TM::ResourceAble::MLDBM - Topic Maps, DBM Storage (synchronous)


    use TM::ResourceAble::MLDBM;
    my $tm = new TM::ResourceAble::MLDBM (file => '/tmp/map.dbm');
    # modify the map here.....

    } # it goes out of scope here, and all changes are written back automagically

   # later in the game
    my $tm = new TM::ResourceAble::MLDBM (file => '/tmp/map.dbm');
    # we are back in business, no sync necessary


This package just implements TM with a BerkeleyDB store. Unlike TM::Materialized::MLDBM this module does not need explicit synchronisation with the external resource (the DBM file here). It ties content-wise with the DBM file at constructor time and unties at DESTROY time.

This implementation technique is not so memory-efficient as I had thought. Whenever an assertion or a toplet is referenced, the whole block of toplets, resp. assertions, is loaded from the DB database. For small maps this is really fast, but it can become a drag for larger maps. See TM::ResourceAble::BDB for a more efficient solution.

NOTE: Be careful to use this together with TM::Index::*. The indices will be held as part of the map, and so will be stored along side. If you heavily use the map, this can result in many swapin/swapouts. Better to look at TM::IndexAble for that matter.



The constructor expects a hash with the following keys:

file (no default)

This contains the file name of the DBM file to tie to.


TM, TM::Materialized::MLDBM


Copyright 200[68], Robert Barta <>, All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.