1 files changed, 544 insertions, 0 deletions

diff --git a/db2/hash/hash_dup.c b/db2/hash/hash_dup.c
new file mode 100644
index 0000000000..059eec6f92
--- /dev/null
+++ b/db2/hash/hash_dup.c
@@ -0,0 +1,544 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ *	Sleepycat Software.  All rights reserved.
+ */
+/*
+ * 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.
+ */
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)hash_dup.c	10.5 (Sleepycat) 7/27/97";
+#endif /* not lint */
+
+/*
+ * PACKAGE:  hashing
+ *
+ * DESCRIPTION:
+ *      Manipulation of duplicates for the hash package.
+ *
+ * ROUTINES:
+ *
+ * External
+ *      __add_dup
+ * Internal
+ */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#endif
+
+#include "db_int.h"
+#include "db_page.h"
+#include "db_swap.h"
+#include "hash.h"
+
+static int __ham_check_move __P((HTAB *, HASH_CURSOR *, int32_t));
+static int __ham_dup_convert __P((HTAB *, HASH_CURSOR *));
+static int __ham_make_dup __P((const DBT *, DBT *d, void **, u_int32_t *));
+
+/*
+ * Called from hash_access to add a duplicate key. nval is the new
+ * value that we want to add.  The flags correspond to the flag values
+ * to cursor_put indicating where to add the new element.
+ * There are 4 cases.
+ * Case 1: The existing duplicate set already resides on a separate page.
+ *	   We can use common code for this.
+ * Case 2: The element is small enough to just be added to the existing set.
+ * Case 3: The element is large enough to be a big item, so we're going to
+ *	   have to push the set onto a new page.
+ * Case 4: The element is large enough to push the duplicate set onto a
+ *	   separate page.
+ *
+ * PUBLIC: int __ham_add_dup __P((HTAB *, HASH_CURSOR *, DBT *, int));
+ */
+int
+__ham_add_dup(hashp, hcp, nval, flags)
+	HTAB *hashp;
+	HASH_CURSOR *hcp;
+	DBT *nval;
+	int flags;
+{
+	DBT pval, tmp_val;
+	HKEYDATA *hk;
+	u_int32_t del_len, new_size;
+	int ret;
+
+	if (flags == DB_CURRENT && hcp->dpgno == PGNO_INVALID)
+		del_len = hcp->dup_len;
+	else
+		del_len = 0;
+
+	if ((ret = __ham_check_move(hashp, hcp,
+	    (int32_t)DUP_SIZE(nval->size) - (int32_t)del_len)) != 0)
+		return (ret);
+
+	/*
+	 * Check if resulting duplicate set is going to need to go
+	 * onto a separate duplicate page.  If so, convert the
+	 * duplicate set and add the new one.  After conversion,
+	 * hcp->dndx is the first free ndx or the index of the
+	 * current pointer into the duplicate set.
+	 */
+	hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
+	new_size = DUP_SIZE(nval->size) - del_len + LEN_HKEYDATA(hcp->pagep,
+	    hashp->hdr->pagesize, H_DATAINDEX(hcp->bndx));
+
+	/*
+	 * We convert to off-page duplicates if the item is a big item,
+	 * the addition of the new item will make the set large, or
+	 * if there isn't enough room on this page to add the next item.
