[[!template id=gitbranch branch=smcv/ready/glob-cache
author="[[KathrynAndersen]], [[smcv]]"]]
[[!tag patch]]
I've been profiling my IkiWiki to try to improve speed (with many pages makes speed even more important) and I've written a patch to improve the speed of match_glob. This matcher is a good one to improve the speed of, because it gets called so many times.
Here's my patch - please consider it! -- [[KathrynAndersen]]
It seems to me as though changing glob2re to return qr/$re/, and calling
memoize(glob2re) next to the other memoize calls, would be a less
verbose way to do this? --[[smcv]]
I think so, yeah. Anyway, do you have any benchmark results handy,
Kathryn? --[[Joey]]
See below.
Also, would it make more sense for glob2re to return qr/^$re$/i rather than qr/$re/? Everything that uses glob2re seems to use
$foo =~ /^$re$/i
rather than /$re/ so I think that would make sense.
-- [[KathrynAndersen]]
Git branch smcv/ka-glob-cache has Kathryn's patch. Git
branch smcv/memoize-glob2re does as I suggested, which
is less verbose than Kathryn's patch but also not as
fast; I'm not sure why, tbh. --[[smcv]]
I think it's because my patch focuses on match_glob while the memoize patch focuses on glob2re, and glob2re is called in filecheck, meta and po as well as in match_glob and match_user; thus the memoized glob2re is dealing with a bigger set of globs to look up, and thus could be just that little bit slower. -- [[KathrynAndersen]]
What may be going on is that glob2re is already a fairly fast
function, so the overhead of memoizing it with the very generic
_memoizer (see its source) swamps the memoization gain. Note
that the few functions memoized with the Memoizer before were much
more expensive, so that little overhead was acceptable then.
It also may be that Kathryn's patch is slightly faster due to using
the construct $foo =~ $regexp rather than $foo =~ /$regexp/
(probably avoids a copy or something like that internally) --
this despite checking both exists and defined on the hash, which
should be reundant AFAICS.
My guess is that the best of both worlds would be to move
the byhand memoization to glob2re and have it return a compiled
/^/i regexp that can be used without further modifiction in most
cases. --[[Joey]]
Done, see smcv/ready/glob-cache and smcv/glob-cache-too-far.
Kathryn's patch is a significant improvement; my first patch on top of
that is a trivial cleanup that speeds it up a little, and the next two
patches (using precompiled regexes) have surprisingly little effect
(they don't slow it down either though, so either omit them or merge
them, whichever). Detailed benchmark results below.
Moving the memoization to glob2re actually seems to slow things down
again - I suspect the docwiki has few enough mentions of user() etc.
that caching them is a waste of time, but perhaps it's not the most
representative.
--[[smcv]]
[[done]] --[[Joey]]
[[!toggle id="smcv-benchmark" text="current benchmarks"]]
[[!toggleable id="smcv-benchmark" text="""
master at time of branch:
time elapsed (wall): 29.6348
time running program: 24.9212 (84.09%)
time profiling (est.): 4.7136 (15.91%)
number of calls: 1360181
number of exceptions: 13
%Time Sec. #calls sec/call F name
13.24 3.2986 3408 0.000968 Text::Balanced::_match_tagged
10.94 2.7253 79514 0.000034 IkiWiki::PageSpec::match_glob
3.19 0.7952 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
Improve the speed of match_glob:
time elapsed (wall): 27.9755
time running program: 23.5293 (84.11%)
time profiling (est.): 4.4461 (15.89%)
number of calls: 1280875
number of exceptions: 13
%Time Sec. #calls sec/call F name
14.56 3.4257 3408 0.001005 Text::Balanced::_match_tagged
7.82 1.8403 79514 0.000023 IkiWiki::PageSpec::match_glob
3.27 0.7698 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
match_glob: streamline glob cache slightly:
time elapsed (wall): 27.5753
time running program: 23.1714 (84.03%)
time profiling (est.): 4.4039 (15.97%)
number of calls: 1280875
number of exceptions: 13
%Time Sec. #calls sec/call F name
14.09 3.2637 3408 0.000958 Text::Balanced::_match_tagged
7.74 1.7926 79514 0.000023 IkiWiki::PageSpec::match_glob
3.30 0.7646 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
glob2re: return a precompiled, anchored case-insensitiv...:
time elapsed (wall): 27.5656
time running program: 23.1464 (83.97%)
time profiling (est.): 4.4192 (16.03%)
number of calls: 1282189
number of exceptions: 13
%Time Sec. #calls sec/call F name
14.21 3.2891 3408 0.000965 Text::Balanced::_match_tagged
7.72 1.7872 79514 0.000022 IkiWiki::PageSpec::match_glob
3.32 0.7678 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
make use of precompiled regex objects:
time elapsed (wall): 27.5357
time running program: 23.1289 (84.00%)
time profiling (est.): 4.4068 (16.00%)
number of calls: 1281981
number of exceptions: 13
%Time Sec. #calls sec/call F name
14.17 3.2776 3408 0.000962 Text::Balanced::_match_tagged
7.70 1.7814 79514 0.000022 IkiWiki::PageSpec::match_glob
3.35 0.7756 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
move memoization from match_glob to glob2re:
time elapsed (wall): 28.7677
time running program: 23.9473 (83.24%)
time profiling (est.): 4.8205 (16.76%)
number of calls: 1360181
number of exceptions: 13
%Time Sec. #calls sec/call F name
13.98 3.3469 3408 0.000982 Text::Balanced::_match_tagged
8.85 2.1194 79514 0.000027 IkiWiki::PageSpec::match_glob
3.24 0.7750 59454 0.000013 <anon>:IkiWiki/Plugin/inline.pm:223
--[[smcv]]
"""]]
[[!toggle id="ka-benchmarks" text="Kathryn's benchmarks"]]
[[!toggleable id="ka-benchmarks" text="""
Benchmarks done with Devel::Profile on the same testbed IkiWiki setup. I'm just showing the start of the profile output, since that's what's relevant.
Before:
After:
Note that the seconds per call for match_glob in the "after" case has gone down by about a third.
K.A.
"""]]
[[!toggle id="ka-patch" text="Kathryn's original patch"]]
[[!toggleable id="ka-patch" text="""
"""]]
