哈希函数学习

unsigned int getHashCode(CString str)
{
	if(str.isEmpty())
	return 0;
	int len = str.GetLength();
	unsigned int ihash = 0;
	unsigned int g = 0;
	
	for(int i = 0; i < len;++i)
	{
			byte temp = (byte)(str.GetAt(i));
			ihash = (ihash <<4) + temp;
			g = (unsigned int)(ihash & 0xf0000000);
			if(g != 0)
			{
				ihash ^= (g>>24);
				ihash ^= g;
			}
	}
	return ihash
}