+	 */
+	if (hk->type != H_OFFDUP &&
+	    (hk->type == H_OFFPAGE || ISBIG(hashp, new_size) ||
+	    DUP_SIZE(nval->size) - del_len > P_FREESPACE(hcp->pagep))) {
+
+		if ((ret = __ham_dup_convert(hashp, hcp)) != 0)
+			return (ret);
+		else
+			hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
+	}
+
+	/* There are two separate cases here: on page and off page. */
+	if (hk->type != H_OFFDUP) {
+		if (hk->type != H_DUPLICATE) {
+			hk->type = H_DUPLICATE;
+			pval.flags = 0;
+			pval.data = hk->data;
+			pval.size = LEN_HDATA(hcp->pagep, hashp->hdr->pagesize,
+			    hcp->bndx);
+			if ((ret = __ham_make_dup(&pval, &tmp_val, &hcp->big_data,
+			    &hcp->big_datalen)) != 0 ||
+			    (ret = __ham_replpair(hashp, hcp, &tmp_val, 1)) != 0)
+				return (ret);
+		}
+
+		/* Now make the new entry a duplicate. */
+		if ((ret = __ham_make_dup(nval,
+		    &tmp_val, &hcp->big_data, &hcp->big_datalen)) != 0)
+			return (ret);
+
+		tmp_val.dlen = 0;
+		switch (flags) {			/* On page. */
+		case DB_KEYFIRST:
+			tmp_val.doff = 0;
+			break;
+		case DB_KEYLAST:
+			tmp_val.doff = LEN_HDATA(hcp->pagep,
+			    hashp->hdr->pagesize, hcp->bndx);
+			break;
+		case DB_CURRENT:
+			tmp_val.doff = hcp->dup_off;
+			tmp_val.dlen = DUP_SIZE(hcp->dup_len);
+			break;
+		case DB_BEFORE:
+			tmp_val.doff = hcp->dup_off;
+			break;
+		case DB_AFTER:
+			tmp_val.doff = hcp->dup_off + DUP_SIZE(hcp->dup_len);
+			break;
+		}
+		/* Add the duplicate. */
+		ret = __ham_replpair(hashp, hcp, &tmp_val, 0);
+		if (ret == 0)
+			ret = __ham_dirty_page(hashp, hcp->pagep);
+		__ham_c_update(hashp, hcp, hcp->pgno, tmp_val.size, 1, 1);
+		return (ret);
+	}
+
+	/* If we get here, then we're on duplicate pages. */
+	if (hcp->dpgno == PGNO_INVALID) {
+		memcpy(&hcp->dpgno,
+		    (u_int8_t *)hk + SSZ(HOFFDUP, pgno), sizeof(db_pgno_t));
+		hcp->dndx = 0;
+	}
+
+	switch (flags) {
+	case DB_KEYFIRST:
+		/*
+		 * The only way that we are already on a dup page is
+		 * if we just converted the on-page representation.
+		 * In that case, we've only got one page of duplicates.
+		 */
+		if (hcp->dpagep == NULL && (ret =
+		    __db_dend(hashp->dbp, hcp->dpgno, &hcp->dpagep)) != 0)
+			return (ret);
+		hcp->dndx = 0;
+		break;
+	case DB_KEYLAST:
+		if (hcp->dpagep == NULL && (ret =
+		    __db_dend(hashp->dbp, hcp->dpgno, &hcp->dpagep)) != 0)
+			return (ret);
+		hcp->dpgno = PGNO(hcp->dpagep);
+		hcp->dndx = NUM_ENT(hcp->dpagep);
+		break;
+	case DB_CURRENT:
+		if ((ret = __db_ditem(hashp->dbp, hcp->dpagep, hcp->dndx,
+		    BKEYDATA_SIZE(GET_BKEYDATA(hcp->dpagep, hcp->dndx)->len)))
+		    != 0)
+			return (ret);
+		break;
+	case DB_BEFORE:	/* The default behavior is correct. */
+		break;
+	case DB_AFTER:
+		hcp->dndx++;
+		break;
+	}
+
+	ret = __db_dput(hashp->dbp,
+	    nval, &hcp->dpagep, &hcp->dndx, __ham_overflow_page);
+	hcp->pgno = PGNO(hcp->pagep);
+	__ham_c_update(hashp, hcp, hcp->pgno, nval->size, 1, 1);
+	return (ret);
+}
+
+/*
+ * Convert an on-page set of duplicates to an offpage set of duplicates.
+ */
+static int
+__ham_dup_convert(hashp, hcp)
+	HTAB *hashp;
+	HASH_CURSOR *hcp;
+{
+	BOVERFLOW bo;
+	DBT dbt;
+	HOFFPAGE ho;
+	db_indx_t dndx, len;
+	int ret;
+	u_int8_t *p, *pend;
+
+	/*
+	 * Create a new page for the duplicates.
