I have to create XML files with BIG (as in megs) base64 attributes. I've notice performance issue in doing so. Although I haven't profile the code I believe the major bottle neck is Poco::XMLWriter::writeAttributes uses characters() to apply encoding and so forth which I could do without giving it's base64 data. Using writeXML(string) instead of characters() would, I believe, make a big difference given that characters() ends up calling writeXML(char) for each characters.
Is rewriting my own version of startElement(..., attributes) my only option? Seems like a lot of work as most of the stuff I would need is private in XMLWriter, would have to duplicated most of it.