| Index: third_party/brotli/enc/brotli_bit_stream.h
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| diff --git a/third_party/brotli/enc/brotli_bit_stream.h b/third_party/brotli/enc/brotli_bit_stream.h
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| new file mode 100644
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| index 0000000000000000000000000000000000000000..6c706535c8037af1fd85c44df705e9f95779f190
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| --- /dev/null
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| +++ b/third_party/brotli/enc/brotli_bit_stream.h
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| @@ -0,0 +1,179 @@
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| +/* Copyright 2014 Google Inc. All Rights Reserved.
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| +
|
| + Distributed under MIT license.
|
| + See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
|
| +*/
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| +
|
| +// Functions to convert brotli-related data structures into the
|
| +// brotli bit stream. The functions here operate under
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| +// assumption that there is enough space in the storage, i.e., there are
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| +// no out-of-range checks anywhere.
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| +//
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| +// These functions do bit addressing into a byte array. The byte array
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| +// is called "storage" and the index to the bit is called storage_ix
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| +// in function arguments.
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| +
|
| +#ifndef BROTLI_ENC_BROTLI_BIT_STREAM_H_
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| +#define BROTLI_ENC_BROTLI_BIT_STREAM_H_
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| +
|
| +#include <vector>
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| +
|
| +#include "./entropy_encode.h"
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| +#include "./metablock.h"
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| +#include "./types.h"
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| +
|
| +namespace brotli {
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| +
|
| +// All Store functions here will use a storage_ix, which is always the bit
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| +// position for the current storage.
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| +
|
| +// Stores a number between 0 and 255.
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| +void StoreVarLenUint8(size_t n, size_t* storage_ix, uint8_t* storage);
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| +
|
| +// Stores the compressed meta-block header.
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| +// REQUIRES: length > 0
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| +// REQUIRES: length <= (1 << 24)
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| +void StoreCompressedMetaBlockHeader(bool final_block,
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| + size_t length,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
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| +// Stores the uncompressed meta-block header.
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| +// REQUIRES: length > 0
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| +// REQUIRES: length <= (1 << 24)
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| +void StoreUncompressedMetaBlockHeader(size_t length,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
|
| +// Stores a context map where the histogram type is always the block type.
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| +void StoreTrivialContextMap(size_t num_types,
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| + size_t context_bits,
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| + HuffmanTree* tree,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
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| +void StoreHuffmanTreeOfHuffmanTreeToBitMask(
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| + const int num_codes,
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| + const uint8_t *code_length_bitdepth,
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| + size_t *storage_ix,
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| + uint8_t *storage);
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| +
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| +void StoreHuffmanTree(const uint8_t* depths, size_t num, HuffmanTree* tree,
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| + size_t *storage_ix, uint8_t *storage);
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| +
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| +// Builds a Huffman tree from histogram[0:length] into depth[0:length] and
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| +// bits[0:length] and stores the encoded tree to the bit stream.
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| +void BuildAndStoreHuffmanTree(const uint32_t *histogram,
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| + const size_t length,
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| + HuffmanTree* tree,
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| + uint8_t* depth,
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| + uint16_t* bits,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
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| +void BuildAndStoreHuffmanTreeFast(const uint32_t *histogram,
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| + const size_t histogram_total,
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| + const size_t max_bits,
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| + uint8_t* depth,
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| + uint16_t* bits,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
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| +// Encodes the given context map to the bit stream. The number of different
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| +// histogram ids is given by num_clusters.
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| +void EncodeContextMap(const std::vector<uint32_t>& context_map,
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| + size_t num_clusters,
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| + HuffmanTree* tree,
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| + size_t* storage_ix, uint8_t* storage);
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| +
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| +// Data structure that stores everything that is needed to encode each block
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| +// switch command.
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| +struct BlockSplitCode {
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| + std::vector<uint32_t> type_code;
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| + std::vector<uint32_t> length_prefix;
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| + std::vector<uint32_t> length_nextra;
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| + std::vector<uint32_t> length_extra;
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| + std::vector<uint8_t> type_depths;
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| + std::vector<uint16_t> type_bits;
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| + uint8_t length_depths[kNumBlockLenPrefixes];
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| + uint16_t length_bits[kNumBlockLenPrefixes];
|
| +};
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| +
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| +// Builds a BlockSplitCode data structure from the block split given by the
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| +// vector of block types and block lengths and stores it to the bit stream.
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| +void BuildAndStoreBlockSplitCode(const std::vector<uint8_t>& types,
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| + const std::vector<uint32_t>& lengths,
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| + const size_t num_types,
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| + BlockSplitCode* code,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
|
| +// Stores the block switch command with index block_ix to the bit stream.
|
| +void StoreBlockSwitch(const BlockSplitCode& code,
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| + const size_t block_ix,
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| + size_t* storage_ix,
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| + uint8_t* storage);
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| +
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| +// REQUIRES: length > 0
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| +// REQUIRES: length <= (1 << 24)
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| +void StoreMetaBlock(const uint8_t* input,
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| + size_t start_pos,
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| + size_t length,
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| + size_t mask,
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| + uint8_t prev_byte,
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| + uint8_t prev_byte2,
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| + bool final_block,
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| + uint32_t num_direct_distance_codes,
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| + uint32_t distance_postfix_bits,
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| + ContextType literal_context_mode,
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| + const brotli::Command *commands,
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| + size_t n_commands,
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| + const MetaBlockSplit& mb,
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| + size_t *storage_ix,
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| + uint8_t *storage);
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| +
|
| +// Stores the meta-block without doing any block splitting, just collects
|
| +// one histogram per block category and uses that for entropy coding.
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| +// REQUIRES: length > 0
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| +// REQUIRES: length <= (1 << 24)
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| +void StoreMetaBlockTrivial(const uint8_t* input,
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| + size_t start_pos,
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| + size_t length,
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| + size_t mask,
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| + bool is_last,
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| + const brotli::Command *commands,
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| + 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)
|
| +void StoreMetaBlockFast(const uint8_t* input,
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| + size_t start_pos,
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| + size_t length,
|
| + size_t mask,
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| + bool is_last,
|
| + const brotli::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)
|
| +void StoreUncompressedMetaBlock(bool final_block,
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| + const uint8_t* input,
|
| + size_t position, size_t mask,
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| + size_t len,
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| + size_t* storage_ix,
|
| + uint8_t* storage);
|
| +
|
| +// Stores an empty metadata meta-block and syncs to a byte boundary.
|
| +void StoreSyncMetaBlock(size_t* storage_ix, uint8_t* storage);
|
| +
|
| +} // namespace brotli
|
| +
|
| +#endif // BROTLI_ENC_BROTLI_BIT_STREAM_H_
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|
|