about summary refs log tree commit diff
path: root/db2/btree/bt_put.c
diff options
context:
space:
mode:
Diffstat (limited to 'db2/btree/bt_put.c')
-rw-r--r--db2/btree/bt_put.c919
1 files changed, 919 insertions, 0 deletions
diff --git a/db2/btree/bt_put.c b/db2/btree/bt_put.c
new file mode 100644
index 0000000000..632c3d185b
--- /dev/null
+++ b/db2/btree/bt_put.c
@@ -0,0 +1,919 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ *	Sleepycat Software.  All rights reserved.
+ */
+/*
+ * Copyright (c) 1990, 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ */
+/*
+ * Copyright (c) 1990, 1993, 1994, 1995
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)bt_put.c	10.23 (Sleepycat) 8/22/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#endif
+
+#include "db_int.h"
+#include "db_page.h"
+#include "btree.h"
+
+static int __bam_fixed __P((BTREE *, DBT *));
+static int __bam_lookup __P((DB *, DBT *, int *));
+static int __bam_ndup __P((DB *, PAGE *, u_int32_t));
+static int __bam_partial __P((DB *, DBT *, PAGE *, u_int32_t));
+
+/*
+ * __bam_put --
+ *	Add a new key/data pair or replace an existing pair (btree).
+ *
+ * PUBLIC: int __bam_put __P((DB *, DB_TXN *, DBT *, DBT *, int));
+ */
+int
+__bam_put(argdbp, txn, key, data, flags)
+	DB *argdbp;
+	DB_TXN *txn;
+	DBT *key, *data;
+	int flags;
+{
+	BTREE *t;
+	CURSOR c;
+	DB *dbp;
+	PAGE *h;
+	db_indx_t indx;
+	int exact, iflags, newkey, replace, ret, stack;
+
+	DEBUG_LWRITE(argdbp, txn, "bam_put", key, data, flags);
+
+	/* Check flags. */
+	if ((ret = __db_putchk(argdbp, key, data, flags,
+	    F_ISSET(argdbp, DB_AM_RDONLY), F_ISSET(argdbp, DB_AM_DUP))) != 0)
+		return (ret);
+
+	GETHANDLE(argdbp, txn, &dbp, ret);
+	t = dbp->internal;
+
+retry:	/*
+	 * Find the location at which to insert.  The call to bt_lookup()
+	 * leaves the returned page pinned.
+	 */
+	if ((ret = __bam_lookup(dbp, key, &exact)) != 0) {
+		PUTHANDLE(dbp);
+		return (ret);
+	}
+	h = t->bt_csp->page;
+	indx = t->bt_csp->indx;
+	stack = 1;
+
+	/*
+	 * If an identical key is already in the tree, and DB_NOOVERWRITE is
+	 * set, an error is returned.  If an identical key is already in the
+	 * tree and DB_NOOVERWRITE is not set, the key is either added (when
+	 * duplicates are permitted) or an error is returned.  The exception
+	 * is when the item located is referenced by a cursor and marked for
+	 * deletion, in which case we permit the overwrite and flag the cursor.
+	 */
+	replace = 0;
+	if (exact && flags == DB_NOOVERWRITE) {
+		if (!GET_BKEYDATA(h, indx + O_INDX)->deleted) {
+			ret = DB_KEYEXIST;
+			goto err;
+		}
+		replace = 1;
+		__bam_ca_replace(dbp, h->pgno, indx, REPLACE_SETUP);
+	}
+
+	/*
+	 * If we're inserting into the first or last page of the tree,
+	 * remember where we did it so we can do fast lookup next time.
+	 *
+	 * XXX
+	 * Does reverse order still work (did it ever!?!?)
+	 */
+	t->bt_lpgno =
+	    h->next_pgno == PGNO_INVALID || h->prev_pgno == PGNO_INVALID ?
