xref: /minix3/lib/libc/db/recno/rec_utils.c (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
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 #ifndef __minix
38 __RCSID("$NetBSD: rec_utils.c,v 1.12 2008/09/10 17:52:36 joerg Exp $");
39 #endif
40 
41 #include <sys/param.h>
42 
43 #include <assert.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 #include <db.h>
49 #include "recno.h"
50 
51 /*
52  * __rec_ret --
53  *	Build return data.
54  *
55  * Parameters:
56  *	t:	tree
57  *	e:	key/data pair to be returned
58  *   nrec:	record number
59  *    key:	user's key structure
60  *	data:	user's data structure
61  *
62  * Returns:
63  *	RET_SUCCESS, RET_ERROR.
64  */
65 int
66 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
67 {
68 	RLEAF *rl;
69 	void *p;
70 
71 	if (key == NULL)
72 		goto dataonly;
73 
74 	/* We have to copy the key, it's not on the page. */
75 	if (sizeof(recno_t) > t->bt_rkey.size) {
76 		p = (void *)(t->bt_rkey.data == NULL ?
77 		    malloc(sizeof(recno_t)) :
78 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
79 		if (p == NULL)
80 			return (RET_ERROR);
81 		t->bt_rkey.data = p;
82 		t->bt_rkey.size = sizeof(recno_t);
83 	}
84 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
85 	key->size = sizeof(recno_t);
86 	key->data = t->bt_rkey.data;
87 
88 dataonly:
89 	if (data == NULL)
90 		return (RET_SUCCESS);
91 
92 	/*
93 	 * We must copy big keys/data to make them contigous.  Otherwise,
94 	 * leave the page pinned and don't copy unless the user specified
95 	 * concurrent access.
96 	 */
97 	rl = GETRLEAF(e->page, e->index);
98 	if (rl->flags & P_BIGDATA) {
99 		if (__ovfl_get(t, rl->bytes,
100 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
101 			return (RET_ERROR);
102 		data->data = t->bt_rdata.data;
103 	} else if (F_ISSET(t, B_DB_LOCK)) {
104 		/* Use +1 in case the first record retrieved is 0 length. */
105 		if (rl->dsize + 1 > t->bt_rdata.size) {
106 			p = (void *)(t->bt_rdata.data == NULL ?
107 			    malloc(rl->dsize + 1) :
108 			    realloc(t->bt_rdata.data, rl->dsize + 1));
109 			if (p == NULL)
110 				return (RET_ERROR);
111 			t->bt_rdata.data = p;
112 			t->bt_rdata.size = rl->dsize + 1;
113 		}
114 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
115 		data->size = rl->dsize;
116 		data->data = t->bt_rdata.data;
117 	} else {
118 		data->size = rl->dsize;
119 		data->data = rl->bytes;
120 	}
121 	return (RET_SUCCESS);
122 }
123