1 /* 2 * Definitions for handling the .xz file format 3 * 4 * Author: Lasse Collin <lasse.collin@tukaani.org> 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 /* 14 * See the .xz file format specification at 15 * http://tukaani.org/xz/xz-file-format.txt 16 * to understand the container format. 17 */ 18 19 #define STREAM_HEADER_SIZE 12 20 21 #define HEADER_MAGIC "\3757zXZ" 22 #define HEADER_MAGIC_SIZE 6 23 24 #define FOOTER_MAGIC "YZ" 25 #define FOOTER_MAGIC_SIZE 2 26 27 /* 28 * Variable-length integer can hold a 63-bit unsigned integer or a special 29 * value indicating that the value is unknown. 30 * 31 * Experimental: vli_type can be defined to uint32_t to save a few bytes 32 * in code size (no effect on speed). Doing so limits the uncompressed and 33 * compressed size of the file to less than 256 MiB and may also weaken 34 * error detection slightly. 35 */ 36 typedef uint64_t vli_type; 37 38 #define VLI_MAX ((vli_type)-1 / 2) 39 #define VLI_UNKNOWN ((vli_type)-1) 40 41 /* Maximum encoded size of a VLI */ 42 #define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7) 43 44 /* Integrity Check types */ 45 enum xz_check { 46 XZ_CHECK_NONE = 0, 47 XZ_CHECK_CRC32 = 1, 48 XZ_CHECK_CRC64 = 4, 49 XZ_CHECK_SHA256 = 10 50 }; 51 52 /* Maximum possible Check ID */ 53 #define XZ_CHECK_MAX 15 54 55 #endif 56