1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 // Functions to compress and decompress low entropy entries in the model. 18 19 #ifndef LIBTEXTCLASSIFIER_UTILS_ZLIB_ZLIB_H_ 20 #define LIBTEXTCLASSIFIER_UTILS_ZLIB_ZLIB_H_ 21 22 #include <vector> 23 24 #include "utils/base/integral_types.h" 25 #include "utils/zlib/buffer_generated.h" 26 #include <zlib.h> 27 28 namespace libtextclassifier3 { 29 30 class ZlibDecompressor { 31 public: 32 static std::unique_ptr<ZlibDecompressor> Instance(); 33 ~ZlibDecompressor(); 34 35 bool Decompress(const uint8* buffer, const int buffer_size, 36 const int uncompressed_size, std::string* out); 37 bool MaybeDecompress(const CompressedBuffer* compressed_buffer, 38 std::string* out); 39 bool MaybeDecompress(const CompressedBufferT* compressed_buffer, 40 std::string* out); 41 bool MaybeDecompressOptionallyCompressedBuffer( 42 const flatbuffers::String* uncompressed_buffer, 43 const CompressedBuffer* compressed_buffer, std::string* out); 44 bool MaybeDecompressOptionallyCompressedBuffer( 45 const flatbuffers::Vector<uint8>* uncompressed_buffer, 46 const CompressedBuffer* compressed_buffer, std::string* out); 47 48 private: 49 explicit ZlibDecompressor(); 50 z_stream stream_; 51 bool initialized_; 52 }; 53 54 class ZlibCompressor { 55 public: 56 static std::unique_ptr<ZlibCompressor> Instance(); 57 ~ZlibCompressor(); 58 59 void Compress(const std::string& uncompressed_content, 60 CompressedBufferT* out); 61 62 private: 63 explicit ZlibCompressor(const int level = Z_BEST_COMPRESSION, 64 // Tmp. buffer size was set based on the current set 65 // of patterns to be compressed. 66 const int tmp_buffer_size = 64 * 1024); 67 z_stream stream_; 68 std::unique_ptr<Bytef[]> buffer_; 69 unsigned int buffer_size_; 70 bool initialized_; 71 }; 72 73 } // namespace libtextclassifier3 74 75 #endif // LIBTEXTCLASSIFIER_UTILS_ZLIB_ZLIB_H_ 76