+	    h->pgno : PGNO_INVALID;
+
+	/*
+	 * Select the arguments for __bam_iitem() and do the insert.  If the
+	 * key is an exact match, we're either adding a new duplicate at the
+	 * end of the duplicate set, or we're replacing the data item with a
+	 * new data item.  If the key isn't an exact match, we're inserting
+	 * a new key/data pair, before the search location.
+	 */
+	newkey = dbp->type == DB_BTREE && !exact;
+	if (exact) {
+		if (F_ISSET(dbp, DB_AM_DUP)) {
+			/*
+			 * Make sure that we're not looking at a page of
+			 * duplicates -- if so, move to the last entry on
+			 * that page.
+			 */
+			c.page = h;
+			c.pgno = h->pgno;
+			c.indx = indx;
+			c.dpgno = PGNO_INVALID;
+			c.dindx = 0;
+			if ((ret =
+			    __bam_ovfl_chk(dbp, &c, indx + O_INDX, 1)) != 0)
+				goto err;
+			if (c.dpgno != PGNO_INVALID) {
+				/*
+				 * XXX
+				 * The __bam_ovfl_chk() routine memp_fput() the
+				 * current page and acquired a new one, but did
+				 * not do anything about the lock we're holding.
+				 */
+				t->bt_csp->page = h = c.page;
+				indx = c.dindx;
+			}
+			iflags = DB_AFTER;
+		} else
+			iflags = DB_CURRENT;
+	} else
+		iflags = DB_BEFORE;
+
+	/*
+	 * The pages we're using may be modified by __bam_iitem(), so make
+	 * sure we reset the stack.
+	 */
+	ret = __bam_iitem(dbp,
+	    &h, &indx, key, data, iflags, newkey ? BI_NEWKEY : 0);
+	t->bt_csp->page = h;
+	t->bt_csp->indx = indx;
+
+	switch (ret) {
+	case 0:
+		/*
+		 * Done.  Clean up the cursor, and, if we're doing record
+		 * numbers, adjust the internal page counts.
+		 */
+		if (replace)
+			__bam_ca_replace(dbp, h->pgno, indx, REPLACE_SUCCESS);
+
+		if (!replace && F_ISSET(dbp, DB_BT_RECNUM))
+			ret = __bam_adjust(dbp, t, 1);
+		break;
+	case DB_NEEDSPLIT:
+		/*
+		 * We have to split the page.  Back out the cursor setup,
+		 * discard the stack of pages, and do the split.
+		 */
+		if (replace) {
+			replace = 0;
+			__bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED);
+		}
+
+		(void)__bam_stkrel(dbp);
+		stack = 0;
+
+		if ((ret = __bam_split(dbp, key)) != 0)
+			break;
+
+		goto retry;
+		/* NOTREACHED */
+	default:
+		if (replace)
+			__bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED);
+		break;
+	}
+
+err:	if (stack)
+		(void)__bam_stkrel(dbp);
+
+	PUTHANDLE(dbp);
+	return (ret);
+}
+
+/*
+ * __bam_lookup --
+ *	Find the right location in the tree for the key.
+ */
+static int
+__bam_lookup(dbp, key, exactp)
+	DB *dbp;
+	DBT *key;
+	int *exactp;
+{
+	BTREE *t;
+	DB_LOCK lock;
+	EPG e;
+	PAGE *h;
+	db_indx_t indx;
+	int cmp, ret;
+
+	t = dbp->internal;
+	h = NULL;
+
+	/*
+	 * Record numbers can't be fast-tracked, we have to lock the entire
+	 * tree.
+	 */
+	if (F_ISSET(dbp, DB_BT_RECNUM))
+		goto slow;
+
+	/* Check to see if we've been seeing sorted input. */
+	if (t->bt_lpgno == PGNO_INVALID)
+		goto slow;
+
+	/*
+	 * Retrieve the page on which we did the last insert.  It's okay if
+	 * it doesn't exist, or if it's not the page type we expect, it just
+	 * means that the world changed.
