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Postings from September 2010
On Tue Sep 28 10:07:11 2010, toddr@cpanel.net wrote:
>
> On Sep 26, 2010, at 7:28 PM, Father Chrysostomos via RT wrote:
>
> > On Thu Jul 22 11:09:33 2010, toddr@cpanel.net wrote:
> >> This patch resolves CPAN RT #48118 of the same name.
> >>
> >> The change checks for [ in the string before it attempts to compile
> >> it. If [ is not found, it is able to bypass compile. We've found
> >> that this change benchmarked 9% faster in our code.
> >
> > In my experience, $a !~ /\[/ is faster than $a !~ y/[//, because the
> > former can stop when it finds a [ and doesn’t have to keep count the
> way
> > y/// does.
> >
> > Using Steffen Mueller’s dumbbench script, I confirmed that /\[/
> takes
> > longer to compile, but y/[// takes longer to run.
> >
> > Also, from reading the source (not actually testing this) it seems
> that
> > your patch stops an unmatched clasing bracket from being an error.
> Am I
> > right about this?
> >
>
> Thanks for your careful review of this patch. You were right that the
> patch short circuits error conditions. I've simplified the patch.
> I'm pasting the commit message below since it's got all of my
> thoughts in it:
>
> RT 76668 - Check string to compile for chars ~][ and return
> \"$string" if not found.
> This is a 250% speed improvement on strings which don't require
> compile and only a
> ~2% hit if they did need compiling.
>
> Remove \G since everything is being captured it has no value. This
> means we don't
> have to worry about seting pos $string_to_compile = 0 to prevent
> the previous
> regex from affecting this one. There is a negligible speed
> improvement removing
> the \G
>
> All tests continue to pass.
>
> FYI if you want to benchmark on your own, this is the method I used to
> show the speedup:
>
> Testing compiled string performance:
> perl -Ilib -MBenchmark -MLocale::Maketext -le 'package X;our
> @ISA=qw(Locale::Maketext);package X::en;our @ISA=qw(X);our %Lexicon
> = (_AUTO => 1);package main;my $h=X->get_handle(); my $c = 1;
> timethis(100000, sub{$h->maketext("bar $c [_1]", $c); $c++})'
>
> Testing strings which don't need compile
> perl -Ilib -MBenchmark -MLocale::Maketext -le 'package X;our
> @ISA=qw(Locale::Maketext);package X::en;our @ISA=qw(X);our %Lexicon
> = (_AUTO => 1);package main;my $h=X->get_handle(); my $c = 1;
> timethis(800000, sub{$h->maketext("bar $c"); $c++})'
>
Thank you. I’ve applied this as 152eae845915a3a33260ad109ad3888c8894d666.
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