cache::basecache(3pm) [debian man page]

Cache::BaseCache(3pm)					User Contributed Perl Documentation				     Cache::BaseCache(3pm)

NAME

       Cache::BaseCache -- abstract cache base class

DESCRIPTION

       BaseCache provides functionality common to all instances of a cache.  It differes from the CacheUtils package insofar as it is designed to
       be used as superclass for cache implementations.

SYNOPSIS

       Cache::BaseCache is to be used as a superclass for cache implementations.  The most effective way to use BaseCache is to use the protected
       _set_backend method, which will be used to retrieve the persistance mechanism.  The subclass can then inherit the BaseCache's implentation
       of get, set, etc.  However, due to the difficulty inheriting static methods in Perl, the subclass will likely need to explicitly implement
       Clear, Purge, and Size.	Also, a factory pattern should be used to invoke the _complete_initialization routine after the object is
       constructed.

	 package Cache::MyCache;

	 use vars qw( @ISA );
	 use Cache::BaseCache;
	 use Cache::MyBackend;

	 @ISA = qw( Cache::BaseCache );

	 sub new
	 {
	   my ( $self ) = _new( @_ );

	   $self->_complete_initialization( );

	   return $self;
	 }

	 sub _new
	 {
	   my ( $proto, $p_options_hash_ref ) = @_;
	   my $class = ref( $proto ) || $proto;
	   my $self = $class->SUPER::_new( $p_options_hash_ref );
	   $self->_set_backend( new Cache::MyBackend( ) );
	   return $self;
	 }

	 sub Clear
	 {
	   foreach my $namespace ( _Namespaces( ) )
	   {
	     _Get_Backend( )->delete_namespace( $namespace );
	   }
	 }

	 sub Purge
	 {
	   foreach my $namespace ( _Namespaces( ) )
	   {
	     _Get_Cache( $namespace )->purge( );
	   }
	 }

	 sub Size
	 {
	   my $size = 0;

	   foreach my $namespace ( _Namespaces( ) )
	   {
	     $size += _Get_Cache( $namespace )->size( );
	   }

	   return $size;
	 }

SEE ALSO

       Cache::Cache, Cache::FileCache, Cache::MemoryCache

AUTHOR

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

       Last author:	$Author: dclinton $

       Copyright (C) 2001-2003 DeWitt Clinton

perl v5.12.4							    2009-03-01						     Cache::BaseCache(3pm)

HTML::Mason::Cache::BaseCache(3pm)			User Contributed Perl Documentation			HTML::Mason::Cache::BaseCache(3pm)

NAME

       HTML::Mason::Cache::BaseCache - Base cache object

DESCRIPTION

       This is the base module for all cache implementations used in Mason.  It provides a few additional methods on top of "Cache::BaseCache" in
       Dewitt Clinton's "Cache::Cache" package.

       An object of this class is returned from $m->cache.

METHODS

       clear ()
	   Remove all values in the cache.

       get (key, [%params])
	   Returns the value associated with key or undef if it is non-existent or expired. This is extended with the following optional
	   name/value parameters:

	   busy_lock => duration
	       If the value has expired, set its expiration time to the current time plus duration (instead of removing it from the cache) before
	       returning undef.  This is used to prevent multiple processes from recomputing the same expensive value simultaneously. The duration
	       may be of any form acceptable to set.

	   expire_if => sub
	       If the value exists and has not expired, call sub with the cache object as a single parameter. If sub returns a true value, expire
	       the value.

       get_object (key)
	   Returns the underlying "Cache::Object" object associated with key.  The most useful methods on this object are

	       $co->get_created_at();	 # when was object stored in cache
	       $co->get_accessed_at();	 # when was object last accessed
	       $co->get_expires_at();	 # when does object expire

       expire (key)
	   Expires the value associated with key, if it exists. Differs from remove only in that the cache object is left around, e.g. for
	   retrieval by get_object.

       remove (key)
	   Removes the cache object associated with key, if it exists.

       set (key, data, [duration])
	   Associates data with key in the cache. duration indicates the time until the value should be erased.  If duration is unspecified, the
	   value will never expire by time.

	   $expires_in may be a simple number of seconds, or a string of the form "[number] [unit]", e.g., "10 minutes".  The valid units are s,
	   second, seconds, sec, m, minute, minutes, min, h, hour, hours, d, day, days, w, week, weeks, M, month, months, y, year, and years.

perl v5.14.2							    2012-02-04					HTML::Mason::Cache::BaseCache(3pm)