TM::Synchronizable(3pm)

NAME

TM::Synchronizable - Topic Maps, trait for synchronizable resources

SYNOPSIS

   # you write an input/output driver
   # see for example TM::Synchronizable::MLDBM
   package My::WhatEver;
     # provides source_in and/or source_out methods
     sub source_in  { .... }
     sub source_out { .... }
     1;
   # you construct your map class
   package MySyncableMap;
     use TM;
     use base qw(TM);
     use Class::Trait qw(TM::ResourceAble TM::Synchronizable My::WhatEver);
 
     1;
   # you then use that
   my $tm = MySyncableMap (url => 'file:/where/ever');
   $tm->sync_in;
   # work with the map, etc...
   $tm->sync_out;

DESCRIPTION

This trait implements the abstract synchronization between in-memory topic maps and the resources which are attached to them, i.e. files, web pages, etc. whatever can be addressed via a URI. Consequently, this trait inherits from TM::ResourceAble, although Class::Trait does not do this for you (sadly).

The trait provides the methods "sync_in" and "sync_out" to implement the synchronization. In this process it uses the timestamp of the map ("last_mod") and that of the resource "mtime".

Unfortunately, the granularity of the two are different (at least on current UNIX systems): for the last modification time values from Time::HiRes is used. UNIX resources only use an integer.

Note: This needs a bit of consideration from the user's side.

INTERFACE

Methods

sync_in

$tm->sync_in

This method provides only the main logic, whether a synchronisation from the resource into the in-memory map should occur. If the last modification date of the resource ("mtime") is more recent than that of the map ("last_mod"), then synchronisation from the resource to the in-memory map will be triggered. For this, a method "source_in" has to exist for the map object; that will be invoked.

[Since TM 1.53]: Any additional parameters are passed through to the underlying "source_in" method.

sync_out

$tm->sync_out

This method provides the logic, whether synchronisation from the in-memory map towards the attached resource should occur or not. If the last modification date of the map ("last_mod") is more recent than that of the resource ("mtime"), then a method "source_out" for the object is triggered.

[Since TM 1.53]: Any additional parameters are passed through to the underlying "source_out" method.

AUTHOR INFORMATION

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. http://www.perl.com/perl/misc/Artistic.html