BaseTools/Source/C/BrotliCompress/enc/compress_fragment_two_pass.h

   1 /* Copyright 2015 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 /* Function for fast encoding of an input fragment, independently from the input
   8    history. This function uses two-pass processing: in the first pass we save
   9    the found backward matches and literal bytes into a buffer, and in the
  10    second pass we emit them into the bit stream using prefix codes built based
  11    on the actual command and literal byte histograms. */
  12
  13 #ifndef BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
  14 #define BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
  15
  16 #include "../common/platform.h"
  17 #include <brotli/types.h>
  18 #include "./memory.h"
  19
  20 #if defined(__cplusplus) || defined(c_plusplus)
  21 extern "C" {
  22 #endif
  23
  24 static const size_t kCompressFragmentTwoPassBlockSize = 1 << 17;
  25
  26 /* Compresses "input" string to the "*storage" buffer as one or more complete
  27    meta-blocks, and updates the "*storage_ix" bit position.
  28
  29    If "is_last" is 1, emits an additional empty last meta-block.
  30
  31    REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
  32    REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
  33    REQUIRES: "command_buf" and "literal_buf" point to at least
  34               kCompressFragmentTwoPassBlockSize long arrays.
  35    REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
  36    REQUIRES: "table_size" is a power of two
  37    OUTPUT: maximal copy distance <= |input_size|
  38    OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
  39 BROTLI_INTERNAL void BrotliCompressFragmentTwoPass(MemoryManager* m,
  40                                                    const uint8_t* input,
  41                                                    size_t input_size,
  42                                                    BROTLI_BOOL is_last,
  43                                                    uint32_t* command_buf,
  44                                                    uint8_t* literal_buf,
  45                                                    int* table,
  46                                                    size_t table_size,
  47                                                    size_t* storage_ix,
  48                                                    uint8_t* storage);
  49
  50 #if defined(__cplusplus) || defined(c_plusplus)
  51 }  /* extern "C" */
  52 #endif
  53
  54 #endif  /* BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_ */