* 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.

10 files changed, 3878 insertions, 0 deletions

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;