xref: /openbsd/lib/libc/db/recno/rec_utils.c (revision 5af055cd)
1 /*	$OpenBSD: rec_utils.c,v 1.9 2015/01/16 16:48:51 deraadt Exp $ */
2 /*-
3  * Copyright (c) 1990, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include <db.h>
36 #include "recno.h"
37 
38 /*
39  * __rec_ret --
40  *	Build return data.
41  *
42  * Parameters:
43  *	t:	tree
44  *	e:	key/data pair to be returned
45  *   nrec:	record number
46  *    key:	user's key structure
47  *   data:	user's data structure
48  *
49  * Returns:
50  *	RET_SUCCESS, RET_ERROR.
51  */
52 int
53 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
54 {
55 	RLEAF *rl;
56 	void *p;
57 
58 	if (key == NULL)
59 		goto dataonly;
60 
61 	/* We have to copy the key, it's not on the page. */
62 	if (sizeof(recno_t) > t->bt_rkey.size) {
63 		p = realloc(t->bt_rkey.data, sizeof(recno_t));
64 		if (p == NULL)
65 			return (RET_ERROR);
66 		t->bt_rkey.data = p;
67 		t->bt_rkey.size = sizeof(recno_t);
68 	}
69 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
70 	key->size = sizeof(recno_t);
71 	key->data = t->bt_rkey.data;
72 
73 dataonly:
74 	if (data == NULL)
75 		return (RET_SUCCESS);
76 
77 	/*
78 	 * We must copy big keys/data to make them contigous.  Otherwise,
79 	 * leave the page pinned and don't copy unless the user specified
80 	 * concurrent access.
81 	 */
82 	rl = GETRLEAF(e->page, e->index);
83 	if (rl->flags & P_BIGDATA) {
84 		if (__ovfl_get(t, rl->bytes,
85 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
86 			return (RET_ERROR);
87 		data->data = t->bt_rdata.data;
88 	} else if (F_ISSET(t, B_DB_LOCK)) {
89 		/* Use +1 in case the first record retrieved is 0 length. */
90 		if (rl->dsize + 1 > t->bt_rdata.size) {
91 			p = realloc(t->bt_rdata.data, rl->dsize + 1);
92 			if (p == NULL)
93 				return (RET_ERROR);
94 			t->bt_rdata.data = p;
95 			t->bt_rdata.size = rl->dsize + 1;
96 		}
97 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
98 		data->size = rl->dsize;
99 		data->data = t->bt_rdata.data;
100 	} else {
101 		data->size = rl->dsize;
102 		data->data = rl->bytes;
103 	}
104 	return (RET_SUCCESS);
105 }
106