third_party/brotli/enc/compress_fragment.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 one-pass processing: when we find a backward
// match, we immediately emit the corresponding command and literal codes to
// the bit stream.

#ifndef BROTLI_ENC_COMPRESS_FRAGMENT_H_
#define BROTLI_ENC_COMPRESS_FRAGMENT_H_

#include "./types.h"

namespace brotli {

// 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.
//
// "cmd_depth" and "cmd_bits" contain the command and distance prefix codes
// (see comment in encode.h) used for the encoding of this input fragment.
// If "is_last" is false, they are updated to reflect the statistics
// of this input fragment, to be used for the encoding of the next fragment.
//
// "*cmd_code_numbits" is the number of bits of the compressed representation
// of the command and distance prefix codes, and "cmd_code" is an array of
// at least "(*cmd_code_numbits + 7) >> 3" size that contains the compressed
// command and distance prefix codes. If "is_last" is false, these are also
// updated to represent the updated "cmd_depth" and "cmd_bits".
//
// REQUIRES: "input_size" is greater than zero, or "is_last" is true.
// REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
// REQUIRES: "table_size" is a power of two
void BrotliCompressFragmentFast(const uint8_t* input, size_t input_size,
                                bool is_last,
                                int* table, size_t table_size,
                                uint8_t cmd_depth[128], uint16_t cmd_bits[128],
                                size_t* cmd_code_numbits, uint8_t* cmd_code,
                                size_t* storage_ix, uint8_t* storage);

}  // namespace brotli

#endif  // BROTLI_ENC_COMPRESS_FRAGMENT_H_