struct HTTPParser {
CallBackNotify _onMessageBegin;
CallBackNotify _onHeadersComplete;
CallBackNotify _onMessageComplete;
CallBackNotify _onChunkHeader;
CallBackNotify _onChunkComplete;
CallBackData _onUrl;
CallBackData _onStatus;
CallBackData _onHeaderField;
CallBackData _onHeaderValue;
CallBackData _onBody;
}