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

Revision 1.16, Sat Sep 24 21:31:25 2016 UTC (5 years, 3 months ago) by christos
Branch: MAIN
CVS Tags: prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-2-RELEASE, netbsd-9-1-RELEASE, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, matt-nb8-mediatek-base, matt-nb8-mediatek, is-mlppp-base, is-mlppp, cjep_sun2x-base1, cjep_sun2x-base, cjep_sun2x, cjep_staticlib_x-base1, cjep_staticlib_x-base, cjep_staticlib_x, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, HEAD
Changes since 1.15: +4 -4 lines

remove mpool_getf

/*	$NetBSD: rec_search.c,v 1.16 2016/09/24 21:31:25 christos 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 1.16 2016/09/24 21:31:25 christos 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);
}