1 // Copyright 2017 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef _BSDIFF_PATCH_WRITER_H_ 6 #define _BSDIFF_PATCH_WRITER_H_ 7 8 #include <memory> 9 #include <string> 10 #include <vector> 11 12 #include "bsdiff/compressor_interface.h" 13 #include "bsdiff/patch_writer_interface.h" 14 15 namespace bsdiff { 16 17 // A PatchWriterInterface class with three compressors and a 32-byte header. 18 class BsdiffPatchWriter : public PatchWriterInterface { 19 public: 20 // Create the patch writer using the upstream's "BSDIFF40" format. It uses 21 // bz2 as the compression algorithm and the file |patch_filename| to write 22 // the patch data. 23 explicit BsdiffPatchWriter(const std::string& patch_filename); 24 25 // Create the patch writer using the "BSDF2" format. It uses the compressor 26 // with algorithm |type|; and quality |brotli_quality| if it's brotli. This 27 // writer also writes the patch data to the file |patch_filename|. 28 BsdiffPatchWriter(const std::string& patch_filename, 29 const std::vector<CompressorType>& types, 30 int brotli_quality); 31 32 // PatchWriterInterface overrides. 33 bool Init(size_t new_size) override; 34 bool WriteDiffStream(const uint8_t* data, size_t size) override; 35 bool WriteExtraStream(const uint8_t* data, size_t size) override; 36 bool AddControlEntry(const ControlEntry& entry) override; 37 bool Close() override; 38 39 private: 40 // Add supported compressors to |compressor_list|; return false if we failed 41 // to initialize one of them. 42 bool InitializeCompressorList( 43 std::vector<std::unique_ptr<CompressorInterface>>* compressor_list); 44 45 // Select the compressor in |compressor_list| that produces the smallest 46 // patch, and put the result in |smallest_compressor|. 47 bool SelectSmallestResult( 48 const std::vector<std::unique_ptr<CompressorInterface>>& compressor_list, 49 CompressorInterface** smallest_compressor); 50 51 52 // Write the BSDIFF patch header to the |fp_|. 53 // Arguments: 54 // A three bytes array with the compressor types of ctrl|diff|extra stream 55 // Size of the compressed control block 56 // Size of the compressed diff block. 57 bool WriteHeader(uint8_t types[3], uint64_t ctrl_size, uint64_t diff_size); 58 59 // Bytes of the new files already written. Needed to store the new length in 60 // the header of the file. 61 uint64_t written_output_{0}; 62 63 // The current file we are writing to. 64 FILE* fp_{nullptr}; 65 std::string patch_filename_; 66 67 // The format of bsdiff we're using. 68 BsdiffFormat format_; 69 70 // The compressors we're using. 71 std::vector<CompressorType> types_; 72 73 // The compression quality of the brotli compressor. 74 int brotli_quality_; 75 76 // The list of compressors to try for each stream. 77 std::vector<std::unique_ptr<CompressorInterface>> ctrl_stream_list_; 78 std::vector<std::unique_ptr<CompressorInterface>> diff_stream_list_; 79 std::vector<std::unique_ptr<CompressorInterface>> extra_stream_list_; 80 }; 81 82 } // namespace bsdiff 83 84 #endif // _BSDIFF_PATCH_WRITER_H_ 85