+	 */
+	if ((ret =
+	    __ham_overflow_page(hashp->dbp, P_DUPLICATE, &hcp->dpagep)) != 0)
+		return (ret);
+	hcp->dpagep->type = P_DUPLICATE;
+	hcp->dpgno = PGNO(hcp->dpagep);
+
+	/*
+	 * Now put the duplicates onto the new page.
+	 */
+	dbt.flags = 0;
+	switch (((HKEYDATA *)H_PAIRDATA(hcp->pagep, hcp->bndx))->type) {
+	case H_KEYDATA:
+		/* Simple case, one key on page; move it to dup page. */
+		dndx = 0;
+		dbt.size =
+		    LEN_HDATA(hcp->pagep, hashp->hdr->pagesize, hcp->bndx);
+		dbt.data =
+		    ((HKEYDATA *)H_PAIRDATA(hcp->pagep, hcp->bndx))->data;
+		ret = __db_pitem(hashp->dbp, hcp->dpagep,
+		    (u_int32_t)dndx, BKEYDATA_SIZE(dbt.size), NULL, &dbt);
+		if (ret == 0)
+			__ham_dirty_page(hashp, hcp->dpagep);
+		break;
+	case H_OFFPAGE:
+		/* Simple case, one key on page; move it to dup page. */
+		dndx = 0;
+		memcpy(&ho,
+		    P_ENTRY(hcp->pagep, H_DATAINDEX(hcp->bndx)), HOFFPAGE_SIZE);
+		bo.deleted = 0;
+		bo.type = ho.type;
+		bo.pgno = ho.pgno;
+		bo.tlen = ho.tlen;
+		dbt.size = BOVERFLOW_SIZE;
+		dbt.data = &bo;
+
+		ret = __db_pitem(hashp->dbp, hcp->dpagep,
+		   (u_int32_t)dndx, dbt.size, &dbt, NULL);
+		if (ret == 0)
+			__ham_dirty_page(hashp, hcp->dpagep);
+		break;
+	case H_DUPLICATE:
+		p = ((HKEYDATA *)H_PAIRDATA(hcp->pagep, hcp->bndx))->data;
+		pend = p +
+		    LEN_HDATA(hcp->pagep, hashp->hdr->pagesize, hcp->bndx);
+
+		for (dndx = 0; p < pend; dndx++) {
+			memcpy(&len, p, sizeof(db_indx_t));
+			dbt.size = len;
+			p += sizeof(db_indx_t);
+			dbt.data = p;
+			p += len + sizeof(db_indx_t);
+			ret = __db_dput(hashp->dbp, &dbt,
+			    &hcp->dpagep, &dndx, __ham_overflow_page);
+			if (ret != 0)
+				break;
+		}
+		break;
+	default:
+		ret = __db_pgfmt(hashp->dbp, (u_long)hcp->pgno);
+	}
+	if (ret == 0) {
+		/*
+		 * Now attach this to the source page in place of
+		 * the old duplicate item.
+		 */
+		__ham_move_offpage(hashp, hcp->pagep,
+		    (u_int32_t)H_DATAINDEX(hcp->bndx), hcp->dpgno);
+
+		/* Can probably just do a "put" here. */
+		ret = __ham_dirty_page(hashp, hcp->pagep);
+	} else {
+		(void)__ham_del_page(hashp->dbp, hcp->dpagep);
+		hcp->dpagep = NULL;
+	}
+	return (ret);
+}
+
+static int
+__ham_make_dup(notdup, dup, bufp, sizep)
+	const DBT *notdup;
+	DBT *dup;
+	void **bufp;
+	u_int32_t *sizep;
+{
+	db_indx_t tsize, item_size;
+	int ret;
+	u_int8_t *p;
+
+	item_size = (db_indx_t)notdup->size;
+	tsize = DUP_SIZE(item_size);
+	if ((ret = __ham_init_dbt(dup, tsize, bufp, sizep)) != 0)
+		return (ret);
+
+	dup->dlen = 0;
+	dup->flags = notdup->flags;
+	F_SET(dup, DB_DBT_PARTIAL);
+
+	p = dup->data;
+	memcpy(p, &item_size, sizeof(db_indx_t));
+	p += sizeof(db_indx_t);
+	memcpy(p, notdup->data, notdup->size);
+	p += notdup->size;
+	memcpy(p, &item_size, sizeof(db_indx_t));
+
+	dup->doff = 0;
+	dup->dlen = notdup->size;
+
+	return (0);
+}
+
+static int
+__ham_check_move(hashp, hcp, add_len)
+	HTAB *hashp;
+	HASH_CURSOR *hcp;
+	int32_t add_len;
+{
+	DBT k, d;
+	DB_LSN new_lsn;
+	HKEYDATA *hk;
+	PAGE *next_pagep;
+	db_pgno_t next_pgno;
+	int rectype, ret;
+	u_int32_t new_datalen, old_len;
+
+	/*
+	 * Check if we can do whatever we need to on this page.  If not,
+	 * then we'll have to move the current element to a new page.
