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72 lines
2.2 KiB
72 lines
2.2 KiB
2 years ago
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// Copyright 2015 Google Inc. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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// Algorithms for distributing the literals and commands of a metablock between
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// block types and contexts.
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#ifndef BROTLI_ENC_METABLOCK_H_
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#define BROTLI_ENC_METABLOCK_H_
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#include <vector>
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#include "./command.h"
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#include "./histogram.h"
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namespace brotli {
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struct BlockSplit {
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BlockSplit() : num_types(0) {}
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int num_types;
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std::vector<int> types;
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std::vector<int> lengths;
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};
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struct MetaBlockSplit {
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BlockSplit literal_split;
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BlockSplit command_split;
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BlockSplit distance_split;
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std::vector<int> literal_context_map;
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std::vector<int> distance_context_map;
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std::vector<HistogramLiteral> literal_histograms;
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std::vector<HistogramCommand> command_histograms;
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std::vector<HistogramDistance> distance_histograms;
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};
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void BuildMetaBlock(const uint8_t* ringbuffer,
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const size_t pos,
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const size_t mask,
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uint8_t prev_byte,
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uint8_t prev_byte2,
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const Command* cmds,
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size_t num_commands,
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int literal_context_mode,
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bool enable_context_modleing,
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MetaBlockSplit* mb);
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void BuildMetaBlockGreedy(const uint8_t* ringbuffer,
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size_t pos,
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size_t mask,
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const Command *commands,
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size_t n_commands,
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MetaBlockSplit* mb);
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void OptimizeHistograms(int num_direct_distance_codes,
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int distance_postfix_bits,
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MetaBlockSplit* mb);
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} // namespace brotli
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#endif // BROTLI_ENC_METABLOCK_H_
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