xref: /openbsd-src/lib/libc/db/recno/rec_utils.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static const char rcsid[] = "$OpenBSD: rec_utils.c,v 1.5 2003/06/02 20:18:34 millert Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include <sys/param.h>
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 
40 #include <db.h>
41 #include "recno.h"
42 
43 /*
44  * __rec_ret --
45  *	Build return data.
46  *
47  * Parameters:
48  *	t:	tree
49  *	e:	key/data pair to be returned
50  *   nrec:	record number
51  *    key:	user's key structure
52  *	data:	user's data structure
53  *
54  * Returns:
55  *	RET_SUCCESS, RET_ERROR.
56  */
57 int
58 __rec_ret(t, e, nrec, key, data)
59 	BTREE *t;
60 	EPG *e;
61 	recno_t nrec;
62 	DBT *key, *data;
63 {
64 	RLEAF *rl;
65 	void *p;
66 
67 	if (key == NULL)
68 		goto dataonly;
69 
70 	/* We have to copy the key, it's not on the page. */
71 	if (sizeof(recno_t) > t->bt_rkey.size) {
72 		p = (void *)(t->bt_rkey.data == NULL ?
73 		    malloc(sizeof(recno_t)) :
74 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
75 		if (p == NULL)
76 			return (RET_ERROR);
77 		t->bt_rkey.data = p;
78 		t->bt_rkey.size = sizeof(recno_t);
79 	}
80 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
81 	key->size = sizeof(recno_t);
82 	key->data = t->bt_rkey.data;
83 
84 dataonly:
85 	if (data == NULL)
86 		return (RET_SUCCESS);
87 
88 	/*
89 	 * We must copy big keys/data to make them contigous.  Otherwise,
90 	 * leave the page pinned and don't copy unless the user specified
91 	 * concurrent access.
92 	 */
93 	rl = GETRLEAF(e->page, e->index);
94 	if (rl->flags & P_BIGDATA) {
95 		if (__ovfl_get(t, rl->bytes,
96 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
97 			return (RET_ERROR);
98 		data->data = t->bt_rdata.data;
99 	} else if (F_ISSET(t, B_DB_LOCK)) {
100 		/* Use +1 in case the first record retrieved is 0 length. */
101 		if (rl->dsize + 1 > t->bt_rdata.size) {
102 			p = (void *)(t->bt_rdata.data == NULL ?
103 			    malloc(rl->dsize + 1) :
104 			    realloc(t->bt_rdata.data, rl->dsize + 1));
105 			if (p == NULL)
106 				return (RET_ERROR);
107 			t->bt_rdata.data = p;
108 			t->bt_rdata.size = rl->dsize + 1;
109 		}
110 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
111 		data->size = rl->dsize;
112 		data->data = t->bt_rdata.data;
113 	} else {
114 		data->size = rl->dsize;
115 		data->data = rl->bytes;
116 	}
117 	return (RET_SUCCESS);
118 }
119