+	 */
+
+	hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
+
+	/*
+	 * If the item is already off page duplicates or an offpage item,
+	 * then we know we can do whatever we need to do in-place
+	 */
+	if (hk->type == H_OFFDUP || hk->type == H_OFFPAGE)
+		return (0);
+
+	old_len =
+	    LEN_HITEM(hcp->pagep, hashp->hdr->pagesize, H_DATAINDEX(hcp->bndx));
+	new_datalen = old_len - HKEYDATA_SIZE(0) + add_len;
+
+	/*
+	 * We need to add a new page under two conditions:
+	 * 1. The addition makes the total data length cross the BIG
+	 *    threshold and the OFFDUP structure won't fit on this page.
+	 * 2. The addition does not make the total data cross the
+	 *    threshold, but the new data won't fit on the page.
+	 * If neither of these is true, then we can return.
+	 */
+	if (ISBIG(hashp, new_datalen) && (old_len > HOFFDUP_SIZE ||
+	    HOFFDUP_SIZE - old_len <= P_FREESPACE(hcp->pagep)))
+		return (0);
+
+	if (!ISBIG(hashp, new_datalen) &&
+	    add_len <= (int32_t)P_FREESPACE(hcp->pagep))
+		return (0);
+
+	/*
+	 * If we get here, then we need to move the item to a new page.
+	 * Check if there are more pages in the chain.
+	 */
+
+	new_datalen = ISBIG(hashp, new_datalen) ?
+	    HOFFDUP_SIZE : HKEYDATA_SIZE(new_datalen);
+
+	next_pagep = NULL;
+	for (next_pgno = NEXT_PGNO(hcp->pagep); next_pgno != PGNO_INVALID;
+	    next_pgno = NEXT_PGNO(next_pagep)) {
+		if (next_pagep != NULL &&
+		    (ret = __ham_put_page(hashp->dbp, next_pagep, 0)) != 0)
+			return (ret);
+
+		if ((ret = __ham_get_page(hashp->dbp, next_pgno, &next_pagep)) != 0)
+			return (ret);
+
+		if (P_FREESPACE(next_pagep) >= new_datalen)
+			break;
+	}
+
+	/* No more pages, add one. */
+	if (next_pagep == NULL &&
+	    (ret = __ham_add_ovflpage(hashp, hcp->pagep, 0, &next_pagep)) != 0)
+		return (ret);
+
+	/* Add new page at the end of the chain. */
+	if (P_FREESPACE(next_pagep) < new_datalen &&
+	    (ret = __ham_add_ovflpage(hashp, next_pagep, 1, &next_pagep)) != 0)
+		return (ret);
+
+	/* Copy the item to the new page. */
+	if (DB_LOGGING(hashp->dbp)) {
+		rectype = PUTPAIR;
+		k.flags = 0;
+		d.flags = 0;
+		if (H_PAIRKEY(hcp->pagep, hcp->bndx)->type == H_OFFPAGE) {
+			rectype |= PAIR_KEYMASK;
+			k.data = H_PAIRKEY(hcp->pagep, hcp->bndx);
+			k.size = HOFFPAGE_SIZE;
+		} else {
+			k.data = H_PAIRKEY(hcp->pagep, hcp->bndx)->data;
+			k.size = LEN_HKEY(hcp->pagep,
+			    hashp->hdr->pagesize, hcp->bndx);
+		}
+
+		if (hk->type == H_OFFPAGE) {
