aosp12/external/bsdiff/patch_writer.h

85 lines
3.0 KiB
C++

// Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef _BSDIFF_PATCH_WRITER_H_
#define _BSDIFF_PATCH_WRITER_H_
#include <memory>
#include <string>
#include <vector>
#include "bsdiff/compressor_interface.h"
#include "bsdiff/patch_writer_interface.h"
namespace bsdiff {
// A PatchWriterInterface class with three compressors and a 32-byte header.
class BsdiffPatchWriter : public PatchWriterInterface {
public:
// Create the patch writer using the upstream's "BSDIFF40" format. It uses
// bz2 as the compression algorithm and the file |patch_filename| to write
// the patch data.
explicit BsdiffPatchWriter(const std::string& patch_filename);
// Create the patch writer using the "BSDF2" format. It uses the compressor
// with algorithm |type|; and quality |brotli_quality| if it's brotli. This
// writer also writes the patch data to the file |patch_filename|.
BsdiffPatchWriter(const std::string& patch_filename,
const std::vector<CompressorType>& types,
int brotli_quality);
// PatchWriterInterface overrides.
bool Init(size_t new_size) override;
bool WriteDiffStream(const uint8_t* data, size_t size) override;
bool WriteExtraStream(const uint8_t* data, size_t size) override;
bool AddControlEntry(const ControlEntry& entry) override;
bool Close() override;
private:
// Add supported compressors to |compressor_list|; return false if we failed
// to initialize one of them.
bool InitializeCompressorList(
std::vector<std::unique_ptr<CompressorInterface>>* compressor_list);
// Select the compressor in |compressor_list| that produces the smallest
// patch, and put the result in |smallest_compressor|.
bool SelectSmallestResult(
const std::vector<std::unique_ptr<CompressorInterface>>& compressor_list,
CompressorInterface** smallest_compressor);
// Write the BSDIFF patch header to the |fp_|.
// Arguments:
// A three bytes array with the compressor types of ctrl|diff|extra stream
// Size of the compressed control block
// Size of the compressed diff block.
bool WriteHeader(uint8_t types[3], uint64_t ctrl_size, uint64_t diff_size);
// Bytes of the new files already written. Needed to store the new length in
// the header of the file.
uint64_t written_output_{0};
// The current file we are writing to.
FILE* fp_{nullptr};
std::string patch_filename_;
// The format of bsdiff we're using.
BsdiffFormat format_;
// The compressors we're using.
std::vector<CompressorType> types_;
// The compression quality of the brotli compressor.
int brotli_quality_;
// The list of compressors to try for each stream.
std::vector<std::unique_ptr<CompressorInterface>> ctrl_stream_list_;
std::vector<std::unique_ptr<CompressorInterface>> diff_stream_list_;
std::vector<std::unique_ptr<CompressorInterface>> extra_stream_list_;
};
} // namespace bsdiff
#endif // _BSDIFF_PATCH_WRITER_H_