+	 */
+	skip = argskip;
+	h = sp->pgno == P_ROOT ?
+	    bt_root(t, sp, &l, &r, &skip, ilen) :
+	    bt_page(t, sp, &l, &r, &skip, ilen);
+	if (h == NULL)
+		return (RET_ERROR);
+
+	/*
+	 * Insert the new key/data pair into the leaf page.  (Key inserts
+	 * always cause a leaf page to split first.)
+	 */
+	h->linp[skip] = h->upper -= ilen;
+	dest = (char *)h + h->upper;
+	if (F_ISSET(t, R_RECNO))
+		WR_RLEAF(dest, data, flags)
+	else
+		WR_BLEAF(dest, key, data, flags)
+
+	/* If the root page was split, make it look right. */
+	if (sp->pgno == P_ROOT &&
+	    (F_ISSET(t, R_RECNO) ?
+	    bt_rroot(t, sp, l, r) : bt_broot(t, sp, l, r)) == RET_ERROR)
+		goto err2;
+
+	/*
+	 * Now we walk the parent page stack -- a LIFO stack of the pages that
+	 * were traversed when we searched for the page that split.  Each stack
+	 * entry is a page number and a page index offset.  The offset is for
+	 * the page traversed on the search.  We've just split a page, so we
+	 * have to insert a new key into the parent page.
+	 *
+	 * If the insert into the parent page causes it to split, may have to
+	 * continue splitting all the way up the tree.  We stop if the root
+	 * splits or the page inserted into didn't have to split to hold the
+	 * new key.  Some algorithms replace the key for the old page as well
+	 * as the new page.  We don't, as there's no reason to believe that the
+	 * first key on the old page is any better than the key we have, and,
+	 * in the case of a key being placed at index 0 causing the split, the
+	 * key is unavailable.
+	 *
+	 * There are a maximum of 5 pages pinned at any time.  We keep the left
+	 * and right pages pinned while working on the parent.   The 5 are the
+	 * two children, left parent and right parent (when the parent splits)
+	 * and the root page or the overflow key page when calling bt_preserve.
+	 * This code must make sure that all pins are released other than the
+	 * root page or overflow page which is unlocked elsewhere.
+	 */
+	while ((parent = BT_POP(t)) != NULL) {
+		lchild = l;
+		rchild = r;
+
+		/* Get the parent page. */
+		if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
+			goto err2;
+
+	 	/*
+		 * The new key goes ONE AFTER the index, because the split
+		 * was to the right.
+		 */
+		skip = parent->index + 1;
+
+		/*
+		 * Calculate the space needed on the parent page.
+		 *
+		 * Prefix trees: space hack when inserting into BINTERNAL
+		 * pages.  Retain only what's needed to distinguish between
+		 * the new entry and the LAST entry on the page to its left.
+		 * If the keys compare equal, retain the entire key.  Note,
+		 * we don't touch overflow keys, and the entire key must be
+		 * retained for the next-to-left most key on the leftmost
+		 * page of each level, or the search will fail.  Applicable
+		 * ONLY to internal pages that have leaf pages as children.
+		 * Further reduction of the key between pairs of internal
+		 * pages loses too much information.
+		 */
+		switch (rchild->flags & P_TYPE) {
+		case P_BINTERNAL:
+			bi = GETBINTERNAL(rchild, 0);
+			nbytes = NBINTERNAL(bi->ksize);
+			break;
+		case P_BLEAF:
+			bl = GETBLEAF(rchild, 0);
+			nbytes = NBINTERNAL(bl->ksize);
+			if (t->bt_pfx && !(bl->flags & P_BIGKEY) &&
+			    (h->prevpg != P_INVALID || skip > 1)) {
+				tbl = GETBLEAF(lchild, NEXTINDEX(lchild) - 1);
+				a.size = tbl->ksize;
+				a.data = tbl->bytes;
+				b.size = bl->ksize;
+				b.data = bl->bytes;
+				nksize = t->bt_pfx(&a, &b);
+				n = NBINTERNAL(nksize);
+				if (n < nbytes) {
+#ifdef STATISTICS
+					bt_pfxsaved += nbytes - n;
+#endif
+					nbytes = n;
+				} else
+					nksize = 0;
+			} else
+				nksize = 0;
+			break;
+		case P_RINTERNAL:
+		case P_RLEAF:
+			nbytes = NRINTERNAL;
+			break;
+		default:
+			abort();
+		}
+
+		/* Split the parent page if necessary or shift the indices. */
+		if (h->upper - h->lower < nbytes + sizeof(indx_t)) {
+			sp = h;
+			h = h->pgno == P_ROOT ?
+			    bt_root(t, h, &l, &r, &skip, nbytes) :
+			    bt_page(t, h, &l, &r, &skip, nbytes);
+			if (h == NULL)
+				goto err1;
+			parentsplit = 1;
+		} else {
+			if (skip < (nxtindex = NEXTINDEX(h)))
+				memmove(h->linp + skip + 1, h->linp + skip,
+				    (nxtindex - skip) * sizeof(indx_t));
+			h->lower += sizeof(indx_t);
+			parentsplit = 0;
+		}
+
+		/* Insert the key into the parent page. */
+		switch (rchild->flags & P_TYPE) {
+		case P_BINTERNAL:
+			h->linp[skip] = h->upper -= nbytes;
+			dest = (char *)h + h->linp[skip];
+			memmove(dest, bi, nbytes);
+			((BINTERNAL *)dest)->pgno = rchild->pgno;
+			break;
+		case P_BLEAF:
+			h->linp[skip] = h->upper -= nbytes;
+			dest = (char *)h + h->linp[skip];
+			WR_BINTERNAL(dest, nksize ? nksize : bl->ksize,
+			    rchild->pgno, bl->flags & P_BIGKEY);
+			memmove(dest, bl->bytes, nksize ? nksize : bl->ksize);
+			if (bl->flags & P_BIGKEY &&
+			    bt_preserve(t, *(pgno_t *)bl->bytes) == RET_ERROR)
+				goto err1;
+			break;
+		case P_RINTERNAL:
+			/*
+			 * Update the left page count.  If split
+			 * added at index 0, fix the correct page.
+			 */
+			if (skip > 0)
+				dest = (char *)h + h->linp[skip - 1];
+			else
+				dest = (char *)l + l->linp[NEXTINDEX(l) - 1];
+			((RINTERNAL *)dest)->nrecs = rec_total(lchild);
+			((RINTERNAL *)dest)->pgno = lchild->pgno;
+
+			/* Update the right page count. */
+			h->linp[skip] = h->upper -= nbytes;
+			dest = (char *)h + h->linp[skip];
+			((RINTERNAL *)dest)->nrecs = rec_total(rchild);
+			((RINTERNAL *)dest)->pgno = rchild->pgno;
+			break;
+		case P_RLEAF:
+			/*
+			 * Update the left page count.  If split
+			 * added at index 0, fix the correct page.
+			 */
+			if (skip > 0)
+				dest = (char *)h + h->linp[skip - 1];
+			else
+				dest = (char *)l + l->linp[NEXTINDEX(l) - 1];
+			((RINTERNAL *)dest)->nrecs = NEXTINDEX(lchild);
+			((RINTERNAL *)dest)->pgno = lchild->pgno;
+
+			/* Update the right page count. */
+			h->linp[skip] = h->upper -= nbytes;
+			dest = (char *)h + h->linp[skip];
+			((RINTERNAL *)dest)->nrecs = NEXTINDEX(rchild);
+			((RINTERNAL *)dest)->pgno = rchild->pgno;
+			break;
+		default:
+			abort();
+		}
+
+		/* Unpin the held pages. */
+		if (!parentsplit) {
+			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+			break;
+		}
+
+		/* If the root page was split, make it look right. */
+		if (sp->pgno == P_ROOT &&
+		    (F_ISSET(t, R_RECNO) ?
+		    bt_rroot(t, sp, l, r) : bt_broot(t, sp, l, r)) == RET_ERROR)
+			goto err1;
+
+		mpool_put(t->bt_mp, lchild, MPOOL_DIRTY);
+		mpool_put(t->bt_mp, rchild, MPOOL_DIRTY);
+	}
+
+	/* Unpin the held pages. */
+	mpool_put(t->bt_mp, l, MPOOL_DIRTY);
+	mpool_put(t->bt_mp, r, MPOOL_DIRTY);
+
+	/* Clear any pages left on the stack. */
+	return (RET_SUCCESS);
+
+	/*
+	 * If something fails in the above loop we were already walking back
+	 * up the tree and the tree is now inconsistent.  Nothing much we can
+	 * do about it but release any memory we're holding.
+	 */
+err1:	mpool_put(t->bt_mp, lchild, MPOOL_DIRTY);
+	mpool_put(t->bt_mp, rchild, MPOOL_DIRTY);
+
+err2:	mpool_put(t->bt_mp, l, 0);
+	mpool_put(t->bt_mp, r, 0);
+	__dbpanic(t->bt_dbp);
+	return (RET_ERROR);
+}
+
+/*
+ * BT_PAGE -- Split a non-root page of a btree.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	root page
+ *	lp:	pointer to left page pointer
+ *	rp:	pointer to right page pointer
+ *	skip:	pointer to index to leave open
+ *	ilen:	insert length
+ *
+ * Returns:
+ *	Pointer to page in which to insert or NULL on error.
+ */
+static PAGE *
+bt_page(t, h, lp, rp, skip, ilen)
+	BTREE *t;
+	PAGE *h, **lp, **rp;
+	indx_t *skip;
+	size_t ilen;
+{
+	PAGE *l, *r, *tp;
+	pgno_t npg;
+
+#ifdef STATISTICS
+	++bt_split;
+#endif
+	/* Put the new right page for the split into place. */
+	if ((r = __bt_new(t, &npg)) == NULL)
+		return (NULL);
+	r->pgno = npg;
+	r->lower = BTDATAOFF;
+	r->upper = t->bt_psize;
+	r->nextpg = h->nextpg;
+	r->prevpg = h->pgno;
+	r->flags = h->flags & P_TYPE;
+
+	/*
+	 * If we're splitting the last page on a level because we're appending
+	 * a key to it (skip is NEXTINDEX()), it's likely that the data is
+	 * sorted.  Adding an empty page on the side of the level is less work
+	 * and can push the fill factor much higher than normal.  If we're
+	 * wrong it's no big deal, we'll just do the split the right way next
+	 * time.  It may look like it's equally easy to do a similar hack for
+	 * reverse sorted data, that is, split the tree left, but it's not.
+	 * Don't even try.
+	 */
+	if (h->nextpg == P_INVALID && *skip == NEXTINDEX(h)) {
+#ifdef STATISTICS
+		++bt_sortsplit;
+#endif
+		h->nextpg = r->pgno;
+		r->lower = BTDATAOFF + sizeof(indx_t);
+		*skip = 0;
+		*lp = h;
+		*rp = r;
+		return (r);
+	}
+
+	/* Put the new left page for the split into place. */
+	if ((l = (PAGE *)malloc(t->bt_psize)) == NULL) {
+		mpool_put(t->bt_mp, r, 0);
+		return (NULL);
+	}
+#ifdef PURIFY
+	memset(l, 0xff, t->bt_psize);
+#endif
+	l->pgno = h->pgno;
+	l->nextpg = r->pgno;
+	l->prevpg = h->prevpg;
+	l->lower = BTDATAOFF;
+	l->upper = t->bt_psize;
+	l->flags = h->flags & P_TYPE;
+
+	/* Fix up the previous pointer of the page after the split page. */
+	if (h->nextpg != P_INVALID) {
+		if ((tp = mpool_get(t->bt_mp, h->nextpg, 0)) == NULL) {
+			free(l);
+			/* XXX mpool_free(t->bt_mp, r->pgno); */
+			return (NULL);
+		}
+		tp->prevpg = r->pgno;
+		mpool_put(t->bt_mp, tp, MPOOL_DIRTY);
+	}
+
+	/*
+	 * Split right.  The key/data pairs aren't sorted in the btree page so
+	 * it's simpler to copy the data from the split page onto two new pages
+	 * instead of copying half the data to the right page and compacting
+	 * the left page in place.  Since the left page can't change, we have
+	 * to swap the original and the allocated left page after the split.
+	 */
+	tp = bt_psplit(t, h, l, r, skip, ilen);
+
+	/* Move the new left page onto the old left page. */
+	memmove(h, l, t->bt_psize);
+	if (tp == l)
+		tp = h;
+	free(l);
+
+	*lp = h;
+	*rp = r;
+	return (tp);
+}
+
+/*
+ * BT_ROOT -- Split the root page of a btree.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	root page
+ *	lp:	pointer to left page pointer
+ *	rp:	pointer to right page pointer
+ *	skip:	pointer to index to leave open
+ *	ilen:	insert length
+ *
+ * Returns:
+ *	Pointer to page in which to insert or NULL on error.
+ */
+static PAGE *
+bt_root(t, h, lp, rp, skip, ilen)
+	BTREE *t;
+	PAGE *h, **lp, **rp;
+	indx_t *skip;
+	size_t ilen;
+{
+	PAGE *l, *r, *tp;
+	pgno_t lnpg, rnpg;
+
+#ifdef STATISTICS
+	++bt_split;
+	++bt_rootsplit;
+#endif
+	/* Put the new left and right pages for the split into place. */
+	if ((l = __bt_new(t, &lnpg)) == NULL ||
+	    (r = __bt_new(t, &rnpg)) == NULL)
+		return (NULL);
+	l->pgno = lnpg;
+	r->pgno = rnpg;
+	l->nextpg = r->pgno;
+	r->prevpg = l->pgno;
+	l->prevpg = r->nextpg = P_INVALID;
+	l->lower = r->lower = BTDATAOFF;
+	l->upper = r->upper = t->bt_psize;
+	l->flags = r->flags = h->flags & P_TYPE;
+
+	/* Split the root page. */
+	tp = bt_psplit(t, h, l, r, skip, ilen);
+
+	*lp = l;
+	*rp = r;
+	return (tp);
+}
+
+/*
+ * BT_RROOT -- Fix up the recno root page after it has been split.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	root page
+ *	l:	left page
+ *	r:	right page
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+static int
+bt_rroot(t, h, l, r)
+	BTREE *t;
+	PAGE *h, *l, *r;
+{
+	char *dest;
+
+	/* Insert the left and right keys, set the header information. */
+	h->linp[0] = h->upper = t->bt_psize - NRINTERNAL;
+	dest = (char *)h + h->upper;
+	WR_RINTERNAL(dest,
+	    l->flags & P_RLEAF ? NEXTINDEX(l) : rec_total(l), l->pgno);
+
+	h->linp[1] = h->upper -= NRINTERNAL;
+	dest = (char *)h + h->upper;
+	WR_RINTERNAL(dest,
+	    r->flags & P_RLEAF ? NEXTINDEX(r) : rec_total(r), r->pgno);
+
+	h->lower = BTDATAOFF + 2 * sizeof(indx_t);
+
+	/* Unpin the root page, set to recno internal page. */
+	h->flags &= ~P_TYPE;
+	h->flags |= P_RINTERNAL;
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+	return (RET_SUCCESS);
+}
+
+/*
+ * BT_BROOT -- Fix up the btree root page after it has been split.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	root page
+ *	l:	left page
+ *	r:	right page
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+static int
+bt_broot(t, h, l, r)
+	BTREE *t;
+	PAGE *h, *l, *r;
+{
+	BINTERNAL *bi;
+	BLEAF *bl;
+	u_int32_t nbytes;
+	char *dest;
+
+	/*
+	 * If the root page was a leaf page, change it into an internal page.
+	 * We copy the key we split on (but not the key's data, in the case of
+	 * a leaf page) to the new root page.
+	 *
+	 * The btree comparison code guarantees that the left-most key on any
+	 * level of the tree is never used, so it doesn't need to be filled in.
+	 */
+	nbytes = NBINTERNAL(0);
+	h->linp[0] = h->upper = t->bt_psize - nbytes;
+	dest = (char *)h + h->upper;
+	WR_BINTERNAL(dest, 0, l->pgno, 0);
+
+	switch (h->flags & P_TYPE) {
+	case P_BLEAF:
+		bl = GETBLEAF(r, 0);
+		nbytes = NBINTERNAL(bl->ksize);
+		h->linp[1] = h->upper -= nbytes;
+		dest = (char *)h + h->upper;
+		WR_BINTERNAL(dest, bl->ksize, r->pgno, 0);
+		memmove(dest, bl->bytes, bl->ksize);
+
+		/*
+		 * If the key is on an overflow page, mark the overflow chain
+		 * so it isn't deleted when the leaf copy of the key is deleted.
+		 */
+		if (bl->flags & P_BIGKEY &&
+		    bt_preserve(t, *(pgno_t *)bl->bytes) == RET_ERROR)
+			return (RET_ERROR);
+		break;
+	case P_BINTERNAL:
+		bi = GETBINTERNAL(r, 0);
+		nbytes = NBINTERNAL(bi->ksize);
+		h->linp[1] = h->upper -= nbytes;
+		dest = (char *)h + h->upper;
+		memmove(dest, bi, nbytes);
+		((BINTERNAL *)dest)->pgno = r->pgno;
+		break;
+	default:
+		abort();
+	}
+
+	/* There are two keys on the page. */
+	h->lower = BTDATAOFF + 2 * sizeof(indx_t);
+
+	/* Unpin the root page, set to btree internal page. */
+	h->flags &= ~P_TYPE;
+	h->flags |= P_BINTERNAL;
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+	return (RET_SUCCESS);
+}
+
+/*
+ * BT_PSPLIT -- Do the real work of splitting the page.
+ *
+ * Parameters:
+ *	t:	tree
+ *	h:	page to be split
+ *	l:	page to put lower half of data
+ *	r:	page to put upper half of data
+ *	pskip:	pointer to index to leave open
+ *	ilen:	insert length
+ *
+ * Returns:
+ *	Pointer to page in which to insert.
+ */
+static PAGE *
+bt_psplit(t, h, l, r, pskip, ilen)
+	BTREE *t;
+	PAGE *h, *l, *r;
+	indx_t *pskip;
+	size_t ilen;
+{
+	BINTERNAL *bi;
+	BLEAF *bl;
+	CURSOR *c;
+	RLEAF *rl;
+	PAGE *rval;
+	void *src;
+	indx_t full, half, nxt, off, skip, top, used;
+	u_int32_t nbytes;
+	int bigkeycnt, isbigkey;
+
+	/*
+	 * Split the data to the left and right pages.  Leave the skip index
+	 * open.  Additionally, make some effort not to split on an overflow
+	 * key.  This makes internal page processing faster and can save
+	 * space as overflow keys used by internal pages are never deleted.
+	 */
+	bigkeycnt = 0;
+	skip = *pskip;
+	full = t->bt_psize - BTDATAOFF;
+	half = full / 2;
+	used = 0;
+	for (nxt = off = 0, top = NEXTINDEX(h); nxt < top; ++off) {
+		if (skip == off) {
+			nbytes = ilen;
+			isbigkey = 0;		/* XXX: not really known. */
+		} else
+			switch (h->flags & P_TYPE) {
+			case P_BINTERNAL:
+				src = bi = GETBINTERNAL(h, nxt);
+				nbytes = NBINTERNAL(bi->ksize);
+				isbigkey = bi->flags & P_BIGKEY;
+				break;
+			case P_BLEAF:
+				src = bl = GETBLEAF(h, nxt);
+				nbytes = NBLEAF(bl);
+				isbigkey = bl->flags & P_BIGKEY;
+				break;
+			case P_RINTERNAL:
+				src = GETRINTERNAL(h, nxt);
+				nbytes = NRINTERNAL;
+				isbigkey = 0;
+				break;
+			case P_RLEAF:
+				src = rl = GETRLEAF(h, nxt);
+				nbytes = NRLEAF(rl);
+				isbigkey = 0;
+				break;
+			default:
+				abort();
+			}
+
+		/*
+		 * If the key/data pairs are substantial fractions of the max
+		 * possible size for the page, it's possible to get situations
+		 * where we decide to try and copy too much onto the left page.
+		 * Make sure that doesn't happen.
+		 */
+		if (skip <= off && used + nbytes >= full) {
+			--off;
+			break;
+		}
+
+		/* Copy the key/data pair, if not the skipped index. */
+		if (skip != off) {
+			++nxt;
+
+			l->linp[off] = l->upper -= nbytes;
+			memmove((char *)l + l->upper, src, nbytes);
+		}
+
+		used += nbytes;
+		if (used >= half) {
+			if (!isbigkey || bigkeycnt == 3)
+				break;
+			else
+				++bigkeycnt;
+		}
+	}
+
+	/*
+	 * Off is the last offset that's valid for the left page.
+	 * Nxt is the first offset to be placed on the right page.
+	 */
+	l->lower += (off + 1) * sizeof(indx_t);
+
+	/*
+	 * If splitting the page that the cursor was on, the cursor has to be
+	 * adjusted to point to the same record as before the split.  If the
+	 * cursor is at or past the skipped slot, the cursor is incremented by
+	 * one.  If the cursor is on the right page, it is decremented by the
+	 * number of records split to the left page.
+	 */
+	c = &t->bt_cursor;
+	if (F_ISSET(c, CURS_INIT) && c->pg.pgno == h->pgno) {
+		if (c->pg.index >= skip)
+			++c->pg.index;
+		if (c->pg.index < nxt)			/* Left page. */
+			c->pg.pgno = l->pgno;
+		else {					/* Right page. */
+			c->pg.pgno = r->pgno;
+			c->pg.index -= nxt;
+		}
+	}
+
+	/*
+	 * If the skipped index was on the left page, just return that page.
+	 * Otherwise, adjust the skip index to reflect the new position on
+	 * the right page.
+	 */
+	if (skip <= off) {
+		skip = 0;
+		rval = l;
+	} else {
+		rval = r;
+		*pskip -= nxt;
+	}
+
+	for (off = 0; nxt < top; ++off) {
+		if (skip == nxt) {
+			++off;
+			skip = 0;
+		}
+		switch (h->flags & P_TYPE) {
+		case P_BINTERNAL:
+			src = bi = GETBINTERNAL(h, nxt);
+			nbytes = NBINTERNAL(bi->ksize);
+			break;
+		case P_BLEAF:
+			src = bl = GETBLEAF(h, nxt);
+			nbytes = NBLEAF(bl);
+			break;
+		case P_RINTERNAL:
+			src = GETRINTERNAL(h, nxt);
+			nbytes = NRINTERNAL;
+			break;
+		case P_RLEAF:
+			src = rl = GETRLEAF(h, nxt);
+			nbytes = NRLEAF(rl);
+			break;
+		default:
+			abort();
+		}
+		++nxt;
+		r->linp[off] = r->upper -= nbytes;
+		memmove((char *)r + r->upper, src, nbytes);
+	}
+	r->lower += off * sizeof(indx_t);
+
+	/* If the key is being appended to the page, adjust the index. */
+	if (skip == top)
+		r->lower += sizeof(indx_t);
+
+	return (rval);
+}
+
+/*
+ * BT_PRESERVE -- Mark a chain of pages as used by an internal node.
+ *
+ * Chains of indirect blocks pointed to by leaf nodes get reclaimed when the
+ * record that references them gets deleted.  Chains pointed to by internal
+ * pages never get deleted.  This routine marks a chain as pointed to by an
+ * internal page.
+ *
+ * Parameters:
+ *	t:	tree
+ *	pg:	page number of first page in the chain.
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+static int
+bt_preserve(t, pg)
+	BTREE *t;
+	pgno_t pg;
+{
+	PAGE *h;
+
+	if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+		return (RET_ERROR);
+	h->flags |= P_PRESERVE;
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+	return (RET_SUCCESS);
+}
+
+/*
+ * REC_TOTAL -- Return the number of recno entries below a page.
+ *
+ * Parameters:
+ *	h:	page
+ *
+ * Returns:
+ *	The number of recno entries below a page.
+ *
+ * XXX
+ * These values could be set by the bt_psplit routine.  The problem is that the
+ * entry has to be popped off of the stack etc. or the values have to be passed
+ * all the way back to bt_split/bt_rroot and it's not very clean.
+ */
+static recno_t
+rec_total(h)
+	PAGE *h;
+{
+	recno_t recs;
+	indx_t nxt, top;
+
+	for (recs = 0, nxt = 0, top = NEXTINDEX(h); nxt < top; ++nxt)
+		recs += GETRINTERNAL(h, nxt)->nrecs;
+	return (recs);
+}
diff --git a/db/btree/bt_utils.c b/db/btree/bt_utils.c
new file mode 100644
index 0000000000..9c1438eb84
--- /dev/null
+++ b/db/btree/bt_utils.c
@@ -0,0 +1,260 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_utils.c	8.8 (Berkeley) 7/20/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "btree.h"
+
+/*
+ * __bt_ret --
+ *	Build return key/data pair.
+ *
+ * Parameters:
+ *	t:	tree
+ *	e:	key/data pair to be returned
+ *	key:	user's key structure (NULL if not to be filled in)
+ *	rkey:	memory area to hold key
+ *	data:	user's data structure (NULL if not to be filled in)
+ *	rdata:	memory area to hold data
+ *       copy:	always copy the key/data item
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__bt_ret(t, e, key, rkey, data, rdata, copy)
+	BTREE *t;
+	EPG *e;
+	DBT *key, *rkey, *data, *rdata;
+	int copy;
+{
+	BLEAF *bl;
+	void *p;
+
+	bl = GETBLEAF(e->page, e->index);
+
+	/*
+	 * We must copy big keys/data to make them contigous.  Otherwise,
+	 * leave the page pinned and don't copy unless the user specified
+	 * concurrent access.
+	 */
+	if (key == NULL)
+		goto dataonly;
+
+	if (bl->flags & P_BIGKEY) {
+		if (__ovfl_get(t, bl->bytes,
+		    &key->size, &rkey->data, &rkey->size))
+			return (RET_ERROR);
+		key->data = rkey->data;
+	} else if (copy || F_ISSET(t, B_DB_LOCK)) {
+		if (bl->ksize > rkey->size) {
+			p = (void *)(rkey->data == NULL ?
+			    malloc(bl->ksize) : realloc(rkey->data, bl->ksize));
+			if (p == NULL)
+				return (RET_ERROR);
+			rkey->data = p;
+			rkey->size = bl->ksize;
+		}
+		memmove(rkey->data, bl->bytes, bl->ksize);
+		key->size = bl->ksize;
+		key->data = rkey->data;
+	} else {
+		key->size = bl->ksize;
+		key->data = bl->bytes;
+	}
+
+dataonly:
+	if (data == NULL)
+		return (RET_SUCCESS);
+
+	if (bl->flags & P_BIGDATA) {
+		if (__ovfl_get(t, bl->bytes + bl->ksize,
+		    &data->size, &rdata->data, &rdata->size))
+			return (RET_ERROR);
+		data->data = rdata->data;
+	} else if (copy || F_ISSET(t, B_DB_LOCK)) {
+		/* Use +1 in case the first record retrieved is 0 length. */
+		if (bl->dsize + 1 > rdata->size) {
+			p = (void *)(rdata->data == NULL ?
+			    malloc(bl->dsize + 1) :
+			    realloc(rdata->data, bl->dsize + 1));
+			if (p == NULL)
+				return (RET_ERROR);
+			rdata->data = p;
+			rdata->size = bl->dsize + 1;
+		}
+		memmove(rdata->data, bl->bytes + bl->ksize, bl->dsize);
+		data->size = bl->dsize;
+		data->data = rdata->data;
+	} else {
+		data->size = bl->dsize;
+		data->data = bl->bytes + bl->ksize;
+	}
+
+	return (RET_SUCCESS);
+}
+
+/*
+ * __BT_CMP -- Compare a key to a given record.
+ *
+ * Parameters:
+ *	t:	tree
+ *	k1:	DBT pointer of first arg to comparison
+ *	e:	pointer to EPG for comparison
+ *
+ * Returns:
+ *	< 0 if k1 is < record
+ *	= 0 if k1 is = record
+ *	> 0 if k1 is > record
+ */
+int
+__bt_cmp(t, k1, e)
+	BTREE *t;
+	const DBT *k1;
+	EPG *e;
+{
+	BINTERNAL *bi;
+	BLEAF *bl;
+	DBT k2;
+	PAGE *h;
+	void *bigkey;
+
+	/*
+	 * The left-most key on internal pages, at any level of the tree, is
+	 * guaranteed by the following code to be less than any user key.
+	 * This saves us from having to update the leftmost key on an internal
+	 * page when the user inserts a new key in the tree smaller than
+	 * anything we've yet seen.
+	 */
+	h = e->page;
+	if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & P_BLEAF))
+		return (1);
+
+	bigkey = NULL;
+	if (h->flags & P_BLEAF) {
+		bl = GETBLEAF(h, e->index);
+		if (bl->flags & P_BIGKEY)
+			bigkey = bl->bytes;
+		else {
+			k2.data = bl->bytes;
+			k2.size = bl->ksize;
+		}
+	} else {
+		bi = GETBINTERNAL(h, e->index);
+		if (bi->flags & P_BIGKEY)
+			bigkey = bi->bytes;
+		else {
+			k2.data = bi->bytes;
+			k2.size = bi->ksize;
+		}
+	}
+
+	if (bigkey) {
+		if (__ovfl_get(t, bigkey,
+		    &k2.size, &t->bt_rdata.data, &t->bt_rdata.size))
+			return (RET_ERROR);
+		k2.data = t->bt_rdata.data;
+	}
+	return ((*t->bt_cmp)(k1, &k2));
+}
+
+/*
+ * __BT_DEFCMP -- Default comparison routine.
+ *
+ * Parameters:
+ *	a:	DBT #1
+ *	b: 	DBT #2
+ *
+ * Returns:
+ *	< 0 if a is < b
+ *	= 0 if a is = b
+ *	> 0 if a is > b
+ */
+int
+__bt_defcmp(a, b)
+	const DBT *a, *b;
+{
+	register size_t len;
+	register u_char *p1, *p2;
+
+	/*
+	 * XXX
+	 * If a size_t doesn't fit in an int, this routine can lose.
+	 * What we need is a integral type which is guaranteed to be
+	 * larger than a size_t, and there is no such thing.
+	 */
+	len = MIN(a->size, b->size);
+	for (p1 = a->data, p2 = b->data; len--; ++p1, ++p2)
+		if (*p1 != *p2)
+			return ((int)*p1 - (int)*p2);
+	return ((int)a->size - (int)b->size);
+}
+
+/*
+ * __BT_DEFPFX -- Default prefix routine.
+ *
+ * Parameters:
+ *	a:	DBT #1
+ *	b: 	DBT #2
+ *
+ * Returns:
+ *	Number of bytes needed to distinguish b from a.
+ */
+size_t
+__bt_defpfx(a, b)
+	const DBT *a, *b;
+{
+	register u_char *p1, *p2;
+	register size_t cnt, len;
+
+	cnt = 1;
+	len = MIN(a->size, b->size);
+	for (p1 = a->data, p2 = b->data; len--; ++p1, ++p2, ++cnt)
+		if (*p1 != *p2)
+			return (cnt);
+
+	/* a->size must be <= b->size, or they wouldn't be in this order. */
+	return (a->size < b->size ? a->size + 1 : a->size);
+}
diff --git a/db/btree/btree.h b/db/btree/btree.h
new file mode 100644
index 0000000000..36d35c998b
--- /dev/null
+++ b/db/btree/btree.h
@@ -0,0 +1,383 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)btree.h	8.11 (Berkeley) 8/17/94
+ */
+
+/* Macros to set/clear/test flags. */
+#define	F_SET(p, f)	(p)->flags |= (f)
+#define	F_CLR(p, f)	(p)->flags &= ~(f)
+#define	F_ISSET(p, f)	((p)->flags & (f))
+
+#include <mpool.h>
+
+#define	DEFMINKEYPAGE	(2)		/* Minimum keys per page */
+#define	MINCACHE	(5)		/* Minimum cached pages */
+#define	MINPSIZE	(512)		/* Minimum page size */
+
+/*
+ * Page 0 of a btree file contains a copy of the meta-data.  This page is also
+ * used as an out-of-band page, i.e. page pointers that point to nowhere point
+ * to page 0.  Page 1 is the root of the btree.
+ */
+#define	P_INVALID	 0		/* Invalid tree page number. */
+#define	P_META		 0		/* Tree metadata page number. */
+#define	P_ROOT		 1		/* Tree root page number. */
+
+/*
+ * There are five page layouts in the btree: btree internal pages (BINTERNAL),
+ * btree leaf pages (BLEAF), recno internal pages (RINTERNAL), recno leaf pages
+ * (RLEAF) and overflow pages.  All five page types have a page header (PAGE).
+ * This implementation requires that values within structures NOT be padded.
+ * (ANSI C permits random padding.)  If your compiler pads randomly you'll have
+ * to do some work to get this package to run.
+ */
+typedef struct _page {
+	pgno_t	pgno;			/* this page's page number */
+	pgno_t	prevpg;			/* left sibling */
+	pgno_t	nextpg;			/* right sibling */
+
+#define	P_BINTERNAL	0x01		/* btree internal page */
+#define	P_BLEAF		0x02		/* leaf page */
+#define	P_OVERFLOW	0x04		/* overflow page */
+#define	P_RINTERNAL	0x08		/* recno internal page */
+#define	P_RLEAF		0x10		/* leaf page */
+#define P_TYPE		0x1f		/* type mask */
+#define	P_PRESERVE	0x20		/* never delete this chain of pages */
+	u_int32_t flags;
+
+	indx_t	lower;			/* lower bound of free space on page */
+	indx_t	upper;			/* upper bound of free space on page */
+	indx_t	linp[1];		/* indx_t-aligned VAR. LENGTH DATA */
+} PAGE;
+
+/* First and next index. */
+#define	BTDATAOFF							\
+	(sizeof(pgno_t) + sizeof(pgno_t) + sizeof(pgno_t) +		\
+	    sizeof(u_int32_t) + sizeof(indx_t) + sizeof(indx_t))
+#define	NEXTINDEX(p)	(((p)->lower - BTDATAOFF) / sizeof(indx_t))
+
+/*
+ * For pages other than overflow pages, there is an array of offsets into the
+ * rest of the page immediately following the page header.  Each offset is to
+ * an item which is unique to the type of page.  The h_lower offset is just
+ * past the last filled-in index.  The h_upper offset is the first item on the
+ * page.  Offsets are from the beginning of the page.
+ *
+ * If an item is too big to store on a single page, a flag is set and the item
+ * is a { page, size } pair such that the page is the first page of an overflow
+ * chain with size bytes of item.  Overflow pages are simply bytes without any
+ * external structure.
+ *
+ * The page number and size fields in the items are pgno_t-aligned so they can
+ * be manipulated without copying.  (This presumes that 32 bit items can be
+ * manipulated on this system.)
+ */
+#define	LALIGN(n)	(((n) + sizeof(pgno_t) - 1) & ~(sizeof(pgno_t) - 1))
+#define	NOVFLSIZE	(sizeof(pgno_t) + sizeof(u_int32_t))
+
+/*
+ * For the btree internal pages, the item is a key.  BINTERNALs are {key, pgno}
+ * pairs, such that the key compares less than or equal to all of the records
+ * on that page.  For a tree without duplicate keys, an internal page with two
+ * consecutive keys, a and b, will have all records greater than or equal to a
+ * and less than b stored on the page associated with a.  Duplicate keys are
+ * somewhat special and can cause duplicate internal and leaf page records and
+ * some minor modifications of the above rule.
+ */
+typedef struct _binternal {
+	u_int32_t ksize;		/* key size */
+	pgno_t	pgno;			/* page number stored on */
+#define	P_BIGDATA	0x01		/* overflow data */
+#define	P_BIGKEY	0x02		/* overflow key */
+	u_char	flags;
+	char	bytes[1];		/* data */
+} BINTERNAL;
+
+/* Get the page's BINTERNAL structure at index indx. */
+#define	GETBINTERNAL(pg, indx)						\
+	((BINTERNAL *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NBINTERNAL(len)							\
+	LALIGN(sizeof(u_int32_t) + sizeof(pgno_t) + sizeof(u_char) + (len))
+
+/* Copy a BINTERNAL entry to the page. */
+#define	WR_BINTERNAL(p, size, pgno, flags) {				\
+	*(u_int32_t *)p = size;						\
+	p += sizeof(u_int32_t);						\
+	*(pgno_t *)p = pgno;						\
+	p += sizeof(pgno_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+}
+
+/*
+ * For the recno internal pages, the item is a page number with the number of
+ * keys found on that page and below.
+ */
+typedef struct _rinternal {
+	recno_t	nrecs;			/* number of records */
+	pgno_t	pgno;			/* page number stored below */
+} RINTERNAL;
+
+/* Get the page's RINTERNAL structure at index indx. */
+#define	GETRINTERNAL(pg, indx)						\
+	((RINTERNAL *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NRINTERNAL							\
+	LALIGN(sizeof(recno_t) + sizeof(pgno_t))
+
+/* Copy a RINTERAL entry to the page. */
+#define	WR_RINTERNAL(p, nrecs, pgno) {					\
+	*(recno_t *)p = nrecs;						\
+	p += sizeof(recno_t);						\
+	*(pgno_t *)p = pgno;						\
+}
+
+/* For the btree leaf pages, the item is a key and data pair. */
+typedef struct _bleaf {
+	u_int32_t	ksize;		/* size of key */
+	u_int32_t	dsize;		/* size of data */
+	u_char	flags;			/* P_BIGDATA, P_BIGKEY */
+	char	bytes[1];		/* data */
+} BLEAF;
+
+/* Get the page's BLEAF structure at index indx. */
+#define	GETBLEAF(pg, indx)						\
+	((BLEAF *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NBLEAF(p)	NBLEAFDBT((p)->ksize, (p)->dsize)
+
+/* Get the number of bytes in the user's key/data pair. */
+#define NBLEAFDBT(ksize, dsize)						\
+	LALIGN(sizeof(u_int32_t) + sizeof(u_int32_t) + sizeof(u_char) +	\
+	    (ksize) + (dsize))
+
+/* Copy a BLEAF entry to the page. */
+#define	WR_BLEAF(p, key, data, flags) {					\
+	*(u_int32_t *)p = key->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_int32_t *)p = data->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+	memmove(p, key->data, key->size);				\
+	p += key->size;							\
+	memmove(p, data->data, data->size);				\
+}
+
+/* For the recno leaf pages, the item is a data entry. */
+typedef struct _rleaf {
+	u_int32_t	dsize;		/* size of data */
+	u_char	flags;			/* P_BIGDATA */
+	char	bytes[1];
+} RLEAF;
+
+/* Get the page's RLEAF structure at index indx. */
+#define	GETRLEAF(pg, indx)						\
+	((RLEAF *)((char *)(pg) + (pg)->linp[indx]))
+
+/* Get the number of bytes in the entry. */
+#define NRLEAF(p)	NRLEAFDBT((p)->dsize)
+
+/* Get the number of bytes from the user's data. */
+#define	NRLEAFDBT(dsize)						\
+	LALIGN(sizeof(u_int32_t) + sizeof(u_char) + (dsize))
+
+/* Copy a RLEAF entry to the page. */
+#define	WR_RLEAF(p, data, flags) {					\
+	*(u_int32_t *)p = data->size;					\
+	p += sizeof(u_int32_t);						\
+	*(u_char *)p = flags;						\
+	p += sizeof(u_char);						\
+	memmove(p, data->data, data->size);				\
+}
+
+/*
+ * A record in the tree is either a pointer to a page and an index in the page
+ * or a page number and an index.  These structures are used as a cursor, stack
+ * entry and search returns as well as to pass records to other routines.
+ *
+ * One comment about searches.  Internal page searches must find the largest
+ * record less than key in the tree so that descents work.  Leaf page searches
+ * must find the smallest record greater than key so that the returned index
+ * is the record's correct position for insertion.
+ */
+typedef struct _epgno {
+	pgno_t	pgno;			/* the page number */
+	indx_t	index;			/* the index on the page */
+} EPGNO;
+
+typedef struct _epg {
+	PAGE	*page;			/* the (pinned) page */
+	indx_t	 index;			/* the index on the page */
+} EPG;
+
+/*
+ * About cursors.  The cursor (and the page that contained the key/data pair
+ * that it referenced) can be deleted, which makes things a bit tricky.  If
+ * there are no duplicates of the cursor key in the tree (i.e. B_NODUPS is set
+ * or there simply aren't any duplicates of the key) we copy the key that it
+ * referenced when it's deleted, and reacquire a new cursor key if the cursor
+ * is used again.  If there are duplicates keys, we move to the next/previous
+ * key, and set a flag so that we know what happened.  NOTE: if duplicate (to
+ * the cursor) keys are added to the tree during this process, it is undefined
+ * if they will be returned or not in a cursor scan.
+ *
+ * The flags determine the possible states of the cursor:
+ *
+ * CURS_INIT	The cursor references *something*.
+ * CURS_ACQUIRE	The cursor was deleted, and a key has been saved so that
+ *		we can reacquire the right position in the tree.
+ * CURS_AFTER, CURS_BEFORE
+ *		The cursor was deleted, and now references a key/data pair
+ *		that has not yet been returned, either before or after the
+ *		deleted key/data pair.
+ * XXX
+ * This structure is broken out so that we can eventually offer multiple
+ * cursors as part of the DB interface.
+ */
+typedef struct _cursor {
+	EPGNO	 pg;			/* B: Saved tree reference. */
+	DBT	 key;			/* B: Saved key, or key.data == NULL. */
+	recno_t	 rcursor;		/* R: recno cursor (1-based) */
+
+#define	CURS_ACQUIRE	0x01		/*  B: Cursor needs to be reacquired. */
+#define	CURS_AFTER	0x02		/*  B: Unreturned cursor after key. */
+#define	CURS_BEFORE	0x04		/*  B: Unreturned cursor before key. */
+#define	CURS_INIT	0x08		/* RB: Cursor initialized. */
+	u_int8_t flags;
+} CURSOR;
+
+/*
+ * The metadata of the tree.  The nrecs field is used only by the RECNO code.
+ * This is because the btree doesn't really need it and it requires that every
+ * put or delete call modify the metadata.
+ */
+typedef struct _btmeta {
+	u_int32_t	magic;		/* magic number */
+	u_int32_t	version;	/* version */
+	u_int32_t	psize;		/* page size */
+	u_int32_t	free;		/* page number of first free page */
+	u_int32_t	nrecs;		/* R: number of records */
+
+#define	SAVEMETA	(B_NODUPS | R_RECNO)
+	u_int32_t	flags;		/* bt_flags & SAVEMETA */
+} BTMETA;
+
+/* The in-memory btree/recno data structure. */
+typedef struct _btree {
+	MPOOL	 *bt_mp;		/* memory pool cookie */
+
+	DB	 *bt_dbp;		/* pointer to enclosing DB */
+
+	EPG	  bt_cur;		/* current (pinned) page */
+	PAGE	 *bt_pinned;		/* page pinned across calls */
+
+	CURSOR	  bt_cursor;		/* cursor */
+
+#define	BT_PUSH(t, p, i) {						\
+	t->bt_sp->pgno = p; 						\
+	t->bt_sp->index = i; 						\
+	++t->bt_sp;							\
+}
+#define	BT_POP(t)	(t->bt_sp == t->bt_stack ? NULL : --t->bt_sp)
+#define	BT_CLR(t)	(t->bt_sp = t->bt_stack)
+	EPGNO	  bt_stack[50];		/* stack of parent pages */
+	EPGNO	 *bt_sp;		/* current stack pointer */
+
+	DBT	  bt_rkey;		/* returned key */
+	DBT	  bt_rdata;		/* returned data */
+
+	int	  bt_fd;		/* tree file descriptor */
+
+	pgno_t	  bt_free;		/* next free page */
+	u_int32_t bt_psize;		/* page size */
+	indx_t	  bt_ovflsize;		/* cut-off for key/data overflow */
+	int	  bt_lorder;		/* byte order */
+					/* sorted order */
+	enum { NOT, BACK, FORWARD } bt_order;
+	EPGNO	  bt_last;		/* last insert */
+
+					/* B: key comparison function */
+	int	(*bt_cmp) __P((const DBT *, const DBT *));
+					/* B: prefix comparison function */
