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b4f39bf540
The new interface of the backward reference search function makes it possible to use it in a streaming manner. Using the advanced cost model and static dictionary can be turned on/off by template parameters. The distance short codes are now computed as part of the backward reference search. Added a faster version of the Hasher.
91 lines
2.7 KiB
C++
91 lines
2.7 KiB
C++
// Copyright 2013 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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// API for Brotli compression
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#ifndef BROTLI_ENC_ENCODE_H_
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#define BROTLI_ENC_ENCODE_H_
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#include <stddef.h>
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#include <stdint.h>
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#include <string>
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#include <vector>
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#include "./hash.h"
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#include "./ringbuffer.h"
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#include "./static_dict.h"
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namespace brotli {
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struct BrotliParams {
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enum Mode {
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MODE_TEXT = 0,
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MODE_FONT = 1,
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};
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Mode mode;
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BrotliParams() : mode(MODE_TEXT) {}
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};
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class BrotliCompressor {
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public:
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explicit BrotliCompressor(BrotliParams params);
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~BrotliCompressor();
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// Writes the stream header into the internal output buffer.
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void WriteStreamHeader();
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// Encodes the data in input_buffer as a meta-block and writes it to
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// encoded_buffer and sets *encoded_size to the number of bytes that was
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// written.
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void WriteMetaBlock(const size_t input_size,
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const uint8_t* input_buffer,
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const bool is_last,
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size_t* encoded_size,
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uint8_t* encoded_buffer);
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// Writes a zero-length meta-block with end-of-input bit set to the
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// internal output buffer and copies the output buffer to encoded_buffer and
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// sets *encoded_size to the number of bytes written.
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void FinishStream(size_t* encoded_size, uint8_t* encoded_buffer);
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private:
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// Initializes the hasher with the hashes of dictionary words.
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void StoreDictionaryWordHashes();
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BrotliParams params_;
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int window_bits_;
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std::unique_ptr<Hashers> hashers_;
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int hash_type_;
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size_t input_pos_;
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RingBuffer ringbuffer_;
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std::vector<float> literal_cost_;
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int dist_cache_[4];
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int storage_ix_;
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uint8_t* storage_;
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static StaticDictionary *static_dictionary_;
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};
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// Compresses the data in input_buffer into encoded_buffer, and sets
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// *encoded_size to the compressed length.
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// Returns 0 if there was an error and 1 otherwise.
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int BrotliCompressBuffer(BrotliParams params,
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size_t input_size,
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const uint8_t* input_buffer,
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size_t* encoded_size,
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uint8_t* encoded_buffer);
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} // namespace brotli
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#endif // BROTLI_ENC_ENCODE_H_
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