1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef SYSTEM_WRAPPERS_INCLUDE_FILE_WRAPPER_H_ 12 #define SYSTEM_WRAPPERS_INCLUDE_FILE_WRAPPER_H_ 13 14 #include <stddef.h> 15 #include <stdio.h> 16 17 #include "common_types.h" // NOLINT(build/include) 18 #include "rtc_base/criticalsection.h" 19 #include "typedefs.h" // NOLINT(build/include) 20 21 // Implementation of an InStream and OutStream that can read (exclusive) or 22 // write from/to a file. 23 24 namespace webrtc { 25 26 // TODO(tommi): Remove the base classes, rename to rtc::File and move to base. 27 class FileWrapper : public InStream, public OutStream { 28 public: 29 static const size_t kMaxFileNameSize = 1024; 30 31 // Factory methods. 32 // TODO(tommi): Remove Create(). 33 static FileWrapper* Create(); 34 static FileWrapper Open(const char* file_name_utf8, bool read_only); 35 36 FileWrapper(FILE* file, size_t max_size); 37 ~FileWrapper() override; 38 39 // Support for move semantics. 40 FileWrapper(FileWrapper&& other); 41 FileWrapper& operator=(FileWrapper&& other); 42 43 // Returns true if a file has been opened. is_open()44 bool is_open() const { return file_ != nullptr; } 45 46 // Opens a file in read or write mode, decided by the read_only parameter. 47 bool OpenFile(const char* file_name_utf8, bool read_only); 48 49 // Initializes the wrapper from an existing handle. The wrapper 50 // takes ownership of |handle| and closes it in CloseFile(). 51 bool OpenFromFileHandle(FILE* handle); 52 53 void CloseFile(); 54 55 // Limits the file size to |bytes|. Writing will fail after the cap 56 // is hit. Pass zero to use an unlimited size. 57 // TODO(tommi): Could we move this out into a separate class? 58 void SetMaxFileSize(size_t bytes); 59 60 // Flush any pending writes. Note: Flushing when closing, is not required. 61 int Flush(); 62 63 // Rewinds the file to the start. 64 int Rewind() override; 65 int Read(void* buf, size_t length) override; 66 bool Write(const void* buf, size_t length) override; 67 68 private: 69 FileWrapper(); 70 71 void CloseFileImpl(); 72 int FlushImpl(); 73 74 // TODO(tommi): Remove the lock. 75 rtc::CriticalSection lock_; 76 77 FILE* file_ = nullptr; 78 size_t position_ = 0; 79 size_t max_size_in_bytes_ = 0; 80 81 // Copying is not supported. 82 FileWrapper(const FileWrapper&) = delete; 83 FileWrapper& operator=(const FileWrapper&) = delete; 84 }; 85 86 } // namespace webrtc 87 88 #endif // SYSTEM_WRAPPERS_INCLUDE_FILE_WRAPPER_H_ 89