text: /* Copyright 2016 Google Inc. All Rights Reserved.
  
     Distributed under MIT license.
     See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
  */
  
  #ifndef BROTLI_COMMON_CONSTANTS_H_
  #define BROTLI_COMMON_CONSTANTS_H_
  
  /* Specification: 7.3. Encoding of the context map */
  #define BROTLI_CONTEXT_MAP_MAX_RLE 16
  
  /* Specification: 2. Compressed representation overview */
  #define BROTLI_MAX_NUMBER_OF_BLOCK_TYPES 256
  
  /* Specification: 3.3. Alphabet sizes: insert-and-copy length */
  #define BROTLI_NUM_LITERAL_SYMBOLS 256
  #define BROTLI_NUM_COMMAND_SYMBOLS 704
  #define BROTLI_NUM_BLOCK_LEN_SYMBOLS 26
  #define BROTLI_MAX_CONTEXT_MAP_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + \
                                          BROTLI_CONTEXT_MAP_MAX_RLE)
  #define BROTLI_MAX_BLOCK_TYPE_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 2)
  
  /* Specification: 3.5. Complex prefix codes */
  #define BROTLI_REPEAT_PREVIOUS_CODE_LENGTH 16
  #define BROTLI_REPEAT_ZERO_CODE_LENGTH 17
  #define BROTLI_CODE_LENGTH_CODES (BROTLI_REPEAT_ZERO_CODE_LENGTH + 1)
  /* "code length of 8 is repeated" */
  #define BROTLI_INITIAL_REPEATED_CODE_LENGTH 8
  
  /* "Large Window Brotli" */
  #define BROTLI_LARGE_MAX_DISTANCE_BITS 62U
  #define BROTLI_LARGE_MIN_WBITS 10
  #define BROTLI_LARGE_MAX_WBITS 30
  
  /* Specification: 4. Encoding of distances */
  #define BROTLI_NUM_DISTANCE_SHORT_CODES 16
  #define BROTLI_MAX_NPOSTFIX 3
  #define BROTLI_MAX_NDIRECT 120
  #define BROTLI_MAX_DISTANCE_BITS 24U
  #define BROTLI_DISTANCE_ALPHABET_SIZE(NPOSTFIX, NDIRECT, MAXNBITS) ( \
      BROTLI_NUM_DISTANCE_SHORT_CODES + (NDIRECT) +                    \
      ((MAXNBITS) << ((NPOSTFIX) + 1)))
  /* BROTLI_NUM_DISTANCE_SYMBOLS == 1128 */
  #define BROTLI_NUM_DISTANCE_SYMBOLS \
      BROTLI_DISTANCE_ALPHABET_SIZE(  \
          BROTLI_MAX_NDIRECT, BROTLI_MAX_NPOSTFIX, BROTLI_LARGE_MAX_DISTANCE_BITS)
  #define BROTLI_MAX_DISTANCE 0x3FFFFFC
  #define BROTLI_MAX_ALLOWED_DISTANCE 0x7FFFFFFC
  
  /* 7.1. Context modes and context ID lookup for literals */
  /* "context IDs for literals are in the range of 0..63" */
  #define BROTLI_LITERAL_CONTEXT_BITS 6
  
  /* 7.2. Context ID for distances */
  #define BROTLI_DISTANCE_CONTEXT_BITS 2
  
  /* 9.1. Format of the Stream Header */
  /* Number of slack bytes for window size. Don't confuse
     with BROTLI_NUM_DISTANCE_SHORT_CODES. */
  #define BROTLI_WINDOW_GAP 16
  #define BROTLI_MAX_BACKWARD_LIMIT(W) (((size_t)1 << (W)) - BROTLI_WINDOW_GAP)
  
  #endif  /* BROTLI_COMMON_CONSTANTS_H_ */
  