On Tue, 2010-09-14 at 09:25 -0600, Ron Jensen wrote:
> On Monday 13 September 2010 19:57:55 Alasdair wrote:
> > I have recently been delving into FG's innards, with a view to fixing
> > some problems with the speech handling capabilities. This has led
> > indirecly to my having to understand how XML files are parsed.
> >
> > Now in SG's XML folder is a program called easyxml.cxx which reads the
> > XML files before passing contents to expat's xmlparse.c. The problem I
> > have discovered is that an entire XML file is read in _one_ chunk into a
> > 16k buffer declared at line 222. A dozen or so lines later a read
> > operation is performed which reads the _entire_ XML file into that
> > buffer. Now since preferences.xml is more than 3 times the size of this
> > only one third of it gets parsed, with means that the final partial line
> > that makes it into the buffer is in an indeterminate state. That happens
> > arount line 410 of preferences.xml. Furthermore garbage is passed to the
> > parser when when the end of the buffer is reached on readback.
> >
> > I am so astonished with this discovery that I can barely believe the
> > evidence of my eyes and my tests.
> >
> > Can someone confirm that I have not gone loopy? Because if I am right
> > this could explain a lot of strange goings on. Where am I going wrong?
> >
> > Kind regards,
> >
> > Alasdair Campbell
>
> Sorry Alasdair, you've looped. :) Or more correctly, you missed the loop!
>
> Simplifying from line 223 we have:
> while (!input.eof())
> {
> input.read(buf,16384);
> XML_Parse(parser, buf, input.gcount();
> }
>
> Everything else is just error checking and such. So we read the file in 16k
> chunks until we've read the whole thing. I haven't looked at what goes on in
> XML_Parse() for partial lines and tags, but we feed a lot of files through
> easyxml that are larger than 16k bytes...
>
> Ron
>
aaargh!
Thank you Ron, Frederic & Torsten
I think I was hit by a lightning bolt just before I wrote.
I really must start going to bed earlier!
Alasdair
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