Thieu Le | 5c7d975 | 2010-12-15 16:09:28 -0800 | [diff] [blame^] | 1 | // Copyright (c) 2010 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__ |
| 6 | #define CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__ |
| 7 | |
| 8 | #include "update_engine/delta_diff_generator.h" |
| 9 | #include "update_engine/graph_types.h" |
| 10 | |
| 11 | namespace chromeos_update_engine { |
| 12 | |
| 13 | class Metadata { |
| 14 | public: |
| 15 | // Reads metadata from old image and new image and determines |
| 16 | // the smallest way to encode the metadata for the diff. |
| 17 | // If there's no change in the metadata, it creates a MOVE |
| 18 | // operation. If there is a change, the smallest of REPLACE, REPLACE_BZ, |
| 19 | // or BSDIFF wins. It writes the diff to data_fd and updates data_file_size |
| 20 | // accordingly. It also adds the required operation to the graph and adds the |
| 21 | // metadata extents to blocks. |
| 22 | // Returns true on success. |
| 23 | static bool DeltaReadMetadata(Graph* graph, |
| 24 | std::vector<DeltaDiffGenerator::Block>* blocks, |
| 25 | const std::string& old_image, |
| 26 | const std::string& new_image, |
| 27 | int data_fd, |
| 28 | off_t* data_file_size); |
| 29 | |
| 30 | private: |
| 31 | // This should never be constructed. |
| 32 | DISALLOW_IMPLICIT_CONSTRUCTORS(Metadata); |
| 33 | }; |
| 34 | |
| 35 | }; // namespace chromeos_update_engine |
| 36 | |
| 37 | #endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__ |