NAME

Cache::CacheMetaData -- data about objects in the cache

DESCRIPTION

The CacheMetaData object is used by size aware caches to keep track of the state of the cache and effeciently return information such as an objects size or an ordered list of indentifiers to be removed when a cache size is being limited. End users will not normally use CacheMetaData directly.

SYNOPSIS

 use Cache::CacheMetaData;

 my $cache_meta_data = new Cache::CacheMetaData( );

 $cache_meta_data->insert( $object );

 my $current_size = $cache_meta_data->get_cache_size( );

 my @removal_list;

 $cache_meta_data->build_removal_list( \@removal_list );

METHODS

new( )

Construct a new Cache::CacheMetaData object

insert( $object )

Inform the CacheMetaData about an object in the cache.

$object

The object to be examined for its meta data

remove( $identifier )

Inform the CacheMetaData that an object is no longer in the cache

$identifier

The key under which the object was stored.

build_removal_list( $removal_list_ref )

Create a list of the identifiers in the cache, ordered as follows:

1) objects that expire now

2) objects expiring at a particular time, with ties broken by the time at which they were least recently accessed

3) objects that never expire, sub ordered by the time at which they were least recently accessed

NOTE: This could be improved further by taking the size into account on accessed_at ties. However, this type of tie is unlikely in normal usage.

$removal_list_ref

A reference to the list that should hold the result

build_object_size( $identifier, $object_size_ref )

Determine the size of an object that the CacheMetaData knows about

$identifier

The key under which the object was stored.

$object_size_ref

A reference to the scalar that should hold the result

PROPERTIES

get_cache_size

The total size of the objects in the cache

SEE ALSO

Cache::Cache

AUTHOR

Original author: DeWitt Clinton <dewitt@unto.net>

Last author: $Author: dclinton $

Copyright (C) 2001 DeWitt Clinton