관리-도구

편집 파일: brotli_bit_stream.h

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

/* Functions to convert brotli-related data structures into the
   brotli bit stream. The functions here operate under
   assumption that there is enough space in the storage, i.e., there are
   no out-of-range checks anywhere.

These functions do bit addressing into a byte array. The byte array
   is called "storage" and the index to the bit is called storage_ix
   in function arguments. */

#ifndef BROTLI_ENC_BROTLI_BIT_STREAM_H_
#define BROTLI_ENC_BROTLI_BIT_STREAM_H_

#include <brotli/types.h>
#include "./command.h"
#include "./context.h"
#include "./entropy_encode.h"
#include "./memory.h"
#include "./metablock.h"
#include "./port.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

/* All Store functions here will use a storage_ix, which is always the bit
   position for the current storage. */

BROTLI_INTERNAL void BrotliStoreHuffmanTree(const uint8_t* depths, size_t num,
    HuffmanTree* tree, size_t *storage_ix, uint8_t *storage);

BROTLI_INTERNAL void BrotliBuildAndStoreHuffmanTreeFast(
    MemoryManager* m, const uint32_t* histogram, const size_t histogram_total,
    const size_t max_bits, uint8_t* depth, uint16_t* bits, size_t* storage_ix,
    uint8_t* storage);

/* REQUIRES: length > 0 */
/* REQUIRES: length <= (1 << 24) */
BROTLI_INTERNAL void BrotliStoreMetaBlock(MemoryManager* m,
                                          const uint8_t* input,
                                          size_t start_pos,
                                          size_t length,
                                          size_t mask,
                                          uint8_t prev_byte,
                                          uint8_t prev_byte2,
                                          BROTLI_BOOL is_final_block,
                                          uint32_t num_direct_distance_codes,
                                          uint32_t distance_postfix_bits,
                                          ContextType literal_context_mode,
                                          const Command* commands,
                                          size_t n_commands,
                                          const MetaBlockSplit* mb,
                                          size_t* storage_ix,
                                          uint8_t* storage);

/* Stores the meta-block without doing any block splitting, just collects
   one histogram per block category and uses that for entropy coding.
   REQUIRES: length > 0
   REQUIRES: length <= (1 << 24) */
BROTLI_INTERNAL void BrotliStoreMetaBlockTrivial(MemoryManager* m,
                                                 const uint8_t* input,
                                                 size_t start_pos,
                                                 size_t length,
                                                 size_t mask,
                                                 BROTLI_BOOL is_last,
                                                 const Command *commands,
                                                 size_t n_commands,
                                                 size_t* storage_ix,
                                                 uint8_t* storage);

/* Same as above, but uses static prefix codes for histograms with a only a few
   symbols, and uses static code length prefix codes for all other histograms.
   REQUIRES: length > 0
   REQUIRES: length <= (1 << 24) */
BROTLI_INTERNAL void BrotliStoreMetaBlockFast(MemoryManager* m,
                                              const uint8_t* input,
                                              size_t start_pos,
                                              size_t length,
                                              size_t mask,
                                              BROTLI_BOOL is_last,
                                              const Command *commands,
                                              size_t n_commands,
                                              size_t* storage_ix,
                                              uint8_t* storage);

/* This is for storing uncompressed blocks (simple raw storage of
   bytes-as-bytes).
   REQUIRES: length > 0
   REQUIRES: length <= (1 << 24) */
BROTLI_INTERNAL void BrotliStoreUncompressedMetaBlock(
    BROTLI_BOOL is_final_block, const uint8_t* input, size_t position,
    size_t mask, size_t len, size_t* storage_ix, uint8_t* storage);

#if defined(__cplusplus) || defined(c_plusplus)
}  /* extern "C" */
#endif

#endif  /* BROTLI_ENC_BROTLI_BIT_STREAM_H_ */