I was looking and arunshankar.c's post XML parsing and thought same could be done (slightly faster) using localized $INPUT_RECORD_SEPARATOR.
I assumed (don't know why) that it will faster using $INPUT_RECORD_SEPARATOR. To see how much faster it is I did a small benchmark, but was astonished at the results.

Below are the results and the benchmark code I used.

#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw(cmpthese);

my $count = -100;
cmpthese($count, {
    'Split' => sub {
        my $document;
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        while (<FILE>) { $document .= $_ }
        my @lines = split('\|',$document);
    },
    'IRS_while' => sub {
        local $/ = '|';
        my @lines;
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        while (<FILE>) {
            chomp;
            push @lines, $_;            
        }
    },
    'IRS_map' => sub {
        local $/ = '|';
        open(FILE, 'removed.xml') or die "Error [$!]\n"; 
        my @lines = map {chomp; $_} (<FILE>);
    },
});

[download]
            Rate   IRS_map IRS_while     Split
IRS_map   4936/s        --       -7%       -8%
IRS_while 5303/s        7%        --       -2%
Split     5394/s        9%        2%        --

[download]

I have run this multiple times with different values of $count, Spiting string seems to have slight advantage in all cases. For a while I though I may be doing something wrong in the code, though at least I am not able to see if there is any issue with the code. I guess splitting is a bit faster (probably not significant, but it is what it is).
Can someone please help me to understand why is Split faster than using $INPUT_RECORD_SEPARATOR.
Thanks in advance.

P.S: Don't know if its important but just for information, I am using Active Perl 5.16 on Windows 7, 32 bit, Intel Core i3.

Regards,
Ashish

In reply to Benchmark results | localizing $INPUT_RECORD_SEPARATOR vs spliting contents of file on $INPUT_RECORD_SEPARATOR by ashish.kvarma

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