2 * Copyright (c) 2003-2007 Tim Kientzle
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
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23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 #include "archive_platform.h"
27 __FBSDID("$FreeBSD: src/lib/libarchive/archive_read_open_memory.c,v 1.6 2007/07/06 15:51:59 kientzle Exp $");
36 * Glue to read an archive from a block of memory.
38 * This is mostly a huge help in building test harnesses;
39 * test programs can build archives in memory and read them
40 * back again without having to mess with files on disk.
43 struct read_memory_data {
44 const unsigned char *start;
45 const unsigned char *p;
46 const unsigned char *end;
50 static int memory_read_close(struct archive *, void *);
51 static int memory_read_open(struct archive *, void *);
52 static int64_t memory_read_seek(struct archive *, void *, int64_t offset, int whence);
53 static int64_t memory_read_skip(struct archive *, void *, int64_t request);
54 static ssize_t memory_read(struct archive *, void *, const void **buff);
57 archive_read_open_memory(struct archive *a, const void *buff, size_t size)
59 return archive_read_open_memory2(a, buff, size, size);
63 * Don't use _open_memory2() in production code; the archive_read_open_memory()
64 * version is the one you really want. This is just here so that
65 * test harnesses can exercise block operations inside the library.
68 archive_read_open_memory2(struct archive *a, const void *buff,
69 size_t size, size_t read_size)
71 struct read_memory_data *mine;
73 mine = (struct read_memory_data *)calloc(1, sizeof(*mine));
75 archive_set_error(a, ENOMEM, "No memory");
76 return (ARCHIVE_FATAL);
78 mine->start = mine->p = (const unsigned char *)buff;
79 mine->end = mine->start + size;
80 mine->read_size = read_size;
81 archive_read_set_open_callback(a, memory_read_open);
82 archive_read_set_read_callback(a, memory_read);
83 archive_read_set_seek_callback(a, memory_read_seek);
84 archive_read_set_skip_callback(a, memory_read_skip);
85 archive_read_set_close_callback(a, memory_read_close);
86 archive_read_set_callback_data(a, mine);
87 return (archive_read_open1(a));
91 * There's nothing to open.
94 memory_read_open(struct archive *a, void *client_data)
97 (void)client_data; /* UNUSED */
102 * This is scary simple: Just advance a pointer. Limiting
103 * to read_size is not technically necessary, but it exercises
104 * more of the internal logic when used with a small block size
105 * in a test harness. Production use should not specify a block
106 * size; then this is much faster.
109 memory_read(struct archive *a, void *client_data, const void **buff)
111 struct read_memory_data *mine = (struct read_memory_data *)client_data;
114 (void)a; /* UNUSED */
116 size = mine->end - mine->p;
117 if (size > mine->read_size)
118 size = mine->read_size;
124 * Advancing is just as simple. Again, this is doing more than
125 * necessary in order to better exercise internal code when used
129 memory_read_skip(struct archive *a, void *client_data, int64_t skip)
131 struct read_memory_data *mine = (struct read_memory_data *)client_data;
133 (void)a; /* UNUSED */
134 if ((int64_t)skip > (int64_t)(mine->end - mine->p))
135 skip = mine->end - mine->p;
136 /* Round down to block size. */
137 skip /= mine->read_size;
138 skip *= mine->read_size;
147 memory_read_seek(struct archive *a, void *client_data, int64_t offset, int whence)
149 struct read_memory_data *mine = (struct read_memory_data *)client_data;
151 (void)a; /* UNUSED */
154 mine->p = mine->start + offset;
160 mine->p = mine->end + offset;
163 return ARCHIVE_FATAL;
165 if (mine->p < mine->start) {
166 mine->p = mine->start;
167 return ARCHIVE_FAILED;
169 if (mine->p > mine->end) {
171 return ARCHIVE_FAILED;
173 return (mine->p - mine->start);
177 * Close is just cleaning up our one small bit of data.
180 memory_read_close(struct archive *a, void *client_data)
182 struct read_memory_data *mine = (struct read_memory_data *)client_data;
183 (void)a; /* UNUSED */