enc/compress_fragment_two_pass.h

/* Copyright 2015 Google Inc. All Rights Reserved.

   Distributed under MIT license.
   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/

// Function for fast encoding of an input fragment, independently from the input
// history. This function uses two-pass processing: in the first pass we save
// the found backward matches and literal bytes into a buffer, and in the
// second pass we emit them into the bit stream using prefix codes built based
// on the actual command and literal byte histograms.

#ifndef BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
#define BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_

#include "./types.h"

namespace brotli {

static const size_t kCompressFragmentTwoPassBlockSize = 1 << 17;

// Compresses "input" string to the "*storage" buffer as one or more complete
// meta-blocks, and updates the "*storage_ix" bit position.
//
// If "is_last" is true, emits an additional empty last meta-block.
//
// REQUIRES: "input_size" is greater than zero, or "is_last" is true.
// REQUIRES: "command_buf" and "literal_buf" point to at least
//            kCompressFragmentTwoPassBlockSize long arrays.
// REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
// REQUIRES: "table_size" is a power of two
void BrotliCompressFragmentTwoPass(const uint8_t* input, size_t input_size,
                                   bool is_last,
                                   uint32_t* command_buf, uint8_t* literal_buf,
                                   int* table, size_t table_size,
                                   size_t* storage_ix, uint8_t* storage);

}  // namespace brotli

#endif  // BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_