1 // 2 // Copyright (C) 2016 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_COMMON_FILE_FETCHER_H_ 18 #define UPDATE_ENGINE_COMMON_FILE_FETCHER_H_ 19 20 #include <memory> 21 #include <string> 22 #include <utility> 23 24 #include <base/logging.h> 25 #include <base/macros.h> 26 #include <brillo/message_loops/message_loop.h> 27 #include <brillo/streams/stream.h> 28 29 #include "update_engine/common/http_fetcher.h" 30 31 // This is a concrete implementation of HttpFetcher that reads files 32 // asynchronously. 33 34 namespace chromeos_update_engine { 35 36 class FileFetcher : public HttpFetcher { 37 public: 38 // Returns whether the passed url is supported. 39 static bool SupportedUrl(const std::string& url); 40 41 FileFetcher() : HttpFetcher(nullptr) {} 42 43 // Cleans up all internal state. Does not notify delegate. 44 ~FileFetcher() override; 45 46 // HttpFetcher overrides. 47 void SetOffset(off_t offset) override { offset_ = offset; } 48 void SetLength(size_t length) override { data_length_ = length; } 49 void UnsetLength() override { SetLength(0); } 50 51 // Begins the transfer if it hasn't already begun. 52 void BeginTransfer(const std::string& url) override; 53 54 // If the transfer is in progress, aborts the transfer early. The transfer 55 // cannot be resumed. 56 void TerminateTransfer() override; 57 58 // Ignore all extra headers for files. 59 void SetHeader(const std::string& header_name, 60 const std::string& header_value) override {}; 61 62 // Suspend the asynchronous file read. 63 void Pause() override; 64 65 // Resume the suspended file read. 66 void Unpause() override; 67 68 size_t GetBytesDownloaded() override { 69 return static_cast<size_t>(bytes_copied_); 70 } 71 72 // Ignore all the time limits for files. 73 void set_low_speed_limit(int low_speed_bps, int low_speed_sec) override {} 74 void set_connect_timeout(int connect_timeout_seconds) override {} 75 void set_max_retry_count(int max_retry_count) override {} 76 77 private: 78 // Cleans up the fetcher, resetting its status to a newly constructed one. 79 void CleanUp(); 80 81 // Schedule a new asynchronous read if the stream is not paused and no other 82 // read is in process. This method can be called at any point. 83 void ScheduleRead(); 84 85 // Called from the main loop when a single read from |stream_| succeeds or 86 // fails, calling OnReadDoneCallback() and OnReadErrorCallback() respectively. 87 void OnReadDoneCallback(size_t bytes_read); 88 void OnReadErrorCallback(const brillo::Error* error); 89 90 // Whether the transfer was started and didn't finish yet. 91 bool transfer_in_progress_{false}; 92 93 // Whether the transfer is paused. 94 bool transfer_paused_{false}; 95 96 // Whether there's an ongoing asynchronous read. When this value is true, the 97 // the |buffer_| is being used by the |stream_|. 98 bool ongoing_read_{false}; 99 100 // Total number of bytes copied. 101 uint64_t bytes_copied_{0}; 102 103 // The offset inside the file where the read should start. 104 uint64_t offset_{0}; 105 106 // The length of the data or -1 if unknown (will read until EOF). 107 int64_t data_length_{-1}; 108 109 brillo::StreamPtr stream_; 110 111 // The buffer used for reading from the stream. 112 brillo::Blob buffer_; 113 114 DISALLOW_COPY_AND_ASSIGN(FileFetcher); 115 }; 116 117 } // namespace chromeos_update_engine 118 119 #endif // UPDATE_ENGINE_COMMON_FILE_FETCHER_H_ 120
