xref: /freebsd/lib/libc/db/recno/rec_utils.c (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
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 char sccsid[] = "@(#)rec_utils.c	8.6 (Berkeley) 7/16/94";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 
42 #include <db.h>
43 #include "recno.h"
44 
45 /*
46  * __rec_ret --
47  *	Build return data.
48  *
49  * Parameters:
50  *	t:	tree
51  *	e:	key/data pair to be returned
52  *   nrec:	record number
53  *    key:	user's key structure
54  *   data:	user's data structure
55  *
56  * Returns:
57  *	RET_SUCCESS, RET_ERROR.
58  */
59 int
60 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
61 {
62 	RLEAF *rl;
63 	void *p;
64 
65 	if (key == NULL)
66 		goto dataonly;
67 
68 	/* We have to copy the key, it's not on the page. */
69 	if (sizeof(recno_t) > t->bt_rkey.size) {
70 		p = realloc(t->bt_rkey.data, sizeof(recno_t));
71 		if (p == NULL)
72 			return (RET_ERROR);
73 		t->bt_rkey.data = p;
74 		t->bt_rkey.size = sizeof(recno_t);
75 	}
76 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
77 	key->size = sizeof(recno_t);
78 	key->data = t->bt_rkey.data;
79 
80 dataonly:
81 	if (data == NULL)
82 		return (RET_SUCCESS);
83 
84 	/*
85 	 * We must copy big keys/data to make them contigous.  Otherwise,
86 	 * leave the page pinned and don't copy unless the user specified
87 	 * concurrent access.
88 	 */
89 	rl = GETRLEAF(e->page, e->index);
90 	if (rl->flags & P_BIGDATA) {
91 		if (__ovfl_get(t, rl->bytes,
92 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
93 			return (RET_ERROR);
94 		data->data = t->bt_rdata.data;
95 	} else if (F_ISSET(t, B_DB_LOCK)) {
96 		/* Use +1 in case the first record retrieved is 0 length. */
97 		if (rl->dsize + 1 > t->bt_rdata.size) {
98 			p = realloc(t->bt_rdata.data, rl->dsize + 1);
99 			if (p == NULL)
100 				return (RET_ERROR);
101 			t->bt_rdata.data = p;
102 			t->bt_rdata.size = rl->dsize + 1;
103 		}
104 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
105 		data->size = rl->dsize;
106 		data->data = t->bt_rdata.data;
107 	} else {
108 		data->size = rl->dsize;
109 		data->data = rl->bytes;
110 	}
111 	return (RET_SUCCESS);
112 }
113