1229159Sadrian/*
2229159Sadrian * Definitions for handling the .xz file format
3229159Sadrian *
4229159Sadrian * Author: Lasse Collin <lasse.collin@tukaani.org>
5229159Sadrian *
6229159Sadrian * This file has been put into the public domain.
7229159Sadrian * You can do whatever you want with this file.
8229159Sadrian */
9229159Sadrian
10229159Sadrian#ifndef XZ_STREAM_H
11229159Sadrian#define XZ_STREAM_H
12229159Sadrian
13229159Sadrian#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
14229159Sadrian#	include <linux/crc32.h>
15229159Sadrian#	undef crc32
16229159Sadrian#	define xz_crc32(buf, size, crc) \
17229159Sadrian		(~crc32_le(~(uint32_t)(crc), buf, size))
18229159Sadrian#endif
19229159Sadrian
20229159Sadrian/*
21229159Sadrian * See the .xz file format specification at
22229159Sadrian * http://tukaani.org/xz/xz-file-format.txt
23229159Sadrian * to understand the container format.
24229159Sadrian */
25229159Sadrian
26229159Sadrian#define STREAM_HEADER_SIZE 12
27229159Sadrian
28229159Sadrian#define HEADER_MAGIC "\3757zXZ"
29229159Sadrian#define HEADER_MAGIC_SIZE 6
30229159Sadrian
31229159Sadrian#define FOOTER_MAGIC "YZ"
32229159Sadrian#define FOOTER_MAGIC_SIZE 2
33229159Sadrian
34229159Sadrian/*
35229159Sadrian * Variable-length integer can hold a 63-bit unsigned integer or a special
36229159Sadrian * value indicating that the value is unknown.
37229159Sadrian *
38229159Sadrian * Experimental: vli_type can be defined to uint32_t to save a few bytes
39229159Sadrian * in code size (no effect on speed). Doing so limits the uncompressed and
40229159Sadrian * compressed size of the file to less than 256 MiB and may also weaken
41229159Sadrian * error detection slightly.
42229159Sadrian */
43229159Sadriantypedef uint64_t vli_type;
44229159Sadrian
45229159Sadrian#define VLI_MAX ((vli_type)-1 / 2)
46229159Sadrian#define VLI_UNKNOWN ((vli_type)-1)
47229159Sadrian
48229159Sadrian/* Maximum encoded size of a VLI */
49229159Sadrian#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
50229159Sadrian
51229159Sadrian/* Integrity Check types */
52229159Sadrianenum xz_check {
53229159Sadrian	XZ_CHECK_NONE = 0,
54229159Sadrian	XZ_CHECK_CRC32 = 1,
55229159Sadrian	XZ_CHECK_CRC64 = 4,
56229159Sadrian	XZ_CHECK_SHA256 = 10
57229159Sadrian};
58229159Sadrian
59229159Sadrian/* Maximum possible Check ID */
60229159Sadrian#define XZ_CHECK_MAX 15
61229159Sadrian
62229159Sadrian#endif
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