use strict;
use warnings;

use MCE::Loop;
use MCE::Candy;

my $infile  = shift or die "Usage: $0 infile\n";
my $newfile = 'output.dat';

open my $fh_out, '>', $newfile or die "open error $newfile: $!\n";

MCE::Loop::init {
    chunk_size => 'auto', max_workers => 8,
    gather => MCE::Candy::out_iter_fh($fh_out),
    init_relay => 1
};

mce_loop_f {
    my ($mce, $chunk_ref, $chunk_id) = @_;
    my @lines;

    foreach my $line (@{ $chunk_ref }) {
        $line =~ s/\r//g; chomp $line;

        my ($f1,$f2,$f3,$items,$f5,$f6,$f7) = split /\|/, $line;
        my @items_array = split /;/, $items;

        foreach my $item (@items_array) {
            push @lines, "$item|$f1|$f2|$f3|$f5|$f6|$f7\n";
        }
    }

    my $idx = MCE::relay { $_ += scalar @lines };
    my $buf = '';

    foreach my $line ( @lines ) {
        $buf .= sprintf "%015d|%s", $idx++, $line
    }

    MCE->gather($chunk_id, $buf);

} $infile;

MCE::Loop::finish();
close $fh_out;