[linux.git] / lib / xz / xz_stream.h

/*
 * Definitions for handling the .xz file format
 *
 * Author: Lasse Collin <[email protected]>
 *
 * 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
 * https://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
Commit	Line	Data
24fa0402 LC	1	/*
	2	* Definitions for handling the .xz file format
	3	*
	4	* Author: Lasse Collin <[email protected]>
	5	*
	6	* This file has been put into the public domain.
	7	* You can do whatever you want with this file.
	8	*/
	9
	10	#ifndef XZ_STREAM_H
	11	#define XZ_STREAM_H
	12
	13	#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
	14	# include <linux/crc32.h>
	15	# undef crc32
	16	# define xz_crc32(buf, size, crc) \
	17	(~crc32_le(~(uint32_t)(crc), buf, size))
	18	#endif
	19
	20	/*
	21	* See the .xz file format specification at
d89775fc	22	* https://tukaani.org/xz/xz-file-format.txt
24fa0402 LC	23	* to understand the container format.
	24	*/
	25
	26	#define STREAM_HEADER_SIZE 12
	27
	28	#define HEADER_MAGIC "\3757zXZ"
	29	#define HEADER_MAGIC_SIZE 6
	30
	31	#define FOOTER_MAGIC "YZ"
	32	#define FOOTER_MAGIC_SIZE 2
	33
	34	/*
	35	* Variable-length integer can hold a 63-bit unsigned integer or a special
	36	* value indicating that the value is unknown.
	37	*
	38	* Experimental: vli_type can be defined to uint32_t to save a few bytes
	39	* in code size (no effect on speed). Doing so limits the uncompressed and
	40	* compressed size of the file to less than 256 MiB and may also weaken
	41	* error detection slightly.
	42	*/
	43	typedef uint64_t vli_type;
	44
	45	#define VLI_MAX ((vli_type)-1 / 2)
	46	#define VLI_UNKNOWN ((vli_type)-1)
	47
	48	/* Maximum encoded size of a VLI */
	49	#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
	50
	51	/* Integrity Check types */
	52	enum xz_check {
	53	XZ_CHECK_NONE = 0,
	54	XZ_CHECK_CRC32 = 1,
	55	XZ_CHECK_CRC64 = 4,
	56	XZ_CHECK_SHA256 = 10
	57	};
	58
	59	/* Maximum possible Check ID */
	60	#define XZ_CHECK_MAX 15
	61
	62	#endif