1//
2// Copyright (C) 2016 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17// A filesystem parser based on the Android .map files. When generating a
18// filesystem with the Android tools, either squashfs or ext4, a .map file can
19// be generated at the same time with the list of files and the 4K-blocks where
20// the data for those files is located in the filesystem. This class parses this
21// .map text file instead of parsing the structure of the actual filesystem
22// contents.
23
24#ifndef UPDATE_ENGINE_PAYLOAD_GENERATOR_MAPFILE_FILESYSTEM_H_
25#define UPDATE_ENGINE_PAYLOAD_GENERATOR_MAPFILE_FILESYSTEM_H_
26
27#include "update_engine/payload_generator/filesystem_interface.h"
28
29#include <memory>
30#include <string>
31#include <vector>
32
33namespace chromeos_update_engine {
34
35class MapfileFilesystem : public FilesystemInterface {
36 public:
37  static std::unique_ptr<MapfileFilesystem> CreateFromFile(
38      const std::string& filename, const std::string& mapfile_filename);
39  virtual ~MapfileFilesystem() = default;
40
41  // FilesystemInterface overrides.
42  size_t GetBlockSize() const override;
43  size_t GetBlockCount() const override;
44
45  // All the generated FilesystemInterface::File are reported as regular files.
46  // Files may overlap with other files in the same block.
47  bool GetFiles(std::vector<File>* files) const override;
48
49  bool LoadSettings(brillo::KeyValueStore* store) const override;
50
51 private:
52  MapfileFilesystem(const std::string& mapfile_filename, off_t num_blocks);
53
54  // The file where the map filesystem is stored.
55  std::string mapfile_filename_;
56
57  // The number of blocks in the filesystem.
58  off_t num_blocks_;
59
60  DISALLOW_COPY_AND_ASSIGN(MapfileFilesystem);
61};
62
63}  // namespace chromeos_update_engine
64
65#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_MAPFILE_FILESYSTEM_H_
66