+	size_t	(*bt_pfx) __P((const DBT *, const DBT *));
+					/* R: recno input function */
+	int	(*bt_irec) __P((struct _btree *, recno_t));
+
+	FILE	 *bt_rfp;		/* R: record FILE pointer */
+	int	  bt_rfd;		/* R: record file descriptor */
+
+	caddr_t	  bt_cmap;		/* R: current point in mapped space */
+	caddr_t	  bt_smap;		/* R: start of mapped space */
+	caddr_t   bt_emap;		/* R: end of mapped space */
+	size_t	  bt_msize;		/* R: size of mapped region. */
+
+	recno_t	  bt_nrecs;		/* R: number of records */
+	size_t	  bt_reclen;		/* R: fixed record length */
+	u_char	  bt_bval;		/* R: delimiting byte/pad character */
+
+/*
+ * NB:
+ * B_NODUPS and R_RECNO are stored on disk, and may not be changed.
+ */
+#define	B_INMEM		0x00001		/* in-memory tree */
+#define	B_METADIRTY	0x00002		/* need to write metadata */
+#define	B_MODIFIED	0x00004		/* tree modified */
+#define	B_NEEDSWAP	0x00008		/* if byte order requires swapping */
+#define	B_RDONLY	0x00010		/* read-only tree */
+
+#define	B_NODUPS	0x00020		/* no duplicate keys permitted */
+#define	R_RECNO		0x00080		/* record oriented tree */
+
+#define	R_CLOSEFP	0x00040		/* opened a file pointer */
+#define	R_EOF		0x00100		/* end of input file reached. */
+#define	R_FIXLEN	0x00200		/* fixed length records */
+#define	R_MEMMAPPED	0x00400		/* memory mapped file. */
+#define	R_INMEM		0x00800		/* in-memory file */
+#define	R_MODIFIED	0x01000		/* modified file */
+#define	R_RDONLY	0x02000		/* read-only file */
+
+#define	B_DB_LOCK	0x04000		/* DB_LOCK specified. */
+#define	B_DB_SHMEM	0x08000		/* DB_SHMEM specified. */
+#define	B_DB_TXN	0x10000		/* DB_TXN specified. */
+	u_int32_t flags;
+} BTREE;
+
+#include "extern.h"
diff --git a/db/btree/extern.h b/db/btree/extern.h
new file mode 100644
index 0000000000..ebd9c54923
--- /dev/null
+++ b/db/btree/extern.h
@@ -0,0 +1,70 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)extern.h	8.10 (Berkeley) 7/20/94
+ */
+
+int	 __bt_close __P((DB *));
+int	 __bt_cmp __P((BTREE *, const DBT *, EPG *));
+int	 __bt_crsrdel __P((BTREE *, EPGNO *));
+int	 __bt_defcmp __P((const DBT *, const DBT *));
+size_t	 __bt_defpfx __P((const DBT *, const DBT *));
+int	 __bt_delete __P((const DB *, const DBT *, u_int));
+int	 __bt_dleaf __P((BTREE *, const DBT *, PAGE *, u_int));
+int	 __bt_fd __P((const DB *));
+int	 __bt_free __P((BTREE *, PAGE *));
+int	 __bt_get __P((const DB *, const DBT *, DBT *, u_int));
+PAGE	*__bt_new __P((BTREE *, pgno_t *));
+void	 __bt_pgin __P((void *, pgno_t, void *));
+void	 __bt_pgout __P((void *, pgno_t, void *));
+int	 __bt_push __P((BTREE *, pgno_t, int));
+int	 __bt_put __P((const DB *dbp, DBT *, const DBT *, u_int));
+int	 __bt_ret __P((BTREE *, EPG *, DBT *, DBT *, DBT *, DBT *, int));
+EPG	*__bt_search __P((BTREE *, const DBT *, int *));
+int	 __bt_seq __P((const DB *, DBT *, DBT *, u_int));
+void	 __bt_setcur __P((BTREE *, pgno_t, u_int));
+int	 __bt_split __P((BTREE *, PAGE *,
+	    const DBT *, const DBT *, int, size_t, u_int32_t));
+int	 __bt_sync __P((const DB *, u_int));
+
+int	 __ovfl_delete __P((BTREE *, void *));
+int	 __ovfl_get __P((BTREE *, void *, size_t *, void **, size_t *));
+int	 __ovfl_put __P((BTREE *, const DBT *, pgno_t *));
+
+#ifdef DEBUG
+void	 __bt_dnpage __P((DB *, pgno_t));
+void	 __bt_dpage __P((PAGE *));
+void	 __bt_dump __P((DB *));
+#endif
+#ifdef STATISTICS
+void	 __bt_stat __P((DB *));
+#endif
diff --git a/db/compat.h b/db/compat.h
new file mode 100644
index 0000000000..706e58265d
--- /dev/null
+++ b/db/compat.h
@@ -0,0 +1,49 @@
+/* Values for building 4.4 BSD db routines in the GNU C library.  */
+
+#ifndef _compat_h_
+#define _compat_h_
+
+#include <fcntl.h>
+
+/*
+ * If you can't provide lock values in the open(2) call.  Note, this
+ * allows races to happen.
+ */
+#ifndef O_EXLOCK			/* 4.4BSD extension. */
+#define	O_EXLOCK	0
+#endif
+
+#ifndef O_SHLOCK			/* 4.4BSD extension. */
+#define	O_SHLOCK	0
+#endif
+
+#include <errno.h>
+
+#ifndef EFTYPE
+#define	EFTYPE		EINVAL		/* POSIX 1003.1 format errno. */
+#endif
+
+#include <unistd.h>
+#include <limits.h>
+
+#ifndef _POSIX_VDISABLE			/* POSIX 1003.1 disabling char. */
+#define	_POSIX_VDISABLE	0		/* Some systems used 0. */
+#endif
+
+#include <termios.h>
+
+#ifndef	TCSASOFT			/* 4.4BSD extension. */
+#define	TCSASOFT	0
+#endif
+
+#include <sys/param.h>
+
+#ifndef	MAX				/* Usually found in <sys/param.h>. */
+#define	MAX(_a,_b)	((_a)<(_b)?(_b):(_a))
+#endif
+#ifndef	MIN				/* Usually found in <sys/param.h>. */
+#define	MIN(_a,_b)	((_a)<(_b)?(_a):(_b))
+#endif
+
+
+#endif /* compat.h */
diff --git a/db/db.h b/db/db.h
new file mode 100644
index 0000000000..13c7495d64
--- /dev/null
+++ b/db/db.h
@@ -0,0 +1,236 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)db.h	8.7 (Berkeley) 6/16/94
+ */
+
+#ifndef _DB_H_
+#define	_DB_H_
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+
+#include <limits.h>
+
+#ifdef __DBINTERFACE_PRIVATE
+#include <compat.h>
+#endif
+
+#define	RET_ERROR	-1		/* Return values. */
+#define	RET_SUCCESS	 0
+#define	RET_SPECIAL	 1
+
+#ifndef	__BIT_TYPES_DEFINED__
+#define	__BIT_TYPES_DEFINED__
+typedef	__signed char		   int8_t;
+typedef	unsigned char		 u_int8_t;
+typedef	short			  int16_t;
+typedef	unsigned short		u_int16_t;
+typedef	int			  int32_t;
+typedef	unsigned int		u_int32_t;
+#ifdef WE_DONT_NEED_QUADS
+typedef	long long		  int64_t;
+typedef	unsigned long long	u_int64_t;
+#endif
+#endif
+
+#define	MAX_PAGE_NUMBER	0xffffffff	/* >= # of pages in a file */
+typedef u_int32_t	pgno_t;
+#define	MAX_PAGE_OFFSET	65535		/* >= # of bytes in a page */
+typedef u_int16_t	indx_t;
+#define	MAX_REC_NUMBER	0xffffffff	/* >= # of records in a tree */
+typedef u_int32_t	recno_t;
+
+/* Key/data structure -- a Data-Base Thang. */
+typedef struct {
+	void	*data;			/* data */
+	size_t	 size;			/* data length */
+} DBT;
+
+/* Routine flags. */
+#define	R_CURSOR	1		/* del, put, seq */
+#define	__R_UNUSED	2		/* UNUSED */
+#define	R_FIRST		3		/* seq */
+#define	R_IAFTER	4		/* put (RECNO) */
+#define	R_IBEFORE	5		/* put (RECNO) */
+#define	R_LAST		6		/* seq (BTREE, RECNO) */
+#define	R_NEXT		7		/* seq */
+#define	R_NOOVERWRITE	8		/* put */
+#define	R_PREV		9		/* seq (BTREE, RECNO) */
+#define	R_SETCURSOR	10		/* put (RECNO) */
+#define	R_RECNOSYNC	11		/* sync (RECNO) */
+
+typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
+
+/*
+ * !!!
+ * The following flags are included in the dbopen(3) call as part of the
+ * open(2) flags.  In order to avoid conflicts with the open flags, start
+ * at the top of the 16 or 32-bit number space and work our way down.  If
+ * the open flags were significantly expanded in the future, it could be
+ * a problem.  Wish I'd left another flags word in the dbopen call.
+ *
+ * !!!
+ * None of this stuff is implemented yet.  The only reason that it's here
+ * is so that the access methods can skip copying the key/data pair when
+ * the DB_LOCK flag isn't set.
+ */
+#if UINT_MAX > 65535
+#define	DB_LOCK		0x20000000	/* Do locking. */
+#define	DB_SHMEM	0x40000000	/* Use shared memory. */
+#define	DB_TXN		0x80000000	/* Do transactions. */
+#else
+#define	DB_LOCK		    0x2000	/* Do locking. */
+#define	DB_SHMEM	    0x4000	/* Use shared memory. */
+#define	DB_TXN		    0x8000	/* Do transactions. */
+#endif
+
+/* Access method description structure. */
+typedef struct __db {
+	DBTYPE type;			/* Underlying db type. */
+	int (*close)	__P((struct __db *));
+	int (*del)	__P((const struct __db *, const DBT *, u_int));
+	int (*get)	__P((const struct __db *, const DBT *, DBT *, u_int));
+	int (*put)	__P((const struct __db *, DBT *, const DBT *, u_int));
+	int (*seq)	__P((const struct __db *, DBT *, DBT *, u_int));
+	int (*sync)	__P((const struct __db *, u_int));
+	void *internal;			/* Access method private. */
+	int (*fd)	__P((const struct __db *));
+} DB;
+
+#define	BTREEMAGIC	0x053162
+#define	BTREEVERSION	3
+
+/* Structure used to pass parameters to the btree routines. */
+typedef struct {
+#define	R_DUP		0x01	/* duplicate keys */
+	u_long	flags;
+	u_int	cachesize;	/* bytes to cache */
+	int	maxkeypage;	/* maximum keys per page */
+	int	minkeypage;	/* minimum keys per page */
+	u_int	psize;		/* page size */
+	int	(*compare)	/* comparison function */
+	    __P((const DBT *, const DBT *));
+	size_t	(*prefix)	/* prefix function */
+	    __P((const DBT *, const DBT *));
+	int	lorder;		/* byte order */
+} BTREEINFO;
+
+#define	HASHMAGIC	0x061561
+#define	HASHVERSION	2
+
+/* Structure used to pass parameters to the hashing routines. */
+typedef struct {
+	u_int	bsize;		/* bucket size */
+	u_int	ffactor;	/* fill factor */
+	u_int	nelem;		/* number of elements */
+	u_int	cachesize;	/* bytes to cache */
+	u_int32_t		/* hash function */
+		(*hash) __P((const void *, size_t));
+	int	lorder;		/* byte order */
+} HASHINFO;
+
+/* Structure used to pass parameters to the record routines. */
+typedef struct {
+#define	R_FIXEDLEN	0x01	/* fixed-length records */
+#define	R_NOKEY		0x02	/* key not required */
+#define	R_SNAPSHOT	0x04	/* snapshot the input */
+	u_long	flags;
+	u_int	cachesize;	/* bytes to cache */
+	u_int	psize;		/* page size */
+	int	lorder;		/* byte order */
+	size_t	reclen;		/* record length (fixed-length records) */
+	u_char	bval;		/* delimiting byte (variable-length records */
+	char	*bfname;	/* btree file name */ 
+} RECNOINFO;
+
+#ifdef __DBINTERFACE_PRIVATE
+/*
+ * Little endian <==> big endian 32-bit swap macros.
+ *	M_32_SWAP	swap a memory location
+ *	P_32_SWAP	swap a referenced memory location
+ *	P_32_COPY	swap from one location to another
+ */
+#define	M_32_SWAP(a) {							\
+	u_int32_t _tmp = a;						\
+	((char *)&a)[0] = ((char *)&_tmp)[3];				\
+	((char *)&a)[1] = ((char *)&_tmp)[2];				\
+	((char *)&a)[2] = ((char *)&_tmp)[1];				\
+	((char *)&a)[3] = ((char *)&_tmp)[0];				\
+}
+#define	P_32_SWAP(a) {							\
+	u_int32_t _tmp = *(u_int32_t *)a;				\
+	((char *)a)[0] = ((char *)&_tmp)[3];				\
+	((char *)a)[1] = ((char *)&_tmp)[2];				\
+	((char *)a)[2] = ((char *)&_tmp)[1];				\
+	((char *)a)[3] = ((char *)&_tmp)[0];				\
+}
+#define	P_32_COPY(a, b) {						\
+	((char *)&(b))[0] = ((char *)&(a))[3];				\
+	((char *)&(b))[1] = ((char *)&(a))[2];				\
+	((char *)&(b))[2] = ((char *)&(a))[1];				\
+	((char *)&(b))[3] = ((char *)&(a))[0];				\
+}
+
+/*
+ * Little endian <==> big endian 16-bit swap macros.
+ *	M_16_SWAP	swap a memory location
+ *	P_16_SWAP	swap a referenced memory location
+ *	P_16_COPY	swap from one location to another
+ */
+#define	M_16_SWAP(a) {							\
+	u_int16_t _tmp = a;						\
+	((char *)&a)[0] = ((char *)&_tmp)[1];				\
+	((char *)&a)[1] = ((char *)&_tmp)[0];				\
+}
+#define	P_16_SWAP(a) {							\
+	u_int16_t _tmp = *(u_int16_t *)a;				\
+	((char *)a)[0] = ((char *)&_tmp)[1];				\
+	((char *)a)[1] = ((char *)&_tmp)[0];				\
+}
+#define	P_16_COPY(a, b) {						\
+	((char *)&(b))[0] = ((char *)&(a))[1];				\
+	((char *)&(b))[1] = ((char *)&(a))[0];				\
+}
+#endif
+
+__BEGIN_DECLS
+DB *dbopen __P((const char *, int, int, DBTYPE, const void *));
+
+#ifdef __DBINTERFACE_PRIVATE
+DB	*__bt_open __P((const char *, int, int, const BTREEINFO *, int));
+DB	*__hash_open __P((const char *, int, int, const HASHINFO *, int));
+DB	*__rec_open __P((const char *, int, int, const RECNOINFO *, int));
+void	 __dbpanic __P((DB *dbp));
+#endif
+__END_DECLS
+#endif /* !_DB_H_ */
diff --git a/db/db/db.c b/db/db/db.c
new file mode 100644
index 0000000000..a18f056db8
--- /dev/null
+++ b/db/db/db.c
@@ -0,0 +1,99 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)db.c	8.4 (Berkeley) 2/21/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include <db.h>
+
+DB *
+dbopen(fname, flags, mode, type, openinfo)
+	const char *fname;
+	int flags, mode;
+	DBTYPE type;
+	const void *openinfo;
+{
+
+#define	DB_FLAGS	(DB_LOCK | DB_SHMEM | DB_TXN)
+#define	USE_OPEN_FLAGS							\
+	(O_CREAT | O_EXCL | O_EXLOCK | O_NONBLOCK | O_RDONLY |		\
+	 O_RDWR | O_SHLOCK | O_TRUNC)
+
+	if ((flags & ~(USE_OPEN_FLAGS | DB_FLAGS)) == 0)
+		switch (type) {
+		case DB_BTREE:
+			return (__bt_open(fname, flags & USE_OPEN_FLAGS,
+			    mode, openinfo, flags & DB_FLAGS));
+		case DB_HASH:
+			return (__hash_open(fname, flags & USE_OPEN_FLAGS,
+			    mode, openinfo, flags & DB_FLAGS));
+		case DB_RECNO:
+			return (__rec_open(fname, flags & USE_OPEN_FLAGS,
+			    mode, openinfo, flags & DB_FLAGS));
+		}
+	errno = EINVAL;
+	return (NULL);
+}
+
+static int
+__dberr()
+{
+	return (RET_ERROR);
+}
+
+/*
+ * __DBPANIC -- Stop.
+ *
+ * Parameters:
+ *	dbp:	pointer to the DB structure.
+ */
+void
+__dbpanic(dbp)
+	DB *dbp;
+{
+	/* The only thing that can succeed is a close. */
+	dbp->del = (int (*)())__dberr;
+	dbp->fd = (int (*)())__dberr;
+	dbp->get = (int (*)())__dberr;
+	dbp->put = (int (*)())__dberr;
+	dbp->seq = (int (*)())__dberr;
+	dbp->sync = (int (*)())__dberr;
+}
diff --git a/db/hash/extern.h b/db/hash/extern.h
new file mode 100644
index 0000000000..3167e6d0f7
--- /dev/null
+++ b/db/hash/extern.h
@@ -0,0 +1,65 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)extern.h	8.4 (Berkeley) 6/16/94
+ */
+
+BUFHEAD	*__add_ovflpage __P((HTAB *, BUFHEAD *));
+int	 __addel __P((HTAB *, BUFHEAD *, const DBT *, const DBT *));
+int	 __big_delete __P((HTAB *, BUFHEAD *));
+int	 __big_insert __P((HTAB *, BUFHEAD *, const DBT *, const DBT *));
+int	 __big_keydata __P((HTAB *, BUFHEAD *, DBT *, DBT *, int));
+int	 __big_return __P((HTAB *, BUFHEAD *, int, DBT *, int));
+int	 __big_split __P((HTAB *, BUFHEAD *, BUFHEAD *, BUFHEAD *,
+		int, u_int32_t, SPLIT_RETURN *));
+int	 __buf_free __P((HTAB *, int, int));
+void	 __buf_init __P((HTAB *, int));
+u_int32_t	 __call_hash __P((HTAB *, char *, int));
+int	 __delpair __P((HTAB *, BUFHEAD *, int));
+int	 __expand_table __P((HTAB *));
+int	 __find_bigpair __P((HTAB *, BUFHEAD *, int, char *, int));
+u_int16_t	 __find_last_page __P((HTAB *, BUFHEAD **));
+void	 __free_ovflpage __P((HTAB *, BUFHEAD *));
+BUFHEAD	*__get_buf __P((HTAB *, u_int32_t, BUFHEAD *, int));
+int	 __get_page __P((HTAB *, char *, u_int32_t, int, int, int));
+int	 __ibitmap __P((HTAB *, int, int, int));
+u_int32_t	 __log2 __P((u_int32_t));
+int	 __put_page __P((HTAB *, char *, u_int32_t, int, int));
+void	 __reclaim_buf __P((HTAB *, BUFHEAD *));
+int	 __split_page __P((HTAB *, u_int32_t, u_int32_t));
+
+/* Default hash routine. */
+extern u_int32_t (*__default_hash) __P((const void *, size_t));
+
+#ifdef HASH_STATISTICS
+extern int hash_accesses, hash_collisions, hash_expansions, hash_overflows;
+#endif
diff --git a/db/hash/hash.c b/db/hash/hash.c
new file mode 100644
index 0000000000..4b7b732a8f
--- /dev/null
+++ b/db/hash/hash.c
@@ -0,0 +1,994 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash.c	8.9 (Berkeley) 6/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static int   alloc_segs __P((HTAB *, int));
+static int   flush_meta __P((HTAB *));
+static int   hash_access __P((HTAB *, ACTION, DBT *, DBT *));
+static int   hash_close __P((DB *));
+static int   hash_delete __P((const DB *, const DBT *, u_int32_t));
+static int   hash_fd __P((const DB *));
+static int   hash_get __P((const DB *, const DBT *, DBT *, u_int32_t));
+static int   hash_put __P((const DB *, DBT *, const DBT *, u_int32_t));
+static void *hash_realloc __P((SEGMENT **, int, int));
+static int   hash_seq __P((const DB *, DBT *, DBT *, u_int32_t));
+static int   hash_sync __P((const DB *, u_int32_t));
+static int   hdestroy __P((HTAB *));
+static HTAB *init_hash __P((HTAB *, const char *, HASHINFO *));
+static int   init_htab __P((HTAB *, int));
+#if BYTE_ORDER == LITTLE_ENDIAN
+static void  swap_header __P((HTAB *));
+static void  swap_header_copy __P((HASHHDR *, HASHHDR *));
+#endif
+
+/* Fast arithmetic, relying on powers of 2, */
+#define MOD(x, y)		((x) & ((y) - 1))
+
+#define RETURN_ERROR(ERR, LOC)	{ save_errno = ERR; goto LOC; }
+
+/* Return values */
+#define	SUCCESS	 (0)
+#define	ERROR	(-1)
+#define	ABNORMAL (1)
+
+#ifdef HASH_STATISTICS
+int hash_accesses, hash_collisions, hash_expansions, hash_overflows;
+#endif
+
+/************************** INTERFACE ROUTINES ***************************/
+/* OPEN/CLOSE */
+
+extern DB *
+__hash_open(file, flags, mode, info, dflags)
+	const char *file;
+	int flags, mode, dflags;
+	const HASHINFO *info;	/* Special directives for create */
+{
+	HTAB *hashp;
+	struct stat statbuf;
+	DB *dbp;
+	int bpages, hdrsize, new_table, nsegs, save_errno;
+
+	if ((flags & O_ACCMODE) == O_WRONLY) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB))))
+		return (NULL);
+	hashp->fp = -1;
+
+	/*
+	 * Even if user wants write only, we need to be able to read
+	 * the actual file, so we need to open it read/write. But, the
+	 * field in the hashp structure needs to be accurate so that
+	 * we can check accesses.
+	 */
+	hashp->flags = flags;
+
+	new_table = 0;
+	if (!file || (flags & O_TRUNC) ||
+	    (stat(file, &statbuf) && (errno == ENOENT))) {
+		if (errno == ENOENT)
+			errno = 0; /* Just in case someone looks at errno */
+		new_table = 1;
+	}
+	if (file) {
+		if ((hashp->fp = open(file, flags, mode)) == -1)
+			RETURN_ERROR(errno, error0);
+		(void)fcntl(hashp->fp, F_SETFD, 1);
+	}
+	if (new_table) {
+		if (!(hashp = init_hash(hashp, file, (HASHINFO *)info)))
+			RETURN_ERROR(errno, error1);
+	} else {
+		/* Table already exists */
+		if (info && info->hash)
+			hashp->hash = info->hash;
+		else
+			hashp->hash = __default_hash;
+
+		hdrsize = read(hashp->fp, &hashp->hdr, sizeof(HASHHDR));
+#if BYTE_ORDER == LITTLE_ENDIAN
+		swap_header(hashp);
+#endif
+		if (hdrsize == -1)
+			RETURN_ERROR(errno, error1);
+		if (hdrsize != sizeof(HASHHDR))
+			RETURN_ERROR(EFTYPE, error1);
+		/* Verify file type, versions and hash function */
+		if (hashp->MAGIC != HASHMAGIC)
+			RETURN_ERROR(EFTYPE, error1);
+#define	OLDHASHVERSION	1
+		if (hashp->VERSION != HASHVERSION &&
+		    hashp->VERSION != OLDHASHVERSION)
+			RETURN_ERROR(EFTYPE, error1);
+		if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != hashp->H_CHARKEY)
+			RETURN_ERROR(EFTYPE, error1);
+		/*
+		 * Figure out how many segments we need.  Max_Bucket is the
+		 * maximum bucket number, so the number of buckets is
+		 * max_bucket + 1.
+		 */
+		nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) /
+			 hashp->SGSIZE;
+		hashp->nsegs = 0;
+		if (alloc_segs(hashp, nsegs))
+			/*
+			 * If alloc_segs fails, table will have been destroyed
+			 * and errno will have been set.
+			 */
+			return (NULL);
+		/* Read in bitmaps */
+		bpages = (hashp->SPARES[hashp->OVFL_POINT] +
+		    (hashp->BSIZE << BYTE_SHIFT) - 1) >>
+		    (hashp->BSHIFT + BYTE_SHIFT);
+
+		hashp->nmaps = bpages;
+		(void)memset(&hashp->mapp[0], 0, bpages * sizeof(u_int32_t *));
+	}
+
+	/* Initialize Buffer Manager */
+	if (info && info->cachesize)
+		__buf_init(hashp, info->cachesize);
+	else
+		__buf_init(hashp, DEF_BUFSIZE);
+
+	hashp->new_file = new_table;
+	hashp->save_file = file && (hashp->flags & O_RDWR);
+	hashp->cbucket = -1;
+	if (!(dbp = (DB *)malloc(sizeof(DB)))) {
+		save_errno = errno;
+		hdestroy(hashp);
+		errno = save_errno;
+		return (NULL);
+	}
+	dbp->internal = hashp;
+	dbp->close = hash_close;
+	dbp->del = hash_delete;
+	dbp->fd = hash_fd;
+	dbp->get = hash_get;
+	dbp->put = hash_put;
+	dbp->seq = hash_seq;
+	dbp->sync = hash_sync;
+	dbp->type = DB_HASH;
+
+#ifdef DEBUG
+	(void)fprintf(stderr,
+"%s\n%s%x\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n",
+	    "init_htab:",
+	    "TABLE POINTER   ", hashp,
+	    "BUCKET SIZE     ", hashp->BSIZE,
+	    "BUCKET SHIFT    ", hashp->BSHIFT,
+	    "DIRECTORY SIZE  ", hashp->DSIZE,
+	    "SEGMENT SIZE    ", hashp->SGSIZE,
+	    "SEGMENT SHIFT   ", hashp->SSHIFT,
+	    "FILL FACTOR     ", hashp->FFACTOR,
+	    "MAX BUCKET      ", hashp->MAX_BUCKET,
+	    "OVFL POINT	     ", hashp->OVFL_POINT,
+	    "LAST FREED      ", hashp->LAST_FREED,
+	    "HIGH MASK       ", hashp->HIGH_MASK,
+	    "LOW  MASK       ", hashp->LOW_MASK,
+	    "NSEGS           ", hashp->nsegs,
+	    "NKEYS           ", hashp->NKEYS);
+#endif
+#ifdef HASH_STATISTICS
+	hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
+#endif
+	return (dbp);
+
+error1:
+	if (hashp != NULL)
+		(void)close(hashp->fp);
+
+error0:
+	free(hashp);
+	errno = save_errno;
+	return (NULL);
+}
+
+static int
+hash_close(dbp)
+	DB *dbp;
+{
+	HTAB *hashp;
+	int retval;
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	retval = hdestroy(hashp);
+	free(dbp);
+	return (retval);
+}
+
+static int
+hash_fd(dbp)
+	const DB *dbp;
+{
+	HTAB *hashp;
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	if (hashp->fp == -1) {
+		errno = ENOENT;
+		return (-1);
+	}
+	return (hashp->fp);
+}
+
+/************************** LOCAL CREATION ROUTINES **********************/
+static HTAB *
+init_hash(hashp, file, info)
+	HTAB *hashp;
+	const char *file;
+	HASHINFO *info;
+{
+	struct stat statbuf;
+	int nelem;
+
+	nelem = 1;
+	hashp->NKEYS = 0;
+	hashp->LORDER = BYTE_ORDER;
+	hashp->BSIZE = DEF_BUCKET_SIZE;
+	hashp->BSHIFT = DEF_BUCKET_SHIFT;
+	hashp->SGSIZE = DEF_SEGSIZE;
+	hashp->SSHIFT = DEF_SEGSIZE_SHIFT;
+	hashp->DSIZE = DEF_DIRSIZE;
+	hashp->FFACTOR = DEF_FFACTOR;
+	hashp->hash = __default_hash;
+	memset(hashp->SPARES, 0, sizeof(hashp->SPARES));
+	memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS));
+
+	/* Fix bucket size to be optimal for file system */
+	if (file != NULL) {
+		if (stat(file, &statbuf))
+			return (NULL);
+		hashp->BSIZE = statbuf.st_blksize;
+		hashp->BSHIFT = __log2(hashp->BSIZE);
+	}
+
+	if (info) {
+		if (info->bsize) {
+			/* Round pagesize up to power of 2 */
+			hashp->BSHIFT = __log2(info->bsize);
+			hashp->BSIZE = 1 << hashp->BSHIFT;
+			if (hashp->BSIZE > MAX_BSIZE) {
+				errno = EINVAL;
+				return (NULL);
+			}
+		}
+		if (info->ffactor)
+			hashp->FFACTOR = info->ffactor;
+		if (info->hash)
+			hashp->hash = info->hash;
+		if (info->nelem)
+			nelem = info->nelem;
+		if (info->lorder) {
+			if (info->lorder != BIG_ENDIAN &&
+			    info->lorder != LITTLE_ENDIAN) {
+				errno = EINVAL;
+				return (NULL);
+			}
+			hashp->LORDER = info->lorder;
+		}
+	}
+	/* init_htab should destroy the table and set errno if it fails */
+	if (init_htab(hashp, nelem))
+		return (NULL);
+	else
+		return (hashp);
+}
+/*
+ * This calls alloc_segs which may run out of memory.  Alloc_segs will destroy
+ * the table and set errno, so we just pass the error information along.
+ *
+ * Returns 0 on No Error
+ */
+static int
+init_htab(hashp, nelem)
+	HTAB *hashp;
+	int nelem;
+{
+	register int nbuckets, nsegs;
+	int l2;
+
+	/*
+	 * Divide number of elements by the fill factor and determine a
+	 * desired number of buckets.  Allocate space for the next greater
+	 * power of two number of buckets.
+	 */
+	nelem = (nelem - 1) / hashp->FFACTOR + 1;
+
+	l2 = __log2(MAX(nelem, 2));
+	nbuckets = 1 << l2;
+
+	hashp->SPARES[l2] = l2 + 1;
+	hashp->SPARES[l2 + 1] = l2 + 1;
+	hashp->OVFL_POINT = l2;
+	hashp->LAST_FREED = 2;
+
+	/* First bitmap page is at: splitpoint l2 page offset 1 */
+	if (__ibitmap(hashp, OADDR_OF(l2, 1), l2 + 1, 0))
+		return (-1);
+
+	hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
+	hashp->HIGH_MASK = (nbuckets << 1) - 1;
+	hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
+	    hashp->BSHIFT) + 1;
+
+	nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
+	nsegs = 1 << __log2(nsegs);
+
+	if (nsegs > hashp->DSIZE)
+		hashp->DSIZE = nsegs;
+	return (alloc_segs(hashp, nsegs));
+}
+
+/********************** DESTROY/CLOSE ROUTINES ************************/
+
+/*
+ * Flushes any changes to the file if necessary and destroys the hashp
+ * structure, freeing all allocated space.
+ */
+static int
+hdestroy(hashp)
+	HTAB *hashp;
+{
+	int i, save_errno;
+
+	save_errno = 0;
+
+#ifdef HASH_STATISTICS
+	(void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n",
+	    hash_accesses, hash_collisions);
+	(void)fprintf(stderr, "hdestroy: expansions %ld\n",
+	    hash_expansions);
+	(void)fprintf(stderr, "hdestroy: overflows %ld\n",
+	    hash_overflows);
+	(void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n",
+	    hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs);
+
+	for (i = 0; i < NCACHED; i++)
+		(void)fprintf(stderr,
+		    "spares[%d] = %d\n", i, hashp->SPARES[i]);
+#endif
+	/*
+	 * Call on buffer manager to free buffers, and if required,
+	 * write them to disk.
+	 */
+	if (__buf_free(hashp, 1, hashp->save_file))
+		save_errno = errno;
+	if (hashp->dir) {
+		free(*hashp->dir);	/* Free initial segments */
+		/* Free extra segments */
+		while (hashp->exsegs--)
+			free(hashp->dir[--hashp->nsegs]);
+		free(hashp->dir);
+	}
+	if (flush_meta(hashp) && !save_errno)
+		save_errno = errno;
+	/* Free Bigmaps */
+	for (i = 0; i < hashp->nmaps; i++)
+		if (hashp->mapp[i])
+			free(hashp->mapp[i]);
+
+	if (hashp->fp != -1)
+		(void)close(hashp->fp);
+
+	free(hashp);
+
+	if (save_errno) {
+		errno = save_errno;
+		return (ERROR);
+	}
+	return (SUCCESS);
+}
+/*
+ * Write modified pages to disk
+ *
+ * Returns:
+ *	 0 == OK
+ *	-1 ERROR
+ */
+static int
+hash_sync(dbp, flags)
+	const DB *dbp;
+	u_int32_t flags;
+{
+	HTAB *hashp;
+
+	if (flags != 0) {
+		errno = EINVAL;
+		return (ERROR);
+	}
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	if (!hashp->save_file)
+		return (0);
+	if (__buf_free(hashp, 0, 1) || flush_meta(hashp))
+		return (ERROR);
+	hashp->new_file = 0;
+	return (0);
+}
+
+/*
+ * Returns:
+ *	 0 == OK
+ *	-1 indicates that errno should be set
+ */
+static int
+flush_meta(hashp)
+	HTAB *hashp;
+{
+	HASHHDR *whdrp;
+#if BYTE_ORDER == LITTLE_ENDIAN
+	HASHHDR whdr;
+#endif
+	int fp, i, wsize;
+
+	if (!hashp->save_file)
+		return (0);
+	hashp->MAGIC = HASHMAGIC;
+	hashp->VERSION = HASHVERSION;
+	hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY));
+
+	fp = hashp->fp;
+	whdrp = &hashp->hdr;
+#if BYTE_ORDER == LITTLE_ENDIAN
+	whdrp = &whdr;
+	swap_header_copy(&hashp->hdr, whdrp);
+#endif
+	if ((lseek(fp, (off_t)0, SEEK_SET) == -1) ||
+	    ((wsize = write(fp, whdrp, sizeof(HASHHDR))) == -1))
+		return (-1);
+	else
+		if (wsize != sizeof(HASHHDR)) {
+			errno = EFTYPE;
+			hashp->errno = errno;
+			return (-1);
+		}
+	for (i = 0; i < NCACHED; i++)
+		if (hashp->mapp[i])
+			if (__put_page(hashp, (char *)hashp->mapp[i],
+				hashp->BITMAPS[i], 0, 1))
+				return (-1);
+	return (0);
+}
+
+/*******************************SEARCH ROUTINES *****************************/
+/*
+ * All the access routines return
+ *
+ * Returns:
+ *	 0 on SUCCESS
+ *	 1 to indicate an external ERROR (i.e. key not found, etc)
+ *	-1 to indicate an internal ERROR (i.e. out of memory, etc)
+ */
+static int
+hash_get(dbp, key, data, flag)
+	const DB *dbp;
+	const DBT *key;
+	DBT *data;
+	u_int32_t flag;
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	return (hash_access(hashp, HASH_GET, (DBT *)key, data));
+}
+
+static int
+hash_put(dbp, key, data, flag)
+	const DB *dbp;
+	DBT *key;
+	const DBT *data;
+	u_int32_t flag;
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_NOOVERWRITE) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+		hashp->errno = errno = EPERM;
+		return (ERROR);
+	}
+	return (hash_access(hashp, flag == R_NOOVERWRITE ?
+	    HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data));
+}
+
+static int
+hash_delete(dbp, key, flag)
+	const DB *dbp;
+	const DBT *key;
+	u_int32_t flag;		/* Ignored */
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_CURSOR) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+		hashp->errno = errno = EPERM;
+		return (ERROR);
+	}
+	return (hash_access(hashp, HASH_DELETE, (DBT *)key, NULL));
+}
+
+/*
+ * Assume that hashp has been set in wrapper routine.
+ */
+static int
+hash_access(hashp, action, key, val)
+	HTAB *hashp;
+	ACTION action;
+	DBT *key, *val;
+{
+	register BUFHEAD *rbufp;
+	BUFHEAD *bufp, *save_bufp;
+	register u_int16_t *bp;
+	register int n, ndx, off, size;
+	register char *kp;
+	u_int16_t pageno;
+
+#ifdef HASH_STATISTICS
+	hash_accesses++;
+#endif
+
+	off = hashp->BSIZE;
+	size = key->size;
+	kp = (char *)key->data;
+	rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
+	if (!rbufp)
+		return (ERROR);
+	save_bufp = rbufp;
+
+	/* Pin the bucket chain */
+	rbufp->flags |= BUF_PIN;
+	for (bp = (u_int16_t *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
+		if (bp[1] >= REAL_KEY) {
+			/* Real key/data pair */
+			if (size == off - *bp &&
+			    memcmp(kp, rbufp->page + *bp, size) == 0)
+				goto found;
+			off = bp[1];
+#ifdef HASH_STATISTICS
+			hash_collisions++;
+#endif
+			bp += 2;
+			ndx += 2;
+		} else if (bp[1] == OVFLPAGE) {
+			rbufp = __get_buf(hashp, *bp, rbufp, 0);
+			if (!rbufp) {
+				save_bufp->flags &= ~BUF_PIN;
+				return (ERROR);
+			}
+			/* FOR LOOP INIT */
+			bp = (u_int16_t *)rbufp->page;
+			n = *bp++;
+			ndx = 1;
+			off = hashp->BSIZE;
+		} else if (bp[1] < REAL_KEY) {
+			if ((ndx =
+			    __find_bigpair(hashp, rbufp, ndx, kp, size)) > 0)
+				goto found;
+			if (ndx == -2) {
+				bufp = rbufp;
+				if (!(pageno =
+				    __find_last_page(hashp, &bufp))) {
+					ndx = 0;
+					rbufp = bufp;
+					break;	/* FOR */
+				}
+				rbufp = __get_buf(hashp, pageno, bufp, 0);
+				if (!rbufp) {
+					save_bufp->flags &= ~BUF_PIN;
+					return (ERROR);
+				}
+				/* FOR LOOP INIT */
+				bp = (u_int16_t *)rbufp->page;
+				n = *bp++;
+				ndx = 1;
+				off = hashp->BSIZE;
+			} else {
+				save_bufp->flags &= ~BUF_PIN;
+				return (ERROR);
+			}
+		}
+
+	/* Not found */
+	switch (action) {
+	case HASH_PUT:
+	case HASH_PUTNEW:
+		if (__addel(hashp, rbufp, key, val)) {
+			save_bufp->flags &= ~BUF_PIN;
+			return (ERROR);
+		} else {
+			save_bufp->flags &= ~BUF_PIN;
+			return (SUCCESS);
+		}
+	case HASH_GET:
+	case HASH_DELETE:
+	default:
+		save_bufp->flags &= ~BUF_PIN;
+		return (ABNORMAL);
+	}
+
+found:
+	switch (action) {
+	case HASH_PUTNEW:
+		save_bufp->flags &= ~BUF_PIN;
+		return (ABNORMAL);
+	case HASH_GET:
+		bp = (u_int16_t *)rbufp->page;
+		if (bp[ndx + 1] < REAL_KEY) {
+			if (__big_return(hashp, rbufp, ndx, val, 0))
+				return (ERROR);
+		} else {
+			val->data = (u_char *)rbufp->page + (int)bp[ndx + 1];
+			val->size = bp[ndx] - bp[ndx + 1];
+		}
+		break;
+	case HASH_PUT:
+		if ((__delpair(hashp, rbufp, ndx)) ||
+		    (__addel(hashp, rbufp, key, val))) {
+			save_bufp->flags &= ~BUF_PIN;
+			return (ERROR);
+		}
+		break;
+	case HASH_DELETE:
+		if (__delpair(hashp, rbufp, ndx))
+			return (ERROR);
+		break;
+	default:
+		abort();
+	}
+	save_bufp->flags &= ~BUF_PIN;
+	return (SUCCESS);
+}
+
+static int
+hash_seq(dbp, key, data, flag)
+	const DB *dbp;
+	DBT *key, *data;
+	u_int32_t flag;
+{
+	register u_int32_t bucket;
+	register BUFHEAD *bufp;
+	HTAB *hashp;
+	u_int16_t *bp, ndx;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_FIRST && flag != R_NEXT) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+#ifdef HASH_STATISTICS
+	hash_accesses++;
+#endif
+	if ((hashp->cbucket < 0) || (flag == R_FIRST)) {
+		hashp->cbucket = 0;
+		hashp->cndx = 1;
+		hashp->cpage = NULL;
+	}
+
+	for (bp = NULL; !bp || !bp[0]; ) {
+		if (!(bufp = hashp->cpage)) {
+			for (bucket = hashp->cbucket;
+			    bucket <= hashp->MAX_BUCKET;
+			    bucket++, hashp->cndx = 1) {
+				bufp = __get_buf(hashp, bucket, NULL, 0);
+				if (!bufp)
+					return (ERROR);
+				hashp->cpage = bufp;
+				bp = (u_int16_t *)bufp->page;
+				if (bp[0])
+					break;
+			}
+			hashp->cbucket = bucket;
+			if (hashp->cbucket > hashp->MAX_BUCKET) {
+				hashp->cbucket = -1;
+				return (ABNORMAL);
+			}
+		} else
+			bp = (u_int16_t *)hashp->cpage->page;
+
+#ifdef DEBUG
+		assert(bp);
+		assert(bufp);
+#endif
+		while (bp[hashp->cndx + 1] == OVFLPAGE) {
+			bufp = hashp->cpage =
+			    __get_buf(hashp, bp[hashp->cndx], bufp, 0);
+			if (!bufp)
+				return (ERROR);
+			bp = (u_int16_t *)(bufp->page);
+			hashp->cndx = 1;
+		}
+		if (!bp[0]) {
+			hashp->cpage = NULL;
+			++hashp->cbucket;
+		}
+	}
+	ndx = hashp->cndx;
+	if (bp[ndx + 1] < REAL_KEY) {
+		if (__big_keydata(hashp, bufp, key, data, 1))
+			return (ERROR);
+	} else {
+		key->data = (u_char *)hashp->cpage->page + bp[ndx];
+		key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
+		data->data = (u_char *)hashp->cpage->page + bp[ndx + 1];
+		data->size = bp[ndx] - bp[ndx + 1];
+		ndx += 2;
+		if (ndx > bp[0]) {
+			hashp->cpage = NULL;
+			hashp->cbucket++;
+			hashp->cndx = 1;
+		} else
+			hashp->cndx = ndx;
+	}
+	return (SUCCESS);
+}
+
+/********************************* UTILITIES ************************/
+
+/*
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==> Error
+ */
+extern int
+__expand_table(hashp)
+	HTAB *hashp;
+{
+	u_int32_t old_bucket, new_bucket;
+	int dirsize, new_segnum, spare_ndx;
+
+#ifdef HASH_STATISTICS
+	hash_expansions++;
+#endif
+	new_bucket = ++hashp->MAX_BUCKET;
+	old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK);
+
+	new_segnum = new_bucket >> hashp->SSHIFT;
+
+	/* Check if we need a new segment */
+	if (new_segnum >= hashp->nsegs) {
+		/* Check if we need to expand directory */
+		if (new_segnum >= hashp->DSIZE) {
+			/* Reallocate directory */
+			dirsize = hashp->DSIZE * sizeof(SEGMENT *);
+			if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1))
+				return (-1);
+			hashp->DSIZE = dirsize << 1;
+		}
+		if ((hashp->dir[new_segnum] =
+		    (SEGMENT)calloc(hashp->SGSIZE, sizeof(SEGMENT))) == NULL)
+			return (-1);
+		hashp->exsegs++;
+		hashp->nsegs++;
+	}
+	/*
+	 * If the split point is increasing (MAX_BUCKET's log base 2
+	 * * increases), we need to copy the current contents of the spare
+	 * split bucket to the next bucket.
+	 */
+	spare_ndx = __log2(hashp->MAX_BUCKET + 1);
+	if (spare_ndx > hashp->OVFL_POINT) {
+		hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT];
+		hashp->OVFL_POINT = spare_ndx;
+	}
+
+	if (new_bucket > hashp->HIGH_MASK) {
+		/* Starting a new doubling */
+		hashp->LOW_MASK = hashp->HIGH_MASK;
+		hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK;
+	}
+	/* Relocate records to the new bucket */
+	return (__split_page(hashp, old_bucket, new_bucket));
+}
+
+/*
+ * If realloc guarantees that the pointer is not destroyed if the realloc
+ * fails, then this routine can go away.
+ */
+static void *
+hash_realloc(p_ptr, oldsize, newsize)
+	SEGMENT **p_ptr;
+	int oldsize, newsize;
+{
+	register void *p;
+
+	if (p = malloc(newsize)) {
+		memmove(p, *p_ptr, oldsize);
+		memset((char *)p + oldsize, 0, newsize - oldsize);
+		free(*p_ptr);
+		*p_ptr = p;
+	}
+	return (p);
+}
+
+extern u_int32_t
+__call_hash(hashp, k, len)
+	HTAB *hashp;
+	char *k;
+	int len;
+{
+	int n, bucket;
+
+	n = hashp->hash(k, len);
+	bucket = n & hashp->HIGH_MASK;
+	if (bucket > hashp->MAX_BUCKET)
+		bucket = bucket & hashp->LOW_MASK;
+	return (bucket);
+}
+
+/*
+ * Allocate segment table.  On error, destroy the table and set errno.
+ *
+ * Returns 0 on success
+ */
+static int
+alloc_segs(hashp, nsegs)
+	HTAB *hashp;
+	int nsegs;
+{
+	register int i;
+	register SEGMENT store;
+
+	int save_errno;
+
+	if ((hashp->dir =
+	    (SEGMENT *)calloc(hashp->DSIZE, sizeof(SEGMENT *))) == NULL) {
+		save_errno = errno;
+		(void)hdestroy(hashp);
+		errno = save_errno;
+		return (-1);
+	}
+	/* Allocate segments */
+	if ((store =
+	    (SEGMENT)calloc(nsegs << hashp->SSHIFT, sizeof(SEGMENT))) == NULL) {
+		save_errno = errno;
+		(void)hdestroy(hashp);
+		errno = save_errno;
+		return (-1);
+	}
+	for (i = 0; i < nsegs; i++, hashp->nsegs++)
+		hashp->dir[i] = &store[i << hashp->SSHIFT];
+	return (0);
+}
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+/*
+ * Hashp->hdr needs to be byteswapped.
+ */
+static void
+swap_header_copy(srcp, destp)
+	HASHHDR *srcp, *destp;
+{
+	int i;
+
+	P_32_COPY(srcp->magic, destp->magic);
+	P_32_COPY(srcp->version, destp->version);
+	P_32_COPY(srcp->lorder, destp->lorder);
+	P_32_COPY(srcp->bsize, destp->bsize);
+	P_32_COPY(srcp->bshift, destp->bshift);
+	P_32_COPY(srcp->dsize, destp->dsize);
+	P_32_COPY(srcp->ssize, destp->ssize);
+	P_32_COPY(srcp->sshift, destp->sshift);
+	P_32_COPY(srcp->ovfl_point, destp->ovfl_point);
+	P_32_COPY(srcp->last_freed, destp->last_freed);
