xref: /openbsd-src/lib/libc/db/recno/rec_utils.c (revision 53b37aa960c5e4c03a5a2e490de17e3dee91b98f)
1 /*	$OpenBSD: rec_utils.c,v 1.7 2005/08/05 13:03:00 espie 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 <sys/param.h>
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 
37 #include <db.h>
38 #include "recno.h"
39 
40 /*
41  * __rec_ret --
42  *	Build return data.
43  *
44  * Parameters:
45  *	t:	tree
46  *	e:	key/data pair to be returned
47  *   nrec:	record number
48  *    key:	user's key structure
49  *	data:	user's data structure
50  *
51  * Returns:
52  *	RET_SUCCESS, RET_ERROR.
53  */
54 int
55 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
56 {
57 	RLEAF *rl;
58 	void *p;
59 
60 	if (key == NULL)
61 		goto dataonly;
62 
63 	/* We have to copy the key, it's not on the page. */
64 	if (sizeof(recno_t) > t->bt_rkey.size) {
65 		p = (void *)(t->bt_rkey.data == NULL ?
66 		    malloc(sizeof(recno_t)) :
67 		    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 = (void *)(t->bt_rdata.data == NULL ?
96 			    malloc(rl->dsize + 1) :
97 			    realloc(t->bt_rdata.data, rl->dsize + 1));
98 			if (p == NULL)
99 				return (RET_ERROR);
100 			t->bt_rdata.data = p;
101 			t->bt_rdata.size = rl->dsize + 1;
102 		}
103 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
104 		data->size = rl->dsize;
105 		data->data = t->bt_rdata.data;
106 	} else {
107 		data->size = rl->dsize;
108 		data->data = rl->bytes;
109 	}
110 	return (RET_SUCCESS);
111 }
112