www.pudn.com > mir3serveandkehuyuandaima.rar > EnDecode.cpp

// EnDecode.cpp : Defines the entry point for the DLL application. 
// 
 
#include "stdafx.h" 
 
static unsigned char Decode6BitMask[5] = { 0xfc, 0xf8, 0xf0, 0xe0, 0xc0 }; 
 
int WINAPI fnEncode6BitBuf(unsigned char *pszSrc, char *pszDest, int nSrcLen, int nDestLen) 
{ 
	int				nDestPos	= 0; 
	int				nRestCount	= 0; 
	unsigned char	chMade = 0, chRest = 0; 
 
	for (int i = 0; i < nSrcLen; i++) 
	{ 
		if (nDestPos >= nDestLen) break; 
		 
		chMade = ((chRest | (pszSrc[i] >> (2 + nRestCount))) & 0x3f); 
		chRest = (((pszSrc[i] << (8 - (2 + nRestCount))) >> 2) & 0x3f); 
 
		nRestCount += 2; 
 
		if (nRestCount < 6) 
			pszDest[nDestPos++] = chMade + 0x3c; 
		else 
		{ 
			if (nDestPos < nDestLen - 1) 
			{ 
				pszDest[nDestPos++]	= chMade + 0x3c; 
				pszDest[nDestPos++]	= chRest + 0x3c; 
			} 
			else 
				pszDest[nDestPos++] = chMade + 0x3c; 
 
			nRestCount	= 0; 
			chRest		= 0; 
		} 
	} 
 
	if (nRestCount > 0) 
		pszDest[nDestPos++] = chRest + 0x3c; 
 
	pszDest[nDestPos] = '\0'; 
 
	return nDestPos; 
} 
 
int  WINAPI fnDecode6BitBuf(char *pszSrc, char *pszDest, int nDestLen) 
{ 
	int				nLen = strlen((const char *)pszSrc); 
	int				nDestPos = 0, nBitPos = 2; 
	int				nMadeBit = 0; 
	unsigned char	ch, chCode, tmp; 
 
	for (int i = 0; i < nLen; i++) 
	{ 
		if ((pszSrc[i] - 0x3c) >= 0) 
			ch = pszSrc[i] - 0x3c; 
		else 
		{ 
			nDestPos = 0; 
			break; 
		} 
 
		if (nDestPos >= nDestLen) break; 
 
		if ((nMadeBit + 6) >= 8) 
		{ 
			chCode = (tmp | ((ch & 0x3f) >> (6 - nBitPos))); 
			pszDest[nDestPos++] = chCode; 
 
			nMadeBit = 0; 
 
			if (nBitPos < 6)  
				nBitPos += 2; 
			else 
			{ 
				nBitPos = 2; 
				continue; 
			} 
		} 
 
		tmp = ((ch << nBitPos) & Decode6BitMask[nBitPos - 2]); 
 
		nMadeBit += (8 - nBitPos); 
	} 
 
//	pszDest[nDestPos] = '\0'; 
 
	return nDestPos; 
} 
 
int WINAPI fnEncodeMessage(_LPTDEFAULTMESSAGE lptdm, char *pszBuf, int nLen) 
{ 
	unsigned char	btBuffer[32]; 
 
	memcpy(btBuffer, (void *)lptdm, sizeof(_TDEFAULTMESSAGE)); 
 
	return fnEncode6BitBuf(btBuffer, pszBuf, sizeof(_TDEFAULTMESSAGE), nLen); 
} 
 
int  WINAPI fnDecodeMessage(_LPTDEFAULTMESSAGE lptdm, char *pszBuf) 
	{ return fnDecode6BitBuf(pszBuf, (char *)lptdm, sizeof(_TDEFAULTMESSAGE)); } 
 
void WINAPI fnMakeDefMessage(_LPTDEFAULTMESSAGE lptdm, WORD wIdent, int nRecog, WORD wParam, WORD wTag, WORD wSeries) 
	{ lptdm->wIdent	= wIdent; lptdm->nRecog	= nRecog; lptdm->wParam	= wParam; lptdm->wTag = wTag; lptdm->wSeries = wSeries; }