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 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)rec_utils.c	8.6 (Berkeley) 7/16/94";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/param.h>
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "db-int.h"
45 #include "recno.h"
46 
47 /*
48  * __rec_ret --
49  *	Build return data.
50  *
51  * Parameters:
52  *	t:	tree
53  *	e:	key/data pair to be returned
54  *   nrec:	record number
55  *    key:	user's key structure
56  *	data:	user's data structure
57  *
58  * Returns:
59  *	RET_SUCCESS, RET_ERROR.
60  */
61 int
__rec_ret(t,e,nrec,key,data)62 __rec_ret(t, e, nrec, key, data)
63 	BTREE *t;
64 	EPG *e;
65 	recno_t nrec;
66 	DBT *key, *data;
67 {
68 	RLEAF *rl;
69 	void *p;
70 
71 	if (key == NULL)
72 		goto dataonly;
73 
74 	/* We have to copy the key, it's not on the page. */
75 	if (sizeof(recno_t) > t->bt_rkey.size) {
76 		p = (void *)(t->bt_rkey.data == NULL ?
77 		    malloc(sizeof(recno_t)) :
78 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
79 		if (p == NULL)
80 			return (RET_ERROR);
81 		t->bt_rkey.data = p;
82 		t->bt_rkey.size = sizeof(recno_t);
83 	}
84 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
85 	key->size = sizeof(recno_t);
86 	key->data = t->bt_rkey.data;
87 
88 dataonly:
89 	if (data == NULL)
90 		return (RET_SUCCESS);
91 
92 	/*
93 	 * We must copy big keys/data to make them contigous.  Otherwise,
94 	 * leave the page pinned and don't copy unless the user specified
95 	 * concurrent access.
96 	 */
97 	rl = GETRLEAF(e->page, e->index);
98 	if (rl->flags & P_BIGDATA) {
99 		if (__ovfl_get(t, rl->bytes,
100 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
101 			return (RET_ERROR);
102 		data->data = t->bt_rdata.data;
103 	} else if (F_ISSET(t, B_DB_LOCK)) {
104 		/* Use +1 in case the first record retrieved is 0 length. */
105 		if (rl->dsize + 1 > t->bt_rdata.size) {
106 			p = (void *)(t->bt_rdata.data == NULL ?
107 			    malloc(rl->dsize + 1) :
108 			    realloc(t->bt_rdata.data, rl->dsize + 1));
109 			if (p == NULL)
110 				return (RET_ERROR);
111 			t->bt_rdata.data = p;
112 			t->bt_rdata.size = rl->dsize + 1;
113 		}
114 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
115 		data->size = rl->dsize;
116 		data->data = t->bt_rdata.data;
117 	} else {
118 		data->size = rl->dsize;
119 		data->data = rl->bytes;
120 	}
121 	return (RET_SUCCESS);
122 }
123