1 // 2 // Copyright (C) 2020 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 #ifndef UPDATE_ENGINE_SNAPSHOT_EXTENT_WRITER_H_ 18 #define UPDATE_ENGINE_SNAPSHOT_EXTENT_WRITER_H_ 19 20 #include <cstdint> 21 #include <vector> 22 23 #include <libsnapshot/cow_writer.h> 24 25 #include "update_engine/payload_consumer/extent_writer.h" 26 #include "update_engine/update_metadata.pb.h" 27 28 namespace chromeos_update_engine { 29 30 class SnapshotExtentWriter : public chromeos_update_engine::ExtentWriter { 31 public: 32 explicit SnapshotExtentWriter(android::snapshot::ICowWriter* cow_writer); 33 ~SnapshotExtentWriter(); 34 // Returns true on success. 35 bool Init(const google::protobuf::RepeatedPtrField<Extent>& extents, 36 uint32_t block_size) override; 37 // Returns true on success. 38 // This will construct a COW_REPLACE operation and forward it to CowWriter. It 39 // is important that caller does not perform SOURCE_COPY operation on this 40 // class, otherwise raw data will be stored. Caller should find ways to use 41 // COW_COPY whenever possible. 42 bool Write(const void* bytes, size_t count) override; 43 44 private: 45 bool next_extent(); 46 [[nodiscard]] size_t ConsumeWithBuffer(const uint8_t* bytes, size_t count); 47 // It's a non-owning pointer, because PartitionWriter owns the CowWruter. This 48 // allows us to use a single instance of CowWriter for all operations applied 49 // to the same partition. 50 android::snapshot::ICowWriter* cow_writer_; 51 google::protobuf::RepeatedPtrField<Extent> extents_; 52 size_t cur_extent_idx_; 53 std::vector<uint8_t> buffer_; 54 size_t block_size_; 55 }; 56 57 } // namespace chromeos_update_engine 58 59 #endif 60