Hello everyone,
I have a two sets of code that I'd like to know which one is "fastest",
so I turned to the Benchmark module to help solve the mystery. My code:
#!/usr/bin/perl
use warnings;
use strict;
use Benchmark qw( timethese cmpthese);
my $string = '01/23/2004';
my $x = 3;
my $r = timethese( -5, {
sbstr => sub{my $ko = substr($string, 0, 2)},
regex => sub{my $ko = $string =~ /(\d{2})/},
} );
cmpthese $r;
Returns:
Benchmark: running regex, sbstr for at least 5 CPU seconds...
regex: 4 wallclock secs ( 5.00 usr + 0.00 sys = 5.00 CPU) @
309749.20/s (n=1548746)
sbstr: 5 wallclock secs ( 5.28 usr + 0.00 sys = 5.28 CPU) @
993059.28/s (n=5243353)
Rate regex sbstr
regex 309749/s -- -69%
sbstr 993059/s 221% --
This is great information, but a little confusing. After looking over
the POD documentation for Benchmark, I think I understand, but would
like clarification.
If I understand correctly, of the 5 CPU seconds each subroutine was run
the 'regex' subroutine took 4 wallclock seconds and the 'sbstr'
subroutine took 5 wallclock seconds.
What's confusing is everything after the word "seconds" for each
subroutine...and the chart that has percentages in it. Does that chart
mean that the 'regex' subroutine is 221% "faster" than the 'sbstr'
subroutine?
Also, what is the "translation" of '( 5.00 usr + 0.00 sys = 5.00 CPU)
@ 309749.20/s (n=1548746)' and '( 5.28 usr + 0.00 sys = 5.28 CPU) @
993059.28/s (n=5243353)'. I assume from the percentage chart that the
'309749.20/s' and '993059.28/s' is the Rate, but what does that actually
mean?
Any help is appreciated,
Kevin
--
Kevin Old <[EMAIL PROTECTED]>
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