mirror of
https://github.com/google/brotli.git
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216 lines
6.0 KiB
C
216 lines
6.0 KiB
C
/* Copyright 2015 Google Inc. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/* Brotli state for partial streaming decoding. */
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#ifndef BROTLI_DEC_STATE_H_
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#define BROTLI_DEC_STATE_H_
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#include <stdio.h>
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#include "./bit_reader.h"
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#include "./huffman.h"
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#include "./streams.h"
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#include "./types.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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typedef enum {
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BROTLI_STATE_UNINITED,
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BROTLI_STATE_BITREADER_WARMUP,
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BROTLI_STATE_METABLOCK_BEGIN,
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BROTLI_STATE_METABLOCK_HEADER,
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BROTLI_STATE_CONTEXT_MODES,
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BROTLI_STATE_COMMAND_BEGIN,
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BROTLI_STATE_COMMAND_INNER,
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BROTLI_STATE_UNCOMPRESSED,
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BROTLI_STATE_METADATA,
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BROTLI_STATE_COMMAND_INNER_WRITE,
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BROTLI_STATE_METABLOCK_DONE,
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BROTLI_STATE_COMMAND_POST_WRITE_1,
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BROTLI_STATE_COMMAND_POST_WRITE_2,
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BROTLI_STATE_COMMAND_POST_WRAP_COPY,
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BROTLI_STATE_HUFFMAN_CODE_0,
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BROTLI_STATE_HUFFMAN_CODE_1,
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BROTLI_STATE_HUFFMAN_CODE_2,
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BROTLI_STATE_HUFFMAN_CODE_3,
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BROTLI_STATE_CONTEXT_MAP_1,
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BROTLI_STATE_CONTEXT_MAP_2,
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BROTLI_STATE_TREE_GROUP,
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BROTLI_STATE_DONE
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} BrotliRunningState;
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typedef enum {
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BROTLI_STATE_METABLOCK_HEADER_NONE,
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BROTLI_STATE_METABLOCK_HEADER_EMPTY,
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BROTLI_STATE_METABLOCK_HEADER_NIBBLES,
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BROTLI_STATE_METABLOCK_HEADER_SIZE,
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BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED,
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BROTLI_STATE_METABLOCK_HEADER_RESERVED,
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BROTLI_STATE_METABLOCK_HEADER_BYTES,
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BROTLI_STATE_METABLOCK_HEADER_METADATA
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} BrotliRunningMetablockHeaderState;
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typedef enum {
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BROTLI_STATE_UNCOMPRESSED_NONE,
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BROTLI_STATE_UNCOMPRESSED_SHORT,
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BROTLI_STATE_UNCOMPRESSED_COPY,
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BROTLI_STATE_UNCOMPRESSED_WRITE
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} BrotliRunningUncompressedState;
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typedef enum {
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BROTLI_STATE_TREE_GROUP_NONE,
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BROTLI_STATE_TREE_GROUP_LOOP
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} BrotliRunningTreeGroupState;
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typedef enum {
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BROTLI_STATE_CONTEXT_MAP_NONE,
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BROTLI_STATE_CONTEXT_MAP_READ_PREFIX,
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BROTLI_STATE_CONTEXT_MAP_HUFFMAN,
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BROTLI_STATE_CONTEXT_MAP_DECODE
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} BrotliRunningContextMapState;
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typedef enum {
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BROTLI_STATE_HUFFMAN_NONE,
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BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS
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} BrotliRunningHuffmanState;
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typedef enum {
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BROTLI_STATE_DECODE_UINT8_NONE,
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BROTLI_STATE_DECODE_UINT8_SHORT,
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BROTLI_STATE_DECODE_UINT8_LONG
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} BrotliRunningDecodeUint8State;
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typedef struct {
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BrotliRunningState state;
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/* This counter is reused for several disjoint loops. */
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BrotliBitReader br;
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int loop_counter;
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int pos;
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int max_backward_distance;
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int max_backward_distance_minus_custom_dict_size;
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int max_distance;
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int ringbuffer_size;
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int ringbuffer_mask;
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int dist_rb_idx;
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int dist_rb[4];
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uint8_t* ringbuffer;
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uint8_t* ringbuffer_end;
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HuffmanCode* htree_command;
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const uint8_t* context_lookup1;
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const uint8_t* context_lookup2;
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uint8_t* context_map_slice;
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uint8_t* dist_context_map_slice;
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/* This ring buffer holds a few past copy distances that will be used by */
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/* some special distance codes. */
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HuffmanTreeGroup literal_hgroup;
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HuffmanTreeGroup insert_copy_hgroup;
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HuffmanTreeGroup distance_hgroup;
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HuffmanCode* block_type_trees;
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HuffmanCode* block_len_trees;
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/* This is true if the literal context map histogram type always matches the
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block type. It is then not needed to keep the context (faster decoding). */
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int trivial_literal_context;
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int distance_context;
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int meta_block_remaining_len;
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int block_length[3];
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int num_block_types[3];
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int block_type_rb[6];
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int distance_postfix_bits;
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int num_direct_distance_codes;
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int distance_postfix_mask;
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int num_dist_htrees;
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uint8_t* dist_context_map;
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HuffmanCode *literal_htree;
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uint8_t literal_htree_index;
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uint8_t dist_htree_index;
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uint8_t repeat_code_len;
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uint8_t prev_code_len;
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int copy_length;
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int distance_code;
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/* For partial write operations */
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int to_write;
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int partially_written;
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/* For ReadHuffmanCode */
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uint32_t symbol;
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uint32_t repeat;
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uint32_t space;
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HuffmanCode table[32];
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/* List of of symbol chains. */
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uint16_t* symbol_lists;
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/* Storage from symbol_lists. */
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uint16_t symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1 +
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BROTLI_HUFFMAN_MAX_CODE_LENGTHS_SIZE];
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/* Tails of symbol chains. */
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int next_symbol[32];
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uint8_t code_length_code_lengths[18];
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/* Population counts for the code lengths */
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uint16_t code_length_histo[16];
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/* For HuffmanTreeGroupDecode */
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int htree_index;
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HuffmanCode* next;
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/* For DecodeContextMap */
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int context_index;
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int max_run_length_prefix;
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HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_TABLE_SIZE];
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/* For InverseMoveToFrontTransform */
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int mtf_upper_bound;
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uint8_t mtf[256];
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/* For custom dictionaries */
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const uint8_t* custom_dict;
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int custom_dict_size;
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/* less used attributes are in the end of this struct */
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/* States inside function calls */
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BrotliRunningMetablockHeaderState substate_metablock_header;
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BrotliRunningTreeGroupState substate_tree_group;
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BrotliRunningContextMapState substate_context_map;
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BrotliRunningUncompressedState substate_uncompressed;
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BrotliRunningHuffmanState substate_huffman;
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BrotliRunningDecodeUint8State substate_decode_uint8;
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uint8_t is_last_metablock;
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uint8_t is_uncompressed;
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uint8_t is_metadata;
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uint8_t size_nibbles;
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uint32_t window_bits;
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int num_literal_htrees;
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uint8_t* context_map;
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uint8_t* context_modes;
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} BrotliState;
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void BrotliStateInit(BrotliState* s);
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void BrotliStateCleanup(BrotliState* s);
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void BrotliStateMetablockBegin(BrotliState* s);
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void BrotliStateCleanupAfterMetablock(BrotliState* s);
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#if defined(__cplusplus) || defined(c_plusplus)
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} /* extern "C" */
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#endif
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#endif /* BROTLI_DEC_STATE_H_ */
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