www.pudn.com > CRC32.rar > CRC32Ex.cpp

 
/* 
	Copyright 2006 - 2008, All Rights Reserved. 
 
	CRC32类之扩展 
 
	作者	- 张鲁夺(zhangluduo) 
	MSN		- zhangluduo@msn.com 
	QQ群	- 34064264 
 
	为所有爱我的人和我爱的人努力! 
*/ 
 
#include "stdafx.h" 
#include "CRC32Ex.h" 
 
CRC32Ex::CRC32Ex() 
{ 
 
} 
 
CRC32Ex::~CRC32Ex() 
{ 
 
} 
 
void CRC32Ex::OnFileProcessing(int nProgress, MemberFxn addr) 
{ 
	void*			pThis	= addr.GetThis(); 
	unsigned long	Addr	= addr.GetAddr(); 
 
	/** the Calling Convention must be __stdcall or  
		thiscall (thiscall not a keyword), 
		thiscall is the default calling convention used by C++ member functions  
	*/ 
	__asm 
	{ 
		push	nProgress	; 
	 	mov		ecx, pThis	; 
		call	Addr		; 
	} 
} 
 
void CRC32Ex::StopCalcFile() 
{ 
	m_bTerminate = true; 
} 
 
string CRC32Ex::GetError() 
{ 
	return m_strErr; 
} 
 
string CRC32Ex::GetCRC32FromFile(char* FileName, bool bUpper, MemberFxn addr) 
{ 
	FILE *file							= 0; 
	unsigned char buffer[BUFFER_SIZE]	= { 0 }; 
	m_bTerminate						= false; 
	m_strErr							= ""; 
	 
	try 
	{ 
		if ((file = fopen (FileName, "rb")) == NULL) 
		{ 
			m_strErr = "The file can't be opened!"; 
			return ""; 
		} 
		else  
		{ 
			int len					= 0; 
			int ReadCount			= 0; 
			unsigned long nFileSize = 0; 
 
			// 获取文件大小, 以下方式只能获取小于2^32字节的文件大小 
			{ 
				HANDLE hFile = CreateFile(FileName, NULL, FILE_SHARE_READ, NULL, OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL, 0); 
				if(hFile== NULL) 
				{ 
					m_strErr = "Get file size failed!"; 
					return ""; 
				} 
				nFileSize=::GetFileSize(hFile, NULL); 
				CloseHandle(hFile); 
			} 
 
			if(!addr.IsNull()) 
				OnFileProcessing(0, addr); 
 
			unsigned long CRCResult; 
			CRCInit(CRCResult); 
 
			while (len = fread (buffer, 1, BUFFER_SIZE, file)) 
			{ 
				ReadCount++; 
 
				if(m_bTerminate) 
				{ 
					m_strErr = "User terminate calculate!"; 
					return ""; 
				} 
				 
				CRCUpdate((unsigned char *)buffer, len, CRCResult); 
 
				if(!addr.IsNull()) 
				{ 
					int n = (int)(nFileSize / 100); 
					if(n <= 0) 
						n = 1; 
					OnFileProcessing((int)(BUFFER_SIZE * ReadCount / n), addr); 
				} 
 
				memset(buffer, 0, BUFFER_SIZE); 
			} 
 
			CRCFinal(CRCResult); 
 
			if(!addr.IsNull()) 
				OnFileProcessing(100, addr); 
 
			fclose (file); 
			return ResultToHex(CRCResult, bUpper); 
		} 
	} 
	catch(...) 
	{ 
		m_strErr = "UnKnow error!"; 
		return ""; 
	} 
} 
 
string CRC32Ex::ResultToHex(unsigned long Result, bool bUpper) 
{ 
	char buf[10] = { 0 }; 
	if(bUpper) 
		sprintf(buf, "%.8X", Result); 
	else  
		sprintf(buf, "%.8x", Result); 
	return string(buf); 
} 
 
string CRC32Ex::GetCRC32FromBuffer	(unsigned char* pData, unsigned long DataLen, bool bUpper) 
{ 
	m_strErr = ""; 
	unsigned long CRCResult; 
	CRCInit(CRCResult); 
	CRCUpdate(pData, DataLen, CRCResult); 
	CRCFinal(CRCResult); 
	return ResultToHex(CRCResult, bUpper); 
}