Rails - Jan 2006 - cached_model-1.0.1 ActiveRecords + memcache

The new version of cached_model features bug fixes and tests!

Bugs fixed:

Updating a model no longer stores associations into the cache.  This  
could cause strange, hard-to-debug bugs when an invalid set of  
assocations was retrieved along with a cached model.

Reloading a model refreshes the cache.

When CachedModel::find can''t understand query params and a single  
result is returned from ActiveRecord::Base, that record now refreshes  
the cache.

= CachedModel

Rubyforge Project:

http://rubyforge.org/projects/rctools/

Documentation:

http://dev.robotcoop.com/Libraries/cached_model/

== About

CachedModel stores Rails ActiveRecord objects in memcache allowing  
for very
fast retrievals.  CachedModel uses the ActiveRecord::Locking to  
ensure that
you don''t perform multiple updates.

== Using CachedModel

First, install the cached_model gem:

   $ sudo gem install cached_model

Then set up memcache-client:

   $ tail -n 20  config/environments/production.rb
   memcache_options = {
     :c_threshold => 10_000,
     :compression => true,
     :debug => false,
     :namespace => ''my_rails_app'',
     :readonly => false,
     :urlencode => false
   }

   CACHE = MemCache.new memcache_options
   CACHE.servers = ''localhost:11211''

   session_options = {
     :database_manager => CGI::Session::MemCacheStore,
     :cache => CACHE,
     :session_domain => ''trackmap.robotcoop.com''
   }

   ActionController::CgiRequest::DEFAULT_SESSION_OPTIONS.update  
session_options

You will need separate namespaces for production and development, if  
using
memcache on the same machine.

Note that using memcache with tests will cause test failures, so set  
your
memcache to be readonly for the test environment.

Then make Rails load the gem:

   $ tail -n 4 config/environment.rb
   # Include your application configuration below

   require_gem ''cached_model''

Then edit your ActiveRecord model to inherit from CachedModel instead of
ActiveRecord::Base:

   $ head -n 8 app/models/photo.rb
   ##
   # A Photo from Flickr.

   class Photo < CachedModel

     belongs_to :point
     belongs_to :route

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com