archive_read_support_format_empty.c revision 368707 
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__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/archive_read_support_format_empty.c 368707 2020-12-16 22:25:20Z mm $");
28
29#include "archive.h"
30#include "archive_entry.h"
31#include "archive_private.h"
32#include "archive_read_private.h"
33
34static int	archive_read_format_empty_bid(struct archive_read *, int);
35static int	archive_read_format_empty_read_data(struct archive_read *,
36		    const void **, size_t *, int64_t *);
37static int	archive_read_format_empty_read_header(struct archive_read *,
38		    struct archive_entry *);
39int
40archive_read_support_format_empty(struct archive *_a)
41{
42	struct archive_read *a = (struct archive_read *)_a;
43	int r;
44
45	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
46	    ARCHIVE_STATE_NEW, "archive_read_support_format_empty");
47
48	r = __archive_read_register_format(a,
49	    NULL,
50	    "empty",
51	    archive_read_format_empty_bid,
52	    NULL,
53	    archive_read_format_empty_read_header,
54	    archive_read_format_empty_read_data,
55	    NULL,
56	    NULL,
57	    NULL,
58	    NULL,
59	    NULL);
60
61	return (r);
62}
63
64
65static int
66archive_read_format_empty_bid(struct archive_read *a, int best_bid)
67{
68	if (best_bid < 1 && __archive_read_ahead(a, 1, NULL) == NULL)
69		return (1);
70	return (-1);
71}
72
73static int
74archive_read_format_empty_read_header(struct archive_read *a,
75    struct archive_entry *entry)
76{
77	(void)a; /* UNUSED */
78	(void)entry; /* UNUSED */
79
80	a->archive.archive_format = ARCHIVE_FORMAT_EMPTY;
81	a->archive.archive_format_name = "Empty file";
82
83	return (ARCHIVE_EOF);
84}
85
86static int
87archive_read_format_empty_read_data(struct archive_read *a,
88    const void **buff, size_t *size, int64_t *offset)
89{
90	(void)a; /* UNUSED */
91	(void)buff; /* UNUSED */
92	(void)size; /* UNUSED */
93	(void)offset; /* UNUSED */
94
95	return (ARCHIVE_EOF);
96}
97