1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*
28 * Much like calloc, but with functions to report the size of the
29 * allocation given only the pointer.
30 */
31
32#include <assert.h>
33#include <string.h>
34#include <malloc.h>
35#include "sized_array.h"
36
37/*
38 * Assumes that int is at least 32 bits and that nothing needs more than
39 * 8-byte alignment.
40 */
41
42/* COOKIE provides some bad-pointer protection. */
43#define	COOKIE	"SACOOKIE"
44
45struct sized_array {
46	int	n;
47	int	sz;
48#if	defined(COOKIE)
49	char	cookie[8];
50#endif
51};
52
53
54void *
55sized_array(size_t n, size_t sz)
56{
57	struct sized_array *sa;
58	size_t total;
59
60	total = sizeof (struct sized_array) + n*sz;
61
62	sa = malloc(total);
63
64	if (sa == NULL)
65		return (NULL);
66
67	(void) memset(sa, 0, total);
68
69	sa->n = n;
70	sa->sz = sz;
71
72#if	defined(COOKIE)
73	(void) memcpy(sa->cookie, COOKIE, sizeof (sa->cookie));
74#endif
75
76	return ((void *)(sa + 1));
77}
78
79void
80sized_array_free(void *p)
81{
82	struct sized_array *sa;
83
84	if (p == NULL)
85		return;
86
87	sa = ((struct sized_array *)p)-1;
88
89#if	defined(COOKIE)
90	assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
91#endif
92
93	free(sa);
94}
95
96size_t
97sized_array_n(void *p)
98{
99	struct sized_array *sa;
100
101	sa = ((struct sized_array *)p)-1;
102
103#if	defined(COOKIE)
104	assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
105#endif
106
107	return (sa->n);
108}
109
110size_t
111sized_array_sz(void *p)
112{
113	struct sized_array *sa;
114
115	sa = ((struct sized_array *)p)-1;
116
117#if	defined(COOKIE)
118	assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
119#endif
120
121	return (sa->sz);
122}
123