update_engine/fake_file_writer.h

// Copyright 2009 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UPDATE_ENGINE_FAKE_FILE_WRITER_H_
#define UPDATE_ENGINE_FAKE_FILE_WRITER_H_

#include <vector>

#include <brillo/secure_blob.h>

#include "update_engine/payload_consumer/file_writer.h"

// FakeFileWriter is an implementation of FileWriter. It will succeed
// calls to Open(), Close(), but not do any work. All calls to Write()
// will append the passed data to an internal vector.

namespace chromeos_update_engine {

class FakeFileWriter : public FileWriter {
 public:
  FakeFileWriter() : was_opened_(false), was_closed_(false) {}
  FakeFileWriter(const FakeFileWriter&) = delete;
  FakeFileWriter& operator=(const FakeFileWriter&) = delete;

  virtual int Open(const char* path, int flags, mode_t mode) {
    CHECK(!was_opened_);
    CHECK(!was_closed_);
    was_opened_ = true;
    return 0;
  }

  virtual ssize_t Write(const void* bytes, size_t count) {
    CHECK(was_opened_);
    CHECK(!was_closed_);
    const char* char_bytes = reinterpret_cast<const char*>(bytes);
    bytes_.insert(bytes_.end(), char_bytes, char_bytes + count);
    return count;
  }

  virtual int Close() {
    CHECK(was_opened_);
    CHECK(!was_closed_);
    was_closed_ = true;
    return 0;
  }

  const brillo::Blob& bytes() { return bytes_; }

 private:
  // The internal store of all bytes that have been written
  brillo::Blob bytes_;

  // These are just to ensure FileWriter methods are called properly.
  bool was_opened_;
  bool was_closed_;
};

}  // namespace chromeos_update_engine

#endif  // UPDATE_ENGINE_FAKE_FILE_WRITER_H_