NAME

       Cache::BaseCache -- abstract cache base class

DESCRIPTION

       BaseCache provides functionality common to all instances of a cache.  It differs 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 persistence mechanism.  The subclass can then inherit the BaseCache's
       implementation 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