+			rectype |= PAIR_DATAMASK;
+			d.data = H_PAIRDATA(hcp->pagep, hcp->bndx);
+			d.size = HOFFPAGE_SIZE;
+		} else {
+			d.data = H_PAIRDATA(hcp->pagep, hcp->bndx)->data;
+			d.size = LEN_HDATA(hcp->pagep,
+			    hashp->hdr->pagesize, hcp->bndx);
+		}
+
+
+		if ((ret = __ham_insdel_log(hashp->dbp->dbenv->lg_info,
+		    (DB_TXN *)hashp->dbp->txn, &new_lsn, 0, rectype,
+		    hashp->dbp->log_fileid, PGNO(next_pagep),
+		    (u_int32_t)H_NUMPAIRS(next_pagep), &LSN(next_pagep),
+		    &k, &d)) != 0)
+			return (ret);
+
+		/* Move lsn onto page. */
+		LSN(next_pagep) = new_lsn;	/* Structure assignment. */
+	}
+
+	__ham_copy_item(hashp, hcp->pagep, H_KEYINDEX(hcp->bndx), next_pagep);
+	__ham_copy_item(hashp, hcp->pagep, H_DATAINDEX(hcp->bndx), next_pagep);
+
+	/* Now delete the pair from the current page. */
+	ret = __ham_del_pair(hashp, hcp);
+
+	(void)__ham_put_page(hashp->dbp, hcp->pagep, 1);
+	hcp->pagep = next_pagep;
+	hcp->pgno = PGNO(hcp->pagep);
+	hcp->bndx = H_NUMPAIRS(hcp->pagep) - 1;
+	F_SET(hcp, H_EXPAND);
+	return (ret);
+}
+
+/*
+ * Replace an onpage set of duplicates with the OFFDUP structure that
+ * references the duplicate page.
+ * XXX This is really just a special case of __onpage_replace; we should
+ * probably combine them.
+ * PUBLIC: void __ham_move_offpage __P((HTAB *, PAGE *, u_int32_t, db_pgno_t));
+ */
+void
+__ham_move_offpage(hashp, pagep, ndx, pgno)
+	HTAB *hashp;
+	PAGE *pagep;
+	u_int32_t ndx;
+	db_pgno_t pgno;
+{
+	DBT new_dbt;
+	DBT old_dbt;
+	HOFFDUP od;
+	db_indx_t i;
+	int32_t shrink;
+	u_int8_t *src;
+
+	od.type = H_OFFDUP;
+	od.pgno = pgno;
+
+	if (DB_LOGGING(hashp->dbp)) {
+		new_dbt.data = &od;
+		new_dbt.size = HOFFDUP_SIZE;
+		old_dbt.data = P_ENTRY(pagep, ndx);
+		old_dbt.size = LEN_HITEM(pagep, hashp->hdr->pagesize, ndx);
+		(void)__ham_replace_log(hashp->dbp->dbenv->lg_info,
+		    (DB_TXN *)hashp->dbp->txn, &LSN(pagep), 0,
+		    hashp->dbp->log_fileid, PGNO(pagep), (u_int32_t)ndx,
+		    &LSN(pagep), -1, &old_dbt, &new_dbt, 0);
+	}
+
+	shrink =
+	    LEN_HITEM(pagep, hashp->hdr->pagesize, ndx) - HOFFDUP_SIZE;
+
+	if (shrink != 0) {
+		/* Copy data. */
+		src = (u_int8_t *)(pagep) + HOFFSET(pagep);
+		memmove(src + shrink, src, pagep->inp[ndx] - HOFFSET(pagep));
+		HOFFSET(pagep) += shrink;
+
+		/* Update index table. */
+		for (i = ndx; i < NUM_ENT(pagep); i++)
+			pagep->inp[i] += shrink;
+	}
+
+	/* Now copy the offdup entry onto the page. */
+	memcpy(P_ENTRY(pagep, ndx), &od, HOFFDUP_SIZE);
+}