[Python-Dev] Performance of various marshallers (original) (raw)

Fredrik Lundh fredrik@pythonware.com
Wed, 3 Oct 2001 00🔞02 +0200

paul wrote:

> XML-RPC's relationship to Unicode is ill-defined. The spec that Dave Winer > wrote requires all data to be US-ASCII, so XML-RPC isn't really > XML-compliant. (You'll have to take up issues of standards compliance with > Dave.)

Most XML-RPC implementations support Unicode, Dave Winer notwithstanding. Plus, the XML-RPC spec says nothing to indicate that XML-RPC documents may not be encoded in either of XML's two built-in encodings (even if the data is restricted to ASCII values).

the specification says that XML-RPC uses XML and HTTP. it doesn't say anything about a Dave-specific subset of XML or HTTP...

(like so many other parts of the specification, the "string" type isn't exactly well-specified. the specification first says that strings contains ASCII characters, and later that "any characters are allowed in a string" and that "a string can be used to encode binary data")

Yes, an incomplete XML parser could be faster if it ignores Unicode, ignores character references, and does not do all of the error checking required by the spec. I'm not sure if this would really improve performance anyhow.

well, sgmlop is a bit faster than expat (up to 50%, in some tests). expat does a bit more error checking.

xmlrpclib on the other hand, is entirely written in Python. Is there a Python XML-RPC implementation that uses no Python code but does use a true XML parser?

the _xmlrpclib accelerator (see the xmlrpclib.py source) uses expat, with a really fast C layer. judging from Skip's benchmarks, expat is a bit slower than the py-xmlrpc parser (which is why I asked).