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 #pragma once 18 19 #include <optional> 20 #include <vector> 21 22 #include <android-base/file.h> 23 #include <libsnapshot/cow_reader.h> 24 #include <payload_consumer/file_descriptor.h> 25 26 namespace android { 27 namespace snapshot { 28 29 class CompressedSnapshotReader : public chromeos_update_engine::FileDescriptor { 30 public: 31 CompressedSnapshotReader(std::unique_ptr<ICowReader>&& cow, 32 const std::optional<std::string>& source_device, 33 std::optional<uint64_t> block_dev_size); 34 35 bool Open(const char* path, int flags, mode_t mode) override; 36 bool Open(const char* path, int flags) override; 37 ssize_t Write(const void* buf, size_t count) override; 38 bool BlkIoctl(int request, uint64_t start, uint64_t length, int* result) override; 39 ssize_t Read(void* buf, size_t count) override; 40 off64_t Seek(off64_t offset, int whence) override; 41 uint64_t BlockDevSize() override; 42 bool Close() override; 43 bool IsSettingErrno() override; 44 bool IsOpen() override; 45 bool Flush() override; 46 47 private: 48 ssize_t ReadBlock(uint64_t chunk, size_t start_offset, void* buffer, size_t size); 49 android::base::borrowed_fd GetSourceFd(); 50 51 std::unique_ptr<ICowReader> cow_; 52 std::unique_ptr<ICowOpIter> op_iter_; 53 uint32_t block_size_ = 0; 54 55 std::optional<std::string> source_device_; 56 android::base::unique_fd source_fd_; 57 uint64_t block_device_size_ = 0; 58 off64_t offset_ = 0; 59 60 std::vector<const CowOperation*> ops_; 61 }; 62 63 } // namespace snapshot 64 } // namespace android 65