KiokuDB::LiveObjects(3) Live object set tracking

VERSION

version 0.57

SYNOPSIS


$live_objects->insert( $entry => $object );
$live_objects->insert( $id => $object );
my $id = $live_objects->object_to_id( $object );
my $obj = $live_objects->id_to_object( $id );
my $scope = $live_objects->new_scope;

DESCRIPTION

This object keeps track of the set of live objects, their associated IDs, and the storage entries.

ATTRIBUTES

clear_leaks
Boolean. Defaults to false.

If true, when the last known scope is removed but some objects are still live they will be removed from the live object set.

Note that this does NOT prevent leaks (memory cannot be reclaimed), it merely prevents stale objects from staying loaded.

leak_tracker
This is a coderef or object.

If any objects are leaked (see "clear_leaks") then the this can be used to report them, or to break the circular structure.

When an object is provided the "leaked_objects" method is called. The coderef is simply invoked with the objects as arguments.

Triggered after "clear_leaks" causes "clear" to be called.

For example, to break cycles you can use Data::Structure::Util's "circular_off" function: 

    use Data::Structure::Util qw(circular_off);
    $dir->live_objects->leak_tracker(sub {
        my @leaked_objects = @_;
        circular_off($_) for @leaked_objects;
    });
keep_entries
EXPERIMENTAL

When true (the default), KiokuDB::Entries loaded from the backend or created by the collapser are kept around.

This results in a considerable memory overhead, so it's no longer required.

METHODS

insert
Takes pairs, id or entry as the key, and object as the value, registering the objects.
objects_to_ids
object_to_id
Given objects, returns their IDs, or undef for objects which not registered.
objects_to_entries
object_to_entry
Given objects, find the corresponding entries.
ids_to_objects
id_to_object
Given IDs, find the corresponding objects.
ids_to_entries
Given IDs, find the corresponding entries.
update_entries
Given entries, replaces the live entries of the corresponding objects with the newly updated ones.

The objects must already be in the live object set.

This method is called on a successful transaction commit.

new_scope
Creates a new KiokuDB::LiveObjects::Scope, with the current scope as its parent.
current_scope
The current KiokuDB::LiveObjects::Scope instance.

This is the scope into which newly registered objects are pushed.

new_txn
Creates a new KiokuDB::LiveObjects::TXNScope, with the current txn scope as its parent.
txn_scope
The current KiokuDB::LiveObjects::TXNScope.
clear
Forces a clear of the live object set.

This removes all objects and entries, and can be useful in the case of leaks (to prevent false positives on lookups).

Note that this does not actually break the circular structures, so the leak is unresolved, but the objects are no longer considered live by the KiokuDB instance.

live_entries
live_objects
live_ids
Enumerates the live entries, objects or ids.
rollback_entries
Called by ``rollback'' in KiokuDB::LiveObjects::TXNScope.
remove
Removes entries from the live object set.
remove_scope $scope
Removes a scope from the set of known scopes.

Also calls "detach_scope", and calls "KiokuDB::LiveObjects::Scope/clear" on the scope itself.

detach_scope $scope
Detaches $scope if it's the current scope.

This prevents "push" from being called on this scope object implicitly anymore.

AUTHOR

Yuval Kogman <[email protected]>

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.

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