Re: How to cache a regular expression in a DBIx::Class object

Try something like

sub match_re {
    my $self = shift;

    # retrieve from cache if it's there:
    my $re = $self->{match_re};
    return $re if defined $re;

    # otherwise compute it and store it:
    $re = $self->match_string;
    $re = qr/\Q$re\E/;
    return $self->{match_re} = $re;
}
[download]

in the result class.

Perl 6 - second systems done right

Comment on Re: How to cache a regular expression in a DBIx::Class object Download Code

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Re^2: How to cache a regular expression in a DBIx::Class object by chrestomanci (Priest) on Apr 08, 2011 at 21:04 UTC
Thank you for replying. Unfortunately I have tried that and it did not work. When processing log output, I set a breakpoint in the perl debugger on the second line of the input file. (using `$DB::single=1 if 0 != $INPUT_LINE_NUMBER`) When I hit that breakpoint I stepped into the `$watch_string->match_re()` method and found that the regular expression that should have been cached was not there. It looks like DBIx::Class was re-creating objects every time. There are about 10 rows in the tblWatchString table, so I would not have thought that objects would be cleared as part of a memory saving or garbage collection system.	[reply] [d/l] [select]
Re^3: How to cache a regular expression in a DBIx::Class object by moritz (Cardinal) on Apr 09, 2011 at 11:31 UTC
It looks like DBIx::Class was re-creating objects every time. Oh, I missed that part. There's a much easier for that - move the retrieval of the DBIx::Class objects out of the loop: `my @watchstrings = $schema->resultset('WatchString')->all while( my $line <INPUT> ) { for my $w (@watchstrings) { ... } }` [download] Perl 6 - second systems done right	[reply] [d/l]