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bt_get.c revision 1.9 
      1 /*	$NetBSD: bt_get.c,v 1.9 1997/07/21 14:06:32 jtc 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 1.9 1997/07/21 14:06:32 jtc Exp $");
     45 #endif
     46 #endif /* LIBC_SCCS and not lint */
     47 
     48 #include "namespace.h"
     49 #include <sys/types.h>
     50 
     51 #include <errno.h>
     52 #include <stddef.h>
     53 #include <stdio.h>
     54 
     55 #include <db.h>
     56 #include "btree.h"
     57 
     58 /*
     59  * __BT_GET -- Get a record from the btree.
     60  *
     61  * Parameters:
     62  *	dbp:	pointer to access method
     63  *	key:	key to find
     64  *	data:	data to return
     65  *	flag:	currently unused
     66  *
     67  * Returns:
     68  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
     69  */
     70 int
     71 __bt_get(dbp, key, data, flags)
     72 	const DB *dbp;
     73 	const DBT *key;
     74 	DBT *data;
     75 	u_int flags;
     76 {
     77 	BTREE *t;
     78 	EPG *e;
     79 	int exact, status;
     80 
     81 	t = dbp->internal;
     82 
     83 	/* Toss any page pinned across calls. */
     84 	if (t->bt_pinned != NULL) {
     85 		mpool_put(t->bt_mp, t->bt_pinned, 0);
     86 		t->bt_pinned = NULL;
     87 	}
     88 
     89 	/* Get currently doesn't take any flags. */
     90 	if (flags) {
     91 		errno = EINVAL;
     92 		return (RET_ERROR);
     93 	}
     94 
     95 	if ((e = __bt_search(t, key, &exact)) == NULL)
     96 		return (RET_ERROR);
     97 	if (!exact) {
     98 		mpool_put(t->bt_mp, e->page, 0);
     99 		return (RET_SPECIAL);
    100 	}
    101 
    102 	status = __bt_ret(t, e, NULL, NULL, data, &t->bt_rdata, 0);
    103 
    104 	/*
    105 	 * If the user is doing concurrent access, we copied the
    106 	 * key/data, toss the page.
    107 	 */
    108 	if (F_ISSET(t, B_DB_LOCK))
    109 		mpool_put(t->bt_mp, e->page, 0);
    110 	else
    111 		t->bt_pinned = e->page;
    112 	return (status);
    113 }
    114