xref: /openbsd-src/lib/libc/db/btree/bt_get.c (revision 7ae68d51a02c87d3c56b7f5939be167a4c2c928c)
1 /*	$OpenBSD: bt_get.c,v 1.5 2003/05/01 20:23:40 avsm 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 #if defined(LIBC_SCCS) && !defined(lint)
40 #if 0
41 static char sccsid[] = "@(#)bt_get.c	8.6 (Berkeley) 7/20/94";
42 #else
43 static const char rcsid[] = "$OpenBSD: bt_get.c,v 1.5 2003/05/01 20:23:40 avsm Exp $";
44 #endif
45 #endif /* LIBC_SCCS and not lint */
46 
47 #include <sys/types.h>
48 
49 #include <errno.h>
50 #include <stddef.h>
51 #include <stdio.h>
52 
53 #include <db.h>
54 #include "btree.h"
55 
56 /*
57  * __BT_GET -- Get a record from the btree.
58  *
59  * Parameters:
60  *	dbp:	pointer to access method
61  *	key:	key to find
62  *	data:	data to return
63  *	flag:	currently unused
64  *
65  * Returns:
66  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
67  */
68 int
69 __bt_get(dbp, key, data, flags)
70 	const DB *dbp;
71 	const DBT *key;
72 	DBT *data;
73 	u_int flags;
74 {
75 	BTREE *t;
76 	EPG *e;
77 	int exact, status;
78 
79 	t = dbp->internal;
80 
81 	/* Toss any page pinned across calls. */
82 	if (t->bt_pinned != NULL) {
83 		mpool_put(t->bt_mp, t->bt_pinned, 0);
84 		t->bt_pinned = NULL;
85 	}
86 
87 	/* Get currently doesn't take any flags. */
88 	if (flags) {
89 		errno = EINVAL;
90 		return (RET_ERROR);
91 	}
92 
93 	if ((e = __bt_search(t, key, &exact)) == NULL)
94 		return (RET_ERROR);
95 	if (!exact) {
96 		mpool_put(t->bt_mp, e->page, 0);
97 		return (RET_SPECIAL);
98 	}
99 
100 	status = __bt_ret(t, e, NULL, NULL, data, &t->bt_rdata, 0);
101 
102 	/*
103 	 * If the user is doing concurrent access, we copied the
104 	 * key/data, toss the page.
105 	 */
106 	if (F_ISSET(t, B_DB_LOCK))
107 		mpool_put(t->bt_mp, e->page, 0);
108 	else
109 		t->bt_pinned = e->page;
110 	return (status);
111 }
112