+	 */
+	if (__bam_lget(dbp, 0, t->bt_lpgno, DB_LOCK_WRITE, &lock))
+		goto miss;
+	if (__bam_pget(dbp, &h, &t->bt_lpgno, 0)) {
+		(void)__BT_LPUT(dbp, lock);
+		goto miss;
+	}
+	if (TYPE(h) != P_LBTREE)
+		goto miss;
+	if (NUM_ENT(h) == 0)
+		goto miss;
+
+	/*
+	 * We have to be at the end or beginning of the tree to know that
+	 * we're inserting in a sort order.  If that's the case and we're
+	 * in the right order in comparison to the first/last key/data pair,
+	 * we have the right position.
+	 */
+	if (h->next_pgno == PGNO_INVALID) {
+		e.page = h;
+		e.indx = NUM_ENT(h) - P_INDX;
+		if ((cmp = __bam_cmp(dbp, key, &e)) >= 0) {
+			if (cmp > 0)
+				e.indx += P_INDX;
+			goto fast;
+		}
+	}
+	if (h->prev_pgno == PGNO_INVALID) {
+		e.page = h;
+		e.indx = 0;
+		if ((cmp = __bam_cmp(dbp, key, &e)) <= 0) {
+			/*
+			 * We're doing a put, so we want to insert as the last
+			 * of any set of duplicates.
+			 */
+			if (cmp == 0) {
+				for (indx = 0;
+				    indx < (db_indx_t)(NUM_ENT(h) - P_INDX) &&
+				    h->inp[indx] == h->inp[indx + P_INDX];
+				    indx += P_INDX);
+				e.indx = indx;
+			}
+			goto fast;
+		}
+	}
+	goto miss;
+
+	/* Set the exact match flag in case we've already inserted this key. */
+fast:	*exactp = cmp == 0;
+
+	/* Enter the entry in the stack. */
+	BT_STK_CLR(t);
+	BT_STK_ENTER(t, e.page, e.indx, lock, ret);
+	if (ret != 0)
+		return (ret);
+
+	++t->lstat.bt_cache_hit;
+	return (0);
+
+miss:	++t->lstat.bt_cache_miss;
+	if (h != NULL) {
+		(void)memp_fput(dbp->mpf, h, 0);
+		(void)__BT_LPUT(dbp, lock);
+	}
+
+slow:	return (__bam_search(dbp, key, S_INSERT, 1, NULL, exactp));
+}
+
+/*
+ * OVPUT --
+ *	Copy an overflow item onto a page.
+ */
+#undef	OVPUT
+#define	OVPUT(h, indx, bo) do {						\
+	DBT __hdr;							\
+	memset(&__hdr, 0, sizeof(__hdr));				\
+	__hdr.data = &bo;						\
+	__hdr.size = BOVERFLOW_SIZE;					\
+	if ((ret = __db_pitem(dbp,					\
+	    h, indx, BOVERFLOW_SIZE, &__hdr, NULL)) != 0)		\
+		return (ret);						\
+} while (0)
+
+/*
+ * __bam_iitem --
+ *	Insert an item into the tree.
+ *
+ * PUBLIC: int __bam_iitem __P((DB *,
+ * PUBLIC:    PAGE **, db_indx_t *, DBT *, DBT *, int, int));
+ */
+int
+__bam_iitem(dbp, hp, indxp, key, data, op, flags)
+	DB *dbp;
+	PAGE **hp;
+	db_indx_t *indxp;
+	DBT *key, *data;
+	int op, flags;
+{
+	BTREE *t;
+	BKEYDATA *bk;
+	BOVERFLOW kbo, dbo;
+	DBT tdbt;
+	PAGE *h;
+	db_indx_t indx;
+	u_int32_t have_bytes, need_bytes, needed;
+	int bigkey, bigdata, dcopy, dupadjust, ret;
+
+	t = dbp->internal;
+	h = *hp;
+	indx = *indxp;
+
+	dupadjust = 0;
+	bk = NULL;			/* XXX: Shut the compiler up. */
+
+	/*
+	 * If it's a page of duplicates, call the common code to do the work.