+	P_32_COPY(srcp->max_bucket, destp->max_bucket);
+	P_32_COPY(srcp->high_mask, destp->high_mask);
+	P_32_COPY(srcp->low_mask, destp->low_mask);
+	P_32_COPY(srcp->ffactor, destp->ffactor);
+	P_32_COPY(srcp->nkeys, destp->nkeys);
+	P_32_COPY(srcp->hdrpages, destp->hdrpages);
+	P_32_COPY(srcp->h_charkey, destp->h_charkey);
+	for (i = 0; i < NCACHED; i++) {
+		P_32_COPY(srcp->spares[i], destp->spares[i]);
+		P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]);
+	}
+}
+
+static void
+swap_header(hashp)
+	HTAB *hashp;
+{
+	HASHHDR *hdrp;
+	int i;
+
+	hdrp = &hashp->hdr;
+
+	M_32_SWAP(hdrp->magic);
+	M_32_SWAP(hdrp->version);
+	M_32_SWAP(hdrp->lorder);
+	M_32_SWAP(hdrp->bsize);
+	M_32_SWAP(hdrp->bshift);
+	M_32_SWAP(hdrp->dsize);
+	M_32_SWAP(hdrp->ssize);
+	M_32_SWAP(hdrp->sshift);
+	M_32_SWAP(hdrp->ovfl_point);
+	M_32_SWAP(hdrp->last_freed);
+	M_32_SWAP(hdrp->max_bucket);
+	M_32_SWAP(hdrp->high_mask);
+	M_32_SWAP(hdrp->low_mask);
+	M_32_SWAP(hdrp->ffactor);
+	M_32_SWAP(hdrp->nkeys);
+	M_32_SWAP(hdrp->hdrpages);
+	M_32_SWAP(hdrp->h_charkey);
+	for (i = 0; i < NCACHED; i++) {
+		M_32_SWAP(hdrp->spares[i]);
+		M_16_SWAP(hdrp->bitmaps[i]);
+	}
+}
+#endif
diff --git a/db/hash/hash.h b/db/hash/hash.h
new file mode 100644
index 0000000000..913e82b400
--- /dev/null
+++ b/db/hash/hash.h
@@ -0,0 +1,293 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)hash.h	8.3 (Berkeley) 5/31/94
+ */
+
+/* Operations */
+typedef enum {
+	HASH_GET, HASH_PUT, HASH_PUTNEW, HASH_DELETE, HASH_FIRST, HASH_NEXT
+} ACTION;
+
+/* Buffer Management structures */
+typedef struct _bufhead BUFHEAD;
+
+struct _bufhead {
+	BUFHEAD		*prev;		/* LRU links */
+	BUFHEAD		*next;		/* LRU links */
+	BUFHEAD		*ovfl;		/* Overflow page buffer header */
+	u_int32_t	 addr;		/* Address of this page */
+	char		*page;		/* Actual page data */
+	char	 	flags;
+#define	BUF_MOD		0x0001
+#define BUF_DISK	0x0002
+#define	BUF_BUCKET	0x0004
+#define	BUF_PIN		0x0008
+};
+
+#define IS_BUCKET(X)	((X) & BUF_BUCKET)
+
+typedef BUFHEAD **SEGMENT;
+
+/* Hash Table Information */
+typedef struct hashhdr {		/* Disk resident portion */
+	int		magic;		/* Magic NO for hash tables */
+	int		version;	/* Version ID */
+	u_int32_t	lorder;		/* Byte Order */
+	int		bsize;		/* Bucket/Page Size */
+	int		bshift;		/* Bucket shift */
+	int		dsize;		/* Directory Size */
+	int		ssize;		/* Segment Size */
+	int		sshift;		/* Segment shift */
+	int		ovfl_point;	/* Where overflow pages are being 
+					 * allocated */
+	int		last_freed;	/* Last overflow page freed */
+	int		max_bucket;	/* ID of Maximum bucket in use */
+	int		high_mask;	/* Mask to modulo into entire table */
+	int		low_mask;	/* Mask to modulo into lower half of 
+					 * table */
+	int		ffactor;	/* Fill factor */
+	int		nkeys;		/* Number of keys in hash table */
+	int		hdrpages;	/* Size of table header */
+	int		h_charkey;	/* value of hash(CHARKEY) */
+#define NCACHED	32			/* number of bit maps and spare 
+					 * points */
+	int		spares[NCACHED];/* spare pages for overflow */
+	u_int16_t	bitmaps[NCACHED];	/* address of overflow page 
+						 * bitmaps */
+} HASHHDR;
+
+typedef struct htab	 {		/* Memory resident data structure */
+	HASHHDR 	hdr;		/* Header */
+	int		nsegs;		/* Number of allocated segments */
+	int		exsegs;		/* Number of extra allocated 
+					 * segments */
+	u_int32_t			/* Hash function */
+	    (*hash)__P((const void *, size_t));
+	int		flags;		/* Flag values */
+	int		fp;		/* File pointer */
+	char		*tmp_buf;	/* Temporary Buffer for BIG data */
+	char		*tmp_key;	/* Temporary Buffer for BIG keys */
+	BUFHEAD 	*cpage;		/* Current page */
+	int		cbucket;	/* Current bucket */
+	int		cndx;		/* Index of next item on cpage */
+	int		errno;		/* Error Number -- for DBM 
+					 * compatability */
+	int		new_file;	/* Indicates if fd is backing store 
+					 * or no */
+	int		save_file;	/* Indicates whether we need to flush 
+					 * file at
+					 * exit */
+	u_int32_t	*mapp[NCACHED];	/* Pointers to page maps */
+	int		nmaps;		/* Initial number of bitmaps */
+	int		nbufs;		/* Number of buffers left to 
+					 * allocate */
+	BUFHEAD 	bufhead;	/* Header of buffer lru list */
+	SEGMENT 	*dir;		/* Hash Bucket directory */
+} HTAB;
+
+/*
+ * Constants
+ */
+#define	MAX_BSIZE		65536		/* 2^16 */
+#define MIN_BUFFERS		6
+#define MINHDRSIZE		512
+#define DEF_BUFSIZE		65536		/* 64 K */
+#define DEF_BUCKET_SIZE		4096
+#define DEF_BUCKET_SHIFT	12		/* log2(BUCKET) */
+#define DEF_SEGSIZE		256
+#define DEF_SEGSIZE_SHIFT	8		/* log2(SEGSIZE)	 */
+#define DEF_DIRSIZE		256
+#define DEF_FFACTOR		65536
+#define MIN_FFACTOR		4
+#define SPLTMAX			8
+#define CHARKEY			"%$sniglet^&"
+#define NUMKEY			1038583
+#define BYTE_SHIFT		3
+#define INT_TO_BYTE		2
+#define INT_BYTE_SHIFT		5
+#define ALL_SET			((u_int32_t)0xFFFFFFFF)
+#define ALL_CLEAR		0
+
+#define PTROF(X)	((BUFHEAD *)((ptrdiff_t)(X)&~0x3))
+#define ISMOD(X)	((u_int32_t)(ptrdiff_t)(X)&0x1)
+#define DOMOD(X)	((X) = (char *)((ptrdiff_t)(X)|0x1))
+#define ISDISK(X)	((u_int32_t)(ptrdiff_t)(X)&0x2)
+#define DODISK(X)	((X) = (char *)((ptrdiff_t)(X)|0x2))
+
+#define BITS_PER_MAP	32
+
+/* Given the address of the beginning of a big map, clear/set the nth bit */
+#define CLRBIT(A, N)	((A)[(N)/BITS_PER_MAP] &= ~(1<<((N)%BITS_PER_MAP)))
+#define SETBIT(A, N)	((A)[(N)/BITS_PER_MAP] |= (1<<((N)%BITS_PER_MAP)))
+#define ISSET(A, N)	((A)[(N)/BITS_PER_MAP] & (1<<((N)%BITS_PER_MAP)))
+
+/* Overflow management */
+/*
+ * Overflow page numbers are allocated per split point.  At each doubling of
+ * the table, we can allocate extra pages.  So, an overflow page number has
+ * the top 5 bits indicate which split point and the lower 11 bits indicate
+ * which page at that split point is indicated (pages within split points are
+ * numberered starting with 1).
+ */
+
+#define SPLITSHIFT	11
+#define SPLITMASK	0x7FF
+#define SPLITNUM(N)	(((u_int32_t)(N)) >> SPLITSHIFT)
+#define OPAGENUM(N)	((N) & SPLITMASK)
+#define	OADDR_OF(S,O)	((u_int32_t)((u_int32_t)(S) << SPLITSHIFT) + (O))
+
+#define BUCKET_TO_PAGE(B) \
+	(B) + hashp->HDRPAGES + ((B) ? hashp->SPARES[__log2((B)+1)-1] : 0)
+#define OADDR_TO_PAGE(B) 	\
+	BUCKET_TO_PAGE ( (1 << SPLITNUM((B))) -1 ) + OPAGENUM((B));
+
+/*
+ * page.h contains a detailed description of the page format.
+ *
+ * Normally, keys and data are accessed from offset tables in the top of
+ * each page which point to the beginning of the key and data.  There are
+ * four flag values which may be stored in these offset tables which indicate
+ * the following:
+ *
+ *
+ * OVFLPAGE	Rather than a key data pair, this pair contains
+ *		the address of an overflow page.  The format of
+ *		the pair is:
+ *		    OVERFLOW_PAGE_NUMBER OVFLPAGE
+ *
+ * PARTIAL_KEY	This must be the first key/data pair on a page
+ *		and implies that page contains only a partial key.
+ *		That is, the key is too big to fit on a single page
+ *		so it starts on this page and continues on the next.
+ *		The format of the page is:
+ *		    KEY_OFF PARTIAL_KEY OVFL_PAGENO OVFLPAGE
+ *		
+ *		    KEY_OFF -- offset of the beginning of the key
+ *		    PARTIAL_KEY -- 1
+ *		    OVFL_PAGENO - page number of the next overflow page
+ *		    OVFLPAGE -- 0
+ *
+ * FULL_KEY	This must be the first key/data pair on the page.  It
+ *		is used in two cases.
+ *
+ *		Case 1:
+ *		    There is a complete key on the page but no data
+ *		    (because it wouldn't fit).  The next page contains
+ *		    the data.
+ *
+ *		    Page format it:
+ *		    KEY_OFF FULL_KEY OVFL_PAGENO OVFL_PAGE
+ *
+ *		    KEY_OFF -- offset of the beginning of the key
+ *		    FULL_KEY -- 2
+ *		    OVFL_PAGENO - page number of the next overflow page
+ *		    OVFLPAGE -- 0
+ *
+ *		Case 2:
+ *		    This page contains no key, but part of a large
+ *		    data field, which is continued on the next page.
+ *
+ *		    Page format it:
+ *		    DATA_OFF FULL_KEY OVFL_PAGENO OVFL_PAGE
+ *
+ *		    KEY_OFF -- offset of the beginning of the data on
+ *				this page
+ *		    FULL_KEY -- 2
+ *		    OVFL_PAGENO - page number of the next overflow page
+ *		    OVFLPAGE -- 0
+ *
+ * FULL_KEY_DATA 
+ *		This must be the first key/data pair on the page.
+ *		There are two cases:
+ *
+ *		Case 1:
+ *		    This page contains a key and the beginning of the
+ *		    data field, but the data field is continued on the
+ *		    next page.
+ *
+ *		    Page format is:
+ *		    KEY_OFF FULL_KEY_DATA OVFL_PAGENO DATA_OFF
+ *
+ *		    KEY_OFF -- offset of the beginning of the key
+ *		    FULL_KEY_DATA -- 3
+ *		    OVFL_PAGENO - page number of the next overflow page
+ *		    DATA_OFF -- offset of the beginning of the data
+ *
+ *		Case 2:
+ *		    This page contains the last page of a big data pair.
+ *		    There is no key, only the  tail end of the data
+ *		    on this page.
+ *
+ *		    Page format is:
+ *		    DATA_OFF FULL_KEY_DATA <OVFL_PAGENO> <OVFLPAGE>
+ *
+ *		    DATA_OFF -- offset of the beginning of the data on
+ *				this page
+ *		    FULL_KEY_DATA -- 3
+ *		    OVFL_PAGENO - page number of the next overflow page
+ *		    OVFLPAGE -- 0
+ *
+ *		    OVFL_PAGENO and OVFLPAGE are optional (they are
+ *		    not present if there is no next page).
+ */
+
+#define OVFLPAGE	0
+#define PARTIAL_KEY	1
+#define FULL_KEY	2
+#define FULL_KEY_DATA	3
+#define	REAL_KEY	4
+
+/* Short hands for accessing structure */
+#define BSIZE		hdr.bsize
+#define BSHIFT		hdr.bshift
+#define DSIZE		hdr.dsize
+#define SGSIZE		hdr.ssize
+#define SSHIFT		hdr.sshift
+#define LORDER		hdr.lorder
+#define OVFL_POINT	hdr.ovfl_point
+#define	LAST_FREED	hdr.last_freed
+#define MAX_BUCKET	hdr.max_bucket
+#define FFACTOR		hdr.ffactor
+#define HIGH_MASK	hdr.high_mask
+#define LOW_MASK	hdr.low_mask
+#define NKEYS		hdr.nkeys
+#define HDRPAGES	hdr.hdrpages
+#define SPARES		hdr.spares
+#define BITMAPS		hdr.bitmaps
+#define VERSION		hdr.version
+#define MAGIC		hdr.magic
+#define NEXT_FREE	hdr.next_free
+#define H_CHARKEY	hdr.h_charkey
diff --git a/db/hash/hash_bigkey.c b/db/hash/hash_bigkey.c
new file mode 100644
index 0000000000..578314a645
--- /dev/null
+++ b/db/hash/hash_bigkey.c
@@ -0,0 +1,667 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_bigkey.c	8.3 (Berkeley) 5/31/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * PACKAGE: hash
+ * DESCRIPTION:
+ *	Big key/data handling for the hashing package.
+ *
+ * ROUTINES:
+ * External
+ *	__big_keydata
+ *	__big_split
+ *	__big_insert
+ *	__big_return
+ *	__big_delete
+ *	__find_last_page
+ * Internal
+ *	collect_key
+ *	collect_data
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static int collect_key __P((HTAB *, BUFHEAD *, int, DBT *, int));
+static int collect_data __P((HTAB *, BUFHEAD *, int, int));
+
+/*
+ * Big_insert
+ *
+ * You need to do an insert and the key/data pair is too big
+ *
+ * Returns:
+ * 0 ==> OK
+ *-1 ==> ERROR
+ */
+extern int
+__big_insert(hashp, bufp, key, val)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	const DBT *key, *val;
+{
+	register u_int16_t *p;
+	int key_size, n, val_size;
+	u_int16_t space, move_bytes, off;
+	char *cp, *key_data, *val_data;
+
+	cp = bufp->page;		/* Character pointer of p. */
+	p = (u_int16_t *)cp;
+
+	key_data = (char *)key->data;
+	key_size = key->size;
+	val_data = (char *)val->data;
+	val_size = val->size;
+
+	/* First move the Key */
+	for (space = FREESPACE(p) - BIGOVERHEAD; key_size;
+	    space = FREESPACE(p) - BIGOVERHEAD) {
+		move_bytes = MIN(space, key_size);
+		off = OFFSET(p) - move_bytes;
+		memmove(cp + off, key_data, move_bytes);
+		key_size -= move_bytes;
+		key_data += move_bytes;
+		n = p[0];
+		p[++n] = off;
+		p[0] = ++n;
+		FREESPACE(p) = off - PAGE_META(n);
+		OFFSET(p) = off;
+		p[n] = PARTIAL_KEY;
+		bufp = __add_ovflpage(hashp, bufp);
+		if (!bufp)
+			return (-1);
+		n = p[0];
+		if (!key_size)
+			if (FREESPACE(p)) {
+				move_bytes = MIN(FREESPACE(p), val_size);
+				off = OFFSET(p) - move_bytes;
+				p[n] = off;
+				memmove(cp + off, val_data, move_bytes);
+				val_data += move_bytes;
+				val_size -= move_bytes;
+				p[n - 2] = FULL_KEY_DATA;
+				FREESPACE(p) = FREESPACE(p) - move_bytes;
+				OFFSET(p) = off;
+			} else
+				p[n - 2] = FULL_KEY;
+		p = (u_int16_t *)bufp->page;
+		cp = bufp->page;
+		bufp->flags |= BUF_MOD;
+	}
+
+	/* Now move the data */
+	for (space = FREESPACE(p) - BIGOVERHEAD; val_size;
+	    space = FREESPACE(p) - BIGOVERHEAD) {
+		move_bytes = MIN(space, val_size);
+		/*
+		 * Here's the hack to make sure that if the data ends on the
+		 * same page as the key ends, FREESPACE is at least one.
+		 */
+		if (space == val_size && val_size == val->size)
+			move_bytes--;
+		off = OFFSET(p) - move_bytes;
+		memmove(cp + off, val_data, move_bytes);
+		val_size -= move_bytes;
+		val_data += move_bytes;
+		n = p[0];
+		p[++n] = off;
+		p[0] = ++n;
+		FREESPACE(p) = off - PAGE_META(n);
+		OFFSET(p) = off;
+		if (val_size) {
+			p[n] = FULL_KEY;
+			bufp = __add_ovflpage(hashp, bufp);
+			if (!bufp)
+				return (-1);
+			cp = bufp->page;
+			p = (u_int16_t *)cp;
+		} else
+			p[n] = FULL_KEY_DATA;
+		bufp->flags |= BUF_MOD;
+	}
+	return (0);
+}
+
+/*
+ * Called when bufp's page  contains a partial key (index should be 1)
+ *
+ * All pages in the big key/data pair except bufp are freed.  We cannot
+ * free bufp because the page pointing to it is lost and we can't get rid
+ * of its pointer.
+ *
+ * Returns:
+ * 0 => OK
+ *-1 => ERROR
+ */
+extern int
+__big_delete(hashp, bufp)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+{
+	register BUFHEAD *last_bfp, *rbufp;
+	u_int16_t *bp, pageno;
+	int key_done, n;
+
+	rbufp = bufp;
+	last_bfp = NULL;
+	bp = (u_int16_t *)bufp->page;
+	pageno = 0;
+	key_done = 0;
+
+	while (!key_done || (bp[2] != FULL_KEY_DATA)) {
+		if (bp[2] == FULL_KEY || bp[2] == FULL_KEY_DATA)
+			key_done = 1;
+
+		/*
+		 * If there is freespace left on a FULL_KEY_DATA page, then
+		 * the data is short and fits entirely on this page, and this
+		 * is the last page.
+		 */
+		if (bp[2] == FULL_KEY_DATA && FREESPACE(bp))
+			break;
+		pageno = bp[bp[0] - 1];
+		rbufp->flags |= BUF_MOD;
+		rbufp = __get_buf(hashp, pageno, rbufp, 0);
+		if (last_bfp)
+			__free_ovflpage(hashp, last_bfp);
+		last_bfp = rbufp;
+		if (!rbufp)
+			return (-1);		/* Error. */
+		bp = (u_int16_t *)rbufp->page;
+	}
+
+	/*
+	 * If we get here then rbufp points to the last page of the big
+	 * key/data pair.  Bufp points to the first one -- it should now be
+	 * empty pointing to the next page after this pair.  Can't free it
+	 * because we don't have the page pointing to it.
+	 */
+
+	/* This is information from the last page of the pair. */
+	n = bp[0];
+	pageno = bp[n - 1];
+
+	/* Now, bp is the first page of the pair. */
+	bp = (u_int16_t *)bufp->page;
+	if (n > 2) {
+		/* There is an overflow page. */
+		bp[1] = pageno;
+		bp[2] = OVFLPAGE;
+		bufp->ovfl = rbufp->ovfl;
+	} else
+		/* This is the last page. */
+		bufp->ovfl = NULL;
+	n -= 2;
+	bp[0] = n;
+	FREESPACE(bp) = hashp->BSIZE - PAGE_META(n);
+	OFFSET(bp) = hashp->BSIZE - 1;
+
+	bufp->flags |= BUF_MOD;
+	if (rbufp)
+		__free_ovflpage(hashp, rbufp);
+	if (last_bfp != rbufp)
+		__free_ovflpage(hashp, last_bfp);
+
+	hashp->NKEYS--;
+	return (0);
+}
+/*
+ * Returns:
+ *  0 = key not found
+ * -1 = get next overflow page
+ * -2 means key not found and this is big key/data
+ * -3 error
+ */
+extern int
+__find_bigpair(hashp, bufp, ndx, key, size)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	int ndx;
+	char *key;
+	int size;
+{
+	register u_int16_t *bp;
+	register char *p;
+	int ksize;
+	u_int16_t bytes;
+	char *kkey;
+
+	bp = (u_int16_t *)bufp->page;
+	p = bufp->page;
+	ksize = size;
+	kkey = key;
+
+	for (bytes = hashp->BSIZE - bp[ndx];
+	    bytes <= size && bp[ndx + 1] == PARTIAL_KEY;
+	    bytes = hashp->BSIZE - bp[ndx]) {
+		if (memcmp(p + bp[ndx], kkey, bytes))
+			return (-2);
+		kkey += bytes;
+		ksize -= bytes;
+		bufp = __get_buf(hashp, bp[ndx + 2], bufp, 0);
+		if (!bufp)
+			return (-3);
+		p = bufp->page;
+		bp = (u_int16_t *)p;
+		ndx = 1;
+	}
+
+	if (bytes != ksize || memcmp(p + bp[ndx], kkey, bytes)) {
+#ifdef HASH_STATISTICS
+		++hash_collisions;
+#endif
+		return (-2);
+	} else
+		return (ndx);
+}
+
+/*
+ * Given the buffer pointer of the first overflow page of a big pair,
+ * find the end of the big pair
+ *
+ * This will set bpp to the buffer header of the last page of the big pair.
+ * It will return the pageno of the overflow page following the last page
+ * of the pair; 0 if there isn't any (i.e. big pair is the last key in the
+ * bucket)
+ */
+extern u_int16_t
+__find_last_page(hashp, bpp)
+	HTAB *hashp;
+	BUFHEAD **bpp;
+{
+	BUFHEAD *bufp;
+	u_int16_t *bp, pageno;
+	int n;
+
+	bufp = *bpp;
+	bp = (u_int16_t *)bufp->page;
+	for (;;) {
+		n = bp[0];
+
+		/*
+		 * This is the last page if: the tag is FULL_KEY_DATA and
+		 * either only 2 entries OVFLPAGE marker is explicit there
+		 * is freespace on the page.
+		 */
+		if (bp[2] == FULL_KEY_DATA &&
+		    ((n == 2) || (bp[n] == OVFLPAGE) || (FREESPACE(bp))))
+			break;
+
+		pageno = bp[n - 1];
+		bufp = __get_buf(hashp, pageno, bufp, 0);
+		if (!bufp)
+			return (0);	/* Need to indicate an error! */
+		bp = (u_int16_t *)bufp->page;
+	}
+
+	*bpp = bufp;
+	if (bp[0] > 2)
+		return (bp[3]);
+	else
+		return (0);
+}
+
+/*
+ * Return the data for the key/data pair that begins on this page at this
+ * index (index should always be 1).
+ */
+extern int
+__big_return(hashp, bufp, ndx, val, set_current)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	int ndx;
+	DBT *val;
+	int set_current;
+{
+	BUFHEAD *save_p;
+	u_int16_t *bp, len, off, save_addr;
+	char *tp;
+
+	bp = (u_int16_t *)bufp->page;
+	while (bp[ndx + 1] == PARTIAL_KEY) {
+		bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!bufp)
+			return (-1);
+		bp = (u_int16_t *)bufp->page;
+		ndx = 1;
+	}
+
+	if (bp[ndx + 1] == FULL_KEY) {
+		bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!bufp)
+			return (-1);
+		bp = (u_int16_t *)bufp->page;
+		save_p = bufp;
+		save_addr = save_p->addr;
+		off = bp[1];
+		len = 0;
+	} else
+		if (!FREESPACE(bp)) {
+			/*
+			 * This is a hack.  We can't distinguish between
+			 * FULL_KEY_DATA that contains complete data or
+			 * incomplete data, so we require that if the data
+			 * is complete, there is at least 1 byte of free
+			 * space left.
+			 */
+			off = bp[bp[0]];
+			len = bp[1] - off;
+			save_p = bufp;
+			save_addr = bufp->addr;
+			bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+			if (!bufp)
+				return (-1);
+			bp = (u_int16_t *)bufp->page;
+		} else {
+			/* The data is all on one page. */
+			tp = (char *)bp;
+			off = bp[bp[0]];
+			val->data = (u_char *)tp + off;
+			val->size = bp[1] - off;
+			if (set_current) {
+				if (bp[0] == 2) {	/* No more buckets in
+							 * chain */
+					hashp->cpage = NULL;
+					hashp->cbucket++;
+					hashp->cndx = 1;
+				} else {
+					hashp->cpage = __get_buf(hashp,
+					    bp[bp[0] - 1], bufp, 0);
+					if (!hashp->cpage)
+						return (-1);
+					hashp->cndx = 1;
+					if (!((u_int16_t *)
+					    hashp->cpage->page)[0]) {
+						hashp->cbucket++;
+						hashp->cpage = NULL;
+					}
+				}
+			}
+			return (0);
+		}
+
+	val->size = collect_data(hashp, bufp, (int)len, set_current);
+	if (val->size == -1)
+		return (-1);
+	if (save_p->addr != save_addr) {
+		/* We are pretty short on buffers. */
+		errno = EINVAL;			/* OUT OF BUFFERS */
+		return (-1);
+	}
+	memmove(hashp->tmp_buf, (save_p->page) + off, len);
+	val->data = (u_char *)hashp->tmp_buf;
+	return (0);
+}
+/*
+ * Count how big the total datasize is by recursing through the pages.  Then
+ * allocate a buffer and copy the data as you recurse up.
+ */
+static int
+collect_data(hashp, bufp, len, set)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	int len, set;
+{
+	register u_int16_t *bp;
+	register char *p;
+	BUFHEAD *xbp;
+	u_int16_t save_addr;
+	int mylen, totlen;
+
+	p = bufp->page;
+	bp = (u_int16_t *)p;
+	mylen = hashp->BSIZE - bp[1];
+	save_addr = bufp->addr;
+
+	if (bp[2] == FULL_KEY_DATA) {		/* End of Data */
+		totlen = len + mylen;
+		if (hashp->tmp_buf)
+			free(hashp->tmp_buf);
+		if ((hashp->tmp_buf = (char *)malloc(totlen)) == NULL)
+			return (-1);
+		if (set) {
+			hashp->cndx = 1;
+			if (bp[0] == 2) {	/* No more buckets in chain */
+				hashp->cpage = NULL;
+				hashp->cbucket++;
+			} else {
+				hashp->cpage =
+				    __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+				if (!hashp->cpage)
+					return (-1);
+				else if (!((u_int16_t *)hashp->cpage->page)[0]) {
+					hashp->cbucket++;
+					hashp->cpage = NULL;
+				}
+			}
+		}
+	} else {
+		xbp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!xbp || ((totlen =
+		    collect_data(hashp, xbp, len + mylen, set)) < 1))
+			return (-1);
+	}
+	if (bufp->addr != save_addr) {
+		errno = EINVAL;			/* Out of buffers. */
+		return (-1);
+	}
+	memmove(&hashp->tmp_buf[len], (bufp->page) + bp[1], mylen);
+	return (totlen);
+}
+
+/*
+ * Fill in the key and data for this big pair.
+ */
+extern int
+__big_keydata(hashp, bufp, key, val, set)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	DBT *key, *val;
+	int set;
+{
+	key->size = collect_key(hashp, bufp, 0, val, set);
+	if (key->size == -1)
+		return (-1);
+	key->data = (u_char *)hashp->tmp_key;
+	return (0);
+}
+
+/*
+ * Count how big the total key size is by recursing through the pages.  Then
+ * collect the data, allocate a buffer and copy the key as you recurse up.
+ */
+static int
+collect_key(hashp, bufp, len, val, set)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	int len;
+	DBT *val;
+	int set;
+{
+	BUFHEAD *xbp;
+	char *p;
+	int mylen, totlen;
+	u_int16_t *bp, save_addr;
+
+	p = bufp->page;
+	bp = (u_int16_t *)p;
+	mylen = hashp->BSIZE - bp[1];
+
+	save_addr = bufp->addr;
+	totlen = len + mylen;
+	if (bp[2] == FULL_KEY || bp[2] == FULL_KEY_DATA) {    /* End of Key. */
+		if (hashp->tmp_key != NULL)
+			free(hashp->tmp_key);
+		if ((hashp->tmp_key = (char *)malloc(totlen)) == NULL)
+			return (-1);
+		if (__big_return(hashp, bufp, 1, val, set))
+			return (-1);
+	} else {
+		xbp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!xbp || ((totlen =
+		    collect_key(hashp, xbp, totlen, val, set)) < 1))
+			return (-1);
+	}
+	if (bufp->addr != save_addr) {
+		errno = EINVAL;		/* MIS -- OUT OF BUFFERS */
+		return (-1);
+	}
+	memmove(&hashp->tmp_key[len], (bufp->page) + bp[1], mylen);
+	return (totlen);
+}
+
+/*
+ * Returns:
+ *  0 => OK
+ * -1 => error
+ */
+extern int
+__big_split(hashp, op, np, big_keyp, addr, obucket, ret)
+	HTAB *hashp;
+	BUFHEAD *op;	/* Pointer to where to put keys that go in old bucket */
+	BUFHEAD *np;	/* Pointer to new bucket page */
+			/* Pointer to first page containing the big key/data */
+	BUFHEAD *big_keyp;
+	int addr;	/* Address of big_keyp */
+	u_int32_t   obucket;/* Old Bucket */
+	SPLIT_RETURN *ret;
+{
+	register BUFHEAD *tmpp;
+	register u_int16_t *tp;
+	BUFHEAD *bp;
+	DBT key, val;
+	u_int32_t change;
+	u_int16_t free_space, n, off;
+
+	bp = big_keyp;
+
+	/* Now figure out where the big key/data goes */
+	if (__big_keydata(hashp, big_keyp, &key, &val, 0))
+		return (-1);
+	change = (__call_hash(hashp, key.data, key.size) != obucket);
+
+	if (ret->next_addr = __find_last_page(hashp, &big_keyp)) {
+		if (!(ret->nextp =
+		    __get_buf(hashp, ret->next_addr, big_keyp, 0)))
+			return (-1);;
+	} else
+		ret->nextp = NULL;
+
+	/* Now make one of np/op point to the big key/data pair */
+#ifdef DEBUG
+	assert(np->ovfl == NULL);
+#endif
+	if (change)
+		tmpp = np;
+	else
+		tmpp = op;
+
+	tmpp->flags |= BUF_MOD;
+#ifdef DEBUG1
+	(void)fprintf(stderr,
+	    "BIG_SPLIT: %d->ovfl was %d is now %d\n", tmpp->addr,
+	    (tmpp->ovfl ? tmpp->ovfl->addr : 0), (bp ? bp->addr : 0));
+#endif
+	tmpp->ovfl = bp;	/* one of op/np point to big_keyp */
+	tp = (u_int16_t *)tmpp->page;
+#ifdef DEBUG
+	assert(FREESPACE(tp) >= OVFLSIZE);
+#endif
+	n = tp[0];
+	off = OFFSET(tp);
+	free_space = FREESPACE(tp);
+	tp[++n] = (u_int16_t)addr;
+	tp[++n] = OVFLPAGE;
+	tp[0] = n;
+	OFFSET(tp) = off;
+	FREESPACE(tp) = free_space - OVFLSIZE;
+
+	/*
+	 * Finally, set the new and old return values. BIG_KEYP contains a
+	 * pointer to the last page of the big key_data pair. Make sure that
+	 * big_keyp has no following page (2 elements) or create an empty
+	 * following page.
+	 */
+
+	ret->newp = np;
+	ret->oldp = op;
+
+	tp = (u_int16_t *)big_keyp->page;
+	big_keyp->flags |= BUF_MOD;
+	if (tp[0] > 2) {
+		/*
+		 * There may be either one or two offsets on this page.  If
+		 * there is one, then the overflow page is linked on normally
+		 * and tp[4] is OVFLPAGE.  If there are two, tp[4] contains
+		 * the second offset and needs to get stuffed in after the
+		 * next overflow page is added.
+		 */
+		n = tp[4];
+		free_space = FREESPACE(tp);
+		off = OFFSET(tp);
+		tp[0] -= 2;
+		FREESPACE(tp) = free_space + OVFLSIZE;
+		OFFSET(tp) = off;
+		tmpp = __add_ovflpage(hashp, big_keyp);
+		if (!tmpp)
+			return (-1);
+		tp[4] = n;
+	} else
+		tmpp = big_keyp;
+
+	if (change)
+		ret->newp = tmpp;
+	else
+		ret->oldp = tmpp;
+	return (0);
+}
diff --git a/db/hash/hash_buf.c b/db/hash/hash_buf.c
new file mode 100644
index 0000000000..92e1f933ad
--- /dev/null
+++ b/db/hash/hash_buf.c
@@ -0,0 +1,355 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_buf.c	8.5 (Berkeley) 7/15/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * PACKAGE: hash
+ *
+ * DESCRIPTION:
+ *	Contains buffer management
+ *
+ * ROUTINES:
+ * External
+ *	__buf_init
+ *	__get_buf
+ *	__buf_free
+ *	__reclaim_buf
+ * Internal
+ *	newbuf
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static BUFHEAD *newbuf __P((HTAB *, u_int32_t, BUFHEAD *));
+
+/* Unlink B from its place in the lru */
+#define BUF_REMOVE(B) { \
+	(B)->prev->next = (B)->next; \
+	(B)->next->prev = (B)->prev; \
+}
+
+/* Insert B after P */
+#define BUF_INSERT(B, P) { \
+	(B)->next = (P)->next; \
+	(B)->prev = (P); \
+	(P)->next = (B); \
+	(B)->next->prev = (B); \
+}
+
+#define	MRU	hashp->bufhead.next
+#define	LRU	hashp->bufhead.prev
+
+#define MRU_INSERT(B)	BUF_INSERT((B), &hashp->bufhead)
+#define LRU_INSERT(B)	BUF_INSERT((B), LRU)
+
+/*
+ * We are looking for a buffer with address "addr".  If prev_bp is NULL, then
+ * address is a bucket index.  If prev_bp is not NULL, then it points to the
+ * page previous to an overflow page that we are trying to find.
+ *
+ * CAVEAT:  The buffer header accessed via prev_bp's ovfl field may no longer
+ * be valid.  Therefore, you must always verify that its address matches the
+ * address you are seeking.
+ */
+extern BUFHEAD *
+__get_buf(hashp, addr, prev_bp, newpage)
+	HTAB *hashp;
+	u_int32_t addr;
+	BUFHEAD *prev_bp;
+	int newpage;	/* If prev_bp set, indicates a new overflow page. */
+{
+	register BUFHEAD *bp;
+	register u_int32_t is_disk_mask;
+	register int is_disk, segment_ndx;
+	SEGMENT segp;
+
+	is_disk = 0;
+	is_disk_mask = 0;
+	if (prev_bp) {
+		bp = prev_bp->ovfl;
+		if (!bp || (bp->addr != addr))
+			bp = NULL;
+		if (!newpage)
+			is_disk = BUF_DISK;
+	} else {
+		/* Grab buffer out of directory */
+		segment_ndx = addr & (hashp->SGSIZE - 1);
+
+		/* valid segment ensured by __call_hash() */
+		segp = hashp->dir[addr >> hashp->SSHIFT];
+#ifdef DEBUG
+		assert(segp != NULL);
+#endif
+		bp = PTROF(segp[segment_ndx]);
+		is_disk_mask = ISDISK(segp[segment_ndx]);
+		is_disk = is_disk_mask || !hashp->new_file;
+	}
+
+	if (!bp) {
+		bp = newbuf(hashp, addr, prev_bp);
+		if (!bp ||
+		    __get_page(hashp, bp->page, addr, !prev_bp, is_disk, 0))
+			return (NULL);
+		if (!prev_bp)
+			segp[segment_ndx] =
+			    (BUFHEAD *)((ptrdiff_t)bp | is_disk_mask);
+	} else {
+		BUF_REMOVE(bp);
+		MRU_INSERT(bp);
+	}
+	return (bp);
+}
+
+/*
+ * We need a buffer for this page. Either allocate one, or evict a resident
+ * one (if we have as many buffers as we're allowed) and put this one in.
+ *
+ * If newbuf finds an error (returning NULL), it also sets errno.
+ */
+static BUFHEAD *
+newbuf(hashp, addr, prev_bp)
+	HTAB *hashp;
+	u_int32_t addr;
+	BUFHEAD *prev_bp;
+{
+	register BUFHEAD *bp;		/* The buffer we're going to use */
+	register BUFHEAD *xbp;		/* Temp pointer */
+	register BUFHEAD *next_xbp;
+	SEGMENT segp;
+	int segment_ndx;
+	u_int16_t oaddr, *shortp;
+
+	oaddr = 0;
+	bp = LRU;
+	/*
+	 * If LRU buffer is pinned, the buffer pool is too small. We need to
+	 * allocate more buffers.
+	 */
+	if (hashp->nbufs || (bp->flags & BUF_PIN)) {
+		/* Allocate a new one */
+		if ((bp = (BUFHEAD *)malloc(sizeof(BUFHEAD))) == NULL)
+			return (NULL);
+#ifdef PURIFY
+		memset(bp, 0xff, sizeof(BUFHEAD));
+#endif
+		if ((bp->page = (char *)malloc(hashp->BSIZE)) == NULL) {
+			free(bp);
+			return (NULL);
+		}
+#ifdef PURIFY
+		memset(bp->page, 0xff, hashp->BSIZE);
+#endif
+		if (hashp->nbufs)
+			hashp->nbufs--;
+	} else {
+		/* Kick someone out */
+		BUF_REMOVE(bp);
+		/*
+		 * If this is an overflow page with addr 0, it's already been
+		 * flushed back in an overflow chain and initialized.
+		 */
+		if ((bp->addr != 0) || (bp->flags & BUF_BUCKET)) {
+			/*
+			 * Set oaddr before __put_page so that you get it
+			 * before bytes are swapped.
+			 */
+			shortp = (u_int16_t *)bp->page;
+			if (shortp[0])
+				oaddr = shortp[shortp[0] - 1];
+			if ((bp->flags & BUF_MOD) && __put_page(hashp, bp->page,
+			    bp->addr, (int)IS_BUCKET(bp->flags), 0))
+				return (NULL);
+			/*
+			 * Update the pointer to this page (i.e. invalidate it).
+			 *
+			 * If this is a new file (i.e. we created it at open
+			 * time), make sure that we mark pages which have been
+			 * written to disk so we retrieve them from disk later,
+			 * rather than allocating new pages.
+			 */
+			if (IS_BUCKET(bp->flags)) {
+				segment_ndx = bp->addr & (hashp->SGSIZE - 1);
+				segp = hashp->dir[bp->addr >> hashp->SSHIFT];
+#ifdef DEBUG
+				assert(segp != NULL);
+#endif
+
+				if (hashp->new_file &&
+				    ((bp->flags & BUF_MOD) ||
+				    ISDISK(segp[segment_ndx])))
+					segp[segment_ndx] = (BUFHEAD *)BUF_DISK;
+				else
+					segp[segment_ndx] = NULL;
+			}
+			/*
+			 * Since overflow pages can only be access by means of
+			 * their bucket, free overflow pages associated with
+			 * this bucket.
+			 */
+			for (xbp = bp; xbp->ovfl;) {
+				next_xbp = xbp->ovfl;
+				xbp->ovfl = 0;
+				xbp = next_xbp;
+
+				/* Check that ovfl pointer is up date. */
+				if (IS_BUCKET(xbp->flags) ||
+				    (oaddr != xbp->addr))
+					break;
+
+				shortp = (u_int16_t *)xbp->page;
+				if (shortp[0])
+					/* set before __put_page */
+					oaddr = shortp[shortp[0] - 1];
+				if ((xbp->flags & BUF_MOD) && __put_page(hashp,
+				    xbp->page, xbp->addr, 0, 0))
+					return (NULL);
+				xbp->addr = 0;
+				xbp->flags = 0;
+				BUF_REMOVE(xbp);
+				LRU_INSERT(xbp);
+			}
+		}
+	}
+
+	/* Now assign this buffer */
+	bp->addr = addr;
+#ifdef DEBUG1
+	(void)fprintf(stderr, "NEWBUF1: %d->ovfl was %d is now %d\n",
+	    bp->addr, (bp->ovfl ? bp->ovfl->addr : 0), 0);
+#endif
+	bp->ovfl = NULL;
+	if (prev_bp) {
+		/*
+		 * If prev_bp is set, this is an overflow page, hook it in to
+		 * the buffer overflow links.
+		 */
+#ifdef DEBUG1
+		(void)fprintf(stderr, "NEWBUF2: %d->ovfl was %d is now %d\n",
+		    prev_bp->addr, (prev_bp->ovfl ? bp->ovfl->addr : 0),
+		    (bp ? bp->addr : 0));
+#endif
+		prev_bp->ovfl = bp;
+		bp->flags = 0;
+	} else
+		bp->flags = BUF_BUCKET;
+	MRU_INSERT(bp);
+	return (bp);
+}
+
+extern void
+__buf_init(hashp, nbytes)
+	HTAB *hashp;
+	int nbytes;
+{
+	BUFHEAD *bfp;
+	int npages;
+
+	bfp = &(hashp->bufhead);
+	npages = (nbytes + hashp->BSIZE - 1) >> hashp->BSHIFT;
+	npages = MAX(npages, MIN_BUFFERS);
+
+	hashp->nbufs = npages;
+	bfp->next = bfp;
+	bfp->prev = bfp;
+	/*
+	 * This space is calloc'd so these are already null.
+	 *
+	 * bfp->ovfl = NULL;
+	 * bfp->flags = 0;
+	 * bfp->page = NULL;
+	 * bfp->addr = 0;
+	 */
+}
+
+extern int
+__buf_free(hashp, do_free, to_disk)
+	HTAB *hashp;
+	int do_free, to_disk;
+{
+	BUFHEAD *bp;
+
+	/* Need to make sure that buffer manager has been initialized */
+	if (!LRU)
+		return (0);
+	for (bp = LRU; bp != &hashp->bufhead;) {
+		/* Check that the buffer is valid */
+		if (bp->addr || IS_BUCKET(bp->flags)) {
+			if (to_disk && (bp->flags & BUF_MOD) &&
+			    __put_page(hashp, bp->page,
+			    bp->addr, IS_BUCKET(bp->flags), 0))
+				return (-1);
+		}
+		/* Check if we are freeing stuff */
+		if (do_free) {
+			if (bp->page)
+				free(bp->page);
+			BUF_REMOVE(bp);
+			free(bp);
+			bp = LRU;
+		} else
+			bp = bp->prev;
+	}
+	return (0);
+}
+
+extern void
+__reclaim_buf(hashp, bp)
+	HTAB *hashp;
+	BUFHEAD *bp;
+{
+	bp->ovfl = 0;
+	bp->addr = 0;
+	bp->flags = 0;
+	BUF_REMOVE(bp);
+	LRU_INSERT(bp);
+}
diff --git a/db/hash/hash_func.c b/db/hash/hash_func.c
new file mode 100644
index 0000000000..a5ec434ee9
--- /dev/null
+++ b/db/hash/hash_func.c
@@ -0,0 +1,212 @@
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_func.c	8.2 (Berkeley) 2/21/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static u_int32_t hash1 __P((const void *, size_t));
+static u_int32_t hash2 __P((const void *, size_t));
+static u_int32_t hash3 __P((const void *, size_t));
+static u_int32_t hash4 __P((const void *, size_t));
+
+/* Global default hash function */
+u_int32_t (*__default_hash) __P((const void *, size_t)) = hash4;
+
+/*
+ * HASH FUNCTIONS
+ *
+ * Assume that we've already split the bucket to which this key hashes,
+ * calculate that bucket, and check that in fact we did already split it.
+ *
+ * This came from ejb's hsearch.
+ */
+
+#define PRIME1		37
+#define PRIME2		1048583
+
+static u_int32_t
+hash1(keyarg, len)
+	const void *keyarg;
+	register size_t len;
+{
+	register const u_char *key;
+	register u_int32_t h;
+
+	/* Convert string to integer */
+	for (key = keyarg, h = 0; len--;)
+		h = h * PRIME1 ^ (*key++ - ' ');
+	h %= PRIME2;
+	return (h);
+}
+
+/*
+ * Phong's linear congruential hash
+ */
+#define dcharhash(h, c)	((h) = 0x63c63cd9*(h) + 0x9c39c33d + (c))
+
+static u_int32_t
+hash2(keyarg, len)
+	const void *keyarg;
+	size_t len;
+{
+	register const u_char *e, *key;
+	register u_int32_t h;
+	register u_char c;
+
+	key = keyarg;
+	e = key + len;
+	for (h = 0; key != e;) {
+		c = *key++;
+		if (!c && key > e)
+			break;
+		dcharhash(h, c);
+	}
+	return (h);
+}
+
+/*
+ * This is INCREDIBLY ugly, but fast.  We break the string up into 8 byte
+ * units.  On the first time through the loop we get the "leftover bytes"
+ * (strlen % 8).  On every other iteration, we perform 8 HASHC's so we handle
+ * all 8 bytes.  Essentially, this saves us 7 cmp & branch instructions.  If
+ * this routine is heavily used enough, it's worth the ugly coding.
+ *
+ * OZ's original sdbm hash
+ */
+static u_int32_t
+hash3(keyarg, len)
+	const void *keyarg;
+	register size_t len;
+{
+	register const u_char *key;
+	register size_t loop;
+	register u_int32_t h;
+
+#define HASHC   h = *key++ + 65599 * h
+
+	h = 0;
+	key = keyarg;
+	if (len > 0) {
+		loop = (len + 8 - 1) >> 3;
+
+		switch (len & (8 - 1)) {
+		case 0:
+			do {
+				HASHC;
+				/* FALLTHROUGH */
+		case 7:
+				HASHC;
+				/* FALLTHROUGH */
+		case 6:
+				HASHC;
+				/* FALLTHROUGH */
+		case 5:
+				HASHC;
+				/* FALLTHROUGH */
+		case 4:
+				HASHC;
+				/* FALLTHROUGH */
+		case 3:
+				HASHC;
+				/* FALLTHROUGH */
+		case 2:
+				HASHC;
+				/* FALLTHROUGH */
+		case 1:
+				HASHC;
+			} while (--loop);
+		}
+	}
+	return (h);
+}
+
+/* Hash function from Chris Torek. */
+static u_int32_t
+hash4(keyarg, len)
+	const void *keyarg;
+	register size_t len;
+{
+	register const u_char *key;
+	register size_t loop;
+	register u_int32_t h;
+
+#define HASH4a   h = (h << 5) - h + *key++;
+#define HASH4b   h = (h << 5) + h + *key++;
+#define HASH4 HASH4b
+
+	h = 0;
+	key = keyarg;
+	if (len > 0) {
+		loop = (len + 8 - 1) >> 3;
+
+		switch (len & (8 - 1)) {
+		case 0:
+			do {
+				HASH4;
+				/* FALLTHROUGH */
+		case 7:
+				HASH4;
+				/* FALLTHROUGH */
+		case 6:
+				HASH4;
+				/* FALLTHROUGH */
+		case 5:
+				HASH4;
