Dan Christensen <jdc@uwo.ca> writes:

> I'm now thinking that caching the parsed time in "time value" format (a
> pair of integers) rather than a float might be more useful, since many
> parts of Gnus need this information.  

It turns out that someone thought of this before, and implemented it as
gnus-date-get-time in gnus-util, which caches the emacs time value as a
text property on the date string that is being parsed!  Clever idea:  it
works more generally than my method and doesn't require api changes to
various functions.  So all I had to do was call this function in a few
places, and things are faster.  For a group with about 6000 articles,
the time for sorting with gnus-thread-sort-by-most-recent-date when from
about 12 seconds to 1 second, and the time for generating the summary
went from 8 seconds to 6 seconds.

The patch below includes a ChangeLog.  It also adds a message to
gnus-sort-threads if the recursive sort fails and it falls back to the
loop.  That could be useful debugging information when timing these
things.

Please test and apply.

Dan