+	 *
+	 * !!!
+	 * Here's where the hp and indxp are important.  The duplicate code
+	 * may decide to rework/rearrange the pages and indices we're using,
+	 * so the caller must understand that the stack has to change.
+	 */
+	if (TYPE(h) == P_DUPLICATE) {
+		/* Adjust the index for the new item if it's a DB_AFTER op. */
+		if (op == DB_AFTER)
+			++*indxp;
+
+		/* Remove the current item if it's a DB_CURRENT op. */
+		if (op == DB_CURRENT && (ret = __db_ditem(dbp, *hp, *indxp,
+		    BKEYDATA_SIZE(GET_BKEYDATA(*hp, *indxp)->len))) != 0)
+			return (ret);
+
+		/* Put the new/replacement item onto the page. */
+		return (__db_dput(dbp, data, hp, indxp, __bam_new));
+	}
+
+	/*
+	 * XXX
+	 * Handle partial puts.
+	 *
+	 * This is truly awful from a performance standput.  We don't optimize
+	 * for partial puts at all, we delete the record and add it back in,
+	 * regardless of size or if we're simply overwriting current data.
+	 * The hash access method does this a lot better than we do, and we're
+	 * eventually going to have to fix it.
+	 */
+	if (F_ISSET(data, DB_DBT_PARTIAL)) {
+		tdbt = *data;
+		if ((ret = __bam_partial(dbp, &tdbt, h, indx)) != 0)
+			return (ret);
+		data = &tdbt;
+	}
+
+	/* If it's a short fixed-length record, fix it up. */
+	if (F_ISSET(dbp, DB_RE_FIXEDLEN) && data->size != t->bt_recno->re_len) {
+		tdbt = *data;
+		if ((ret = __bam_fixed(t, &tdbt)) != 0)
+			return (ret);
+		data = &tdbt;
+	}
+
+	/*
+	 * If the key or data item won't fit on a page, store it in the
+	 * overflow pages.
+	 *
+	 * !!!
+	 * From this point on, we have to recover the allocated overflow
+	 * pages on error.
+	 */
+	bigkey = bigdata = 0;
+	if (LF_ISSET(BI_NEWKEY) && key->size > t->bt_ovflsize) {
+		kbo.deleted = 0;
+		kbo.type = B_OVERFLOW;
+		kbo.tlen = key->size;
+		if ((ret = __db_poff(dbp, key, &kbo.pgno, __bam_new)) != 0)
+			goto err;
+		bigkey = 1;
+	}
+	if (data->size > t->bt_ovflsize) {
+		dbo.deleted = 0;
+		dbo.type = B_OVERFLOW;
+		dbo.tlen = data->size;
+		if ((ret = __db_poff(dbp, data, &dbo.pgno, __bam_new)) != 0)
+			goto err;
+		bigdata = 1;
+	}
+
+	dcopy = 0;
+	needed = 0;
+	if (LF_ISSET(BI_NEWKEY)) {
+		/* If BI_NEWKEY is set we're adding a new key and data pair. */
+		if (bigkey)
+			needed += BOVERFLOW_PSIZE;
+		else
+			needed += BKEYDATA_PSIZE(key->size);
+		if (bigdata)
+			needed += BOVERFLOW_PSIZE;
+		else
+			needed += BKEYDATA_PSIZE(data->size);
+	} else {
+		/*
+		 * We're either overwriting the data item of a key/data pair
+		 * or we're adding the data item only, i.e. a new duplicate.
