sub chunks_add {
my($tref, @chunks) = @_;
my($chunk);
foreach $chunk (@chunks) {
$$tref{$chunk} = $$tref{$chunk} + 1;
}
return $tref;
}
sub chunks_drop {
my($tref, @chunks) = @_;
my( $chunk, $count);
foreach $chunk (@chunks) {
$count = $$tref{$chunk} - 1;
if($count > 0) { $$tref{$chunk} = $count;}
elsif ($count == 0) {delete $$tref{$chunk}; }
else {die
"Decrementing a chunk (\"$chunk\") not in the table";}
}
return $tref;
}