1 // 2 // Copyright (C) 2009 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_PAYLOAD_CONSUMER_EXTENT_WRITER_H_ 18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_EXTENT_WRITER_H_ 19 20 #include <memory> 21 #include <utility> 22 23 #include <base/logging.h> 24 #include <brillo/secure_blob.h> 25 26 #include "update_engine/common/utils.h" 27 #include "update_engine/payload_consumer/file_descriptor.h" 28 #include "update_engine/update_metadata.pb.h" 29 30 // ExtentWriter is an abstract class which synchronously writes to a given 31 // file descriptor at the extents given. 32 33 namespace chromeos_update_engine { 34 35 class ExtentWriter { 36 public: 37 ExtentWriter() = default; 38 virtual ~ExtentWriter() = default; 39 40 // Returns true on success. 41 virtual bool Init(FileDescriptorPtr fd, 42 const google::protobuf::RepeatedPtrField<Extent>& extents, 43 uint32_t block_size) = 0; 44 45 // Returns true on success. 46 virtual bool Write(const void* bytes, size_t count) = 0; 47 }; 48 49 // DirectExtentWriter is probably the simplest ExtentWriter implementation. 50 // It writes the data directly into the extents. 51 52 class DirectExtentWriter : public ExtentWriter { 53 public: 54 DirectExtentWriter() = default; 55 ~DirectExtentWriter() override = default; 56 57 bool Init(FileDescriptorPtr fd, 58 const google::protobuf::RepeatedPtrField<Extent>& extents, 59 uint32_t block_size) override { 60 fd_ = fd; 61 block_size_ = block_size; 62 extents_ = extents; 63 cur_extent_ = extents_.begin(); 64 return true; 65 } 66 bool Write(const void* bytes, size_t count) override; 67 68 private: 69 FileDescriptorPtr fd_{nullptr}; 70 71 size_t block_size_{0}; 72 // Bytes written into |cur_extent_| thus far. 73 uint64_t extent_bytes_written_{0}; 74 google::protobuf::RepeatedPtrField<Extent> extents_; 75 // The next call to write should correspond to |cur_extents_|. 76 google::protobuf::RepeatedPtrField<Extent>::iterator cur_extent_; 77 }; 78 79 } // namespace chromeos_update_engine 80 81 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_EXTENT_WRITER_H_ 82