Sequel's built-in caching plugin supports caching to any object that implements the Ruby-Memcache API (or memcached API with the :ignore_exceptions option):
cache_store.set(key, obj, time) # Associate the obj with the given key # in the cache for the time (specified # in seconds). cache_store.get(key) # => obj # Returns object set with same key. cache_store.get(key2) # => nil # nil returned if there isn't an object # currently in the cache with that key. cache_store.delete(key) # Remove key from cache
If the :ignore_exceptions option is true, exceptions raised by cache_store.get are ignored and nil is returned instead. The memcached API is to raise an exception for a missing record, so if you use memcached, you will want to use this option.
Note that only lookups by primary key are cached using this plugin. The following methods use a lookup by primary key:
Model.with_pk
Model.with_pk!
Model.[] # when argument is not hash or nil
many_to_one association method # without dynamic callback, when primary key matches
Usage:
# Make all subclasses use the same cache (called before loading subclasses) # using the Ruby-Memcache API, with the cache stored in the CACHE constant Sequel::Model.plugin :caching, CACHE # Make the Album class use the cache with a 30 minute time-to-live Album.plugin :caching, CACHE, ttl: 1800 # Make the Artist class use a cache with the memcached protocol Artist.plugin :caching, MEMCACHED_CACHE, ignore_exceptions: true
Set the cache_store and cache_ttl attributes for the given model. If the :ttl option is not given, 3600 seconds is the default.
# File lib/sequel/plugins/caching.rb, line 44 def self.configure(model, store, opts=OPTS) model.instance_exec do @cache_store = store @cache_ttl = opts[:ttl] || 3600 @cache_ignore_exceptions = opts[:ignore_exceptions] end end