Re: [matplotlib-devel] Add some caching to texmanager.py?

[John H. <jdh...@ac...>]

>>>>> "Fernando" == Fernando Perez <Fer...@co...> writes:

    Fernando> This was in a long-running session with very large
    Fernando> memory allocations, but it dawned on me that
    Fernando> get_dvipng_version(self) should cache its return value.
    Fernando> There's no point in forcing a popen() call every single
    Fernando> time, is there?

It already does cache the version

    def get_dvipng_version(self):
        if self.dvipngVersion is not None: return self.dvipngVersion
        sin, sout = os.popen2('dvipng --version')
        ...snip...

I think the reason it is failing in your case is that is each renderer
creation creates a new TexManager instance.  The cache should be on a
class basis and not on a per instance basis (slaps self on head).
Moving

        self.dvipngVersion = None

to the class level and out of __init__ should suffice.  I made this
change, and similar changes in texmanager and backend_agg, so that
caching is shared between instances.  Update from CVS and let me know
if everything still works :-)

    Fernando> I also just saw pylab crash when a user was trying to
    Fernando> run with $PWD being something he didn't have write
    Fernando> access to.  Are there any checks in the code to fall
    Fernando> back to /tmp or something sensible if texmanager can't
    Fernando> write the temp files it needs?  Sorry for not giving a
    Fernando> traceback, but I only saw this on someone else's screen
    Fernando> while helping them, and for some odd reason it's not
    Fernando> happening on my box.

This is probably failing on the tex/latex temporary files.  I spent
some time initially trying to figure out how to get these to go into
~/.tex.cache but didn't succeed.  If anyone knows how to direct
tex/latex to put the various *.aux, *.log, etc, files in a specified
directory, pass it my way.

Thanks,
JDH