1 // 2 // Copyright (C) 2017 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_CACHED_FILE_DESCRIPTOR_H_ 18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_CACHED_FILE_DESCRIPTOR_H_ 19 20 #include <errno.h> 21 #include <sys/types.h> 22 23 #include <memory> 24 #include <vector> 25 26 #include <brillo/secure_blob.h> 27 28 #include "update_engine/payload_consumer/file_descriptor.h" 29 30 namespace chromeos_update_engine { 31 32 class CachedFileDescriptor : public FileDescriptor { 33 public: 34 CachedFileDescriptor(FileDescriptorPtr fd, size_t cache_size) : fd_(fd) { 35 cache_.resize(cache_size); 36 } 37 ~CachedFileDescriptor() override = default; 38 39 bool Open(const char* path, int flags, mode_t mode) override { 40 return fd_->Open(path, flags, mode); 41 } 42 bool Open(const char* path, int flags) override { 43 return fd_->Open(path, flags); 44 } 45 ssize_t Read(void* buf, size_t count) override { 46 return fd_->Read(buf, count); 47 } 48 ssize_t Write(const void* buf, size_t count) override; 49 off64_t Seek(off64_t offset, int whence) override; 50 uint64_t BlockDevSize() override { return fd_->BlockDevSize(); } 51 bool BlkIoctl(int request, 52 uint64_t start, 53 uint64_t length, 54 int* result) override { 55 return fd_->BlkIoctl(request, start, length, result); 56 } 57 bool Flush() override; 58 bool Close() override; 59 bool IsSettingErrno() override { return fd_->IsSettingErrno(); } 60 bool IsOpen() override { return fd_->IsOpen(); } 61 62 private: 63 // Internal flush without the need to call |fd_->Flush()|. 64 bool FlushCache(); 65 66 FileDescriptorPtr fd_; 67 brillo::Blob cache_; 68 size_t bytes_cached_{0}; 69 off64_t offset_{0}; 70 71 DISALLOW_COPY_AND_ASSIGN(CachedFileDescriptor); 72 }; 73 74 } // namespace chromeos_update_engine 75 76 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_CACHED_FILE_DESCRIPTOR_H_ 77
