update_engine/payload_consumer/bzip_extent_writer.h

//
// Copyright (C) 2009 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.
//

#ifndef UPDATE_ENGINE_PAYLOAD_CONSUMER_BZIP_EXTENT_WRITER_H_
#define UPDATE_ENGINE_PAYLOAD_CONSUMER_BZIP_EXTENT_WRITER_H_

#include <bzlib.h>
#include <memory>
#include <vector>

#include <brillo/secure_blob.h>

#include "update_engine/common/utils.h"
#include "update_engine/payload_consumer/extent_writer.h"

// BzipExtentWriter is a concrete ExtentWriter subclass that bzip-decompresses
// what it's given in Write. It passes the decompressed data to an underlying
// ExtentWriter.

namespace chromeos_update_engine {

class BzipExtentWriter : public ExtentWriter {
 public:
  explicit BzipExtentWriter(std::unique_ptr<ExtentWriter> next)
      : next_(std::move(next)) {
    memset(&stream_, 0, sizeof(stream_));
  }
  ~BzipExtentWriter() override = default;

  bool Init(FileDescriptorPtr fd,
            const std::vector<Extent>& extents,
            uint32_t block_size) override;
  bool Write(const void* bytes, size_t count) override;
  bool EndImpl() override;

 private:
  std::unique_ptr<ExtentWriter> next_;  // The underlying ExtentWriter.
  bz_stream stream_;  // the libbz2 stream
  brillo::Blob input_buffer_;
};

}  // namespace chromeos_update_engine

#endif  // UPDATE_ENGINE_PAYLOAD_CONSUMER_BZIP_EXTENT_WRITER_H_