blob: 66cb5a7055ec83298de08e625902e1e229c9ce42 [file] [log] [blame]
/*
* Definitions for handling the .xz file format
*
* Author: Lasse Collin <lasse.collin@tukaani.org>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_STREAM_H
#define XZ_STREAM_H
#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
# include <linux/crc32.h>
# undef crc32
# define xz_crc32(buf, size, crc) \
(~crc32_le(~(uint32_t)(crc), buf, size))
#endif
/*
* See the .xz file format specification at
* http://tukaani.org/xz/xz-file-format.txt
* to understand the container format.
*/
#define STREAM_HEADER_SIZE 12
#define HEADER_MAGIC "\3757zXZ"
#define HEADER_MAGIC_SIZE 6
#define FOOTER_MAGIC "YZ"
#define FOOTER_MAGIC_SIZE 2
/*
* Variable-length integer can hold a 63-bit unsigned integer or a special
* value indicating that the value is unknown.
*
* Experimental: vli_type can be defined to uint32_t to save a few bytes
* in code size (no effect on speed). Doing so limits the uncompressed and
* compressed size of the file to less than 256 MiB and may also weaken
* error detection slightly.
*/
typedef uint64_t vli_type;
#define VLI_MAX ((vli_type)-1 / 2)
#define VLI_UNKNOWN ((vli_type)-1)
/* Maximum encoded size of a VLI */
#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
/* Integrity Check types */
enum xz_check {
XZ_CHECK_NONE = 0,
XZ_CHECK_CRC32 = 1,
XZ_CHECK_CRC64 = 4,
XZ_CHECK_SHA256 = 10
};
/* Maximum possible Check ID */
#define XZ_CHECK_MAX 15
#endif