xref: /dragonfly/lib/libc/db/recno/rec_utils.c (revision b40e316c)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)rec_utils.c	8.6 (Berkeley) 7/16/94
34  * $DragonFly: src/lib/libc/db/recno/rec_utils.c,v 1.2 2003/06/17 04:26:42 dillon Exp $
35  */
36 
37 #include <sys/param.h>
38 
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #include <db.h>
44 #include "recno.h"
45 
46 /*
47  * __rec_ret --
48  *	Build return data.
49  *
50  * Parameters:
51  *	t:	tree
52  *	e:	key/data pair to be returned
53  *   nrec:	record number
54  *    key:	user's key structure
55  *	data:	user's data structure
56  *
57  * Returns:
58  *	RET_SUCCESS, RET_ERROR.
59  */
60 int
61 __rec_ret(t, e, nrec, key, data)
62 	BTREE *t;
63 	EPG *e;
64 	recno_t nrec;
65 	DBT *key, *data;
66 {
67 	RLEAF *rl;
68 	void *p;
69 
70 	if (key == NULL)
71 		goto dataonly;
72 
73 	/* We have to copy the key, it's not on the page. */
74 	if (sizeof(recno_t) > t->bt_rkey.size) {
75 		p = (void *)(t->bt_rkey.data == NULL ?
76 		    malloc(sizeof(recno_t)) :
77 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
78 		if (p == NULL)
79 			return (RET_ERROR);
80 		t->bt_rkey.data = p;
81 		t->bt_rkey.size = sizeof(recno_t);
82 	}
83 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
84 	key->size = sizeof(recno_t);
85 	key->data = t->bt_rkey.data;
86 
87 dataonly:
88 	if (data == NULL)
89 		return (RET_SUCCESS);
90 
91 	/*
92 	 * We must copy big keys/data to make them contigous.  Otherwise,
93 	 * leave the page pinned and don't copy unless the user specified
94 	 * concurrent access.
95 	 */
96 	rl = GETRLEAF(e->page, e->index);
97 	if (rl->flags & P_BIGDATA) {
98 		if (__ovfl_get(t, rl->bytes,
99 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
100 			return (RET_ERROR);
101 		data->data = t->bt_rdata.data;
102 	} else if (F_ISSET(t, B_DB_LOCK)) {
103 		/* Use +1 in case the first record retrieved is 0 length. */
104 		if (rl->dsize + 1 > t->bt_rdata.size) {
105 			p = (void *)(t->bt_rdata.data == NULL ?
106 			    malloc(rl->dsize + 1) :
107 			    realloc(t->bt_rdata.data, rl->dsize + 1));
108 			if (p == NULL)
109 				return (RET_ERROR);
110 			t->bt_rdata.data = p;
111 			t->bt_rdata.size = rl->dsize + 1;
112 		}
113 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
114 		data->size = rl->dsize;
115 		data->data = t->bt_rdata.data;
116 	} else {
117 		data->size = rl->dsize;
118 		data->data = rl->bytes;
119 	}
120 	return (RET_SUCCESS);
121 }
122