URLEncode

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URLEncode

I use this functions to prepare POST strings with XML data. The first function URLEncode1 uses less memory but is slower than the second URLEncode2. Both functions return a CString and get a CString as the input parameter.

The demo project contains sample usage with execution time of presented functions.

Source

Helper function

inline BYTE toHex(const BYTE &x)
{
	return x > 9 ? x + 55: x + 48;
}

URLEncode1

CString URLEncode1(CString sIn)
{
    CString sOut;
	
    int k;
    const int nLen = sIn.GetLength() + 1;

    register LPBYTE pOutTmp = NULL;
    LPBYTE pOutBuf = NULL;
    register LPBYTE pInTmp = NULL;
    LPBYTE pInBuf =(LPBYTE)sIn.GetBuffer(nLen);
    BYTE b = 0;

    //count not alphanumeric characters
    k = 0;
	
    pInTmp = pInBuf;
    while(*pInTmp)
    {
        if (!isalnum(*pInTmp) && !isalnum(*pInTmp))
            k++;
        pInTmp++;
    }

    //alloc out buffer
    pOutBuf = (LPBYTE)sOut.GetBuffer(nLen  + 2 * k); //new BYTE [nLen  + 3 * k];

    if(pOutBuf)
    {
        pInTmp	= pInBuf;
	pOutTmp = pOutBuf;
		
	// do encoding
	while (*pInTmp)
        {
	    if(isalnum(*pInTmp))
                *pOutTmp++ = *pInTmp;
	    else
		if(isspace(*pInTmp))
		    *pOutTmp++ = '+';
		else
		{
		    *pOutTmp++ = '%';
		    *pOutTmp++ = toHex(*pInTmp>>4);
		     *pOutTmp++ = toHex(*pInTmp%16);
		}
	    pInTmp++;
	}
	
	*pOutTmp = '\0';
	//sOut=pOutBuf;
	//delete [] pOutBuf;
	sOut.ReleaseBuffer();
    }
    sIn.ReleaseBuffer();
    return sOut;
}

URLEncode2

CString URLEncode2(CString sIn)
{
    CString sOut;
	
    const int nLen = sIn.GetLength() + 1;

    register LPBYTE pOutTmp = NULL;
    LPBYTE pOutBuf = NULL;
    register LPBYTE pInTmp = NULL;
    LPBYTE pInBuf =(LPBYTE)sIn.GetBuffer(nLen);
    BYTE b = 0;
	
    //alloc out buffer
    pOutBuf = (LPBYTE)sOut.GetBuffer(nLen  * 3 - 2);//new BYTE [nLen  * 3];

    if(pOutBuf)
    {
        pInTmp	= pInBuf;
	pOutTmp = pOutBuf;
		
	// do encoding
	while (*pInTmp)
	{
	    if(isalnum(*pInTmp))
	        *pOutTmp++ = *pInTmp;
	    else
	        if(isspace(*pInTmp))
		    *pOutTmp++ = '+';
		else
		{
		    *pOutTmp++ = '%';
		    *pOutTmp++ = toHex(*pInTmp>>4);
		    *pOutTmp++ = toHex(*pInTmp%16);
		}
	    pInTmp++;
	}
	*pOutTmp = '\0';
	//sOut=pOutBuf;
	//delete [] pOutBuf;
	sOut.ReleaseBuffer();
    }
    sIn.ReleaseBuffer();
    return sOut;
}

Modifications

26.06.2001 - changed out buffer memory allocation (thx 2 Marc Brooks and Matthias)