kc3-lang/brotli/c/common/dictionary.h

• Show log

  Commit

• Hash : da254cff
  Author :
  Date : 2017-12-12T14:33:12
  

  Update (#630)
  
   * merge {dec|enc}/port.h into common/platform.h
   * fix one-shot q=10 1-byte input compression
   * fix some unprefixed definitions
   * make hashers host-endianness-independent
   * extract enc/params.h from enc/quality.h
   * fix API documentation / typos
   * improve `BrotliEncoderMaxCompressedSize`

Download

• c/common/dictionary.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
  */
  
  /* Collection of static dictionary words. */
  
  #ifndef BROTLI_COMMON_DICTIONARY_H_
  #define BROTLI_COMMON_DICTIONARY_H_
  
  #include <brotli/port.h>
  #include <brotli/types.h>
  
  #if defined(__cplusplus) || defined(c_plusplus)
  extern "C" {
  #endif
  
  typedef struct BrotliDictionary {
    /**
     * Number of bits to encode index of dictionary word in a bucket.
     *
     * Specification: Appendix A. Static Dictionary Data
     *
     * Words in a dictionary are bucketed by length.
     * @c 0 means that there are no words of a given length.
     * Dictionary consists of words with length of [4..24] bytes.
     * Values at [0..3] and [25..31] indices should not be addressed.
     */
    uint8_t size_bits_by_length[32];
  
    /* assert(offset[i + 1] == offset[i] + (bits[i] ? (i << bits[i]) : 0)) */
    uint32_t offsets_by_length[32];
  
    /* assert(data_size == offsets_by_length[31]) */
    size_t data_size;
  
    /* Data array is not bound, and should obey to size_bits_by_length values.
       Specified size matches default (RFC 7932) dictionary. Its size is
       defined by data_size */
    const uint8_t* data;
  } BrotliDictionary;
  
  BROTLI_COMMON_API const BrotliDictionary* BrotliGetDictionary(void);
  
  /**
   * Sets dictionary data.
   *
   * When dictionary data is already set / present, this method is no-op.
   *
   * Dictionary data MUST be provided before BrotliGetDictionary is invoked.
   * This method is used ONLY in multi-client environment (e.g. C + Java),
   * to reduce storage by sharing single dictionary between implementations.
   */
  BROTLI_COMMON_API void BrotliSetDictionaryData(const uint8_t* data);
  
  #define BROTLI_MIN_DICTIONARY_WORD_LENGTH 4
  #define BROTLI_MAX_DICTIONARY_WORD_LENGTH 24
  
  #if defined(__cplusplus) || defined(c_plusplus)
  }  /* extern "C" */
  #endif
  
  #endif  /* BROTLI_COMMON_DICTIONARY_H_ */
  

Download