Caching URL encoder for Perl

urlencoder

#!/usr/bin/perl -w
use strict;
use warnings;
use feature (qw/state/);

sub encode {
    state %hashMap;

    if (not %hashMap) {
        %hashMap = ();

        my $encodeStr = "!\"#$%&'()*+,-./0123456789:;<=>?@[\\]^_`" .
                        "abcdefghijklmnopqrstuvwxyz{|}~ ABCDEFGHIJK" .
                        "LMNOPQRSTUVXYZ";
        for (my $i=0; $i<length($encodeStr); $i++) {
            my $ch = substr($encodeStr, $i, 1);
            $hashMap{$ch} = sprintf('%%%x', ord($ch));
        }
    }

    my $target = shift;

    if (exists($hashMap{$target})) {
        return $hashMap{$target};
    } else {
        return $target;
    }
}