+				/* FALLTHROUGH */
+		case 4:
+				HASH4;
+				/* FALLTHROUGH */
+		case 3:
+				HASH4;
+				/* FALLTHROUGH */
+		case 2:
+				HASH4;
+				/* FALLTHROUGH */
+		case 1:
+				HASH4;
+			} while (--loop);
+		}
+	}
+	return (h);
+}
diff --git a/db/hash/hash_log2.c b/db/hash/hash_log2.c
new file mode 100644
index 0000000000..c8c56bff2d
--- /dev/null
+++ b/db/hash/hash_log2.c
@@ -0,0 +1,54 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_log2.c	8.2 (Berkeley) 5/31/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <db.h>
+
+u_int32_t
+__log2(num)
+	u_int32_t num;
+{
+	register u_int32_t i, limit;
+
+	limit = 1;
+	for (i = 0; limit < num; limit = limit << 1, i++);
+	return (i);
+}
diff --git a/db/hash/hash_page.c b/db/hash/hash_page.c
new file mode 100644
index 0000000000..e1dfe6b8d6
--- /dev/null
+++ b/db/hash/hash_page.c
@@ -0,0 +1,944 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)hash_page.c	8.7 (Berkeley) 8/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * PACKAGE:  hashing
+ *
+ * DESCRIPTION:
+ *	Page manipulation for hashing package.
+ *
+ * ROUTINES:
+ *
+ * External
+ *	__get_page
+ *	__add_ovflpage
+ * Internal
+ *	overflow_page
+ *	open_temp
+ */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static u_int32_t	*fetch_bitmap __P((HTAB *, int));
+static u_int32_t	 first_free __P((u_int32_t));
+static int	 open_temp __P((HTAB *));
+static u_int16_t	 overflow_page __P((HTAB *));
+static void	 putpair __P((char *, const DBT *, const DBT *));
+static void	 squeeze_key __P((u_int16_t *, const DBT *, const DBT *));
+static int	 ugly_split
+		    __P((HTAB *, u_int32_t, BUFHEAD *, BUFHEAD *, int, int));
+
+#define	PAGE_INIT(P) { \
+	((u_int16_t *)(P))[0] = 0; \
+	((u_int16_t *)(P))[1] = hashp->BSIZE - 3 * sizeof(u_int16_t); \
+	((u_int16_t *)(P))[2] = hashp->BSIZE; \
+}
+
+/*
+ * This is called AFTER we have verified that there is room on the page for
+ * the pair (PAIRFITS has returned true) so we go right ahead and start moving
+ * stuff on.
+ */
+static void
+putpair(p, key, val)
+	char *p;
+	const DBT *key, *val;
+{
+	register u_int16_t *bp, n, off;
+
+	bp = (u_int16_t *)p;
+
+	/* Enter the key first. */
+	n = bp[0];
+
+	off = OFFSET(bp) - key->size;
+	memmove(p + off, key->data, key->size);
+	bp[++n] = off;
+
+	/* Now the data. */
+	off -= val->size;
+	memmove(p + off, val->data, val->size);
+	bp[++n] = off;
+
+	/* Adjust page info. */
+	bp[0] = n;
+	bp[n + 1] = off - ((n + 3) * sizeof(u_int16_t));
+	bp[n + 2] = off;
+}
+
+/*
+ * Returns:
+ *	 0 OK
+ *	-1 error
+ */
+extern int
+__delpair(hashp, bufp, ndx)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	register int ndx;
+{
+	register u_int16_t *bp, newoff;
+	register int n;
+	u_int16_t pairlen;
+
+	bp = (u_int16_t *)bufp->page;
+	n = bp[0];
+
+	if (bp[ndx + 1] < REAL_KEY)
+		return (__big_delete(hashp, bufp));
+	if (ndx != 1)
+		newoff = bp[ndx - 1];
+	else
+		newoff = hashp->BSIZE;
+	pairlen = newoff - bp[ndx + 1];
+
+	if (ndx != (n - 1)) {
+		/* Hard Case -- need to shuffle keys */
+		register int i;
+		register char *src = bufp->page + (int)OFFSET(bp);
+		register char *dst = src + (int)pairlen;
+		memmove(dst, src, bp[ndx + 1] - OFFSET(bp));
+
+		/* Now adjust the pointers */
+		for (i = ndx + 2; i <= n; i += 2) {
+			if (bp[i + 1] == OVFLPAGE) {
+				bp[i - 2] = bp[i];
+				bp[i - 1] = bp[i + 1];
+			} else {
+				bp[i - 2] = bp[i] + pairlen;
+				bp[i - 1] = bp[i + 1] + pairlen;
+			}
+		}
+	}
+	/* Finally adjust the page data */
+	bp[n] = OFFSET(bp) + pairlen;
+	bp[n - 1] = bp[n + 1] + pairlen + 2 * sizeof(u_int16_t);
+	bp[0] = n - 2;
+	hashp->NKEYS--;
+
+	bufp->flags |= BUF_MOD;
+	return (0);
+}
+/*
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==> Error
+ */
+extern int
+__split_page(hashp, obucket, nbucket)
+	HTAB *hashp;
+	u_int32_t obucket, nbucket;
+{
+	register BUFHEAD *new_bufp, *old_bufp;
+	register u_int16_t *ino;
+	register char *np;
+	DBT key, val;
+	int n, ndx, retval;
+	u_int16_t copyto, diff, off, moved;
+	char *op;
+
+	copyto = (u_int16_t)hashp->BSIZE;
+	off = (u_int16_t)hashp->BSIZE;
+	old_bufp = __get_buf(hashp, obucket, NULL, 0);
+	if (old_bufp == NULL)
+		return (-1);
+	new_bufp = __get_buf(hashp, nbucket, NULL, 0);
+	if (new_bufp == NULL)
+		return (-1);
+
+	old_bufp->flags |= (BUF_MOD | BUF_PIN);
+	new_bufp->flags |= (BUF_MOD | BUF_PIN);
+
+	ino = (u_int16_t *)(op = old_bufp->page);
+	np = new_bufp->page;
+
+	moved = 0;
+
+	for (n = 1, ndx = 1; n < ino[0]; n += 2) {
+		if (ino[n + 1] < REAL_KEY) {
+			retval = ugly_split(hashp, obucket, old_bufp, new_bufp,
+			    (int)copyto, (int)moved);
+			old_bufp->flags &= ~BUF_PIN;
+			new_bufp->flags &= ~BUF_PIN;
+			return (retval);
+
+		}
+		key.data = (u_char *)op + ino[n];
+		key.size = off - ino[n];
+
+		if (__call_hash(hashp, key.data, key.size) == obucket) {
+			/* Don't switch page */
+			diff = copyto - off;
+			if (diff) {
+				copyto = ino[n + 1] + diff;
+				memmove(op + copyto, op + ino[n + 1],
+				    off - ino[n + 1]);
+				ino[ndx] = copyto + ino[n] - ino[n + 1];
+				ino[ndx + 1] = copyto;
+			} else
+				copyto = ino[n + 1];
+			ndx += 2;
+		} else {
+			/* Switch page */
+			val.data = (u_char *)op + ino[n + 1];
+			val.size = ino[n] - ino[n + 1];
+			putpair(np, &key, &val);
+			moved += 2;
+		}
+
+		off = ino[n + 1];
+	}
+
+	/* Now clean up the page */
+	ino[0] -= moved;
+	FREESPACE(ino) = copyto - sizeof(u_int16_t) * (ino[0] + 3);
+	OFFSET(ino) = copyto;
+
+#ifdef DEBUG3
+	(void)fprintf(stderr, "split %d/%d\n",
+	    ((u_int16_t *)np)[0] / 2,
+	    ((u_int16_t *)op)[0] / 2);
+#endif
+	/* unpin both pages */
+	old_bufp->flags &= ~BUF_PIN;
+	new_bufp->flags &= ~BUF_PIN;
+	return (0);
+}
+
+/*
+ * Called when we encounter an overflow or big key/data page during split
+ * handling.  This is special cased since we have to begin checking whether
+ * the key/data pairs fit on their respective pages and because we may need
+ * overflow pages for both the old and new pages.
+ *
+ * The first page might be a page with regular key/data pairs in which case
+ * we have a regular overflow condition and just need to go on to the next
+ * page or it might be a big key/data pair in which case we need to fix the
+ * big key/data pair.
+ *
+ * Returns:
+ *	 0 ==> success
+ *	-1 ==> failure
+ */
+static int
+ugly_split(hashp, obucket, old_bufp, new_bufp, copyto, moved)
+	HTAB *hashp;
+	u_int32_t obucket;	/* Same as __split_page. */
+	BUFHEAD *old_bufp, *new_bufp;
+	int copyto;	/* First byte on page which contains key/data values. */
+	int moved;	/* Number of pairs moved to new page. */
+{
+	register BUFHEAD *bufp;	/* Buffer header for ino */
+	register u_int16_t *ino;	/* Page keys come off of */
+	register u_int16_t *np;	/* New page */
+	register u_int16_t *op;	/* Page keys go on to if they aren't moving */
+
+	BUFHEAD *last_bfp;	/* Last buf header OVFL needing to be freed */
+	DBT key, val;
+	SPLIT_RETURN ret;
+	u_int16_t n, off, ov_addr, scopyto;
+	char *cino;		/* Character value of ino */
+
+	bufp = old_bufp;
+	ino = (u_int16_t *)old_bufp->page;
+	np = (u_int16_t *)new_bufp->page;
+	op = (u_int16_t *)old_bufp->page;
+	last_bfp = NULL;
+	scopyto = (u_int16_t)copyto;	/* ANSI */
+
+	n = ino[0] - 1;
+	while (n < ino[0]) {
+		if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {
+			if (__big_split(hashp, old_bufp,
+			    new_bufp, bufp, bufp->addr, obucket, &ret))
+				return (-1);
+			old_bufp = ret.oldp;
+			if (!old_bufp)
+				return (-1);
+			op = (u_int16_t *)old_bufp->page;
+			new_bufp = ret.newp;
+			if (!new_bufp)
+				return (-1);
+			np = (u_int16_t *)new_bufp->page;
+			bufp = ret.nextp;
+			if (!bufp)
+				return (0);
+			cino = (char *)bufp->page;
+			ino = (u_int16_t *)cino;
+			last_bfp = ret.nextp;
+		} else if (ino[n + 1] == OVFLPAGE) {
+			ov_addr = ino[n];
+			/*
+			 * Fix up the old page -- the extra 2 are the fields
+			 * which contained the overflow information.
+			 */
+			ino[0] -= (moved + 2);
+			FREESPACE(ino) =
+			    scopyto - sizeof(u_int16_t) * (ino[0] + 3);
+			OFFSET(ino) = scopyto;
+
+			bufp = __get_buf(hashp, ov_addr, bufp, 0);
+			if (!bufp)
+				return (-1);
+
+			ino = (u_int16_t *)bufp->page;
+			n = 1;
+			scopyto = hashp->BSIZE;
+			moved = 0;
+
+			if (last_bfp)
+				__free_ovflpage(hashp, last_bfp);
+			last_bfp = bufp;
+		}
+		/* Move regular sized pairs of there are any */
+		off = hashp->BSIZE;
+		for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {
+			cino = (char *)ino;
+			key.data = (u_char *)cino + ino[n];
+			key.size = off - ino[n];
+			val.data = (u_char *)cino + ino[n + 1];
+			val.size = ino[n] - ino[n + 1];
+			off = ino[n + 1];
+
+			if (__call_hash(hashp, key.data, key.size) == obucket) {
+				/* Keep on old page */
+				if (PAIRFITS(op, (&key), (&val)))
+					putpair((char *)op, &key, &val);
+				else {
+					old_bufp =
+					    __add_ovflpage(hashp, old_bufp);
+					if (!old_bufp)
+						return (-1);
+					op = (u_int16_t *)old_bufp->page;
+					putpair((char *)op, &key, &val);
+				}
+				old_bufp->flags |= BUF_MOD;
+			} else {
+				/* Move to new page */
+				if (PAIRFITS(np, (&key), (&val)))
+					putpair((char *)np, &key, &val);
+				else {
+					new_bufp =
+					    __add_ovflpage(hashp, new_bufp);
+					if (!new_bufp)
+						return (-1);
+					np = (u_int16_t *)new_bufp->page;
+					putpair((char *)np, &key, &val);
+				}
+				new_bufp->flags |= BUF_MOD;
+			}
+		}
+	}
+	if (last_bfp)
+		__free_ovflpage(hashp, last_bfp);
+	return (0);
+}
+
+/*
+ * Add the given pair to the page
+ *
+ * Returns:
+ *	0 ==> OK
+ *	1 ==> failure
+ */
+extern int
+__addel(hashp, bufp, key, val)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+	const DBT *key, *val;
+{
+	register u_int16_t *bp, *sop;
+	int do_expand;
+
+	bp = (u_int16_t *)bufp->page;
+	do_expand = 0;
+	while (bp[0] && (bp[2] < REAL_KEY || bp[bp[0]] < REAL_KEY))
+		/* Exception case */
+		if (bp[2] == FULL_KEY_DATA && bp[0] == 2)
+			/* This is the last page of a big key/data pair
+			   and we need to add another page */
+			break;
+		else if (bp[2] < REAL_KEY && bp[bp[0]] != OVFLPAGE) {
+			bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+			if (!bufp)
+				return (-1);
+			bp = (u_int16_t *)bufp->page;
+		} else
+			/* Try to squeeze key on this page */
+			if (FREESPACE(bp) > PAIRSIZE(key, val)) {
+				squeeze_key(bp, key, val);
+				return (0);
+			} else {
+				bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+				if (!bufp)
+					return (-1);
+				bp = (u_int16_t *)bufp->page;
+			}
+
+	if (PAIRFITS(bp, key, val))
+		putpair(bufp->page, key, val);
+	else {
+		do_expand = 1;
+		bufp = __add_ovflpage(hashp, bufp);
+		if (!bufp)
+			return (-1);
+		sop = (u_int16_t *)bufp->page;
+
+		if (PAIRFITS(sop, key, val))
+			putpair((char *)sop, key, val);
+		else
+			if (__big_insert(hashp, bufp, key, val))
+				return (-1);
+	}
+	bufp->flags |= BUF_MOD;
+	/*
+	 * If the average number of keys per bucket exceeds the fill factor,
+	 * expand the table.
+	 */
+	hashp->NKEYS++;
+	if (do_expand ||
+	    (hashp->NKEYS / (hashp->MAX_BUCKET + 1) > hashp->FFACTOR))
+		return (__expand_table(hashp));
+	return (0);
+}
+
+/*
+ *
+ * Returns:
+ *	pointer on success
+ *	NULL on error
+ */
+extern BUFHEAD *
+__add_ovflpage(hashp, bufp)
+	HTAB *hashp;
+	BUFHEAD *bufp;
+{
+	register u_int16_t *sp;
+	u_int16_t ndx, ovfl_num;
+#ifdef DEBUG1
+	int tmp1, tmp2;
+#endif
+	sp = (u_int16_t *)bufp->page;
+
+	/* Check if we are dynamically determining the fill factor */
+	if (hashp->FFACTOR == DEF_FFACTOR) {
+		hashp->FFACTOR = sp[0] >> 1;
+		if (hashp->FFACTOR < MIN_FFACTOR)
+			hashp->FFACTOR = MIN_FFACTOR;
+	}
+	bufp->flags |= BUF_MOD;
+	ovfl_num = overflow_page(hashp);
+#ifdef DEBUG1
+	tmp1 = bufp->addr;
+	tmp2 = bufp->ovfl ? bufp->ovfl->addr : 0;
+#endif
+	if (!ovfl_num || !(bufp->ovfl = __get_buf(hashp, ovfl_num, bufp, 1)))
+		return (NULL);
+	bufp->ovfl->flags |= BUF_MOD;
+#ifdef DEBUG1
+	(void)fprintf(stderr, "ADDOVFLPAGE: %d->ovfl was %d is now %d\n",
+	    tmp1, tmp2, bufp->ovfl->addr);
+#endif
+	ndx = sp[0];
+	/*
+	 * Since a pair is allocated on a page only if there's room to add
+	 * an overflow page, we know that the OVFL information will fit on
+	 * the page.
+	 */
+	sp[ndx + 4] = OFFSET(sp);
+	sp[ndx + 3] = FREESPACE(sp) - OVFLSIZE;
+	sp[ndx + 1] = ovfl_num;
+	sp[ndx + 2] = OVFLPAGE;
+	sp[0] = ndx + 2;
+#ifdef HASH_STATISTICS
+	hash_overflows++;
+#endif
+	return (bufp->ovfl);
+}
+
+/*
+ * Returns:
+ *	 0 indicates SUCCESS
+ *	-1 indicates FAILURE
+ */
+extern int
+__get_page(hashp, p, bucket, is_bucket, is_disk, is_bitmap)
+	HTAB *hashp;
+	char *p;
+	u_int32_t bucket;
+	int is_bucket, is_disk, is_bitmap;
+{
+	register int fd, page, size;
+	int rsize;
+	u_int16_t *bp;
+
+	fd = hashp->fp;
+	size = hashp->BSIZE;
+
+	if ((fd == -1) || !is_disk) {
+		PAGE_INIT(p);
+		return (0);
+	}
+	if (is_bucket)
+		page = BUCKET_TO_PAGE(bucket);
+	else
+		page = OADDR_TO_PAGE(bucket);
+	if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
+	    ((rsize = read(fd, p, size)) == -1))
+		return (-1);
+	bp = (u_int16_t *)p;
+	if (!rsize)
+		bp[0] = 0;	/* We hit the EOF, so initialize a new page */
+	else
+		if (rsize != size) {
+			errno = EFTYPE;
+			return (-1);
+		}
+	if (!is_bitmap && !bp[0]) {
+		PAGE_INIT(p);
+	} else
+		if (hashp->LORDER != BYTE_ORDER) {
+			register int i, max;
+
+			if (is_bitmap) {
+				max = hashp->BSIZE >> 2; /* divide by 4 */
+				for (i = 0; i < max; i++)
+					M_32_SWAP(((int *)p)[i]);
+			} else {
+				M_16_SWAP(bp[0]);
+				max = bp[0] + 2;
+				for (i = 1; i <= max; i++)
+					M_16_SWAP(bp[i]);
+			}
+		}
+	return (0);
+}
+
+/*
+ * Write page p to disk
+ *
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==>failure
+ */
+extern int
+__put_page(hashp, p, bucket, is_bucket, is_bitmap)
+	HTAB *hashp;
+	char *p;
+	u_int32_t bucket;
+	int is_bucket, is_bitmap;
+{
+	register int fd, page, size;
+	int wsize;
+
+	size = hashp->BSIZE;
+	if ((hashp->fp == -1) && open_temp(hashp))
+		return (-1);
+	fd = hashp->fp;
+
+	if (hashp->LORDER != BYTE_ORDER) {
+		register int i;
+		register int max;
+
+		if (is_bitmap) {
+			max = hashp->BSIZE >> 2;	/* divide by 4 */
+			for (i = 0; i < max; i++)
+				M_32_SWAP(((int *)p)[i]);
+		} else {
+			max = ((u_int16_t *)p)[0] + 2;
+			for (i = 0; i <= max; i++)
+				M_16_SWAP(((u_int16_t *)p)[i]);
+		}
+	}
+	if (is_bucket)
+		page = BUCKET_TO_PAGE(bucket);
+	else
+		page = OADDR_TO_PAGE(bucket);
+	if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
+	    ((wsize = write(fd, p, size)) == -1))
+		/* Errno is set */
+		return (-1);
+	if (wsize != size) {
+		errno = EFTYPE;
+		return (-1);
+	}
+	return (0);
+}
+
+#define BYTE_MASK	((1 << INT_BYTE_SHIFT) -1)
+/*
+ * Initialize a new bitmap page.  Bitmap pages are left in memory
+ * once they are read in.
+ */
+extern int
+__ibitmap(hashp, pnum, nbits, ndx)
+	HTAB *hashp;
+	int pnum, nbits, ndx;
+{
+	u_int32_t *ip;
+	int clearbytes, clearints;
+
+	if ((ip = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
+		return (1);
+	hashp->nmaps++;
+	clearints = ((nbits - 1) >> INT_BYTE_SHIFT) + 1;
+	clearbytes = clearints << INT_TO_BYTE;
+	(void)memset((char *)ip, 0, clearbytes);
+	(void)memset(((char *)ip) + clearbytes, 0xFF,
+	    hashp->BSIZE - clearbytes);
+	ip[clearints - 1] = ALL_SET << (nbits & BYTE_MASK);
+	SETBIT(ip, 0);
+	hashp->BITMAPS[ndx] = (u_int16_t)pnum;
+	hashp->mapp[ndx] = ip;
+	return (0);
+}
+
+static u_int32_t
+first_free(map)
+	u_int32_t map;
+{
+	register u_int32_t i, mask;
+
+	mask = 0x1;
+	for (i = 0; i < BITS_PER_MAP; i++) {
+		if (!(mask & map))
+			return (i);
+		mask = mask << 1;
+	}
+	return (i);
+}
+
+static u_int16_t
+overflow_page(hashp)
+	HTAB *hashp;
+{
+	register u_int32_t *freep;
+	register int max_free, offset, splitnum;
+	u_int16_t addr;
+	int bit, first_page, free_bit, free_page, i, in_use_bits, j;
+#ifdef DEBUG2
+	int tmp1, tmp2;
+#endif
+	splitnum = hashp->OVFL_POINT;
+	max_free = hashp->SPARES[splitnum];
+
+	free_page = (max_free - 1) >> (hashp->BSHIFT + BYTE_SHIFT);
+	free_bit = (max_free - 1) & ((hashp->BSIZE << BYTE_SHIFT) - 1);
+
+	/* Look through all the free maps to find the first free block */
+	first_page = hashp->LAST_FREED >>(hashp->BSHIFT + BYTE_SHIFT);
+	for ( i = first_page; i <= free_page; i++ ) {
+		if (!(freep = (u_int32_t *)hashp->mapp[i]) &&
+		    !(freep = fetch_bitmap(hashp, i)))
+			return (0);
+		if (i == free_page)
+			in_use_bits = free_bit;
+		else
+			in_use_bits = (hashp->BSIZE << BYTE_SHIFT) - 1;
+		
+		if (i == first_page) {
+			bit = hashp->LAST_FREED &
+			    ((hashp->BSIZE << BYTE_SHIFT) - 1);
+			j = bit / BITS_PER_MAP;
+			bit = bit & ~(BITS_PER_MAP - 1);
+		} else {
+			bit = 0;
+			j = 0;
+		}
+		for (; bit <= in_use_bits; j++, bit += BITS_PER_MAP)
+			if (freep[j] != ALL_SET)
+				goto found;
+	}
+
+	/* No Free Page Found */
+	hashp->LAST_FREED = hashp->SPARES[splitnum];
+	hashp->SPARES[splitnum]++;
+	offset = hashp->SPARES[splitnum] -
+	    (splitnum ? hashp->SPARES[splitnum - 1] : 0);
+
+#define	OVMSG	"HASH: Out of overflow pages.  Increase page size\n"
+	if (offset > SPLITMASK) {
+		if (++splitnum >= NCACHED) {
+			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
+			return (0);
+		}
+		hashp->OVFL_POINT = splitnum;
+		hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
+		hashp->SPARES[splitnum-1]--;
+		offset = 1;
+	}
+
+	/* Check if we need to allocate a new bitmap page */
+	if (free_bit == (hashp->BSIZE << BYTE_SHIFT) - 1) {
+		free_page++;
+		if (free_page >= NCACHED) {
+			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
+			return (0);
+		}
+		/*
+		 * This is tricky.  The 1 indicates that you want the new page
+		 * allocated with 1 clear bit.  Actually, you are going to
+		 * allocate 2 pages from this map.  The first is going to be
+		 * the map page, the second is the overflow page we were
+		 * looking for.  The init_bitmap routine automatically, sets
+		 * the first bit of itself to indicate that the bitmap itself
+		 * is in use.  We would explicitly set the second bit, but
+		 * don't have to if we tell init_bitmap not to leave it clear
+		 * in the first place.
+		 */
+		if (__ibitmap(hashp,
+		    (int)OADDR_OF(splitnum, offset), 1, free_page))
+			return (0);
+		hashp->SPARES[splitnum]++;
+#ifdef DEBUG2
+		free_bit = 2;
+#endif
+		offset++;
+		if (offset > SPLITMASK) {
+			if (++splitnum >= NCACHED) {
+				(void)write(STDERR_FILENO, OVMSG,
+				    sizeof(OVMSG) - 1);
+				return (0);
+			}
+			hashp->OVFL_POINT = splitnum;
+			hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
+			hashp->SPARES[splitnum-1]--;
+			offset = 0;
+		}
+	} else {
+		/*
+		 * Free_bit addresses the last used bit.  Bump it to address
+		 * the first available bit.
+		 */
+		free_bit++;
+		SETBIT(freep, free_bit);
+	}
+
+	/* Calculate address of the new overflow page */
+	addr = OADDR_OF(splitnum, offset);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    addr, free_bit, free_page);
+#endif
+	return (addr);
+
+found:
+	bit = bit + first_free(freep[j]);
+	SETBIT(freep, bit);
+#ifdef DEBUG2
+	tmp1 = bit;
+	tmp2 = i;
+#endif
+	/*
+	 * Bits are addressed starting with 0, but overflow pages are addressed
+	 * beginning at 1. Bit is a bit addressnumber, so we need to increment
+	 * it to convert it to a page number.
+	 */
+	bit = 1 + bit + (i * (hashp->BSIZE << BYTE_SHIFT));
+	if (bit >= hashp->LAST_FREED)
+		hashp->LAST_FREED = bit - 1;
+
+	/* Calculate the split number for this page */
+	for (i = 0; (i < splitnum) && (bit > hashp->SPARES[i]); i++);
+	offset = (i ? bit - hashp->SPARES[i - 1] : bit);
+	if (offset >= SPLITMASK)
+		return (0);	/* Out of overflow pages */
+	addr = OADDR_OF(i, offset);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    addr, tmp1, tmp2);
+#endif
+
+	/* Allocate and return the overflow page */
+	return (addr);
+}
+
+/*
+ * Mark this overflow page as free.
+ */
+extern void
+__free_ovflpage(hashp, obufp)
+	HTAB *hashp;
+	BUFHEAD *obufp;
+{
+	register u_int16_t addr;
+	u_int32_t *freep;
+	int bit_address, free_page, free_bit;
+	u_int16_t ndx;
+
+	addr = obufp->addr;
+#ifdef DEBUG1
+	(void)fprintf(stderr, "Freeing %d\n", addr);
+#endif
+	ndx = (((u_int16_t)addr) >> SPLITSHIFT);
+	bit_address =
+	    (ndx ? hashp->SPARES[ndx - 1] : 0) + (addr & SPLITMASK) - 1;
+	 if (bit_address < hashp->LAST_FREED)
+		hashp->LAST_FREED = bit_address;
+	free_page = (bit_address >> (hashp->BSHIFT + BYTE_SHIFT));
+	free_bit = bit_address & ((hashp->BSIZE << BYTE_SHIFT) - 1);
+
+	if (!(freep = hashp->mapp[free_page]))
+		freep = fetch_bitmap(hashp, free_page);
+#ifdef DEBUG
+	/*
+	 * This had better never happen.  It means we tried to read a bitmap
+	 * that has already had overflow pages allocated off it, and we
+	 * failed to read it from the file.
+	 */
+	if (!freep)
+		assert(0);
+#endif
+	CLRBIT(freep, free_bit);
+#ifdef DEBUG2
+	(void)fprintf(stderr, "FREE_OVFLPAGE: ADDR: %d BIT: %d PAGE %d\n",
+	    obufp->addr, free_bit, free_page);
+#endif
+	__reclaim_buf(hashp, obufp);
+}
+
+/*
+ * Returns:
+ *	 0 success
+ *	-1 failure
+ */
+static int
+open_temp(hashp)
+	HTAB *hashp;
+{
+	sigset_t set, oset;
+	static char namestr[] = "_hashXXXXXX";
+
+	/* Block signals; make sure file goes away at process exit. */
+	(void)sigfillset(&set);
+	(void)sigprocmask(SIG_BLOCK, &set, &oset);
+	if ((hashp->fp = mkstemp(namestr)) != -1) {
+		(void)unlink(namestr);
+		(void)fcntl(hashp->fp, F_SETFD, 1);
+	}
+	(void)sigprocmask(SIG_SETMASK, &oset, (sigset_t *)NULL);
+	return (hashp->fp != -1 ? 0 : -1);
+}
+
+/*
+ * We have to know that the key will fit, but the last entry on the page is
+ * an overflow pair, so we need to shift things.
+ */
+static void
+squeeze_key(sp, key, val)
+	u_int16_t *sp;
+	const DBT *key, *val;
+{
+	register char *p;
+	u_int16_t free_space, n, off, pageno;
+
+	p = (char *)sp;
+	n = sp[0];
+	free_space = FREESPACE(sp);
+	off = OFFSET(sp);
+
+	pageno = sp[n - 1];
+	off -= key->size;
+	sp[n - 1] = off;
+	memmove(p + off, key->data, key->size);
+	off -= val->size;
+	sp[n] = off;
+	memmove(p + off, val->data, val->size);
+	sp[0] = n + 2;
+	sp[n + 1] = pageno;
+	sp[n + 2] = OVFLPAGE;
+	FREESPACE(sp) = free_space - PAIRSIZE(key, val);
+	OFFSET(sp) = off;
+}
+
+static u_int32_t *
+fetch_bitmap(hashp, ndx)
+	HTAB *hashp;
+	int ndx;
+{
+	if (ndx >= hashp->nmaps)
+		return (NULL);
+	if ((hashp->mapp[ndx] = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
+		return (NULL);
+	if (__get_page(hashp,
+	    (char *)hashp->mapp[ndx], hashp->BITMAPS[ndx], 0, 1, 1)) {
+		free(hashp->mapp[ndx]);
+		return (NULL);
+	}
+	return (hashp->mapp[ndx]);
+}
+
+#ifdef DEBUG4
+int
+print_chain(addr)
+	int addr;
+{
+	BUFHEAD *bufp;
+	short *bp, oaddr;
+
+	(void)fprintf(stderr, "%d ", addr);
+	bufp = __get_buf(hashp, addr, NULL, 0);
+	bp = (short *)bufp->page;
+	while (bp[0] && ((bp[bp[0]] == OVFLPAGE) ||
+		((bp[0] > 2) && bp[2] < REAL_KEY))) {
+		oaddr = bp[bp[0] - 1];
+		(void)fprintf(stderr, "%d ", (int)oaddr);
+		bufp = __get_buf(hashp, (int)oaddr, bufp, 0);
+		bp = (short *)bufp->page;
+	}
+	(void)fprintf(stderr, "\n");
+}
+#endif
diff --git a/db/hash/ndbm.c b/db/hash/ndbm.c
new file mode 100644
index 0000000000..2cbbe91368
--- /dev/null
+++ b/db/hash/ndbm.c
@@ -0,0 +1,202 @@
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)ndbm.c	8.4 (Berkeley) 7/21/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * This package provides a dbm compatible interface to the new hashing
+ * package described in db(3).
+ */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include <ndbm.h>
+#include "hash.h"
+
+/*
+ * Returns:
+ * 	*DBM on success
+ *	 NULL on failure
+ */
+extern DBM *
+dbm_open(file, flags, mode)
+	const char *file;
+	int flags, mode;
+{
+	HASHINFO info;
+	char path[MAXPATHLEN];
+
+	info.bsize = 4096;
+	info.ffactor = 40;
+	info.nelem = 1;
+	info.cachesize = 0;
+	info.hash = NULL;
+	info.lorder = 0;
+	(void)strcpy(path, file);
+	(void)strcat(path, DBM_SUFFIX);
+	return ((DBM *)__hash_open(path, flags, mode, &info, 0));
+}
+
+extern void
+dbm_close(db)
+	DBM *db;
+{
+	(void)(db->close)(db);
+}
+
+/*
+ * Returns:
+ *	DATUM on success
+ *	NULL on failure
+ */
+extern datum
+dbm_fetch(db, key)
+	DBM *db;
+	datum key;
+{
+	datum retval;
+	int status;
+
+	status = (db->get)(db, (DBT *)&key, (DBT *)&retval, 0);
+	if (status) {
+		retval.dptr = NULL;
+		retval.dsize = 0;
+	}
+	return (retval);
+}
+
+/*
+ * Returns:
+ *	DATUM on success
+ *	NULL on failure
+ */
+extern datum
+dbm_firstkey(db)
+	DBM *db;
+{
+	int status;
+	datum retdata, retkey;
+
+	status = (db->seq)(db, (DBT *)&retkey, (DBT *)&retdata, R_FIRST);
+	if (status)
+		retkey.dptr = NULL;
+	return (retkey);
+}
+
+/*
+ * Returns:
+ *	DATUM on success
+ *	NULL on failure
+ */
+extern datum
+dbm_nextkey(db)
+	DBM *db;
+{
+	int status;
+	datum retdata, retkey;
+
+	status = (db->seq)(db, (DBT *)&retkey, (DBT *)&retdata, R_NEXT);
+	if (status)
+		retkey.dptr = NULL;
+	return (retkey);
+}
+/*
+ * Returns:
+ *	 0 on success
+ *	<0 failure
+ */
+extern int
+dbm_delete(db, key)
+	DBM *db;
+	datum key;
+{
+	int status;
+
+	status = (db->del)(db, (DBT *)&key, 0);
+	if (status)
+		return (-1);
+	else
+		return (0);
+}
+
+/*
+ * Returns:
+ *	 0 on success
+ *	<0 failure
+ *	 1 if DBM_INSERT and entry exists
+ */
+extern int
+dbm_store(db, key, content, flags)
+	DBM *db;
+	datum key, content;
+	int flags;
+{
+	return ((db->put)(db, (DBT *)&key, (DBT *)&content,
+	    (flags == DBM_INSERT) ? R_NOOVERWRITE : 0));
+}
+
+extern int
+dbm_error(db)
+	DBM *db;
+{
+	HTAB *hp;
+
+	hp = (HTAB *)db->internal;
+	return (hp->errno);
+}
+
+extern int
+dbm_clearerr(db)
+	DBM *db;
+{
+	HTAB *hp;
+
+	hp = (HTAB *)db->internal;
+	hp->errno = 0;
+	return (0);
+}
+
+extern int
+dbm_dirfno(db)
+	DBM *db;
+{
+	return(((HTAB *)db->internal)->fp);
+}
diff --git a/db/hash/page.h b/db/hash/page.h
new file mode 100644
index 0000000000..0fc0d5a3e9
--- /dev/null
+++ b/db/hash/page.h
@@ -0,0 +1,92 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)page.h	8.2 (Berkeley) 5/31/94
+ */
+
+/*
+ * Definitions for hashing page file format.
+ */
+
+/*
+ * routines dealing with a data page
+ *
+ * page format:
+ *	+------------------------------+
+ * p	| n | keyoff | datoff | keyoff |
+ * 	+------------+--------+--------+
+ *	| datoff | free  |  ptr  | --> |
+ *	+--------+---------------------+
+ *	|	 F R E E A R E A       |
+ *	+--------------+---------------+
+ *	|  <---- - - - | data          |
+ *	+--------+-----+----+----------+
+ *	|  key   | data     | key      |
+ *	+--------+----------+----------+
+ *
+ * Pointer to the free space is always:  p[p[0] + 2]
+ * Amount of free space on the page is:  p[p[0] + 1]
+ */
+
+/*
+ * How many bytes required for this pair?
+ *	2 shorts in the table at the top of the page + room for the
+ *	key and room for the data
+ *
+ * We prohibit entering a pair on a page unless there is also room to append
+ * an overflow page. The reason for this it that you can get in a situation
+ * where a single key/data pair fits on a page, but you can't append an
+ * overflow page and later you'd have to split the key/data and handle like
+ * a big pair.
+ * You might as well do this up front.
+ */
+
+#define	PAIRSIZE(K,D)	(2*sizeof(u_int16_t) + (K)->size + (D)->size)
+#define BIGOVERHEAD	(4*sizeof(u_int16_t))
+#define KEYSIZE(K)	(4*sizeof(u_int16_t) + (K)->size);
+#define OVFLSIZE	(2*sizeof(u_int16_t))
+#define FREESPACE(P)	((P)[(P)[0]+1])
+#define	OFFSET(P)	((P)[(P)[0]+2])
+#define PAIRFITS(P,K,D) \
+	(((P)[2] >= REAL_KEY) && \
+	    (PAIRSIZE((K),(D)) + OVFLSIZE) <= FREESPACE((P)))
+#define PAGE_META(N)	(((N)+3) * sizeof(u_int16_t))
+
+typedef struct {
+	BUFHEAD *newp;
+	BUFHEAD *oldp;
+	BUFHEAD *nextp;
+	u_int16_t next_addr;
+}       SPLIT_RETURN;
diff --git a/db/mpool.h b/db/mpool.h
new file mode 100644
index 0000000000..40d1022309
--- /dev/null
+++ b/db/mpool.h
@@ -0,0 +1,99 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)mpool.h	8.2 (Berkeley) 7/14/94
+ */
+
+#include <sys/queue.h>
+
+/*
+ * The memory pool scheme is a simple one.  Each in-memory page is referenced
+ * by a bucket which is threaded in up to two of three ways.  All active pages
+ * are threaded on a hash chain (hashed by page number) and an lru chain.
+ * Inactive pages are threaded on a free chain.  Each reference to a memory
+ * pool is handed an opaque MPOOL cookie which stores all of this information.
+ */
+#define	HASHSIZE	128
+#define	HASHKEY(pgno)	((pgno - 1) % HASHSIZE)
+
+/* The BKT structures are the elements of the queues. */
+typedef struct _bkt {
+	CIRCLEQ_ENTRY(_bkt) hq;		/* hash queue */
+	CIRCLEQ_ENTRY(_bkt) q;		/* lru queue */
+	void    *page;			/* page */
+	pgno_t   pgno;			/* page number */
+
+#define	MPOOL_DIRTY	0x01		/* page needs to be written */
+#define	MPOOL_PINNED	0x02		/* page is pinned into memory */
+	u_int8_t flags;			/* flags */
+} BKT;
+
+typedef struct MPOOL {
+	CIRCLEQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */
+					/* hash queue array */
+	CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
+	pgno_t	curcache;		/* current number of cached pages */
+	pgno_t	maxcache;		/* max number of cached pages */
+	pgno_t	npages;			/* number of pages in the file */
+	u_long	pagesize;		/* file page size */
+	int	fd;			/* file descriptor */
+					/* page in conversion routine */
+	void    (*pgin) __P((void *, pgno_t, void *));
+					/* page out conversion routine */
+	void    (*pgout) __P((void *, pgno_t, void *));
+	void	*pgcookie;		/* cookie for page in/out routines */
+#ifdef STATISTICS
+	u_long	cachehit;
+	u_long	cachemiss;
+	u_long	pagealloc;
+	u_long	pageflush;
+	u_long	pageget;
+	u_long	pagenew;
+	u_long	pageput;
+	u_long	pageread;
+	u_long	pagewrite;
+#endif
+} MPOOL;
+
+__BEGIN_DECLS
+MPOOL	*mpool_open __P((void *, int, pgno_t, pgno_t));
+void	 mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *),
+	    void (*)(void *, pgno_t, void *), void *));
+void	*mpool_new __P((MPOOL *, pgno_t *));
+void	*mpool_get __P((MPOOL *, pgno_t, u_int));
+int	 mpool_put __P((MPOOL *, void *, u_int));
+int	 mpool_sync __P((MPOOL *));
+int	 mpool_close __P((MPOOL *));
+#ifdef STATISTICS
+void	 mpool_stat __P((MPOOL *));
+#endif
+__END_DECLS
diff --git a/db/mpool/mpool.c b/db/mpool/mpool.c
new file mode 100644
index 0000000000..a61041e091
--- /dev/null
+++ b/db/mpool/mpool.c
@@ -0,0 +1,463 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)mpool.c	8.5 (Berkeley) 7/26/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/queue.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <db.h>
+
+#define	__MPOOLINTERFACE_PRIVATE
+#include <mpool.h>
+
+static BKT *mpool_bkt __P((MPOOL *));
+static BKT *mpool_look __P((MPOOL *, pgno_t));
+static int  mpool_write __P((MPOOL *, BKT *));
+
+/*
+ * mpool_open --
+ *	Initialize a memory pool.
+ */
+MPOOL *
+mpool_open(key, fd, pagesize, maxcache)
+	void *key;
+	int fd;
+	pgno_t pagesize, maxcache;
+{
+	struct stat sb;
+	MPOOL *mp;
+	int entry;
+
+	/*
+	 * Get information about the file.
+	 *
+	 * XXX
+	 * We don't currently handle pipes, although we should.
+	 */
+	if (fstat(fd, &sb))
+		return (NULL);
+	if (!S_ISREG(sb.st_mode)) {
+		errno = ESPIPE;
+		return (NULL);
+	}
+
+	/* Allocate and initialize the MPOOL cookie. */
+	if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
+		return (NULL);
+	CIRCLEQ_INIT(&mp->lqh);
+	for (entry = 0; entry < HASHSIZE; ++entry)
+		CIRCLEQ_INIT(&mp->hqh[entry]);
+	mp->maxcache = maxcache;
+	mp->npages = sb.st_size / pagesize;
+	mp->pagesize = pagesize;
+	mp->fd = fd;
+	return (mp);
+}
+
+/*
+ * mpool_filter --
+ *	Initialize input/output filters.
+ */
+void
+mpool_filter(mp, pgin, pgout, pgcookie)
+	MPOOL *mp;
+	void (*pgin) __P((void *, pgno_t, void *));
+	void (*pgout) __P((void *, pgno_t, void *));
+	void *pgcookie;
+{
+	mp->pgin = pgin;
+	mp->pgout = pgout;
+	mp->pgcookie = pgcookie;
+}
+	
+/*
+ * mpool_new --
+ *	Get a new page of memory.
+ */
+void *
+mpool_new(mp, pgnoaddr)
+	MPOOL *mp;
+	pgno_t *pgnoaddr;
+{
+	struct _hqh *head;
+	BKT *bp;
+
+	if (mp->npages == MAX_PAGE_NUMBER) {
+		(void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
+		abort();
+	}
+#ifdef STATISTICS
+	++mp->pagenew;
+#endif
+	/*
+	 * Get a BKT from the cache.  Assign a new page number, attach
+	 * it to the head of the hash chain, the tail of the lru chain,
+	 * and return.
+	 */
+	if ((bp = mpool_bkt(mp)) == NULL)
+		return (NULL);
+	*pgnoaddr = bp->pgno = mp->npages++;
+	bp->flags = MPOOL_PINNED;
+
+	head = &mp->hqh[HASHKEY(bp->pgno)];
+	CIRCLEQ_INSERT_HEAD(head, bp, hq);
+	CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
+	return (bp->page);
+}
+
+/*
+ * mpool_get
+ *	Get a page.
+ */
+void *
+mpool_get(mp, pgno, flags)
+	MPOOL *mp;
+	pgno_t pgno;
+	u_int flags;				/* XXX not used? */
+{
+	struct _hqh *head;
+	BKT *bp;
+	off_t off;
+	int nr;
+
+	/* Check for attempt to retrieve a non-existent page. */
+	if (pgno >= mp->npages) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+#ifdef STATISTICS
+	++mp->pageget;
+#endif
+
+	/* Check for a page that is cached. */
+	if ((bp = mpool_look(mp, pgno)) != NULL) {
+#ifdef DEBUG
+		if (bp->flags & MPOOL_PINNED) {
+			(void)fprintf(stderr,
+			    "mpool_get: page %d already pinned\n", bp->pgno);
+			abort();
+		}
+#endif
+		/*
+		 * Move the page to the head of the hash chain and the tail
+		 * of the lru chain.
+		 */
+		head = &mp->hqh[HASHKEY(bp->pgno)];
+		CIRCLEQ_REMOVE(head, bp, hq);
+		CIRCLEQ_INSERT_HEAD(head, bp, hq);
+		CIRCLEQ_REMOVE(&mp->lqh, bp, q);
+		CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
+
+		/* Return a pinned page. */
+		bp->flags |= MPOOL_PINNED;
+		return (bp->page);
+	}
+
+	/* Get a page from the cache. */
+	if ((bp = mpool_bkt(mp)) == NULL)
+		return (NULL);
+
+	/* Read in the contents. */
+#ifdef STATISTICS
+	++mp->pageread;
+#endif
+	off = mp->pagesize * pgno;
+	if (lseek(mp->fd, off, SEEK_SET) != off)
+		return (NULL);
+	if ((nr = read(mp->fd, bp->page, mp->pagesize)) != mp->pagesize) {
+		if (nr >= 0)
+			errno = EFTYPE;
+		return (NULL);
+	}
+
+	/* Set the page number, pin the page. */
+	bp->pgno = pgno;
+	bp->flags = MPOOL_PINNED;
+
+	/*
+	 * Add the page to the head of the hash chain and the tail
+	 * of the lru chain.
+	 */
+	head = &mp->hqh[HASHKEY(bp->pgno)];
+	CIRCLEQ_INSERT_HEAD(head, bp, hq);
+	CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
+
+	/* Run through the user's filter. */
+	if (mp->pgin != NULL)
+		(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
+
+	return (bp->page);
+}
+
+/*
+ * mpool_put
+ *	Return a page.
+ */
+int
+mpool_put(mp, page, flags)
+	MPOOL *mp;
+	void *page;
+	u_int flags;
+{
+	BKT *bp;
+
+#ifdef STATISTICS
+	++mp->pageput;
+#endif
+	bp = (BKT *)((char *)page - sizeof(BKT));
+#ifdef DEBUG
+	if (!(bp->flags & MPOOL_PINNED)) {
+		(void)fprintf(stderr,
+		    "mpool_put: page %d not pinned\n", bp->pgno);
+		abort();
+	}
+#endif
+	bp->flags &= ~MPOOL_PINNED;
+	bp->flags |= flags & MPOOL_DIRTY;
+	return (RET_SUCCESS);
+}
+
+/*
+ * mpool_close
+ *	Close the buffer pool.
+ */
+int
+mpool_close(mp)
+	MPOOL *mp;
+{
+	BKT *bp;
+
+	/* Free up any space allocated to the lru pages. */
+	while ((bp = mp->lqh.cqh_first) != (void *)&mp->lqh) {
+		CIRCLEQ_REMOVE(&mp->lqh, mp->lqh.cqh_first, q);
+		free(bp);
+	}
+
+	/* Free the MPOOL cookie. */
+	free(mp);
+	return (RET_SUCCESS);
+}
+
+/*
+ * mpool_sync
+ *	Sync the pool to disk.
+ */
+int
+mpool_sync(mp)
+	MPOOL *mp;
+{
+	BKT *bp;
+
+	/* Walk the lru chain, flushing any dirty pages to disk. */
+	for (bp = mp->lqh.cqh_first;
+	    bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
+		if (bp->flags & MPOOL_DIRTY &&
+		    mpool_write(mp, bp) == RET_ERROR)
+			return (RET_ERROR);
+
+	/* Sync the file descriptor. */
+	return (fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
+}
+
+/*
+ * mpool_bkt
+ *	Get a page from the cache (or create one).
+ */
+static BKT *
+mpool_bkt(mp)
+	MPOOL *mp;
+{
+	struct _hqh *head;
+	BKT *bp;
+
+	/* If under the max cached, always create a new page. */
+	if (mp->curcache < mp->maxcache)
+		goto new;
+
+	/*
