brotli/enc/brotli_bit_stream.h
2016-08-23 14:40:33 +02:00

108 lines
4.8 KiB
C

/* Copyright 2014 Google Inc. All Rights Reserved.
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);
/* Stores an empty metadata meta-block and syncs to a byte boundary. */
BROTLI_INTERNAL void BrotliStoreSyncMetaBlock(size_t* storage_ix,
uint8_t* storage);
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
#endif /* BROTLI_ENC_BROTLI_BIT_STREAM_H_ */