[apple/libc.git] / db / recno / FreeBSD / rec_search.c

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rec_search.c	8.4 (Berkeley) 7/14/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_search.c,v 1.4 2002/03/21 18:47:38 obrien Exp $");

#include <sys/types.h>

#include <errno.h>
#include <stdio.h>

#include <db.h>
#include "recno.h"

/*
 * __REC_SEARCH -- Search a btree for a key.
 *
 * Parameters:
 *	t:	tree to search
 *	recno:	key to find
 *	op: 	search operation
 *
 * Returns:
 *	EPG for matching record, if any, or the EPG for the location of the
 *	key, if it were inserted into the tree.
 *
 * Returns:
 *	The EPG for matching record, if any, or the EPG for the location
 *	of the key, if it were inserted into the tree, is entered into
 *	the bt_cur field of the tree.  A pointer to the field is returned.
 */
EPG *
__rec_search(t, recno, op)
	BTREE *t;
	recno_t recno;
	enum SRCHOP op;
{
	indx_t index;
	PAGE *h;
	EPGNO *parent;
	RINTERNAL *r;
	pgno_t pg;
	indx_t top;
	recno_t total;
	int sverrno;

	BT_CLR(t);
	for (pg = P_ROOT, total = 0;;) {
		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
			goto err;
		if (h->flags & P_RLEAF) {
			t->bt_cur.page = h;
			t->bt_cur.index = recno - total;
			return (&t->bt_cur);
		}
		for (index = 0, top = NEXTINDEX(h);;) {
			r = GETRINTERNAL(h, index);
			if (++index == top || total + r->nrecs > recno)
				break;
			total += r->nrecs;
		}

		BT_PUSH(t, pg, index - 1);
		
		pg = r->pgno;
		switch (op) {
		case SDELETE:
			--GETRINTERNAL(h, (index - 1))->nrecs;
			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
			break;
		case SINSERT:
			++GETRINTERNAL(h, (index - 1))->nrecs;
			mpool_put(t->bt_mp, h, MPOOL_DIRTY);
			break;
		case SEARCH:
			mpool_put(t->bt_mp, h, 0);
			break;
		}

	}
	/* Try and recover the tree. */
err:	sverrno = errno;
	if (op != SEARCH)
		while  ((parent = BT_POP(t)) != NULL) {
			if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
				break;
			if (op == SINSERT)
				--GETRINTERNAL(h, parent->index)->nrecs;
			else
				++GETRINTERNAL(h, parent->index)->nrecs;
                        mpool_put(t->bt_mp, h, MPOOL_DIRTY);
                }
	errno = sverrno;
	return (NULL);
}
Commit	Line	Data
9385eb3d	1	/*-
e9ce8d39 A	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
9385eb3d A	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)rec_search.c 8.4 (Berkeley) 7/14/94";
	36	#endif /* LIBC_SCCS and not lint */
	37	#include <sys/cdefs.h>
59e0d9fe	38	__FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_search.c,v 1.4 2002/03/21 18:47:38 obrien Exp $");
e9ce8d39 A	39
	40	#include <sys/types.h>
	41
	42	#include <errno.h>
	43	#include <stdio.h>
	44
	45	#include <db.h>
	46	#include "recno.h"
	47
	48	/*
	49	* __REC_SEARCH -- Search a btree for a key.
	50	*
	51	* Parameters:
	52	* t: tree to search
	53	* recno: key to find
	54	* op: search operation
	55	*
	56	* Returns:
	57	* EPG for matching record, if any, or the EPG for the location of the
	58	* key, if it were inserted into the tree.
	59	*
	60	* Returns:
	61	* The EPG for matching record, if any, or the EPG for the location
	62	* of the key, if it were inserted into the tree, is entered into
	63	* the bt_cur field of the tree. A pointer to the field is returned.
	64	*/
	65	EPG *
	66	__rec_search(t, recno, op)
	67	BTREE *t;
	68	recno_t recno;
	69	enum SRCHOP op;
	70	{
9385eb3d A	71	indx_t index;
9385eb3d A	72	PAGE *h;
e9ce8d39 A	73	EPGNO *parent;
	74	RINTERNAL *r;
	75	pgno_t pg;
	76	indx_t top;
	77	recno_t total;
	78	int sverrno;
	79
	80	BT_CLR(t);
	81	for (pg = P_ROOT, total = 0;;) {
	82	if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
	83	goto err;
	84	if (h->flags & P_RLEAF) {
	85	t->bt_cur.page = h;
	86	t->bt_cur.index = recno - total;
	87	return (&t->bt_cur);
	88	}
	89	for (index = 0, top = NEXTINDEX(h);;) {
	90	r = GETRINTERNAL(h, index);
	91	if (++index == top \|\| total + r->nrecs > recno)
	92	break;
	93	total += r->nrecs;
	94	}
	95
9385eb3d	96	BT_PUSH(t, pg, index - 1);
e9ce8d39 A	97
	98	pg = r->pgno;
	99	switch (op) {
	100	case SDELETE:
	101	--GETRINTERNAL(h, (index - 1))->nrecs;
	102	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
	103	break;
	104	case SINSERT:
	105	++GETRINTERNAL(h, (index - 1))->nrecs;
	106	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
	107	break;
	108	case SEARCH:
	109	mpool_put(t->bt_mp, h, 0);
	110	break;
	111	}
	112
	113	}
	114	/* Try and recover the tree. */
	115	err: sverrno = errno;
	116	if (op != SEARCH)
	117	while ((parent = BT_POP(t)) != NULL) {
	118	if ((h = mpool_get(t->bt_mp, parent->pgno, 0)) == NULL)
	119	break;
	120	if (op == SINSERT)
	121	--GETRINTERNAL(h, parent->index)->nrecs;
	122	else
	123	++GETRINTERNAL(h, parent->index)->nrecs;
	124	mpool_put(t->bt_mp, h, MPOOL_DIRTY);
	125	}
	126	errno = sverrno;
	127	return (NULL);
	128	}