+	 * If the cache is max'd out, walk the lru list for a buffer we
+	 * can flush.  If we find one, write it (if necessary) and take it
+	 * off any lists.  If we don't find anything we grow the cache anyway.
+	 * The cache never shrinks.
+	 */
+	for (bp = mp->lqh.cqh_first;
+	    bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
+		if (!(bp->flags & MPOOL_PINNED)) {
+			/* Flush if dirty. */
+			if (bp->flags & MPOOL_DIRTY &&
+			    mpool_write(mp, bp) == RET_ERROR)
+				return (NULL);
+#ifdef STATISTICS
+			++mp->pageflush;
+#endif
+			/* Remove from the hash and lru queues. */
+			head = &mp->hqh[HASHKEY(bp->pgno)];
+			CIRCLEQ_REMOVE(head, bp, hq);
+			CIRCLEQ_REMOVE(&mp->lqh, bp, q);
+#ifdef DEBUG
+			{ void *spage;
+				spage = bp->page;
+				memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
+				bp->page = spage;
+			}
+#endif
+			return (bp);
+		}
+
+new:	if ((bp = (BKT *)malloc(sizeof(BKT) + mp->pagesize)) == NULL)
+		return (NULL);
+#ifdef STATISTICS
+	++mp->pagealloc;
+#endif
+#if defined(DEBUG) || defined(PURIFY)
+	memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
+#endif
+	bp->page = (char *)bp + sizeof(BKT);
+	++mp->curcache;
+	return (bp);
+}
+
+/*
+ * mpool_write
+ *	Write a page to disk.
+ */
+static int
+mpool_write(mp, bp)
+	MPOOL *mp;
+	BKT *bp;
+{
+	off_t off;
+
+#ifdef STATISTICS
+	++mp->pagewrite;
+#endif
+
+	/* Run through the user's filter. */
+	if (mp->pgout)
+		(mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
+
+	off = mp->pagesize * bp->pgno;
+	if (lseek(mp->fd, off, SEEK_SET) != off)
+		return (RET_ERROR);
+	if (write(mp->fd, bp->page, mp->pagesize) != mp->pagesize)
+		return (RET_ERROR);
+
+	bp->flags &= ~MPOOL_DIRTY;
+	return (RET_SUCCESS);
+}
+
+/*
+ * mpool_look
+ *	Lookup a page in the cache.
+ */
+static BKT *
+mpool_look(mp, pgno)
+	MPOOL *mp;
+	pgno_t pgno;
+{
+	struct _hqh *head;
+	BKT *bp;
+
+	head = &mp->hqh[HASHKEY(pgno)];
+	for (bp = head->cqh_first; bp != (void *)head; bp = bp->hq.cqe_next)
+		if (bp->pgno == pgno) {
+#ifdef STATISTICS
+			++mp->cachehit;
+#endif
+			return (bp);
+		}
+#ifdef STATISTICS
+	++mp->cachemiss;
+#endif
+	return (NULL);
+}
+
+#ifdef STATISTICS
+/*
+ * mpool_stat
+ *	Print out cache statistics.
+ */
+void
+mpool_stat(mp)
+	MPOOL *mp;
+{
+	BKT *bp;
+	int cnt;
+	char *sep;
+
+	(void)fprintf(stderr, "%lu pages in the file\n", mp->npages);
+	(void)fprintf(stderr,
+	    "page size %lu, cacheing %lu pages of %lu page max cache\n",
+	    mp->pagesize, mp->curcache, mp->maxcache);
+	(void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
+	    mp->pageput, mp->pageget, mp->pagenew);
+	(void)fprintf(stderr, "%lu page allocs, %lu page flushes\n",
+	    mp->pagealloc, mp->pageflush);
+	if (mp->cachehit + mp->cachemiss)
+		(void)fprintf(stderr,
+		    "%.0f%% cache hit rate (%lu hits, %lu misses)\n", 
+		    ((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
+		    * 100, mp->cachehit, mp->cachemiss);
+	(void)fprintf(stderr, "%lu page reads, %lu page writes\n",
+	    mp->pageread, mp->pagewrite);
+
+	sep = "";
+	cnt = 0;
+	for (bp = mp->lqh.cqh_first;
+	    bp != (void *)&mp->lqh; bp = bp->q.cqe_next) {
+		(void)fprintf(stderr, "%s%d", sep, bp->pgno);
+		if (bp->flags & MPOOL_DIRTY)
+			(void)fprintf(stderr, "d");
+		if (bp->flags & MPOOL_PINNED)
+			(void)fprintf(stderr, "P");
+		if (++cnt == 10) {
+			sep = "\n";
+			cnt = 0;
+		} else
+			sep = ", ";
+			
+	}
+	(void)fprintf(stderr, "\n");
+}
+#endif
diff --git a/db/ndbm.h b/db/ndbm.h
new file mode 100644
index 0000000000..a545bca132
--- /dev/null
+++ b/db/ndbm.h
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Margo Seltzer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)ndbm.h	8.1 (Berkeley) 6/2/93
+ */
+
+#ifndef _NDBM_H_
+#define	_NDBM_H_
+
+#include <db.h>
+
+/* Map dbm interface onto db(3). */
+#define DBM_RDONLY	O_RDONLY
+
+/* Flags to dbm_store(). */
+#define DBM_INSERT      0
+#define DBM_REPLACE     1
+
+/*
+ * The db(3) support for ndbm(3) always appends this suffix to the
+ * file name to avoid overwriting the user's original database.
+ */
+#define	DBM_SUFFIX	".db"
+
+typedef struct {
+	char *dptr;
+	int dsize;
+} datum;
+
+typedef DB DBM;
+#define	dbm_pagfno(a)	DBM_PAGFNO_NOT_AVAILABLE
+
+__BEGIN_DECLS
+void	 dbm_close __P((DBM *));
+int	 dbm_delete __P((DBM *, datum));
+datum	 dbm_fetch __P((DBM *, datum));
+datum	 dbm_firstkey __P((DBM *));
+long	 dbm_forder __P((DBM *, datum));
+datum	 dbm_nextkey __P((DBM *));
+DBM	*dbm_open __P((const char *, int, int));
+int	 dbm_store __P((DBM *, datum, datum, int));
+int	 dbm_dirfno __P((DBM *));
+__END_DECLS
+
+#endif /* !_NDBM_H_ */
diff --git a/db/recno/extern.h b/db/recno/extern.h
new file mode 100644
index 0000000000..feed434453
--- /dev/null
+++ b/db/recno/extern.h
@@ -0,0 +1,54 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)extern.h	8.3 (Berkeley) 6/4/94
+ */
+
+#include "../btree/extern.h"
+
+int	 __rec_close __P((DB *));
+int	 __rec_delete __P((const DB *, const DBT *, u_int));
+int	 __rec_dleaf __P((BTREE *, PAGE *, u_int32_t));
+int	 __rec_fd __P((const DB *));
+int	 __rec_fmap __P((BTREE *, recno_t));
+int	 __rec_fout __P((BTREE *));
+int	 __rec_fpipe __P((BTREE *, recno_t));
+int	 __rec_get __P((const DB *, const DBT *, DBT *, u_int));
+int	 __rec_iput __P((BTREE *, recno_t, const DBT *, u_int));
+int	 __rec_put __P((const DB *dbp, DBT *, const DBT *, u_int));
+int	 __rec_ret __P((BTREE *, EPG *, recno_t, DBT *, DBT *));
+EPG	*__rec_search __P((BTREE *, recno_t, enum SRCHOP));
+int	 __rec_seq __P((const DB *, DBT *, DBT *, u_int));
+int	 __rec_sync __P((const DB *, u_int));
+int	 __rec_vmap __P((BTREE *, recno_t));
+int	 __rec_vout __P((BTREE *));
+int	 __rec_vpipe __P((BTREE *, recno_t));
diff --git a/db/recno/rec_close.c b/db/recno/rec_close.c
new file mode 100644
index 0000000000..16fb0b4eca
--- /dev/null
+++ b/db/recno/rec_close.c
@@ -0,0 +1,182 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_close.c	8.6 (Berkeley) 8/18/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/mman.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __REC_CLOSE -- Close a recno tree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_close(dbp)
+	DB *dbp;
+{
+	BTREE *t;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	if (__rec_sync(dbp, 0) == RET_ERROR)
+		return (RET_ERROR);
+
+	/* Committed to closing. */
+	status = RET_SUCCESS;
+	if (F_ISSET(t, R_MEMMAPPED) && munmap(t->bt_smap, t->bt_msize))
+		status = RET_ERROR;
+
+	if (!F_ISSET(t, R_INMEM))
+		if (F_ISSET(t, R_CLOSEFP)) {
+			if (fclose(t->bt_rfp))
+				status = RET_ERROR;
+		} else
+			if (close(t->bt_rfd))
+				status = RET_ERROR;
+
+	if (__bt_close(dbp) == RET_ERROR)
+		status = RET_ERROR;
+
+	return (status);
+}
+
+/*
+ * __REC_SYNC -- sync the recno tree to disk.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__rec_sync(dbp, flags)
+	const DB *dbp;
+	u_int flags;
+{
+	struct iovec iov[2];
+	BTREE *t;
+	DBT data, key;
+	off_t off;
+	recno_t scursor, trec;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	if (flags == R_RECNOSYNC)
+		return (__bt_sync(dbp, 0));
+
+	if (F_ISSET(t, R_RDONLY | R_INMEM) || !F_ISSET(t, R_MODIFIED))
+		return (RET_SUCCESS);
+
+	/* Read any remaining records into the tree. */
+	if (!F_ISSET(t, R_EOF) && t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
+		return (RET_ERROR);
+
+	/* Rewind the file descriptor. */
+	if (lseek(t->bt_rfd, (off_t)0, SEEK_SET) != 0)
+		return (RET_ERROR);
+
+	/* Save the cursor. */
+	scursor = t->bt_cursor.rcursor;
+
+	key.size = sizeof(recno_t);
+	key.data = &trec;
+
+	if (F_ISSET(t, R_FIXLEN)) {
+		/*
+		 * We assume that fixed length records are all fixed length.
+		 * Any that aren't are either EINVAL'd or corrected by the
+		 * record put code.
+		 */
+		status = (dbp->seq)(dbp, &key, &data, R_FIRST);
+		while (status == RET_SUCCESS) {
+			if (write(t->bt_rfd, data.data, data.size) != data.size)
+				return (RET_ERROR);
+			status = (dbp->seq)(dbp, &key, &data, R_NEXT);
+		}
+	} else {
+		iov[1].iov_base = &t->bt_bval;
+		iov[1].iov_len = 1;
+
+		status = (dbp->seq)(dbp, &key, &data, R_FIRST);
+		while (status == RET_SUCCESS) {
+			iov[0].iov_base = data.data;
+			iov[0].iov_len = data.size;
+			if (writev(t->bt_rfd, iov, 2) != data.size + 1)
+				return (RET_ERROR);
+			status = (dbp->seq)(dbp, &key, &data, R_NEXT);
+		}
+	}
+
+	/* Restore the cursor. */
+	t->bt_cursor.rcursor = scursor;
+
+	if (status == RET_ERROR)
+		return (RET_ERROR);
+	if ((off = lseek(t->bt_rfd, (off_t)0, SEEK_CUR)) == -1)
+		return (RET_ERROR);
+	if (ftruncate(t->bt_rfd, off))
+		return (RET_ERROR);
+	F_CLR(t, R_MODIFIED);
+	return (RET_SUCCESS);
+}
diff --git a/db/recno/rec_delete.c b/db/recno/rec_delete.c
new file mode 100644
index 0000000000..a16593d4e6
--- /dev/null
+++ b/db/recno/rec_delete.c
@@ -0,0 +1,197 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_delete.c	8.7 (Berkeley) 7/14/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <db.h>
+#include "recno.h"
+
+static int rec_rdelete __P((BTREE *, recno_t));
+
+/*
+ * __REC_DELETE -- Delete the item(s) referenced by a key.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key to delete
+ *	flags:	R_CURSOR if deleting what the cursor references
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
+ */
+int
+__rec_delete(dbp, key, flags)
+	const DB *dbp;
+	const DBT *key;
+	u_int flags;
+{
+	BTREE *t;
+	recno_t nrec;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	switch(flags) {
+	case 0:
+		if ((nrec = *(recno_t *)key->data) == 0)
+			goto einval;
+		if (nrec > t->bt_nrecs)
+			return (RET_SPECIAL);
+		--nrec;
+		status = rec_rdelete(t, nrec);
+		break;
+	case R_CURSOR:
+		if (!F_ISSET(&t->bt_cursor, CURS_INIT))
+			goto einval;
+		if (t->bt_nrecs == 0)
+			return (RET_SPECIAL);
+		status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
+		if (status == RET_SUCCESS)
+			--t->bt_cursor.rcursor;
+		break;
+	default:
+einval:		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	if (status == RET_SUCCESS)
+		F_SET(t, B_MODIFIED | R_MODIFIED);
+	return (status);
+}
+
+/*
+ * REC_RDELETE -- Delete the data matching the specified key.
+ *
+ * Parameters:
+ *	tree:	tree
+ *	nrec:	record to delete
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
+ */
+static int
+rec_rdelete(t, nrec)
+	BTREE *t;
+	recno_t nrec;
+{
+	EPG *e;
+	PAGE *h;
+	int status;
+
+	/* Find the record; __rec_search pins the page. */
+	if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
+		return (RET_ERROR);
+
+	/* Delete the record. */
+	h = e->page;
+	status = __rec_dleaf(t, h, e->index);
+	if (status != RET_SUCCESS) {
+		mpool_put(t->bt_mp, h, 0);
+		return (status);
+	}
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+	return (RET_SUCCESS);
+}
+
+/*
+ * __REC_DLEAF -- Delete a single record from a recno leaf page.
+ *
+ * Parameters:
+ *	t:	tree
+ *	index:	index on current page to delete
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__rec_dleaf(t, h, index)
+	BTREE *t;
+	PAGE *h;
+	u_int32_t index;
+{
+	RLEAF *rl;
+	indx_t *ip, cnt, offset;
+	u_int32_t nbytes;
+	char *from;
+	void *to;
+
+	/*
+	 * Delete a record from a recno leaf page.  Internal records are never
+	 * deleted from internal pages, regardless of the records that caused
+	 * them to be added being deleted.  Pages made empty by deletion are
+	 * not reclaimed.  They are, however, made available for reuse.
+	 *
+	 * Pack the remaining entries at the end of the page, shift the indices
+	 * down, overwriting the deleted record and its index.  If the record
+	 * uses overflow pages, make them available for reuse.
+	 */
+	to = rl = GETRLEAF(h, index);
+	if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
+		return (RET_ERROR);
+	nbytes = NRLEAF(rl);
+
+	/*
+	 * Compress the key/data pairs.  Compress and adjust the [BR]LEAF
+	 * offsets.  Reset the headers.
+	 */
+	from = (char *)h + h->upper;
+	memmove(from + nbytes, from, (char *)to - from);
+	h->upper += nbytes;
+
+	offset = h->linp[index];
+	for (cnt = &h->linp[index] - (ip = &h->linp[0]); cnt--; ++ip)
+		if (ip[0] < offset)
+			ip[0] += nbytes;
+	for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
+		ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
+	h->lower -= sizeof(indx_t);
+	--t->bt_nrecs;
+	return (RET_SUCCESS);
+}
diff --git a/db/recno/rec_get.c b/db/recno/rec_get.c
new file mode 100644
index 0000000000..47dd773fb9
--- /dev/null
+++ b/db/recno/rec_get.c
@@ -0,0 +1,311 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_get.c	8.9 (Berkeley) 8/18/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __REC_GET -- Get a record from the btree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key to find
+ *	data:	data to return
+ *	flag:	currently unused
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
+ */
+int
+__rec_get(dbp, key, data, flags)
+	const DB *dbp;
+	const DBT *key;
+	DBT *data;
+	u_int flags;
+{
+	BTREE *t;
+	EPG *e;
+	recno_t nrec;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
+	if (flags || (nrec = *(recno_t *)key->data) == 0) {
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	/*
+	 * If we haven't seen this record yet, try to find it in the
+	 * original file.
+	 */
+	if (nrec > t->bt_nrecs) {
+		if (F_ISSET(t, R_EOF | R_INMEM))
+			return (RET_SPECIAL);
+		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
+			return (status);
+	}
+
+	--nrec;
+	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
+		return (RET_ERROR);
+
+	status = __rec_ret(t, e, 0, NULL, data);
+	if (F_ISSET(t, B_DB_LOCK))
+		mpool_put(t->bt_mp, e->page, 0);
+	else
+		t->bt_pinned = e->page;
+	return (status);
+}
+
+/*
+ * __REC_FPIPE -- Get fixed length records from a pipe.
+ *
+ * Parameters:
+ *	t:	tree
+ *	cnt:	records to read
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_fpipe(t, top)
+	BTREE *t;
+	recno_t top;
+{
+	DBT data;
+	recno_t nrec;
+	size_t len;
+	int ch;
+	u_char *p;
+
+	if (t->bt_rdata.size < t->bt_reclen) {
+		t->bt_rdata.data = t->bt_rdata.data == NULL ?
+		    malloc(t->bt_reclen) :
+		    realloc(t->bt_rdata.data, t->bt_reclen);
+		if (t->bt_rdata.data == NULL)
+			return (RET_ERROR);
+		t->bt_rdata.size = t->bt_reclen;
+	}
+	data.data = t->bt_rdata.data;
+	data.size = t->bt_reclen;
+
+	for (nrec = t->bt_nrecs; nrec < top;) {
+		len = t->bt_reclen;
+		for (p = t->bt_rdata.data;; *p++ = ch)
+			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
+				if (ch != EOF)
+					*p = ch;
+				if (len != 0)
+					memset(p, t->bt_bval, len);
+				if (__rec_iput(t,
+				    nrec, &data, 0) != RET_SUCCESS)
+					return (RET_ERROR);
+				++nrec;
+				break;
+			}
+		if (ch == EOF)
+			break;
+	}
+	if (nrec < top) {
+		F_SET(t, R_EOF);
+		return (RET_SPECIAL);
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __REC_VPIPE -- Get variable length records from a pipe.
+ *
+ * Parameters:
+ *	t:	tree
+ *	cnt:	records to read
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_vpipe(t, top)
+	BTREE *t;
+	recno_t top;
+{
+	DBT data;
+	recno_t nrec;
+	indx_t len;
+	size_t sz;
+	int bval, ch;
+	u_char *p;
+
+	bval = t->bt_bval;
+	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
+		for (p = t->bt_rdata.data,
+		    sz = t->bt_rdata.size;; *p++ = ch, --sz) {
+			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
+				data.data = t->bt_rdata.data;
+				data.size = p - (u_char *)t->bt_rdata.data;
+				if (ch == EOF && data.size == 0)
+					break;
+				if (__rec_iput(t, nrec, &data, 0)
+				    != RET_SUCCESS)
+					return (RET_ERROR);
+				break;
+			}
+			if (sz == 0) {
+				len = p - (u_char *)t->bt_rdata.data;
+				t->bt_rdata.size += (sz = 256);
+				t->bt_rdata.data = t->bt_rdata.data == NULL ?
+				    malloc(t->bt_rdata.size) :
+				    realloc(t->bt_rdata.data, t->bt_rdata.size);
+				if (t->bt_rdata.data == NULL)
+					return (RET_ERROR);
+				p = (u_char *)t->bt_rdata.data + len;
+			}
+		}
+		if (ch == EOF)
+			break;
+	}
+	if (nrec < top) {
+		F_SET(t, R_EOF);
+		return (RET_SPECIAL);
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __REC_FMAP -- Get fixed length records from a file.
+ *
+ * Parameters:
+ *	t:	tree
+ *	cnt:	records to read
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_fmap(t, top)
+	BTREE *t;
+	recno_t top;
+{
+	DBT data;
+	recno_t nrec;
+	u_char *sp, *ep, *p;
+	size_t len;
+
+	if (t->bt_rdata.size < t->bt_reclen) {
+		t->bt_rdata.data = t->bt_rdata.data == NULL ?
+		    malloc(t->bt_reclen) :
+		    realloc(t->bt_rdata.data, t->bt_reclen);
+		if (t->bt_rdata.data == NULL)
+			return (RET_ERROR);
+		t->bt_rdata.size = t->bt_reclen;
+	}
+	data.data = t->bt_rdata.data;
+	data.size = t->bt_reclen;
+
+	sp = (u_char *)t->bt_cmap;
+	ep = (u_char *)t->bt_emap;
+	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
+		if (sp >= ep) {
+			F_SET(t, R_EOF);
+			return (RET_SPECIAL);
+		}
+		len = t->bt_reclen;
+		for (p = t->bt_rdata.data;
+		    sp < ep && len > 0; *p++ = *sp++, --len);
+		if (len != 0)
+			memset(p, t->bt_bval, len);
+		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
+			return (RET_ERROR);
+	}
+	t->bt_cmap = (caddr_t)sp;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __REC_VMAP -- Get variable length records from a file.
+ *
+ * Parameters:
+ *	t:	tree
+ *	cnt:	records to read
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_vmap(t, top)
+	BTREE *t;
+	recno_t top;
+{
+	DBT data;
+	u_char *sp, *ep;
+	recno_t nrec;
+	int bval;
+
+	sp = (u_char *)t->bt_cmap;
+	ep = (u_char *)t->bt_emap;
+	bval = t->bt_bval;
+
+	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
+		if (sp >= ep) {
+			F_SET(t, R_EOF);
+			return (RET_SPECIAL);
+		}
+		for (data.data = sp; sp < ep && *sp != bval; ++sp);
+		data.size = sp - (u_char *)data.data;
+		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
+			return (RET_ERROR);
+		++sp;
+	}
+	t->bt_cmap = (caddr_t)sp;
+	return (RET_SUCCESS);
+}
diff --git a/db/recno/rec_open.c b/db/recno/rec_open.c
new file mode 100644
index 0000000000..51d8a3c260
--- /dev/null
+++ b/db/recno/rec_open.c
@@ -0,0 +1,241 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_open.c	8.10 (Berkeley) 9/1/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <db.h>
+#include "recno.h"
+
+DB *
+__rec_open(fname, flags, mode, openinfo, dflags)
+	const char *fname;
+	int flags, mode, dflags;
+	const RECNOINFO *openinfo;
+{
+	BTREE *t;
+	BTREEINFO btopeninfo;
+	DB *dbp;
+	PAGE *h;
+	struct stat sb;
+	int rfd, sverrno;
+
+	/* Open the user's file -- if this fails, we're done. */
+	if (fname != NULL && (rfd = open(fname, flags, mode)) < 0)
+		return (NULL);
+
+	/* Create a btree in memory (backed by disk). */
+	dbp = NULL;
+	if (openinfo) {
+		if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
+			goto einval;
+		btopeninfo.flags = 0;
+		btopeninfo.cachesize = openinfo->cachesize;
+		btopeninfo.maxkeypage = 0;
+		btopeninfo.minkeypage = 0;
+		btopeninfo.psize = openinfo->psize;
+		btopeninfo.compare = NULL;
+		btopeninfo.prefix = NULL;
+		btopeninfo.lorder = openinfo->lorder;
+		dbp = __bt_open(openinfo->bfname,
+		    O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
+	} else
+		dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
+	if (dbp == NULL)
+		goto err;
+
+	/*
+	 * Some fields in the tree structure are recno specific.  Fill them
+	 * in and make the btree structure look like a recno structure.  We
+	 * don't change the bt_ovflsize value, it's close enough and slightly
+	 * bigger.
+	 */
+	t = dbp->internal;
+	if (openinfo) {
+		if (openinfo->flags & R_FIXEDLEN) {
+			F_SET(t, R_FIXLEN);
+			t->bt_reclen = openinfo->reclen;
+			if (t->bt_reclen == 0)
+				goto einval;
+		}
+		t->bt_bval = openinfo->bval;
+	} else
+		t->bt_bval = '\n';
+
+	F_SET(t, R_RECNO);
+	if (fname == NULL)
+		F_SET(t, R_EOF | R_INMEM);
+	else
+		t->bt_rfd = rfd;
+
+	if (fname != NULL) {
+		/*
+		 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
+		 * Unfortunately, that's not portable, so we use lseek
+		 * and check the errno values.
+		 */
+		errno = 0;
+		if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
+			switch (flags & O_ACCMODE) {
+			case O_RDONLY:
+				F_SET(t, R_RDONLY);
+				break;
+			default:
+				goto einval;
+			}
+slow:			if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
+				goto err;
+			F_SET(t, R_CLOSEFP);
+			t->bt_irec =
+			    F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
+		} else {
+			switch (flags & O_ACCMODE) {
+			case O_RDONLY:
+				F_SET(t, R_RDONLY);
+				break;
+			case O_RDWR:
+				break;
+			default:
+				goto einval;
+			}
+
+			if (fstat(rfd, &sb))
+				goto err;
+			/*
+			 * Kluge -- we'd like to test to see if the file is too
+			 * big to mmap.  Since, we don't know what size or type
+			 * off_t's or size_t's are, what the largest unsigned
+			 * integral type is, or what random insanity the local
+			 * C compiler will perpetrate, doing the comparison in
+			 * a portable way is flatly impossible.  Hope that mmap
+			 * fails if the file is too large.
+			 */
+			if (sb.st_size == 0)
+				F_SET(t, R_EOF);
+			else {
+#ifdef MMAP_NOT_AVAILABLE
+				/*
+				 * XXX
+				 * Mmap doesn't work correctly on many current
+				 * systems.  In particular, it can fail subtly,
+				 * with cache coherency problems.  Don't use it
+				 * for now.
+				 */
+				t->bt_msize = sb.st_size;
+				if ((t->bt_smap = mmap(NULL, t->bt_msize,
+				    PROT_READ, MAP_PRIVATE, rfd,
+				    (off_t)0)) == (caddr_t)-1)
+					goto slow;
+				t->bt_cmap = t->bt_smap;
+				t->bt_emap = t->bt_smap + sb.st_size;
+				t->bt_irec = F_ISSET(t, R_FIXLEN) ?
+				    __rec_fmap : __rec_vmap;
+				F_SET(t, R_MEMMAPPED);
+#else
+				goto slow;
+#endif
+			}
+		}
+	}
+
+	/* Use the recno routines. */
+	dbp->close = __rec_close;
+	dbp->del = __rec_delete;
+	dbp->fd = __rec_fd;
+	dbp->get = __rec_get;
+	dbp->put = __rec_put;
+	dbp->seq = __rec_seq;
+	dbp->sync = __rec_sync;
+
+	/* If the root page was created, reset the flags. */
+	if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
+		goto err;
+	if ((h->flags & P_TYPE) == P_BLEAF) {
+		F_CLR(h, P_TYPE);
+		F_SET(h, P_RLEAF);
+		mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+	} else
+		mpool_put(t->bt_mp, h, 0);
+
+	if (openinfo && openinfo->flags & R_SNAPSHOT &&
+	    !F_ISSET(t, R_EOF | R_INMEM) &&
+	    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
+                goto err;
+	return (dbp);
+
+einval:	errno = EINVAL;
+err:	sverrno = errno;
+	if (dbp != NULL)
+		(void)__bt_close(dbp);
+	if (fname != NULL)
+		(void)close(rfd);
+	errno = sverrno;
+	return (NULL);
+}
+
+int
+__rec_fd(dbp)
+	const DB *dbp;
+{
+	BTREE *t;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/* In-memory database can't have a file descriptor. */
+	if (F_ISSET(t, R_INMEM)) {
+		errno = ENOENT;
+		return (-1);
+	}
+	return (t->bt_rfd);
+}
diff --git a/db/recno/rec_put.c b/db/recno/rec_put.c
new file mode 100644
index 0000000000..1afae0d5a6
--- /dev/null
+++ b/db/recno/rec_put.c
@@ -0,0 +1,280 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_put.c	8.7 (Berkeley) 8/18/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __REC_PUT -- Add a recno item to the tree.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key
+ *	data:	data
+ *	flag:	R_CURSOR, R_IAFTER, R_IBEFORE, R_NOOVERWRITE
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is
+ *	already in the tree and R_NOOVERWRITE specified.
+ */
+int
+__rec_put(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key;
+	const DBT *data;
+	u_int flags;
+{
+	BTREE *t;
+	DBT fdata, tdata;
+	recno_t nrec;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/*
+	 * If using fixed-length records, and the record is long, return
+	 * EINVAL.  If it's short, pad it out.  Use the record data return
+	 * memory, it's only short-term.
+	 */
+	if (F_ISSET(t, R_FIXLEN) && data->size != t->bt_reclen) {
+		if (data->size > t->bt_reclen)
+			goto einval;
+
+		if (t->bt_rdata.size < t->bt_reclen) {
+			t->bt_rdata.data = t->bt_rdata.data == NULL ?
+			    malloc(t->bt_reclen) :
+			    realloc(t->bt_rdata.data, t->bt_reclen);
+			if (t->bt_rdata.data == NULL)
+				return (RET_ERROR);
+			t->bt_rdata.size = t->bt_reclen;
+		}
+		memmove(t->bt_rdata.data, data->data, data->size);
+		memset((char *)t->bt_rdata.data + data->size,
+		    t->bt_bval, t->bt_reclen - data->size);
+		fdata.data = t->bt_rdata.data;
+		fdata.size = t->bt_reclen;
+	} else {
+		fdata.data = data->data;
+		fdata.size = data->size;
+	}
+
+	switch (flags) {
+	case R_CURSOR:
+		if (!F_ISSET(&t->bt_cursor, CURS_INIT))
+			goto einval;
+		nrec = t->bt_cursor.rcursor;
+		break;
+	case R_SETCURSOR:
+		if ((nrec = *(recno_t *)key->data) == 0)
+			goto einval;
+		break;
+	case R_IAFTER:
+		if ((nrec = *(recno_t *)key->data) == 0) {
+			nrec = 1;
+			flags = R_IBEFORE;
+		}
+		break;
+	case 0:
+	case R_IBEFORE:
+		if ((nrec = *(recno_t *)key->data) == 0)
+			goto einval;
+		break;
+	case R_NOOVERWRITE:
+		if ((nrec = *(recno_t *)key->data) == 0)
+			goto einval;
+		if (nrec <= t->bt_nrecs)
+			return (RET_SPECIAL);
+		break;
+	default:
+einval:		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	/*
+	 * Make sure that records up to and including the put record are
+	 * already in the database.  If skipping records, create empty ones.
+	 */
+	if (nrec > t->bt_nrecs) {
+		if (!F_ISSET(t, R_EOF | R_INMEM) &&
+		    t->bt_irec(t, nrec) == RET_ERROR)
+			return (RET_ERROR);
+		if (nrec > t->bt_nrecs + 1) {
+			if (F_ISSET(t, R_FIXLEN)) {
+				if ((tdata.data =
+				    (void *)malloc(t->bt_reclen)) == NULL)
+					return (RET_ERROR);
+				tdata.size = t->bt_reclen;
+				memset(tdata.data, t->bt_bval, tdata.size);
+			} else {
+				tdata.data = NULL;
+				tdata.size = 0;
+			}
+			while (nrec > t->bt_nrecs + 1)
+				if (__rec_iput(t,
+				    t->bt_nrecs, &tdata, 0) != RET_SUCCESS)
+					return (RET_ERROR);
+			if (F_ISSET(t, R_FIXLEN))
+				free(tdata.data);
+		}
+	}
+
+	if ((status = __rec_iput(t, nrec - 1, &fdata, flags)) != RET_SUCCESS)
+		return (status);
+
+	if (flags == R_SETCURSOR)
+		t->bt_cursor.rcursor = nrec;
+	
+	F_SET(t, R_MODIFIED);
+	return (__rec_ret(t, NULL, nrec, key, NULL));
+}
+
+/*
+ * __REC_IPUT -- Add a recno item to the tree.
+ *
+ * Parameters:
+ *	t:	tree
+ *	nrec:	record number
+ *	data:	data
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS
+ */
+int
+__rec_iput(t, nrec, data, flags)
+	BTREE *t;
+	recno_t nrec;
+	const DBT *data;
+	u_int flags;
+{
+	DBT tdata;
+	EPG *e;
+	PAGE *h;
+	indx_t index, nxtindex;
+	pgno_t pg;
+	u_int32_t nbytes;
+	int dflags, status;
+	char *dest, db[NOVFLSIZE];
+
+	/*
+	 * If the data won't fit on a page, store it on indirect pages.
+	 *
+	 * XXX
+	 * If the insert fails later on, these pages aren't recovered.
+	 */
+	if (data->size > t->bt_ovflsize) {
+		if (__ovfl_put(t, data, &pg) == RET_ERROR)
+			return (RET_ERROR);
+		tdata.data = db;
+		tdata.size = NOVFLSIZE;
+		*(pgno_t *)db = pg;
+		*(u_int32_t *)(db + sizeof(pgno_t)) = data->size;
+		dflags = P_BIGDATA;
+		data = &tdata;
+	} else
+		dflags = 0;
+
+	/* __rec_search pins the returned page. */
+	if ((e = __rec_search(t, nrec,
+	    nrec > t->bt_nrecs || flags == R_IAFTER || flags == R_IBEFORE ?
+	    SINSERT : SEARCH)) == NULL)
+		return (RET_ERROR);
+
+	h = e->page;
+	index = e->index;
+
+	/*
+	 * Add the specified key/data pair to the tree.  The R_IAFTER and
+	 * R_IBEFORE flags insert the key after/before the specified key.
+	 *
+	 * Pages are split as required.
+	 */
+	switch (flags) {
+	case R_IAFTER:
+		++index;
+		break;
+	case R_IBEFORE:
+		break;
+	default:
+		if (nrec < t->bt_nrecs &&
+		    __rec_dleaf(t, h, index) == RET_ERROR) {
+			mpool_put(t->bt_mp, h, 0);
+			return (RET_ERROR);
+		}
+		break;
+	}
+
+	/*
+	 * If not enough room, split the page.  The split code will insert
+	 * the key and data and unpin the current page.  If inserting into
+	 * the offset array, shift the pointers up.
+	 */
+	nbytes = NRLEAFDBT(data->size);
+	if (h->upper - h->lower < nbytes + sizeof(indx_t)) {
+		status = __bt_split(t, h, NULL, data, dflags, nbytes, index);
+		if (status == RET_SUCCESS)
+			++t->bt_nrecs;
+		return (status);
+	}
+
+	if (index < (nxtindex = NEXTINDEX(h)))
+		memmove(h->linp + index + 1, h->linp + index,
+		    (nxtindex - index) * sizeof(indx_t));
+	h->lower += sizeof(indx_t);
+
+	h->linp[index] = h->upper -= nbytes;
+	dest = (char *)h + h->upper;
+	WR_RLEAF(dest, data, dflags);
+
+	++t->bt_nrecs;
+	F_SET(t, B_MODIFIED);
+	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+
+	return (RET_SUCCESS);
+}
diff --git a/db/recno/rec_search.c b/db/recno/rec_search.c
new file mode 100644
index 0000000000..acc109e992
--- /dev/null
+++ b/db/recno/rec_search.c
@@ -0,0 +1,126 @@
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_search.c	8.4 (Berkeley) 7/14/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __REC_SEARCH -- Search a btree for a key.
+ *
+ * Parameters:
+ *	t:	tree to search
+ *	recno:	key to find
+ *	op: 	search operation
+ *
+ * Returns:
+ *	EPG for matching record, if any, or the EPG for the location of the
+ *	key, if it were inserted into the tree.
+ *
+ * Returns:
+ *	The EPG for matching record, if any, or the EPG for the location
+ *	of the key, if it were inserted into the tree, is entered into
+ *	the bt_cur field of the tree.  A pointer to the field is returned.
+ */
+EPG *
+__rec_search(t, recno, op)
+	BTREE *t;
+	recno_t recno;
+	enum SRCHOP op;
+{
+	register indx_t index;
+	register PAGE *h;
+	EPGNO *parent;
+	RINTERNAL *r;
+	pgno_t pg;
+	indx_t top;
+	recno_t total;
+	int sverrno;
+
+	BT_CLR(t);
+	for (pg = P_ROOT, total = 0;;) {
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			goto err;
+		if (h->flags & P_RLEAF) {
+			t->bt_cur.page = h;
+			t->bt_cur.index = recno - total;
+			return (&t->bt_cur);
+		}
+		for (index = 0, top = NEXTINDEX(h);;) {
+			r = GETRINTERNAL(h, index);
+			if (++index == top || total + r->nrecs > recno)
+				break;
+			total += r->nrecs;
+		}
+
+		BT_PUSH(t, pg, index - 1);
+		
+		pg = r->pgno;
+		switch (op) {
+		case SDELETE:
+			--GETRINTERNAL(h, (index - 1))->nrecs;
+			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+			break;
+		case SINSERT:
+			++GETRINTERNAL(h, (index - 1))->nrecs;
+			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+			break;
+		case SEARCH:
+			mpool_put(t->bt_mp, h, 0);
+			break;
+		}
+
+	}
+	/* Try and recover the tree. */
+err:	sverrno = errno;
+	if (op != SEARCH)
+		while  ((parent = BT_POP(t)) != NULL) {
+			if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
+				break;
+			if (op == SINSERT)
+				--GETRINTERNAL(h, parent->index)->nrecs;
+			else
+				++GETRINTERNAL(h, parent->index)->nrecs;
+                        mpool_put(t->bt_mp, h, MPOOL_DIRTY);
+                }
+	errno = sverrno;
+	return (NULL);
+}
diff --git a/db/recno/rec_seq.c b/db/recno/rec_seq.c
new file mode 100644
index 0000000000..f80992c598
--- /dev/null
+++ b/db/recno/rec_seq.c
@@ -0,0 +1,131 @@
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)rec_seq.c	8.3 (Berkeley) 7/14/94";
+#endif /* not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __REC_SEQ -- Recno sequential scan interface.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key for positioning and return value
+ *	data:	data return value
+ *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+int
+__rec_seq(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key, *data;
+	u_int flags;
+{
+	BTREE *t;
+	EPG *e;
+	recno_t nrec;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	switch(flags) {
+	case R_CURSOR:
+		if ((nrec = *(recno_t *)key->data) == 0)
+			goto einval;
+		break;
+	case R_NEXT:
+		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
+			nrec = t->bt_cursor.rcursor + 1;
+			break;
+		}
+		/* FALLTHROUGH */
+	case R_FIRST:
+		nrec = 1;
+		break;
+	case R_PREV:
+		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
+			if ((nrec = t->bt_cursor.rcursor - 1) == 0)
+				return (RET_SPECIAL);
+			break;
+		}
+		/* FALLTHROUGH */
+	case R_LAST:
+		if (!F_ISSET(t, R_EOF | R_INMEM) &&
+		    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
+			return (RET_ERROR);
+		nrec = t->bt_nrecs;
+		break;
+	default:
+einval:		errno = EINVAL;
+		return (RET_ERROR);
+	}
+	
+	if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) {
+		if (!F_ISSET(t, R_EOF | R_INMEM) &&
+		    (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
+			return (status);
+		if (t->bt_nrecs == 0 || nrec > t->bt_nrecs)
+			return (RET_SPECIAL);
+	}
+
+	if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL)
+		return (RET_ERROR);
+
+	F_SET(&t->bt_cursor, CURS_INIT);
+	t->bt_cursor.rcursor = nrec;
+
+	status = __rec_ret(t, e, nrec, key, data);
+	if (F_ISSET(t, B_DB_LOCK))
+		mpool_put(t->bt_mp, e->page, 0);
+	else
+		t->bt_pinned = e->page;
+	return (status);
+}
diff --git a/db/recno/rec_utils.c b/db/recno/rec_utils.c
new file mode 100644
index 0000000000..baea3fad50
--- /dev/null
+++ b/db/recno/rec_utils.c
@@ -0,0 +1,122 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)rec_utils.c	8.6 (Berkeley) 7/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <db.h>
+#include "recno.h"
+
+/*
+ * __rec_ret --
+ *	Build return data.
+ *
+ * Parameters:
+ *	t:	tree
+ *	e:	key/data pair to be returned
+ *   nrec:	record number
+ *    key:	user's key structure
+ *	data:	user's data structure
+ *
+ * Returns:
+ *	RET_SUCCESS, RET_ERROR.
+ */
+int
+__rec_ret(t, e, nrec, key, data)
+	BTREE *t;
+	EPG *e;
+	recno_t nrec;
+	DBT *key, *data;
+{
+	RLEAF *rl;
+	void *p;
+
+	if (key == NULL)
+		goto dataonly;
+
+	/* We have to copy the key, it's not on the page. */
+	if (sizeof(recno_t) > t->bt_rkey.size) {
+		p = (void *)(t->bt_rkey.data == NULL ?
+		    malloc(sizeof(recno_t)) :
+		    realloc(t->bt_rkey.data, sizeof(recno_t)));
+		if (p == NULL)
+			return (RET_ERROR);
+		t->bt_rkey.data = p;
+		t->bt_rkey.size = sizeof(recno_t);
+	}
+	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
+	key->size = sizeof(recno_t);
+	key->data = t->bt_rkey.data;
+
+dataonly:
+	if (data == NULL)
+		return (RET_SUCCESS);
+
+	/*
+	 * We must copy big keys/data to make them contigous.  Otherwise,
+	 * leave the page pinned and don't copy unless the user specified
+	 * concurrent access.
+	 */
+	rl = GETRLEAF(e->page, e->index);
+	if (rl->flags & P_BIGDATA) {
+		if (__ovfl_get(t, rl->bytes,
+		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
+			return (RET_ERROR);
+		data->data = t->bt_rdata.data;
+	} else if (F_ISSET(t, B_DB_LOCK)) {
+		/* Use +1 in case the first record retrieved is 0 length. */
+		if (rl->dsize + 1 > t->bt_rdata.size) {
+			p = (void *)(t->bt_rdata.data == NULL ?
+			    malloc(rl->dsize + 1) :
+			    realloc(t->bt_rdata.data, rl->dsize + 1));
+			if (p == NULL)
+				return (RET_ERROR);
+			t->bt_rdata.data = p;
+			t->bt_rdata.size = rl->dsize + 1;
+		}
+		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
+		data->size = rl->dsize;
+		data->data = t->bt_rdata.data;
+	} else {
+		data->size = rl->dsize;
+		data->data = rl->bytes;
+	}
+	return (RET_SUCCESS);
+}
diff --git a/db/recno/recno.h b/db/recno/recno.h
new file mode 100644
index 0000000000..bec772c2fa
--- /dev/null
+++ b/db/recno/recno.h
@@ -0,0 +1,39 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)recno.h	8.1 (Berkeley) 6/4/93
+ */
+
+enum SRCHOP { SDELETE, SINSERT, SEARCH};	/* Rec_search operation. */
+
+#include "../btree/btree.h"
+#include "extern.h"
diff --git a/hurd/hurd/signal.h b/hurd/hurd/signal.h
index b494f4922e..1973bcdb3c 100644
--- a/hurd/hurd/signal.h
+++ b/hurd/hurd/signal.h
@@ -1,5 +1,5 @@
 /* Implementing POSIX.1 signals under the Hurd.
-Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
+Copyright (C) 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 
 The GNU C Library is free software; you can redistribute it and/or
@@ -40,6 +40,7 @@ Cambridge, MA 02139, USA.  */
 #include <cthreads.h>		/* For `struct mutex'.  */
 #include <spin-lock.h>
 #include <hurd/threadvar.h>	/* We cache sigstate in a threadvar.  */
+struct hurd_signal_preempter;	/* <hurd/sigpreempt.h> */
 
