xref: /freebsd/contrib/libarchive/libarchive/archive_read_support_format_empty.c (revision b9128a37faafede823eb456aa65a11ac69997284)
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 
33 static int	archive_read_format_empty_bid(struct archive_read *, int);
34 static int	archive_read_format_empty_read_data(struct archive_read *,
35 		    const void **, size_t *, int64_t *);
36 static int	archive_read_format_empty_read_header(struct archive_read *,
37 		    struct archive_entry *);
38 int
39 archive_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 
64 static int
65 archive_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 
72 static int
73 archive_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 
85 static int
86 archive_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