xref: /freebsd/lib/libc/db/recno/rec_utils.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)rec_utils.c	8.6 (Berkeley) 7/16/94";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include <db.h>
45 #include "recno.h"
46 
47 /*
48  * __rec_ret --
49  *	Build return data.
50  *
51  * Parameters:
52  *	t:	tree
53  *	e:	key/data pair to be returned
54  *   nrec:	record number
55  *    key:	user's key structure
56  *   data:	user's data structure
57  *
58  * Returns:
59  *	RET_SUCCESS, RET_ERROR.
60  */
61 int
62 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *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 = realloc(t->bt_rkey.data, sizeof(recno_t));
73 		if (p == NULL)
74 			return (RET_ERROR);
75 		t->bt_rkey.data = p;
76 		t->bt_rkey.size = sizeof(recno_t);
77 	}
78 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
79 	key->size = sizeof(recno_t);
80 	key->data = t->bt_rkey.data;
81 
82 dataonly:
83 	if (data == NULL)
84 		return (RET_SUCCESS);
85 
86 	/*
87 	 * We must copy big keys/data to make them contigous.  Otherwise,
88 	 * leave the page pinned and don't copy unless the user specified
89 	 * concurrent access.
90 	 */
91 	rl = GETRLEAF(e->page, e->index);
92 	if (rl->flags & P_BIGDATA) {
93 		if (__ovfl_get(t, rl->bytes,
94 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
95 			return (RET_ERROR);
96 		data->data = t->bt_rdata.data;
97 	} else if (F_ISSET(t, B_DB_LOCK)) {
98 		/* Use +1 in case the first record retrieved is 0 length. */
99 		if (rl->dsize + 1 > t->bt_rdata.size) {
100 			p = realloc(t->bt_rdata.data, rl->dsize + 1);
101 			if (p == NULL)
102 				return (RET_ERROR);
103 			t->bt_rdata.data = p;
104 			t->bt_rdata.size = rl->dsize + 1;
105 		}
106 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
107 		data->size = rl->dsize;
108 		data->data = t->bt_rdata.data;
109 	} else {
110 		data->size = rl->dsize;
111 		data->data = rl->bytes;
112 	}
113 	return (RET_SUCCESS);
114 }
115