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]]
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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:
time elapsed (wall): 27.4173
time running program: 22.5909 (82.40%)
time profiling (est.): 4.8264 (17.60%)
number of calls: 1314729
number of exceptions: 65
%Time Sec. #calls sec/call F name
11.05 2.4969 62333 0.000040 IkiWiki::PageSpec::match_glob
4.10 0.9261 679 0.001364 Text::Balanced::_match_tagged
2.72 0.6139 59812 0.000010 IkiWiki::SuccessReason::merge_influences
After:
time elapsed (wall): 26.1843
time running program: 21.5673 (82.37%)
time profiling (est.): 4.6170 (17.63%)
number of calls: 1252433
number of exceptions: 65
%Time Sec. #calls sec/call F name
7.66 1.6521 62333 0.000027 IkiWiki::PageSpec::match_glob
4.33 0.9336 679 0.001375 Text::Balanced::_match_tagged
2.81 0.6057 59812 0.000010 IkiWiki::SuccessReason::merge_influences
Note that the seconds per call for match_glob in the "after" case has gone down by about a third.
K.A.
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A second set of benchmarks, done by rebuilding the docwiki at commit f942c2db05e4
like so:
perl -Iblib/lib -d:Profile ikiwiki.in -setup docwiki.setup --no-verbose
The docwiki appears to use fewer glob matches than Kathryn's wiki.
With master:
time elapsed (wall): 29.6970
time running program: 24.6930 (83.15%)
time profiling (est.): 5.0041 (16.85%)
number of calls: 1359180
number of exceptions: 13
%Time Sec. #calls sec/call F name
13.62 3.3629 3406 0.000987 Text::Balanced::_match_tagged
10.84 2.6773 79442 0.000034 IkiWiki::PageSpec::match_glob
3.08 0.7598 59454 0.000013 :IkiWiki/Plugin/inline.pm:223
3.07 0.7593 29830 0.000025 IkiWiki::bestlink
2.99 0.7378 10231 0.000072 IkiWiki::PageSpec::match_link
With my `smcv/memoize-glob2re` branch:
time elapsed (wall): 30.4931
time running program: 25.1248 (82.39%)
time profiling (est.): 5.3683 (17.61%)
number of calls: 1439943
number of exceptions: 13
%Time Sec. #calls sec/call F name
13.19 3.3146 3406 0.000973 Text::Balanced::_match_tagged
8.41 2.1123 79442 0.000027 IkiWiki::PageSpec::match_glob
3.97 0.9979 86905 0.000011 Memoize::_memoizer
3.05 0.7654 59454 0.000013 :IkiWiki/Plugin/inline.pm:223
3.02 0.7576 29830 0.000025 IkiWiki::bestlink
and in a repeated run:
8.40 2.0905 79442 0.000026 IkiWiki::PageSpec::match_glob
With Kathryn's patch as seen in my `smcv/ka-glob-cache` branch:
time elapsed (wall): 27.7567
time running program: 22.9941 (82.84%)
time profiling (est.): 4.7627 (17.16%)
number of calls: 1279946
number of exceptions: 13
%Time Sec. #calls sec/call F name
14.29 3.2867 3406 0.000965 Text::Balanced::_match_tagged
7.89 1.8136 79442 0.000023 IkiWiki::PageSpec::match_glob
3.30 0.7577 59454 0.000013 :IkiWiki/Plugin/inline.pm:223
3.24 0.7461 29830 0.000025 IkiWiki::bestlink
3.19 0.7332 143 0.005127 ? IkiWiki::pagespec_match_list
and in a repeated run:
7.84 1.8253 79442 0.000023 IkiWiki::PageSpec::match_glob
--[[smcv]]
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diff --git a/IkiWiki.pm b/IkiWiki.pm
index 08a3d78..c187b98 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -2482,6 +2482,8 @@ sub derel ($$) {
return $path;
}
+my %glob_cache;
+
sub match_glob ($$;@) {
my $page=shift;
my $glob=shift;
@@ -2489,8 +2491,15 @@ sub match_glob ($$;@) {
$glob=derel($glob, $params{location});
- my $regexp=IkiWiki::glob2re($glob);
- if ($page=~/^$regexp$/i) {
+ # Instead of converting the glob to a regex every time,
+ # cache the compiled regex to save time.
+ if (!exists $glob_cache{$glob}
+ or !defined $glob_cache{$glob})
+ {
+ my $re=IkiWiki::glob2re($glob);
+ $glob_cache{$glob} = qr/^$re$/i;
+ }
+ if ($page =~ $glob_cache{$glob}) {
if (! IkiWiki::isinternal($page) || $params{internal}) {
return IkiWiki::SuccessReason->new("$glob matches $page");
}
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