+		 */
+		if (op == DB_CURRENT) {
+			bk = GET_BKEYDATA(h,
+			    indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
+			if (bk->type == B_OVERFLOW)
+				have_bytes = BOVERFLOW_PSIZE;
+			else
+				have_bytes = BKEYDATA_PSIZE(bk->len);
+			need_bytes = 0;
+		} else {
+			have_bytes = 0;
+			need_bytes = sizeof(db_indx_t);
+		}
+		if (bigdata)
+			need_bytes += BOVERFLOW_PSIZE;
+		else
+			need_bytes += BKEYDATA_PSIZE(data->size);
+
+		/*
+		 * If we're overwriting a data item, we copy it if it's not a
+		 * special record type and it's the same size (including any
+		 * alignment) and do a delete/insert otherwise.
+		 */
+		if (op == DB_CURRENT && !bigdata &&
+		    bk->type == B_KEYDATA && have_bytes == need_bytes)
+			dcopy = 1;
+		if (have_bytes < need_bytes)
+			needed += need_bytes - have_bytes;
+	}
+
+	/*
+	 * If there's not enough room, or the user has put a ceiling on the
+	 * number of keys permitted in the page, split the page.
+	 *
+	 * XXX
+	 * The t->bt_maxkey test here may be insufficient -- do we have to
+	 * check in the btree split code, so we don't undo it there!?!?
+	 */
+	if (P_FREESPACE(h) < needed ||
+	    (t->bt_maxkey != 0 && NUM_ENT(h) > t->bt_maxkey)) {
+		ret = DB_NEEDSPLIT;
+		goto err;
+	}
+
+	/*
+	 * The code breaks it up into six cases:
+	 *
+	 * 1. Append a new key/data pair.
+	 * 2. Insert a new key/data pair.
+	 * 3. Copy the data item.
+	 * 4. Delete/insert the data item.
+	 * 5. Append a new data item.
+	 * 6. Insert a new data item.
+	 */
+	if (LF_ISSET(BI_NEWKEY)) {
+		switch (op) {
+		case DB_AFTER:		/* 1. Append a new key/data pair. */
+			indx += 2;
+			*indxp += 2;
+			break;
+		case DB_BEFORE:		/* 2. Insert a new key/data pair. */
+			break;
+		default:
+			abort();
+		}
+
+		/* Add the key. */
+		if (bigkey)
+			OVPUT(h, indx, kbo);
+		else {
+			DBT __data;
+			memset(&__data, 0, sizeof(__data));
+			__data.data = key->data;
+			__data.size = key->size;
+			if ((ret = __db_pitem(dbp, h, indx,
+			    BKEYDATA_SIZE(key->size), NULL, &__data)) != 0)
+				goto err;
+		}
+		++indx;
+	} else {
+		switch (op) {
+		case DB_CURRENT:	/* 3. Copy the data item. */
+			/*
+			 * If we're not logging and it's possible, overwrite
+			 * the current item.
+			 *
+			 * XXX
+			 * We should add a separate logging message so that
+			 * we can do this anytime it's possible, including
+			 * for partial record puts.
+			 */
+			if (dcopy && !DB_LOGGING(dbp)) {
+				bk->len = data->size;
+				memcpy(bk->data, data->data, data->size);
+				goto done;
+			}
+					/* 4. Delete/insert the data item. */
+			if (TYPE(h) == P_LBTREE)
+				++indx;
+			if ((ret = __bam_ditem(dbp, h, indx)) != 0)
+				goto err;
+			break;
+		case DB_AFTER:		/* 5. Append a new data item. */
+			if (TYPE(h) == P_LBTREE) {
+				/*
+				 * Adjust the cursor and copy in the key for
+				 * the duplicate.
+				 */
+				if ((ret = __bam_adjindx(dbp,
+				    h, indx + P_INDX, indx, 1)) != 0)
+					goto err;
+
+				indx += 3;
+				dupadjust = 1;
+
+				*indxp += 2;
+			} else {
+				++indx;
+				__bam_ca_di(dbp, h->pgno, indx, 1);
+
+				*indxp += 1;
+			}
+			break;
+		case DB_BEFORE:		/* 6. Insert a new data item. */
+			if (TYPE(h) == P_LBTREE) {
+				/*
+				 * Adjust the cursor and copy in the key for
+				 * the duplicate.
