file.h.svn-base

wince c++ 下 开发的 rss 阅读器源代码

/**
 *  file.h
 *
 *  Copyright (C) 2008  David Andrs <[e-mail]>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef _FILE_H_
#define _FILE_H_

class CBufferedFile {
public:
	CBufferedFile(DWORD bufferSize = 8192);
	virtual ~CBufferedFile();

	HANDLE GetFileHandle() { return File; }

	virtual BOOL Create(LPCTSTR lpFileName, DWORD dwDesiredAccess, DWORD dwShareMode, DWORD dwCreationDispostion, DWORD dwFlagsAndAttributes);
	virtual BOOL Read(LPVOID lpBuffer, DWORD nNumberOfBytesToRead, DWORD *nBytesRead = NULL);
	virtual BOOL Write(LPCVOID lpBuffer, DWORD nNumberOfBytesToWrite, DWORD *nNumberOfBytesWritten = NULL);
	virtual BOOL Close();
	virtual DWORD Seek(LONG lDistanceToMove, DWORD dwMoveMethod);

	void Lock();
	void Unlock();

protected:
	HANDLE File;

	BOOL EndOfFile;
	BYTE *Buffer;
	DWORD BufferSize;						// size of the whole buffer
	DWORD BufferPos;						// internal pointer to the buffer (read/write)
	DWORD BufferFilled;						// number of valid bytes in the buffer (read)
	DWORD BufferStart;						// position within the file where the buffer starts

	DWORD Access;							// desired access to the file

	BOOL EmptyCache();

	CRITICAL_SECTION CS;
};

#endif