#!/usr/bin/perl

# Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

#

# 1.  Redistributions of source code must retain the above copyright

#     notice, this list of conditions and the following disclaimer.

# 2.  Redistributions in binary form must reproduce the above copyright

#     notice, this list of conditions and the following disclaimer in the

#     documentation and/or other materials provided with the distribution.

# 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

#     its contributors may be used to endorse or promote products derived

#     from this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

# DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# This script takes two files that are lists of timings and compares them.

use warnings;

use strict;

use Getopt::Long;

my $usage = "compare-timing-files [-c|--count results] oldFile newFile";

my $count = 1;

GetOptions("c|count=i" => \$count);

my ($file1, $file2) = @ARGV;

die "$usage\n" unless ($file1 && $file2 && @ARGV == 2);

my ($oldAverage, $oldRange, $oldRangePercent) = parseResults($file1);

my ($newAverage, $newRange, $newRangePercent) = parseResults($file2);

print "\n===== $file1 =====\n";

if ($count == 1) {

    print("fastest run: $oldAverage\n");

} else {

    print("average of fastest $count runs: $oldAverage\n");

    printf("range of fastest $count runs: %.2f%% (%d)\n", $oldRangePercent, $oldRange);

}

print "\n===== $file2 =====\n";

if ($count == 1) {

    print("fastest run: $newAverage\n");

} else {

    print("average of fastest $count runs: $newAverage\n");

    printf("range of fastest $count runs: %.2f%% (%d)\n", $newRangePercent, $newRange);

}

my $gainOrLoss = $newAverage <= $oldAverage ? "GAIN" : "LOSS";

my $difference = abs($newAverage - $oldAverage);

my $differencePercent = $difference / $oldAverage * 100;

printf("\nperformance %s of %.2f%% (%.1f / %.1f)\n", $gainOrLoss, $differencePercent, $difference, $oldAverage);

print "\n";

sub parseResults

{

    my ($file) = @_;

    open(FILE, $file) or die "Couldn't open file: $file";

    my @results = <FILE>;

    close(FILE);

    @results = sort(@results);

    my $total = 0;

    for (my $i = 0; $i < $count; $i++) {

        $results[$i] =~ s/\D*//; # cut out non-digits

        $total += $results[$i]; 

    }

    my $average = $total / $count;

    my $range = $results[$count - 1] - $results[0];

    my $rangePercent = $range / $results[$count - 1] * 100;

    return ($average, $range, $rangePercent);

}