+				 */
+				if ((ret =
+				    __bam_adjindx(dbp, h, indx, indx, 1)) != 0)
+					goto err;
+
+				++indx;
+				dupadjust = 1;
+			} else
+				__bam_ca_di(dbp, h->pgno, indx, 1);
+			break;
+		default:
+			abort();
+		}
+	}
+
+	/* Add the data. */
+	if (bigdata)
+		OVPUT(h, indx, dbo);
+	else {
+		BKEYDATA __bk;
+		DBT __hdr, __data;
+		memset(&__data, 0, sizeof(__data));
+		__data.data = data->data;
+		__data.size = data->size;
+
+		if (LF_ISSET(BI_DELETED)) {
+			__bk.len = __data.size;
+			__bk.deleted = 1;
+			__bk.type = B_KEYDATA;
+			__hdr.data = &__bk;
+			__hdr.size = SSZA(BKEYDATA, data);
+			ret = __db_pitem(dbp, h, indx,
+			    BKEYDATA_SIZE(__data.size), &__hdr, &__data);
+		} else
+			ret = __db_pitem(dbp, h, indx,
+			    BKEYDATA_SIZE(data->size), NULL, &__data);
+		if (ret != 0)
+			goto err;
+	}
+
+done:	++t->lstat.bt_added;
+
+	ret = memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY);
+
+	/*
+	 * If the page is at least 50% full, and we added a duplicate, see if
+	 * that set of duplicates takes up at least 25% of the space.  If it
+	 * does, move it off onto its own page.
+	 */
+	if (dupadjust && P_FREESPACE(h) <= dbp->pgsize / 2) {
+		--indx;
+		if ((ret = __bam_ndup(dbp, h, indx)) != 0)
+			goto err;
+	}
+
+	if (t->bt_recno != NULL)
+		F_SET(t->bt_recno, RECNO_MODIFIED);
+
+	if (0) {
+err:		if (bigkey)
+			(void)__db_doff(dbp, kbo.pgno, __bam_free);
+		if (bigdata)
+			(void)__db_doff(dbp, dbo.pgno, __bam_free);
+	}
+	return (ret);
+}
+
+/*
+ * __bam_ndup --
+ *	Check to see if the duplicate set at indx should have its own page.
+ *	If it should, create it.
+ */
+static int
+__bam_ndup(dbp, h, indx)
+	DB *dbp;
+	PAGE *h;
+	u_int32_t indx;
+{
+	BKEYDATA *bk;
+	BOVERFLOW bo;
+	DBT hdr;
+	PAGE *cp;
+	db_indx_t cnt, cpindx, first, sz;
+	int ret;
+
+	while (indx > 0 && h->inp[indx] == h->inp[indx - P_INDX])
+		indx -= P_INDX;
+	for (cnt = 0, sz = 0, first = indx;; ++cnt, indx += P_INDX) {
+		if (indx >= NUM_ENT(h) || h->inp[first] != h->inp[indx])
+			break;
+		bk = GET_BKEYDATA(h, indx);
+		sz += bk->type == B_KEYDATA ?
+		    BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
+		bk = GET_BKEYDATA(h, indx + O_INDX);
+		sz += bk->type == B_KEYDATA ?
+		    BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
+	}
+
+	/*
+	 * If this set of duplicates is using more than 25% of the page, move
+	 * them off.  The choice of 25% is a WAG, but it has to be small enough
+	 * that we can always split regardless of the presence of duplicates.
+	 */
+	if (sz < dbp->pgsize / 4)
+		return (0);
+
+	/* Get a new page. */
+	if ((ret = __bam_new(dbp, P_DUPLICATE, &cp)) != 0)
+		return (ret);
+
+	/*
+	 * Move this set of duplicates off the page.  First points to the first
+	 * key of the first duplicate key/data pair, cnt is the number of pairs
+	 * we're dealing with.
