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 |quality|. This writer also writes the 27 // patch data to the file |patch_filename|. 28 BsdiffPatchWriter(const std::string& patch_filename, 29 CompressorType type, 30 int 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 // Write the BSDIFF patch header to the |fp_| given the size of the compressed 41 // control block and the compressed diff block. 42 bool WriteHeader(uint64_t ctrl_size, uint64_t diff_size); 43 44 // Bytes of the new files already written. Needed to store the new length in 45 // the header of the file. 46 uint64_t written_output_{0}; 47 48 // The current file we are writing to. 49 FILE* fp_{nullptr}; 50 std::string patch_filename_; 51 52 // The format of bsdiff we're using. 53 BsdiffFormat format_; 54 55 // The three internal compressed streams. 56 std::unique_ptr<CompressorInterface> ctrl_stream_{nullptr}; 57 std::unique_ptr<CompressorInterface> diff_stream_{nullptr}; 58 std::unique_ptr<CompressorInterface> extra_stream_{nullptr}; 59 }; 60 61 } // namespace bsdiff 62 63 #endif // _BSDIFF_PATCH_WRITER_H_ 64