Re: Entries caching & Performance

On Mon, Nov 25, 2002 at 11:57:09PM +0000, Philip Martin wrote:
> That's not correct, entries are cached for all operations. At present
> operations that modify the working copy will repeatedly *write* the
> entries file, but it does not get read repeatedly. Writing happens
> repeatedly because a) that's how it worked originally, and b) if it
> didn't then an interrupted operation would lose all its modifications.
> (I know interrupted checkouts cannot be restarted, but that's a bug
> that needs to be fixed.)

I took a quick look at this, and the update editor for checkouts is created
with a null adm_access. Maybe it is created and used later, but I didn't see
it.
>
> Obviously every relevant entries file has to be parsed once. Are you
> seeing the same file parsed repeatedly? How many times does
> svn_wc_entries_read go on to call read_entries?
>
> > implementing cached entries readings for updates & checkouts? This
> > could possibly eliminate a large portion of the time spent during
> > updates.
> >
> > The other half of the time spent comes from ne_xml_parse. I am not
> > sure how this could be made faster short of replacing expat with
> > something faster.
>
> Is there such a thing? I don't know whether expat is fast or slow,
> but simply asking for it to be replaced with something faster isn't
> much help unless you can identify something that is faster :)
>
I don't think there is much we can do here.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kevin Pilch-Bisson                    http://www.pilch-bisson.net
     "Historically speaking, the presences of wheels in Unix
     has never precluded their reinvention." - Larry Wall
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