+	 */
+	memset(&hdr, 0, sizeof(hdr));
+	for (indx = first + O_INDX, cpindx = 0;; ++cpindx) {
+		/* Copy the entry to the new page. */
+		bk = GET_BKEYDATA(h, indx);
+		hdr.data = bk;
+		hdr.size = bk->type == B_KEYDATA ?
+		    BKEYDATA_SIZE(bk->len) : BOVERFLOW_SIZE;
+		if ((ret =
+		    __db_pitem(dbp, cp, cpindx, hdr.size, &hdr, NULL)) != 0)
+			goto err;
+
+		/*
+		 * Move cursors referencing the old entry to the new entry.
+		 * Done after the page put because __db_pitem() adjusts
+		 * cursors on the new page, and before the delete because
+		 * __db_ditem adjusts cursors on the old page.
+		 */
+		__bam_ca_dup(dbp,
+		    PGNO(h), first, indx - O_INDX, PGNO(cp), cpindx);
+
+		/* Delete the data item. */
+		if ((ret = __db_ditem(dbp, h, indx, hdr.size)) != 0)
+			goto err;
+
+		/* Delete all but the first reference to the key. */
+		if (--cnt == 0)
+			break;
+		if ((ret = __bam_adjindx(dbp, h, indx, first, 0)) != 0)
+			goto err;
+	}
+
+	/* Put in a new data item that points to the duplicates page. */
+	bo.deleted = 0;
+	bo.type = B_DUPLICATE;
+	bo.pgno = cp->pgno;
+	bo.tlen = 0;
+
+	OVPUT(h, indx, bo);
+
+	return (memp_fput(dbp->mpf, cp, DB_MPOOL_DIRTY));
+
+err:	(void)__bam_free(dbp, cp);
+	return (ret);
+}
+
+/*
+ * __bam_fixed --
+ *	Build the real record for a fixed length put.
+ */
+static int
+__bam_fixed(t, dbt)
+	BTREE *t;
+	DBT *dbt;
+{
+	RECNO *rp;
+
+	rp = t->bt_recno;
+
+	/*
+	 * If using fixed-length records, and the record is long, return
+	 * EINVAL.  If it's short, pad it out.  Use the record data return
+	 * memory, it's only short-term.
+	 */
+	if (dbt->size > rp->re_len)
+		return (EINVAL);
+	if (t->bt_rdata.ulen < rp->re_len) {
+		t->bt_rdata.data = t->bt_rdata.data == NULL ?
+		    (void *)malloc(rp->re_len) :
+		    (void *)realloc(t->bt_rdata.data, rp->re_len);
+		if (t->bt_rdata.data == NULL) {
+			t->bt_rdata.ulen = 0;
+			return (ENOMEM);
+		}
+		t->bt_rdata.ulen = rp->re_len;
+	}
+	memcpy(t->bt_rdata.data, dbt->data, dbt->size);
+	memset((u_int8_t *)t->bt_rdata.data + dbt->size,
+	    rp->re_pad, rp->re_len - dbt->size);
+
+	/* Set the DBT to reference our new record. */
+	t->bt_rdata.size = rp->re_len;
+	t->bt_rdata.dlen = 0;
+	t->bt_rdata.doff = 0;
+	t->bt_rdata.flags = 0;
+	*dbt = t->bt_rdata;
+	return (0);
+}
+
+/*
+ * __bam_partial --
+ *	Build the real record for a partial put.
+ */
+static int
+__bam_partial(dbp, dbt, h, indx)
+	DB *dbp;
+	DBT *dbt;
+	PAGE *h;
+	u_int32_t indx;
+{
+	BTREE *t;
+	BKEYDATA *bk, tbk;
+	BOVERFLOW *bo;
+	DBT copy;
+	u_int32_t len, nbytes, tlen;
+	int ret;
+	u_int8_t *p;
+
+	bo = NULL;			/* XXX: Shut the compiler up. */
+	t = dbp->internal;
+
+	/*
+	 * Figure out how much total space we'll need.  Worst case is where
+	 * the record is 0 bytes long, in which case doff causes the record
+	 * to extend, and the put data is appended to it.
