##### PACK THE POSTING LIST...
	my $str = '';
    for my $doc_id( 0 .. 30000 ) {
    	print "Doc id:\t",$doc_id,"\n";
        $str .= (pack "I", $doc_id) | $SET_MSB;
        for my $pos ( 0 .. 2 ) {
            $str .= (pack "I", $pos) & $UNSET_MSB;
        }
    }
print "pack time \t",time()-$Aa,"\n";

# UNPACK THE POSTING LIST
my $Aaa=time();

	my $dat = {};
        my $doc_id = undef;
	for( my $i=0;$i<length $str; $i+=4) 
	{
        my $int = unpack "I", (substr $str,$i);
        if ( $int > $MSB ) 
        {
            $doc_id = unpack "I", ((pack "I", $int) & $UNSET_MSB);

        }
        else 
        {
            push @{$dat->{$doc_id}}, $int;
        }
    }

print "unpack time \t",time()-$Aaa,"\n";