www.pudn.com > Wave_Src_func.zip > MemoryMapper.h

////////////////////////////////////////////////////////////////////////////////////////// 
// A simple but very useful memory mapper class. Very useful when dealing with large files 
// that would otherwise be transferred to buffers in the main memory. wave files for eg. 
// this class provides a simple interface for mapping a view of the file and treating it 
// as a stream of bytes. 
// 
// -Vinayak Raghuvamshi 
////////////////////////////////////////////////////////////////////////////////////////// 
#pragma once 
#include  
class CMemoryMapper 
{ 
public: 
	CMemoryMapper(void); 
	virtual ~CMemoryMapper(void); 
	// Opens a file for reading and creates a view of it. Fails if file does not exist. 
	bool OpenFileForRead(const TCHAR *szFile); 
	// Opens a file mapping for writing. use if we want to modify the file 
	bool OpenFileForWrite(const TCHAR *szFile); 
	void Close(void); 
 
	// Gets the underlying Mapped data pointer. 
	BYTE* GetPtrToFileData(void) 
	{ 
		return m_pFileData; 
	} 
 
	DWORD GetSize(void) 
	{ 
		return m_dwSize; 
	} 
 
protected: 
	BYTE	*m_pFileData; // subclasses can directly access the file data as a byte *. 
	DWORD	m_dwSize; 
private: 
	HANDLE  m_hFile; 
	HANDLE  m_hMapOfFile; 
	LPVOID	m_pViewOfFile; 
	// internal open method that gets invoked by open for read and open for write.... 
	bool MapFile(const HANDLE &hFile, DWORD dwPageProtect, DWORD dwPageAccess); 
};