xref: /dragonfly/lib/libc/db/recno/rec_utils.c (revision cfd1aba3)
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  * @(#)rec_utils.c	8.6 (Berkeley) 7/16/94
30  * $FreeBSD: head/lib/libc/db/recno/rec_utils.c 189387 2009-03-05 00:57:01Z delphij $
31  */
32 
33 #include <sys/param.h>
34 
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 
39 #include <db.h>
40 #include "recno.h"
41 
42 /*
43  * __rec_ret --
44  *	Build return data.
45  *
46  * Parameters:
47  *	t:	tree
48  *	e:	key/data pair to be returned
49  *   nrec:	record number
50  *    key:	user's key structure
51  *   data:	user's data structure
52  *
53  * Returns:
54  *	RET_SUCCESS, RET_ERROR.
55  */
56 int
57 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
58 {
59 	RLEAF *rl;
60 	void *p;
61 
62 	if (key == NULL)
63 		goto dataonly;
64 
65 	/* We have to copy the key, it's not on the page. */
66 	if (sizeof(recno_t) > t->bt_rkey.size) {
67 		p = realloc(t->bt_rkey.data, sizeof(recno_t));
68 		if (p == NULL)
69 			return (RET_ERROR);
70 		t->bt_rkey.data = p;
71 		t->bt_rkey.size = sizeof(recno_t);
72 	}
73 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
74 	key->size = sizeof(recno_t);
75 	key->data = t->bt_rkey.data;
76 
77 dataonly:
78 	if (data == NULL)
79 		return (RET_SUCCESS);
80 
81 	/*
82 	 * We must copy big keys/data to make them contigous.  Otherwise,
83 	 * leave the page pinned and don't copy unless the user specified
84 	 * concurrent access.
85 	 */
86 	rl = GETRLEAF(e->page, e->index);
87 	if (rl->flags & P_BIGDATA) {
88 		if (__ovfl_get(t, rl->bytes,
89 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
90 			return (RET_ERROR);
91 		data->data = t->bt_rdata.data;
92 	} else if (F_ISSET(t, B_DB_LOCK)) {
93 		/* Use +1 in case the first record retrieved is 0 length. */
94 		if (rl->dsize + 1 > t->bt_rdata.size) {
95 			p = realloc(t->bt_rdata.data, rl->dsize + 1);
96 			if (p == NULL)
97 				return (RET_ERROR);
98 			t->bt_rdata.data = p;
99 			t->bt_rdata.size = rl->dsize + 1;
100 		}
101 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
102 		data->size = rl->dsize;
103 		data->data = t->bt_rdata.data;
104 	} else {
105 		data->size = rl->dsize;
106 		data->data = rl->bytes;
107 	}
108 	return (RET_SUCCESS);
109 }
110