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Cache::SizeAwareCache.3pm

NAME

Cache::SizeAwareCache -- extends the Cache interface.

DESCRIPTION

The SizeAwareCache interface is implemented by classes that support all of the Cache::Cache interface in addition to the limit_size and max_size features of a size aware cache.

The default cache size limiting algorithm works by removing cache objects in the following order until the desired limit is reached:

   1) objects that have expired
   2) objects that are least recently accessed
   3) objects that that expire next
 
 

SYNOPSIS

   use Cache::SizeAwareCache;
   use vars qw( @ISA );
 
   @ISA = qw( Cache::SizeAwareCache );
 
 

CONSTANTS

Please see Cache::Cache for standard constants

$NO_MAX_SIZE

The cache has no size restrictions

METHODS

Please see Cache::Cache for the standard methods

limit_size( $new_size )

Attempt to resize the cache such that the total disk usage is under the $new_size parameter. $new_size represents t size (in bytes) that the cache should be limited to. Note that this is only a one time adjustment. To maintain the cache size, consider using the max_size option, although it is considered very expensive, and can often be better achieved by peridocally calling limit_size.

OPTIONS

Please see Cache::Cache for the standard options

max_size

Sets the max_size property (size in bytes), which is described in detail below. Defaults to $NO_MAX_SIZE.

PROPERTIES

Please see Cache::Cache for standard properties

(get|set)_max_size

If this property is set, then the cache will try not to exceed the max size value (in bytes) specified. NOTE: This causes the size of the cache to be checked on every set, and can be considered *very* expensive in some implementations. A good alternative approach is leave max_size as $NO_MAX_SIZE and to periodically limit the size of the cache by calling the limit_size( $size ) method.

SEE ALSO

Cache::Cache

AUTHOR

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

Last author: $Author: dclinton $

Copyright (C) 2001-2003 DeWitt Clinton