 
 /* Per-thread signal state.  */
@@ -57,6 +58,13 @@ struct hurd_sigstate
     sigset_t pending;		/* Pending signals, possibly blocked.  */
     struct sigaction actions[NSIG];
     struct sigaltstack sigaltstack;
+
+    /* Chain of thread-local signal preempters; see <hurd/sigpreempt.h>.
+       Each element of this chain is in local stack storage, and the chain
+       parallels the stack: the head of this chain is in the innermost
+       stack frame, and each next element in an outermore frame.  */
+    struct hurd_signal_preempter *preempters;
+
     struct
       {
 	/* For each signal that may be pending, the
@@ -330,45 +338,6 @@ extern mach_msg_timeout_t _hurd_interrupted_rpc_timeout;
 	       __err == MIG_SERVER_DIED);				      \
     __err;								      \
 })
-
-/* Some other parts of the library need to preempt signals, to detect
-   errors that should not result in a POSIX signal.  For example, when
-   some mapped region of memory is used, an extraneous SIGSEGV might be
-   generated when the mapping server returns an error for a page fault.  */
-
-struct hurd_signal_preempt
-  {
-    /* Function to examine a thread receiving a given signal.  The handler
-       is called even for blocked signals.  This function is run in the
-       signal thread, with THREAD's sigstate locked; it should be as simple
-       and robust as possible.  THREAD is the thread which is about to
-       receive the signal.  SIGNO and SIGCODE would be passed to the normal
-       handler.
-
-       If the return value is SIG_DFL, normal signal processing continues.
-       If it is SIG_IGN, the signal is ignored.
-       Any other value is used in place of the normal handler.  */
-    sighandler_t (*handler) (thread_t thread,
-			     int signo, long int sigcode, int sigerror);
-    long int first, last;	/* Range of sigcodes this handler wants.  */
-    struct hurd_signal_preempt *next; /* Next handler on the chain. */
-  };
-
-extern struct hurd_signal_preempt *_hurd_signal_preempt[NSIG];
-extern struct mutex _hurd_signal_preempt_lock;
-
-/* Install a signal preempter for the given signal and range.
-   The caller is responsible for the storage for PREEMPTER.  */
-extern int hurd_preempt_signals (struct hurd_signal_preempt *preempter,
-				 int signo, int first_code, int last_code,
-				 sighandler_t (*handler) (thread_t,
-							  int, long int, int));
-
-/* Remove the signal preempter previously installed by calling
-   `hurd_preempt_signals' with PREEMPTER and SIGNO.  */
-extern int hurd_unpreempt_signals (struct hurd_signal_preempt *preempter,
-				   int signo);
-
 
