Simplest speedup should be to move from reading line-by-line and using parse () to use getline (). This will pay off even more when you allow binary and/or embedded newlines. I did a small benchmark on my machine:

/home/merijn> cat test.pl
#!/pro/bin/perl

use strict;
use warnings;

use Benchmark qw( cmpthese );
use Text::CSV_XS;
use IO::Handle;

my $csv = Text::CSV_XS->new;
my @f;

sub diamond
{
    open my $io, "<", "test.csv" or die "test.csv: $!";
    while (<$io>) {
        $csv->parse ($_);
        @f = $csv->fields;
        }
    } # diamond

sub intern
{
    open my $io, "<", "test.csv" or die "test.csv: $!";
    while (my $row = $csv->getline ($io)) {
        @f = @$row;
        }
    } # intern

cmpthese (-5, { "diamond" => \&diamond, "getline" => \&intern });
/home/merijn> wc -l test.csv
12000 test.csv
/home/merijn> perl test.pl
          Rate diamond getline
diamond 6.89/s      --    -39%
getline 11.3/s     64%      --
/home/merijn>

[download]

You can use the first field to do your after-matches.


Enjoy, Have FUN! H.Merijn

In reply to Re: need to optimize my sub routine by Tux
in thread need to optimize my sub routine by convenientstore

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