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File: [cvs.NetBSD.org] / src / lib / libc / db / recno / rec_search.c (download)

Revision 1.14, Thu Sep 11 12:58:00 2008 UTC (12 years, 1 month ago) by joerg
Branch: MAIN
CVS Tags: yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, wrstuden-revivesa-base-3, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, pgoyette-localcount-base, pgoyette-localcount-20160806, pgoyette-localcount-20160726, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, netbsd-5-base, netbsd-5-2-RELEASE, netbsd-5-2-RC1, netbsd-5-2-3-RELEASE, netbsd-5-2-2-RELEASE, netbsd-5-2-1-RELEASE, netbsd-5-2, netbsd-5-1-RELEASE, netbsd-5-1-RC4, netbsd-5-1-RC3, netbsd-5-1-RC2, netbsd-5-1-RC1, netbsd-5-1-5-RELEASE, netbsd-5-1-4-RELEASE, netbsd-5-1-3-RELEASE, netbsd-5-1-2-RELEASE, netbsd-5-1-1-RELEASE, netbsd-5-1, netbsd-5-0-RELEASE, netbsd-5-0-RC4, netbsd-5-0-RC3, netbsd-5-0-RC2, netbsd-5-0-RC1, netbsd-5-0-2-RELEASE, netbsd-5-0-1-RELEASE, netbsd-5-0, netbsd-5, matt-premerge-20091211, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-nb5-pq3-base, matt-nb5-pq3, matt-nb5-mips64-u2-k2-k4-k7-k8-k9, matt-nb5-mips64-u1-k1-k5, matt-nb5-mips64-premerge-20101231, matt-nb5-mips64-premerge-20091211, matt-nb5-mips64-k15, matt-nb5-mips64, matt-nb4-mips64-k7-u2a-k9b, matt-mips64-premerge-20101231, matt-mips64-base2, localcount-20160914, jym-xensuspend-nbase, jym-xensuspend-base, jym-xensuspend, christos-time_t-nbase, christos-time_t-base, cherry-xenmp-base, cherry-xenmp, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver
Branch point for: pgoyette-localcount, christos-time_t
Changes since 1.13: +6 -2 lines

Consistently include "nbtool_config.h" when cross-compiling.

/*	$NetBSD: rec_search.c,v 1.14 2008/09/11 12:58:00 joerg Exp $	*/

/*-
 * 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. 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 HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
__RCSID("$NetBSD: rec_search.c,v 1.14 2008/09/11 12:58:00 joerg Exp $");

#include "namespace.h"
#include <sys/types.h>

#include <assert.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(BTREE *t, recno_t recno, enum SRCHOP op)
{
	indx_t idx;
	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 (idx = 0, top = NEXTINDEX(h);;) {
			r = GETRINTERNAL(h, idx);
			if (++idx == top || total + r->nrecs > recno)
				break;
			total += r->nrecs;
		}

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