| Subject: | re-use of instantiated XML-Diff 0.5 |
| Date: | Wed, 1 Aug 2007 14:22:27 +0200 (CEST) |
| To: | bug-XML-Diff [...] rt.cpan.org |
| From: | mm [...] artegic.de |
Dear sirs,
being quite happy with Your XML-Diff module, I do have nondeterministic
problems when reusing an instantiated XML-Diff object very frequently.
About my environment:
dbnu053 rel72_ux ~> perl -v
This is perl, v5.8.8 built for x86_64-linux-thread-multi
dbnu053 rel72_ux ~> xml2-config --version
2.6.23
The OS is SLES 10.
I am instantiating the module once and then feeding tens of thousands of
XML documents into it to compare:
sub diff_xml {
my ( $self, $id ) = @_;
my $xml = $self->{'xml'};
my $opts = $self->{'opts'};
$self->{'differ'} ||= XML::Diff->new();
my $differ = $self->{'differ'};
print "\n----------\nDiffing xmls for $id ... ";
# Call differ
my $res;
$res = eval {
$differ->compare(
-old => $$xml{$id}{'wna'},
-new => $$xml{$id}{'ds'},
);
};
# delete( $self->{'differ'} );
return $@ if $@;
return $res->toString( 1 );
}
Now, if I do delete the differ object after each comparison, everything is
fine. If I do reuse the instance, after 50-500 comparisons the first error
will occur and from then 50-80% of the subsequent comparisons will fail
with the following error:
Can't call method "previousSibling" on an undefined value at
<pathto>/usr/lib/perl5/site_perl/5.8.8/XML/Diff.pm line 1389, <FH> line
<lineno>.
This line contains a call to $node instantiated the line before, if I do
dump the full $lookup->{id} table, the actual $id the node is supposed to
be instantiated from is for some reason always 323 and the corresponding
entry not present in the table, while the number of table entries ranges
from 90 to 350 (probably connected to the number of nodes in the original
xmls?).
My guess would be that the differ object does not properly clean up memory
after each run and/or abnormal termination upon returning $@.
Due to time reasons I didn't have a chance to check whether 323 is simply
the first node gone missing due to an occurrence of the error described
below.
Which leads to another problem I have (that I haven't time to investigate
further yet): I do get $@ filled with "Invalid expression" as a return
value from about 5% of the calls. Still all the xmls causing these errors
are valid XML. Is this maybe related to bug #27725: "Tag with empty
content error (<p></p>)"? Or is it maybe a system lib that's faulty?
TIA,
Yours
Martin