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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Functions to compress and decompress low entropy entries in the model.
#ifndef LIBTEXTCLASSIFIER_ZLIB_UTILS_H_
#define LIBTEXTCLASSIFIER_ZLIB_UTILS_H_
#include <memory>
#include "model_generated.h"
#include "util/utf8/unilib.h"
#include "zlib.h"
namespace libtextclassifier2 {
class ZlibDecompressor {
public:
static std::unique_ptr<ZlibDecompressor> Instance();
~ZlibDecompressor();
bool Decompress(const CompressedBuffer* compressed_buffer, std::string* out);
private:
ZlibDecompressor();
z_stream stream_;
bool initialized_;
};
class ZlibCompressor {
public:
static std::unique_ptr<ZlibCompressor> Instance();
~ZlibCompressor();
void Compress(const std::string& uncompressed_content,
CompressedBufferT* out);
private:
explicit ZlibCompressor(int level = Z_BEST_COMPRESSION,
// Tmp. buffer size was set based on the current set
// of patterns to be compressed.
int tmp_buffer_size = 64 * 1024);
z_stream stream_;
std::unique_ptr<Bytef[]> buffer_;
unsigned int buffer_size_;
bool initialized_;
};
// Compresses regex and datetime rules in the model in place.
bool CompressModel(ModelT* model);
// Compresses regex and datetime rules in the model.
std::string CompressSerializedModel(const std::string& model);
// Create and compile a regex pattern from optionally compressed pattern.
std::unique_ptr<UniLib::RegexPattern> UncompressMakeRegexPattern(
const UniLib& unilib, const flatbuffers::String* uncompressed_pattern,
const CompressedBuffer* compressed_pattern, ZlibDecompressor* decompressor);
} // namespace libtextclassifier2
#endif // LIBTEXTCLASSIFIER_ZLIB_UTILS_H_