1 // Copyright 2015 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef _BSDIFF_FILE_INTERFACE_H_ 6 #define _BSDIFF_FILE_INTERFACE_H_ 7 8 #include <sys/types.h> 9 10 namespace bsdiff { 11 12 class FileInterface { 13 public: 14 virtual ~FileInterface() = default; 15 16 // Reads synchronously from the current file position up to |count| bytes into 17 // the passed |buf| buffer. On success, stores in |bytes_read| how many bytes 18 // were actually read from the file. In case of error returns false. This 19 // method may read less than |count| bytes even if there's no error. If the 20 // end of file is reached, 0 bytes will be read and this methods returns true. 21 virtual bool Read(void* buf, size_t count, size_t* bytes_read) = 0; 22 23 // Writes synchronously up to |count| bytes from to passed |buf| buffer to 24 // the file. On success, stores in |bytes_written| how many bytes 25 // were actually written to the file. This method may write less than |count| 26 // bytes and return successfully, or even write 0 bytes if there's no more 27 // space left on the device. Returns whether the write succeeded. 28 virtual bool Write(const void* buf, size_t count, size_t* bytes_written) = 0; 29 30 // Change the current file position to |pos| bytes from the beginning of the 31 // file. Return whether the seek succeeded. 32 virtual bool Seek(off_t pos) = 0; 33 34 // Closes the file and flushes any cached data. Returns whether the close 35 // succeeded. 36 virtual bool Close() = 0; 37 38 // Compute the size of the file and store it in |size|. Returns whether it 39 // computed the size successfully. 40 virtual bool GetSize(uint64_t* size) = 0; 41 42 protected: 43 FileInterface() = default; 44 }; 45 46 } // namespace bsdiff 47 48 #endif // _BSDIFF_FILE_INTERFACE_H_ 49
