find_leaks

#!/usr/bin/perl -w
#
# Given an swf file this will give some diagnostics
# on where our write_through program is going wrong.
#
#


use strict;

# warning this is a security risk, probably
my $file = shift || die "Must pass a file name";

# make a temp name
my $tmp =  $$.time;

# perform a write through an generate the first loads of tags
my @first = `./write_through $file $tmp`;
# do the second one. We should probably error check this.
my @second = `./write_through $tmp $tmp`;

die "There was an error running the external program './write_through'" unless (@first && @second);

# get rid of the tmp file
unlink $tmp;

# the current difference
my $diff = 0;

for (my $i=0; $i<scalar @first; $i++)
{
	# clean up
	chomp ($first[$i]);
	chomp ($second[$i]);
	
	# don't want anything that isn't debug output
	next unless $first[$i] =~ /^\[/;

	# grab the info
	my @a = ($first[$i]  =~ /^\[(\d+)\] \((\d+)\) (.+) (\**)$/);
	my @b = ($second[$i] =~ /^\[(\d+)\] \((\d+)\) (.+) (\**)$/);

	# work out where the tags were in the file and what the difference
        # is between them. 
	my $tdiff = $a[1] - $b[1];

	# normalise
	$tdiff *= -1 if ($tdiff < 0);

	# if it's different to the last difference
	# (if you get what I mean) then the tag before 
	# must have been longer (I think, it could be 
	# this one) 
	if ($tdiff > $diff) {
	
		my @c = ($first[$i-1]   =~ /^\[(\d+)\] \((\d+)\) (.+) (\**)$/);
		my @d = ($second[$i-1]  =~ /^\[(\d+)\] \((\d+)\) (.+) (\**)$/);
		print "$c[2] changed by ".($tdiff-$diff)." bytes in frame $c[0]";
		print " (longtag)" if (defined $c [3] && $c[3] eq '*');
		print ".\n";
		print "Original tag started at ".$c[1]." and the next tag starts at ".$a[1]." size=".($a[1]-$c[1])."\n";
		print "The new  tag started at ".$d[1]." and the next tag starts at ".$b[1]." size=".($b[1]-$d[1])."\n";
		print "\n"; 
		$diff = $tdiff;

	}
		
}


exit 0;