1/*-
2 * Copyright (c) 2003-2007 Tim Kientzle
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "archive_platform.h"
27
28#include "archive.h"
29#include "archive_entry.h"
30#include "archive_private.h"
31#include "archive_read_private.h"
32
33static int	archive_read_format_empty_bid(struct archive_read *, int);
34static int	archive_read_format_empty_read_data(struct archive_read *,
35		    const void **, size_t *, int64_t *);
36static int	archive_read_format_empty_read_header(struct archive_read *,
37		    struct archive_entry *);
38int
39archive_read_support_format_empty(struct archive *_a)
40{
41	struct archive_read *a = (struct archive_read *)_a;
42	int r;
43
44	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
45	    ARCHIVE_STATE_NEW, "archive_read_support_format_empty");
46
47	r = __archive_read_register_format(a,
48	    NULL,
49	    "empty",
50	    archive_read_format_empty_bid,
51	    NULL,
52	    archive_read_format_empty_read_header,
53	    archive_read_format_empty_read_data,
54	    NULL,
55	    NULL,
56	    NULL,
57	    NULL,
58	    NULL);
59
60	return (r);
61}
62
63
64static int
65archive_read_format_empty_bid(struct archive_read *a, int best_bid)
66{
67	if (best_bid < 1 && __archive_read_ahead(a, 1, NULL) == NULL)
68		return (1);
69	return (-1);
70}
71
72static int
73archive_read_format_empty_read_header(struct archive_read *a,
74    struct archive_entry *entry)
75{
76	(void)a; /* UNUSED */
77	(void)entry; /* UNUSED */
78
79	a->archive.archive_format = ARCHIVE_FORMAT_EMPTY;
80	a->archive.archive_format_name = "Empty file";
81
82	return (ARCHIVE_EOF);
83}
84
85static int
86archive_read_format_empty_read_data(struct archive_read *a,
87    const void **buff, size_t *size, int64_t *offset)
88{
89	(void)a; /* UNUSED */
90	(void)buff; /* UNUSED */
91	(void)size; /* UNUSED */
92	(void)offset; /* UNUSED */
93
94	return (ARCHIVE_EOF);
95}
96