NAME¶
KiokuDB::Linker - Relinks live objects from storage entries
VERSION¶
version 0.57
SYNOPSIS¶
# mostly internal
DESCRIPTION¶
The linker reconnects entry data, recreating the connected object graph in
memory.
The linkage process starts with an ID (or several IDs) to be loaded passed to
the "get_or_load_objects" method.
This ID will first be searched for in the live object set
(KiokuDB::LiveObjects). If the object is already live, then it will be
returned as is.
If the object is not live, then the corresponding entry is fetched from the
backend, and expanded into an actual instance.
Expansion consults the KiokuDB::TypeMap using KiokuDB::TypeMap::Resolver, to
find the correct typemap entry (see "COLLAPSING STRATEGIES" in
KiokuDB::Collapser and KiokuDB::TypeMap), and that is used for the actual
expansion.
Most of the grunt work is delegated by the entries back to the linker using the
"inflate_data" method, which handles circular structures, retrying
of tied structures, etc.
Inflated objects are registered with KiokuDB::LiveObjects, and get inserted into
the current live object scope (KiokuDB::LiveObjects::Scope). The scope's job
is to maintain a reference count of at least 1 for any loaded object, until it
is destroyed itself. This ensures that weak references are not destroyed
prematurely, but allows their use in order to avoid memory leaks.
AUTHOR¶
Yuval Kogman <nothingmuch@woobling.org>
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2014 by Yuval Kogman, Infinity Interactive.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.