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* vc-state-heuristic is gone
@ 2014-11-23 21:56 Unknown
  2014-11-24  8:09 ` David Kastrup
                   ` (2 more replies)
  0 siblings, 3 replies; 41+ messages in thread
From: Unknown @ 2014-11-23 21:56 UTC (permalink / raw)
  To: emacs-devel

First, easiest gain from attacking the VC backend API with fire and
sword:  vc-state-heuristic is gone. vc-stay-local is probably next.

These were attempts at performance optimizatiion that made sense when
disk and network operations were much slower than they are now.  I
remember quite clearly that when I first wrote VC mode in 1992 I spent
the majority of my effort on thinking up ways to avoid hitting the
disk.

But the tradeoffs have changed.  The operations I was trying to avoid
are much less expensive today, but the cost of the bugs and edge
conditions produced by incautiously doing repository operations behind
Emacs's back (and this rendering the caching and heuristics involved
ivalid) has not dropped.  If anything, it has risen.

Thus, a brutal and effective simplification: *all caching goes away*.

Affected back ends: SCCS, RCS, CVS, SVN, Bazaar.  I've already tested
with RCS and any change in preformance is now so small that a human is
not capable of registering it.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>

A nation or civilization that continues to produce soft-minded men
purchases its own spiritual death on an installment plan.
	--Martin Luther King, Jr. 



^ permalink raw reply	[flat|nested] 41+ messages in thread

end of thread, other threads:[~2014-11-26 11:46 UTC | newest]

Thread overview: 41+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-11-23 21:56 vc-state-heuristic is gone Unknown
2014-11-24  8:09 ` David Kastrup
2014-11-24  8:33   ` Eric S. Raymond
2014-11-24  9:02     ` David Kastrup
2014-11-24  9:49       ` Eric S. Raymond
2014-11-24 10:35         ` David Kastrup
2014-11-24 10:46           ` Eric S. Raymond
2014-11-24 11:57             ` Michael Albinus
2014-11-24 13:03               ` Testing the new VC code Eric S. Raymond
2014-11-24 18:35                 ` Steinar Bang
2014-11-24 19:05                   ` Eric S. Raymond
2014-11-25  1:52                   ` Yuri Khan
2014-11-25  2:52                     ` Eric S. Raymond
2014-11-25  4:25                       ` Stefan Monnier
2014-11-25  8:31                         ` Steinar Bang
2014-11-25  8:43                           ` Steinar Bang
2014-11-25  9:09                           ` David Kastrup
2014-11-25  9:12                             ` Steinar Bang
2014-11-25 10:03                               ` Andreas Schwab
2014-11-24 19:39                 ` Michael Albinus
2014-11-25  2:50                   ` Eric S. Raymond
2014-11-25  6:44                     ` David Kastrup
2014-11-25 13:22                       ` Ergonomics and neurology for interface designers Eric S. Raymond
2014-11-25 14:15                         ` David Kastrup
2014-11-25 21:29                           ` Eric S. Raymond
2014-11-25 16:32                       ` Testing the new VC code Stephen J. Turnbull
2014-11-25 12:12                     ` Michael Albinus
2014-11-25 13:42                       ` Eric S. Raymond
2014-11-25 14:55                         ` Michael Albinus
2014-11-25 21:17                           ` Eric S. Raymond
2014-11-26 10:12                             ` Michael Albinus
2014-11-26 11:46                               ` Eric S. Raymond
2014-11-25 14:35                       ` Stefan Monnier
2014-11-25 21:25                         ` Eric S. Raymond
2014-11-24 14:40     ` vc-state-heuristic is gone Stefan Monnier
2014-11-24 16:17 ` Richard Stallman
2014-11-25  5:15   ` Karl Fogel
2014-11-25  5:47     ` Eric S. Raymond
2014-11-24 16:17 ` Richard Stallman
2014-11-24 17:52   ` Eric S. Raymond
2014-11-25 13:20     ` Richard Stallman

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