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bt_get.c revision 1.8 
      1 /*	$NetBSD: bt_get.c,v 1.8 1997/07/13 18:51:52 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Mike Olson.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 #if 0
     42 static char sccsid[] = "@(#)bt_get.c	8.6 (Berkeley) 7/20/94";
     43 #else
     44 __RCSID("$NetBSD: bt_get.c,v 1.8 1997/07/13 18:51:52 christos Exp $");
     45 #endif
     46 #endif /* LIBC_SCCS and not lint */
     47 
     48 #include <sys/types.h>
     49 
     50 #include <errno.h>
     51 #include <stddef.h>
     52 #include <stdio.h>
     53 
     54 #include <db.h>
     55 #include "btree.h"
     56 
     57 /*
     58  * __BT_GET -- Get a record from the btree.
     59  *
     60  * Parameters:
     61  *	dbp:	pointer to access method
     62  *	key:	key to find
     63  *	data:	data to return
     64  *	flag:	currently unused
     65  *
     66  * Returns:
     67  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
     68  */
     69 int
     70 __bt_get(dbp, key, data, flags)
     71 	const DB *dbp;
     72 	const DBT *key;
     73 	DBT *data;
     74 	u_int flags;
     75 {
     76 	BTREE *t;
     77 	EPG *e;
     78 	int exact, status;
     79 
     80 	t = dbp->internal;
     81 
     82 	/* Toss any page pinned across calls. */
     83 	if (t->bt_pinned != NULL) {
     84 		mpool_put(t->bt_mp, t->bt_pinned, 0);
     85 		t->bt_pinned = NULL;
     86 	}
     87 
     88 	/* Get currently doesn't take any flags. */
     89 	if (flags) {
     90 		errno = EINVAL;
     91 		return (RET_ERROR);
     92 	}
     93 
     94 	if ((e = __bt_search(t, key, &exact)) == NULL)
     95 		return (RET_ERROR);
     96 	if (!exact) {
     97 		mpool_put(t->bt_mp, e->page, 0);
     98 		return (RET_SPECIAL);
     99 	}
    100 
    101 	status = __bt_ret(t, e, NULL, NULL, data, &t->bt_rdata, 0);
    102 
    103 	/*
    104 	 * If the user is doing concurrent access, we copied the
    105 	 * key/data, toss the page.
    106 	 */
    107 	if (F_ISSET(t, B_DB_LOCK))
    108 		mpool_put(t->bt_mp, e->page, 0);
    109 	else
    110 		t->bt_pinned = e->page;
    111 	return (status);
    112 }
    113