kc3-lang/brotli/enc/literal_cost.h

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• Hash : e7650080
  Author :
  Date : 2014-03-20T14:32:35
  

  Updates to Brotli compression format, decoder and encoder
  
  This commit contains a batch of changes that were made to the Brotli
  compression algorithm in the last month. Most important changes:
  
     * Format change: don't push distances representing static dictionary words to the distance cache.
     * Fix decoder invalid memory access bug caused by building a non-complete Huffman tree.
     * Add a mode parameter to the encoder interface.
     * Use different hashers for text and font mode.
     * Add a heuristics to the hasher for skipping non-compressible data.
     * Exhaustive search of static dictionary during backward reference search.
  

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• enc/literal_cost.h

• // Copyright 2013 Google Inc. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  // http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  //
  // Literal cost model to allow backward reference replacement to be efficient.
  
  #ifndef BROTLI_ENC_LITERAL_COST_H_
  #define BROTLI_ENC_LITERAL_COST_H_
  
  #include <stddef.h>
  #include <stdint.h>
  
  namespace brotli {
  
  // Estimates how many bits the literals in the interval [pos, pos + len) in the
  // ringbuffer (data, mask) will take entropy coded and writes these estimates
  // to the ringbuffer (cost, mask).
  void EstimateBitCostsForLiterals(size_t pos, size_t len, size_t mask,
                                   size_t cost_mask, const uint8_t *data,
                                   float *cost);
  
  void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
                                       size_t cost_mask, const uint8_t *data,
                                       float *cost);
  
  }  // namespace brotli
  
  #endif  // BROTLI_ENC_LITERAL_COST_H_
  

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