kc3-lang/brotli/c/enc/histogram.h

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• Hash : 35e69fc7
  Author :
  Date : 2018-02-26T09:04:36
  

  New feature: "Large Window Brotli" (#640)
  
  * New feature: "Large Window Brotli"
  
  By setting special encoder/decoder flag it is now possible to extend
  LZ-window up to 30 bits; though produced stream will not be RFC7932
  compliant.
  
  Added new dictionary generator - "DSH". It combines speed of "Sieve"
  and quality of "DM". Plus utilities to prepare train corpora
  (remove unique strings).
  
  Improved compression ratio: now two sub-blocks could be stitched:
  the last copy command could be extended to span the next sub-block.
  
  Fixed compression ineffectiveness caused by floating numbers rounding and
  wrong cost heuristic.
  
  Other C changes:
   - combined / moved `context.h` to `common`
   - moved transforms to `common`
   - unified some aspects of code formatting
   - added an abstraction for encoder (static) dictionary
   - moved default allocator/deallocator functions to `common`
  
  brotli CLI:
   - window size is auto-adjusted if not specified explicitly
  
  Java:
   - added "eager" decoding both to JNI wrapper and pure decoder
   - huge speed-up of `DictionaryData` initialization
  
  * Add dictionaryless compressed dictionary
  
  * Fix `sources.lst`
  
  * Fix `sources.lst` and add a note that `libtool` is also required.
  
  * Update setup.py
  
  * Fix `EagerStreamTest`
  
  * Fix BUILD file
  
  * Add missing `libdivsufsort` dependency
  
  * Fix "unused parameter" warning.
  

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• c/enc/histogram.h

• /* Copyright 2013 Google Inc. All Rights Reserved.
  
     Distributed under MIT license.
     See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
  */
  
  /* Models the histograms of literals, commands and distance codes. */
  
  #ifndef BROTLI_ENC_HISTOGRAM_H_
  #define BROTLI_ENC_HISTOGRAM_H_
  
  #include <string.h>  /* memset */
  
  #include "../common/constants.h"
  #include "../common/context.h"
  #include "../common/platform.h"
  #include <brotli/types.h>
  #include "./block_splitter.h"
  #include "./command.h"
  
  #if defined(__cplusplus) || defined(c_plusplus)
  extern "C" {
  #endif
  
  /* The distance symbols effectively used by "Large Window Brotli" (32-bit). */
  #define BROTLI_NUM_HISTOGRAM_DISTANCE_SYMBOLS 544
  
  #define FN(X) X ## Literal
  #define DATA_SIZE BROTLI_NUM_LITERAL_SYMBOLS
  #define DataType uint8_t
  #include "./histogram_inc.h"  /* NOLINT(build/include) */
  #undef DataType
  #undef DATA_SIZE
  #undef FN
  
  #define FN(X) X ## Command
  #define DataType uint16_t
  #define DATA_SIZE BROTLI_NUM_COMMAND_SYMBOLS
  #include "./histogram_inc.h"  /* NOLINT(build/include) */
  #undef DATA_SIZE
  #undef FN
  
  #define FN(X) X ## Distance
  #define DATA_SIZE BROTLI_NUM_HISTOGRAM_DISTANCE_SYMBOLS
  #include "./histogram_inc.h"  /* NOLINT(build/include) */
  #undef DataType
  #undef DATA_SIZE
  #undef FN
  
  BROTLI_INTERNAL void BrotliBuildHistogramsWithContext(
      const Command* cmds, const size_t num_commands,
      const BlockSplit* literal_split, const BlockSplit* insert_and_copy_split,
      const BlockSplit* dist_split, const uint8_t* ringbuffer, size_t pos,
      size_t mask, uint8_t prev_byte, uint8_t prev_byte2,
      const ContextType* context_modes, HistogramLiteral* literal_histograms,
      HistogramCommand* insert_and_copy_histograms,
      HistogramDistance* copy_dist_histograms);
  
  #if defined(__cplusplus) || defined(c_plusplus)
  }  /* extern "C" */
  #endif
  
  #endif  /* BROTLI_ENC_HISTOGRAM_H_ */
  

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