 
 #endif	/* hurd/signal.h */
diff --git a/hurd/hurd/sigpreempt.h b/hurd/hurd/sigpreempt.h
new file mode 100644
index 0000000000..eed67b2e94
--- /dev/null
+++ b/hurd/hurd/sigpreempt.h
@@ -0,0 +1,90 @@
+/* Preemption of Hurd signals before POSIX.1 semantics take over.
+Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#ifndef	_HURD_SIGPREEMPT_H
+
+#define	_HURD_SIGPREEMPT_H	1
+#include <errno.h>
+#include <signal.h>		/* For sigset_t, sighandler_t, SIG_ERR.  */
+struct hurd_sigstate;		/* <hurd/signal.h> */
+
+struct hurd_signal_preempter
+  {
+    /* These members select which signals this structure will apply to.
+       The rest of the structure is only consulted if these match.  */
+    sigset_t signals;		/* Signals preempted.  */
+    unsigned long int first, last; /* Range of sigcode values preempted.  */
+
+    /* This function will be called (with SS->lock held) to decide what to
+       do with the signal described.  It may modify the codes of the signal
+       passed.  If the return value is SIG_ERR, the next matching preempter
+       is tried, or the normal handling is done for the signal (which may
+       have been changed by the preempter function).  Otherwise, the signal
+       is processed as if the return value were its handler setting.  */
+    sighandler_t (*preempter) (struct hurd_signal_preempter *preempter,
+			       struct hurd_sigstate *ss,
+			       int *signo, long int *sigcode, int *sigerror);
+    /* If PREEMPTER is null, act as if it returned HANDLER.  */
+    sighandler_t handler;
+
+    struct hurd_signal_preempter *next;	/* List structure.  */
+  };
+
+#define HURD_PREEMPT_SIGNAL_P(preempter, signo, sigcode) \
+  (((preempter)->signals & sigmask (signo)) && \
+   (sigcode) >= (preempter)->first && (sigcode) <= (preempter)->last)
+
+
+/* Signal preempters applying to all threads; locked by _hurd_siglock.  */
+extern struct hurd_signal_preempter *_hurdsig_preempters;
+extern sigset_t _hurdsig_preempted_set;
+
+
+/* The caller must initialize all members of *PREEMPTER except `next'.
+   The preempter is registered on the global list.  */
+void hurd_preempt_signals (struct hurd_signal_preempter *preempter);
+
+/* Remove a preempter registered with hurd_preempt_signals.  */
+void hurd_unpreempt_signals (struct hurd_signal_preempter *preempter);
+
+
+/* Call *OPERATE and return its value.  If a signal in SIGSET with a sigcode
+   in the range [FIRST,LAST] arrives during the call, catch it.  If HANDLER
+   is a function, it handles the signal in the normal way (i.e. it should
+   longjmp unless it can restart the insn on return).  If it is SIG_ERR,
+   hurd_catch_signal returns the sc_error value from the signal (or
+   EGRATUITOUS if that is zero).
+
+   The preempter structure is passed to *OPERATE, which may modify its
+   sigcode range or functions at any time during which it is guaranteed no
+   signal in SIGSET will arrive.  */
+
+error_t hurd_catch_signal (sigset_t sigset,
+			   unsigned long int first, unsigned long int last,
+			   error_t (*operate) (struct hurd_signal_preempter *),
+			   sighandler_t handler);
+
+
+/* Convenience functions using `hurd_catch_signal'.  */
+
+error_t hurd_safe_memmove (void *dest, const void *src, size_t nbytes);
+error_t hurd_safe_memset (void *dest, int byte, size_t nbytes);
+
+
+#endif	/* hurd/sigpreempt.h */
diff --git a/hurd/preempt-sig.c b/hurd/preempt-sig.c
index 194b49dbe9..6596089f1b 100644
--- a/hurd/preempt-sig.c
+++ b/hurd/preempt-sig.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1994 Free Software Foundation, Inc.
+/* Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 
 The GNU C Library is free software; you can redistribute it and/or
@@ -16,52 +16,53 @@ License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */
 