+	 */
+	if (indx < NUM_ENT(h)) {
+		bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
+		if (bk->type == B_OVERFLOW) {
+			bo = (BOVERFLOW *)bk;
+			nbytes = bo->tlen;
+		} else
+			nbytes = bk->len;
+	} else {
+		bk = &tbk;
+		bk->type = B_KEYDATA;
+		nbytes = bk->len = 0;
+	}
+	nbytes += dbt->doff + dbt->size + dbt->dlen;
+
+	/* Allocate the space. */
+	if (t->bt_rdata.ulen < nbytes) {
+		t->bt_rdata.data = t->bt_rdata.data == NULL ?
+		    (void *)malloc(nbytes) :
+		    (void *)realloc(t->bt_rdata.data, nbytes);
+		if (t->bt_rdata.data == NULL) {
+			t->bt_rdata.ulen = 0;
+			return (ENOMEM);
+		}
+		t->bt_rdata.ulen = nbytes;
+	}
+
+	/* We use nul bytes for extending the record, get it over with. */
+	memset(t->bt_rdata.data, 0, nbytes);
+
+	tlen = 0;
+	if (bk->type == B_OVERFLOW) {
+		/* Take up to doff bytes from the record. */
+		memset(&copy, 0, sizeof(copy));
+		if ((ret = __db_goff(dbp, &copy, bo->tlen,
+		    bo->pgno, &t->bt_rdata.data, &t->bt_rdata.ulen)) != 0)
+			return (ret);
+		tlen += dbt->doff;
+
+		/*
+		 * If the original record was larger than the offset:
+		 *	If dlen > size, shift the remaining data down.
+		 *	If dlen < size, shift the remaining data up.
+		 * Use memmove(), the regions may overlap.
+		 */
+		p = t->bt_rdata.data;
+		if (bo->tlen > dbt->doff)
+			if (dbt->dlen > dbt->size) {
+				tlen += len = bo->tlen -
+				    dbt->doff - (dbt->dlen - dbt->size);
+				memmove(p + dbt->doff + dbt->size,
+				    p + dbt->doff + dbt->dlen, len);
+			} else if (dbt->dlen < dbt->size) {
+				tlen += len = bo->tlen -
+				    dbt->doff - (dbt->size - dbt->dlen);
+				memmove(p + dbt->doff + dbt->dlen,
+				    p + dbt->doff + dbt->size, len);
+			} else
+				tlen += bo->tlen - dbt->doff;
+
+		/* Copy in the user's data. */
+		memcpy((u_int8_t *)t->bt_rdata.data + dbt->doff,
+		    dbt->data, dbt->size);
+		tlen += dbt->size;
+	} else {
+		/* Take up to doff bytes from the record. */
+		memcpy(t->bt_rdata.data,
+		    bk->data, dbt->doff > bk->len ? bk->len : dbt->doff);
+		tlen += dbt->doff;
+
+		/* Copy in the user's data. */
+		memcpy((u_int8_t *)t->bt_rdata.data +
+		    dbt->doff, dbt->data, dbt->size);
+		tlen += dbt->size;
+
+		/* Copy in any remaining data. */
+		len = dbt->doff + dbt->dlen;
+		if (bk->len > len) {
+			memcpy((u_int8_t *)t->bt_rdata.data + dbt->doff +
+			    dbt->size, bk->data + len, bk->len - len);
+			tlen += bk->len - len;
+		}
+	}
+
+	/* Set the DBT to reference our new record. */
+	t->bt_rdata.size = tlen;
+	t->bt_rdata.dlen = 0;
+	t->bt_rdata.doff = 0;
+	t->bt_rdata.flags = 0;
+	*dbt = t->bt_rdata;
+	return (0);
+}