#!/usr/bin/env perl
use strict;
use warnings;
use utf8;

use Benchmark qw(:all);
use File::Find;
use PIR;

my $Usage = "$0 some/path\n";
die $Usage unless @ARGV and -d $ARGV[0];

open( my $fh, ">", '/dev/null' );

cmpthese(
    50,
    {
        'File::Find' => \&try_find,
        'find pipe' => \&try_pipe,
        'find pipe iter' => \&try_pipe_iter,
        'PIR' => \&try_pir,
        'PIR fast' => \&try_pir_fast,
        'perl readdir' => \&try_readdir,
     }
);

sub try_find {
    find( 
        { 
            wanted => sub {
                print $fh $_ if ( -f $_ );
            }, 
            follow_fast => 1 
        },
        $ARGV[0] );
}

sub try_pipe {
    open( FIND, "find -L $ARGV[0] -type f  |" );
    while (<FIND>) {
        print $fh $_;
    }
    close FIND;
}

sub get_pipe_iter {
    open( my $FH, "-|", "find -L $ARGV[0] -type f" );
    return ( sub { return ( <$FH> ); } );
} 

sub try_pipe_iter {
    my $next = get_pipe_iter();
    while ( defined( my $file = $next->() ) ) {
        print $fh $file;
    }
}

sub try_pir {
    my $rule = PIR->new;
    my $next = $rule->iter( $ARGV[0] );
    while ( defined( my $file = $next->() ) ) {
        print $fh $file;
    }
}

sub try_pir_fast {
    my $rule = PIR->new;
    my $next = $rule->iter_fast( $ARGV[0] );
    while ( defined( my $file = $next->() ) ) {
        print $fh $file;
    }
}

sub try_readdir {
    my ( @dirs ) = @_ ? @_ : @ARGV;
    foreach my $dir ( @dirs ) {
        opendir DIR, $dir;
        my @entries = readdir DIR;
        closedir DIR;
        foreach my $entry ( @entries ) {
            next if ( $entry =~ m/^\.+$/ );
            if ( -d "$dir/$entry" ) {
                try_readdir( "$dir/$entry" );
            }
            else {
                print $fh "$dir/$entry";
            }
        }
    }
}