MdeModulePkg/Library/BrotliCustomDecompressLib/common/constants.h

   1 /* Copyright 2016 Google Inc. All Rights Reserved.
   2
   3    Distributed under MIT license.
   4    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
   5 */
   6
   7 #ifndef BROTLI_COMMON_CONSTANTS_H_
   8 #define BROTLI_COMMON_CONSTANTS_H_
   9
  10 /* Specification: 7.3. Encoding of the context map */
  11 #define BROTLI_CONTEXT_MAP_MAX_RLE 16
  12
  13 /* Specification: 2. Compressed representation overview */
  14 #define BROTLI_MAX_NUMBER_OF_BLOCK_TYPES 256
  15
  16 /* Specification: 3.3. Alphabet sizes: insert-and-copy length */
  17 #define BROTLI_NUM_LITERAL_SYMBOLS 256
  18 #define BROTLI_NUM_COMMAND_SYMBOLS 704
  19 #define BROTLI_NUM_BLOCK_LEN_SYMBOLS 26
  20 #define BROTLI_MAX_CONTEXT_MAP_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + \
  21                                         BROTLI_CONTEXT_MAP_MAX_RLE)
  22 #define BROTLI_MAX_BLOCK_TYPE_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 2)
  23
  24 /* Specification: 3.5. Complex prefix codes */
  25 #define BROTLI_REPEAT_PREVIOUS_CODE_LENGTH 16
  26 #define BROTLI_REPEAT_ZERO_CODE_LENGTH 17
  27 #define BROTLI_CODE_LENGTH_CODES (BROTLI_REPEAT_ZERO_CODE_LENGTH + 1)
  28 /* "code length of 8 is repeated" */
  29 #define BROTLI_INITIAL_REPEATED_CODE_LENGTH 8
  30
  31 /* "Large Window Brotli" */
  32 #define BROTLI_LARGE_MAX_DISTANCE_BITS 62U
  33 #define BROTLI_LARGE_MIN_WBITS 10
  34 #define BROTLI_LARGE_MAX_WBITS 30
  35
  36 /* Specification: 4. Encoding of distances */
  37 #define BROTLI_NUM_DISTANCE_SHORT_CODES 16
  38 #define BROTLI_MAX_NPOSTFIX 3
  39 #define BROTLI_MAX_NDIRECT 120
  40 #define BROTLI_MAX_DISTANCE_BITS 24U
  41 #define BROTLI_DISTANCE_ALPHABET_SIZE(NPOSTFIX, NDIRECT, MAXNBITS) ( \
  42     BROTLI_NUM_DISTANCE_SHORT_CODES + (NDIRECT) +                    \
  43     ((MAXNBITS) << ((NPOSTFIX) + 1)))
  44 /* BROTLI_NUM_DISTANCE_SYMBOLS == 1128 */
  45 #define BROTLI_NUM_DISTANCE_SYMBOLS \
  46     BROTLI_DISTANCE_ALPHABET_SIZE(  \
  47         BROTLI_MAX_NDIRECT, BROTLI_MAX_NPOSTFIX, BROTLI_LARGE_MAX_DISTANCE_BITS)
  48 #define BROTLI_MAX_DISTANCE 0x3FFFFFC
  49 #define BROTLI_MAX_ALLOWED_DISTANCE 0x7FFFFFFC
  50
  51 /* 7.1. Context modes and context ID lookup for literals */
  52 /* "context IDs for literals are in the range of 0..63" */
  53 #define BROTLI_LITERAL_CONTEXT_BITS 6
  54
  55 /* 7.2. Context ID for distances */
  56 #define BROTLI_DISTANCE_CONTEXT_BITS 2
  57
  58 /* 9.1. Format of the Stream Header */
  59 /* Number of slack bytes for window size. Don't confuse
  60    with BROTLI_NUM_DISTANCE_SHORT_CODES. */
  61 #define BROTLI_WINDOW_GAP 16
  62 #define BROTLI_MAX_BACKWARD_LIMIT(W) (((size_t)1 << (W)) - BROTLI_WINDOW_GAP)
  63
  64 #endif  /* BROTLI_COMMON_CONSTANTS_H_ */