data::objectdriver::driver::cache::apache(3pm) [debian man page]

Data::ObjectDriver::Driver::Cache::Apache(3pm)		User Contributed Perl Documentation	    Data::ObjectDriver::Driver::Cache::Apache(3pm)

NAME

       Data::ObjectDriver::Driver::Cache::Apache - object driver for caching objects in Apache's request space

SYNOPSIS

	   package MyObject;
	   use base qw( Data::ObjectDriver::BaseObject );

	   __PACKAGE__->install_properties({
	       ...
	       driver => Data::ObjectDriver::Driver::Cache::Apache->new(
		   fallback => Data::ObjectDriver::Driver::Cache::Memcached->new(
		       cache	=> Cache::Memcached->new({ servers => @MEMCACHED_SERVERS }),
		       fallback => Data::ObjectDriver::Driver::DBI->new( @$DBI_INFO ),
		   ),
	       ),
	       ...
	   });

	   1;

DESCRIPTION

       Data::ObjectDriver::Driver::Cache::Apache provides automatic caching of retrieved objects in the per-request memory space of your Apache
       mod_perl processes, when used in conjunction with your actual object driver. It can be used to provide even faster results over memcached
       when requesting objects that have already been requested during the same request by some other part of your application, at the cost of the
       memory necessary to store the objects.

       If your models can be used in an Apache mod_perl application as well as another context such as a command line shell, consider replacing
       the Apache layer of your caching with a "Data::ObjectDriver::Driver::Cache::RAM" layer when Apache is not available. See
       Data::ObjectDriver::Driver::Cache::Apache.

USAGE

       o   Data::ObjectDriver::Driver::Cache::Apache->new(%params)

	   Required members of %params are:

	   o   "fallback"

	       The "Data::ObjectDriver" object driver from which to request objects that are not found in the Apache process cache.

DIAGNOSTICS

       The Apache driver provides integration with the "Data::ObjectDriver" debug and profiling systems. As these systems are designed around SQL
       queries, synthetic queries are logged to represent caching operations. The operations generated by this driver are:

       o   "APACHECACHE_GET ?"

	   Retrieve an object. The argument is the cache key for the requested object.

       o   "APACHECACHE_ADD ?,?"

	   Add an object to the cache. The arguments are the cache key for the object and the flattened representation of the object to cache.

       o   "APACHECACHE_SET ?,?"

	   Put an object in the cache. The arguments are the cache key for the object and the flattened representation of the object to cache.

       o   "APACHECACHE_DELETE ?"

	   Remove an object from the cache. The argument is the cache key for the object to invalidate.

SEE ALSO

       Apache, Apache2::RequestUtil

LICENSE

       Data::ObjectDriver is free software; you may redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR &; COPYRIGHT
       Except where otherwise noted, Data::ObjectDriver is Copyright 2005-2006 Six Apart, cpan@sixapart.com. All rights reserved.

perl v5.12.4							    2011-08-29			    Data::ObjectDriver::Driver::Cache::Apache(3pm)

Data::ObjectDriver::Driver::BaseCache(3pm)		User Contributed Perl Documentation		Data::ObjectDriver::Driver::BaseCache(3pm)

NAME

       Data::ObjectDriver::Driver::BaseCache - parent class for caching object drivers

SYNOPSIS

DESCRIPTION

       Data::ObjectDriver::Driver::BaseCache provides behavior utilized for all caching object drivers for use with Data::ObjectDriver. That
       behavior is looking up requested objects in a cache, and falling back to another Data::ObjectDriver for a cache miss.

USAGE

       Drivers based on Data::ObjectDriver::Driver::BaseCache support all standard operations for Data::ObjectDriver object drivers (lookup,
       search, update, insert, replace, remove, and fetch_data). BaseCache-derived drivers also support:

   "Data::ObjectDriver::Driver::BaseCache->new( %params )"
       Creates a new instance of a BaseCache driver. Required members of %params are:

       o   "cache"

	   The object with which to interface with the external cache. For example, for the "Memcached" caching object driver, the value of the
	   "cache" member should be a "Cache::Memcached" object.

       o   "fallback"

	   The "Data::ObjectDriver" object driver to which to fall back when the cache does not yet contain a requested object. The "fallback"
	   member is also the object driver to which updates and inserts are passed.

   "$driver->cache_key($class, $primary_key)"
       Returns the cache key for an object of the given class with the given primary key. The cache key is used with the external cache to
       identify an object.

       In BaseCache's implementation, the key is the class name and all the column names of the primary key concatenated, separated by single
       colons.

   "$driver->get_multi_from_cache(@cache_keys)"
       Returns the objects corresponding to the given cache keys, as represented in the external cache.

   "Data::ObjectDriver::Driver::BaseClass->Disabled([ $value ])"
       Returns whether caches of the given class are disabled, first updating the disabled state of drivers of the given class to $value, if
       given. When a caching driver is disabled, all operations are automatically passed through to the fallback object driver.

       Note that, if you disable and reenable a caching driver, some of the cached data may be invalid due to updates that were performed while
       the driver was disabled not being reflected in the external cache.

SUBCLASSING

       When creating a caching driver from "BaseCache", the behavior for interaction with the external cache (through the "cache" member of the
       constructor) must be defined by implementing these methods:

   "$driver->add_to_cache($cache_key, $obj_repr)"
       Sets the cache entry for $cache_key to the given object representation. This method is used when the corresponding object is being saved to
       the database for the first time.

   "$driver->update_cache($cache_key, $obj_repr)"
       Sets the cache entry for $cache_key to the given object representation. This method is used when the corresponding object already exists in
       the database and is being saved.

   "$driver->remove_from_cache($cache_key)"
       Clears the given cache entry. This method is used when the corresponding object is being deleted from the database.

   "$driver->get_from_cache($cache_key)"
       Returns the object corresponding to the given cache key, as it exists in the external cache.

   "$driver->inflate($class, $obj_repr)"
       Returns an instance of $class containing the data in the representation $obj_repr, as returned from the "get_from_cache" method.

       In BaseCache's implementation, no operation is performed. "get_from_cache" should itself return the appropriate instances of
       "Data::ObjectDriver::BaseObject".

   "$driver->deflate($obj)"
       Returns a representation of the given "Data::ObjectDriver::BaseObject" instance, suitable for passing to the "add_to_cache" and
       "update_cache" methods.

       In BaseCache's implementation, no operation is performed. "add_to_cache" and "update_cache" should themselves accept
       "Data::ObjectDriver::BaseObject" instances.

LICENSE

       Data::ObjectDriver is free software; you may redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR &; COPYRIGHT
       Except where otherwise noted, Data::ObjectDriver is Copyright 2005-2006 Six Apart, cpan@sixapart.com. All rights reserved.

perl v5.12.4							    2011-08-29				Data::ObjectDriver::Driver::BaseCache(3pm)