xref: /freebsd/lib/libc/db/recno/rec_utils.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include <db.h>
39 #include "recno.h"
40 
41 /*
42  * __rec_ret --
43  *	Build return data.
44  *
45  * Parameters:
46  *	t:	tree
47  *	e:	key/data pair to be returned
48  *   nrec:	record number
49  *    key:	user's key structure
50  *   data:	user's data structure
51  *
52  * Returns:
53  *	RET_SUCCESS, RET_ERROR.
54  */
55 int
56 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
57 {
58 	RLEAF *rl;
59 	void *p;
60 
61 	if (key == NULL)
62 		goto dataonly;
63 
64 	/* We have to copy the key, it's not on the page. */
65 	if (sizeof(recno_t) > t->bt_rkey.size) {
66 		p = realloc(t->bt_rkey.data, sizeof(recno_t));
67 		if (p == NULL)
68 			return (RET_ERROR);
69 		t->bt_rkey.data = p;
70 		t->bt_rkey.size = sizeof(recno_t);
71 	}
72 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
73 	key->size = sizeof(recno_t);
74 	key->data = t->bt_rkey.data;
75 
76 dataonly:
77 	if (data == NULL)
78 		return (RET_SUCCESS);
79 
80 	/*
81 	 * We must copy big keys/data to make them contigous.  Otherwise,
82 	 * leave the page pinned and don't copy unless the user specified
83 	 * concurrent access.
84 	 */
85 	rl = GETRLEAF(e->page, e->index);
86 	if (rl->flags & P_BIGDATA) {
87 		if (__ovfl_get(t, rl->bytes,
88 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
89 			return (RET_ERROR);
90 		data->data = t->bt_rdata.data;
91 	} else if (F_ISSET(t, B_DB_LOCK)) {
92 		/* Use +1 in case the first record retrieved is 0 length. */
93 		if (rl->dsize + 1 > t->bt_rdata.size) {
94 			p = realloc(t->bt_rdata.data, rl->dsize + 1);
95 			if (p == NULL)
96 				return (RET_ERROR);
97 			t->bt_rdata.data = p;
98 			t->bt_rdata.size = rl->dsize + 1;
99 		}
100 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
101 		data->size = rl->dsize;
102 		data->data = t->bt_rdata.data;
103 	} else {
104 		data->size = rl->dsize;
105 		data->data = rl->bytes;
106 	}
107 	return (RET_SUCCESS);
108 }
109