+#include <hurd/sigpreempt.h>
 #include <hurd/signal.h>
+#include <assert.h>
 
-/* Initialize PREEMPTER with the information given and stick it in the
-   chain of preempters for SIGNO.  */
-
-int
-hurd_preempt_signals (struct hurd_signal_preempt *preempter,
-		      int signo, int first_code, int last_code,
-		      sighandler_t (*handler) (thread_t, int, long int, int))
+void
+hurd_preempt_signals (struct hurd_signal_preempter *preempter)
 {
-  if (signo <= 0 || signo >= NSIG)
-    {
-      errno = EINVAL;
-      return -1;
-    }
-  preempter->first = first_code;
-  preempter->last = last_code;
-  preempter->handler = handler;
-  __mutex_lock (&_hurd_signal_preempt_lock);
-  preempter->next = _hurd_signal_preempt[signo];
-  _hurd_signal_preempt[signo] = preempter;
-  __mutex_unlock (&_hurd_signal_preempt_lock);
-  return 0;
+  __mutex_lock (&_hurd_siglock);
+  preempter->next = _hurdsig_preempters;
+  _hurdsig_preempters = preempter;
+  _hurdsig_preempted_set |= preempter->signals;
+  __mutex_unlock (&_hurd_siglock);
 }
 
-/* Remove PREEMPTER from the chain for SIGNO.  */
-
-int
-hurd_unpreempt_signals (struct hurd_signal_preempt *preempter, int signo)
+void
+hurd_unpreempt_signals (struct hurd_signal_preempter *preempter)
 {
-  struct hurd_signal_preempt *p, *lastp;
-  if (signo <= 0 || signo >= NSIG)
-    {
-      errno = EINVAL;
-      return -1;
-    }
-  __mutex_lock (&_hurd_signal_preempt_lock);
-  for (p = _hurd_signal_preempt[signo], lastp = NULL;
-       p != NULL; lastp = p, p = p->next)
-    if (p == preempter)
+  struct hurd_signal_preempter **p;
+  sigset_t preempted = 0;
+
+  __mutex_lock (&_hurd_siglock);
+
+  p = &_hurdsig_preempters;
+  while (*p)
+    if (*p == preempter)
       {
-	(lastp == NULL ? _hurd_signal_preempt[signo] : lastp->next) = p->next;
-	__mutex_unlock (&_hurd_signal_preempt_lock);
-	return 0;
+	/* Found it; take it off the chain.  */
+	*p = (*p)->next;
+	if ((preempter->signals & preempted) != preempter->signals)
+	  {
+	    /* This might have been the only preempter for some
+	       of those signals, so we must collect the full mask
+	       from the others.  */
+	    struct hurd_signal_preempter *pp;
+	    for (pp = *p; pp; pp = pp->next)
+	      preempted |= pp->signals;
+	    _hurdsig_preempted_set = preempted;
+	  }
+	__mutex_unlock (&_hurd_siglock);
+	return;
       }
-  __mutex_unlock (&_hurd_signal_preempt_lock);
-  errno = ENOENT;
-  return -1;
+    else
+      {
+	preempted |= (*p)->signals;
+	p = &(*p)->next;
+      }
+
+  __mutex_unlock (&_hurd_siglock); /* Avoid deadlock during death rattle.  */
+  assert (! "removing absent preempter");
 }
diff --git a/sysdeps/mach/hurd/jmp-unwind.c b/sysdeps/mach/hurd/jmp-unwind.c
index f7540f0dde..822501f8e5 100644
--- a/sysdeps/mach/hurd/jmp-unwind.c
+++ b/sysdeps/mach/hurd/jmp-unwind.c
@@ -22,6 +22,11 @@ Cambridge, MA 02139, USA.  */
 #include <hurd/userlink.h>
 #include <assert.h>
 
+
+#ifndef _JMPBUF_UNWINDS
+ #error "sysdeps/MACHINE/jmp_buf.h fails to define _JMPBUF_UNWINDS"
+#endif
+
 /* This function is called by `longjmp' (with its arguments) to restore
    active resources to a sane state before the frames code using them are
    jumped out of.  */
@@ -31,17 +36,20 @@ _longjmp_unwind (jmp_buf env, int val)
 {
   struct hurd_sigstate *ss = _hurd_self_sigstate ();
   struct hurd_userlink *link;
+  struct hurd_signal_preempter **p;
 
   /* All access to SS->active_resources must take place inside a critical
      section where signal handlers cannot run.  */
   __spin_lock (&ss->lock);
   assert (! ss->critical_section);
   ss->critical_section = 1;
-  __spin_unlock (&ss->lock);
 
-#ifndef _JMPBUF_UNWINDS
- #error "sysdeps/MACHINE/jmp_buf.h fails to define _JMPBUF_UNWINDS"
-#endif
+  /* Remove local signal preempters being unwound past.  */
+  while (ss->preempters &&
+	 _JMPBUF_UNWINDS (env[0].__jmpbuf, ss->preempters))
+    ss->preempters = ss->preempters->next;
+
+  __spin_unlock (&ss->lock);
 
   /* Iterate over the current thread's list of active resources.
      Process the head portion of the list whose links reside
@@ -59,4 +67,4 @@ _longjmp_unwind (jmp_buf env, int val)
       (*link->cleanup) (link->cleanup_data, env, val);
 
   _hurd_critical_section_unlock (ss);
-}    
+}
diff --git a/sysdeps/unix/sysv/linux/sys/param.h b/sysdeps/unix/sysv/linux/sys/param.h
index a2d4984166..4950d58d38 100644
--- a/sysdeps/unix/sysv/linux/sys/param.h
+++ b/sysdeps/unix/sysv/linux/sys/param.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995 Free Software Foundation, Inc.
+/* Copyright (C) 1995, 1996 Free Software Foundation, Inc.
 This file is part of the GNU C Library.
 
 The GNU C Library is free software; you can redistribute it and/or
@@ -23,23 +23,41 @@ Boston, MA 02111-1307, USA.  */
 #include <linux/limits.h>
 #include <linux/param.h>
 
+/* BSD names for some <limits.h> values.  */
+
+#define	NBBY		CHAR_BIT
+#ifndef	NGROUPS
+#define	NGROUPS		NGROUPS_MAX
+#endif
+#define	MAXSYMLINKS	SYMLOOP_MAX
+#define	CANBSIZ		MAX_CANON
+#define	NCARGS		ARG_MAX
+#define MAXPATHLEN      PATH_MAX
+#define NOFILE          OPEN_MAX
+
+
 #include <sys/types.h>
 
+/* Bit map related macros.  */
+#define	setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
+#define	clrbit(a,i)	((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
+#define	isset(a,i)	((a)[(i)/NBBY] & (1<<((i)%NBBY)))
+#define	isclr(a,i)	(((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
 
+/* Macros for counting and rounding.  */
 #ifndef howmany
-# define howmany(x, y)	(((x)+((y)-1))/(y))
+#define	howmany(x, y)	(((x)+((y)-1))/(y))
 #endif
+#define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))
+#define powerof2(x)	((((x)-1)&(x))==0)
 
-#ifndef roundup
-# define roundup(x, y)	((((x)+((y)-1))/(y))*(y))
-#endif
+/* Macros for min/max.  */
+#define	MIN(a,b) (((a)<(b))?(a):(b))
+#define	MAX(a,b) (((a)>(b))?(a):(b))
 
-#define MAXPATHLEN      PATH_MAX
-#define NOFILE          OPEN_MAX
 
-/*  Following the information of some of the kernel people I here assume
-    that block size (i.e. the value of stat.st_blocks) for all filesystem
-    is 512 bytes.  If not tell HJ, Roland, or me.  -- drepper */
+/* Unit of `st_blocks'.  */
 #define DEV_BSIZE       512
 
-#endif
+
+#endif	/* sys/param.h */