xref: /netbsd-src/lib/libc/db/recno/rec_utils.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: rec_utils.c,v 1.12 2008/09/10 17:52:36 joerg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35 
36 #include <sys/cdefs.h>
37 __RCSID("$NetBSD: rec_utils.c,v 1.12 2008/09/10 17:52:36 joerg Exp $");
38 
39 #include <sys/param.h>
40 
41 #include <assert.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include <db.h>
47 #include "recno.h"
48 
49 /*
50  * __rec_ret --
51  *	Build return data.
52  *
53  * Parameters:
54  *	t:	tree
55  *	e:	key/data pair to be returned
56  *   nrec:	record number
57  *    key:	user's key structure
58  *	data:	user's data structure
59  *
60  * Returns:
61  *	RET_SUCCESS, RET_ERROR.
62  */
63 int
64 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
65 {
66 	RLEAF *rl;
67 	void *p;
68 
69 	if (key == NULL)
70 		goto dataonly;
71 
72 	/* We have to copy the key, it's not on the page. */
73 	if (sizeof(recno_t) > t->bt_rkey.size) {
74 		p = (void *)(t->bt_rkey.data == NULL ?
75 		    malloc(sizeof(recno_t)) :
76 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
77 		if (p == NULL)
78 			return (RET_ERROR);
79 		t->bt_rkey.data = p;
80 		t->bt_rkey.size = sizeof(recno_t);
81 	}
82 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
83 	key->size = sizeof(recno_t);
84 	key->data = t->bt_rkey.data;
85 
86 dataonly:
87 	if (data == NULL)
88 		return (RET_SUCCESS);
89 
90 	/*
91 	 * We must copy big keys/data to make them contigous.  Otherwise,
92 	 * leave the page pinned and don't copy unless the user specified
93 	 * concurrent access.
94 	 */
95 	rl = GETRLEAF(e->page, e->index);
96 	if (rl->flags & P_BIGDATA) {
97 		if (__ovfl_get(t, rl->bytes,
98 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
99 			return (RET_ERROR);
100 		data->data = t->bt_rdata.data;
101 	} else if (F_ISSET(t, B_DB_LOCK)) {
102 		/* Use +1 in case the first record retrieved is 0 length. */
103 		if (rl->dsize + 1 > t->bt_rdata.size) {
104 			p = (void *)(t->bt_rdata.data == NULL ?
105 			    malloc(rl->dsize + 1) :
106 			    realloc(t->bt_rdata.data, rl->dsize + 1));
107 			if (p == NULL)
108 				return (RET_ERROR);
109 			t->bt_rdata.data = p;
110 			t->bt_rdata.size = rl->dsize + 1;
111 		}
112 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
113 		data->size = rl->dsize;
114 		data->data = t->bt_rdata.data;
115 	} else {
116 		data->size = rl->dsize;
117 		data->data = rl->bytes;
118 	}
119 	return (RET_SUCCESS);
120 }
121