module Sequel::Plugins::Caching::ClassMethods

Attributes

cache_ignore_exceptions [R]

If true, ignores exceptions when getting cached records (the memcached API).

cache_store [R]

The cache store object for the model, which should implement the Ruby-Memcache (or memcached) API

cache_ttl [R]

The time to live for the cache store, in seconds.

Public Instance Methods

cache_delete_pk (pk)

Source

   # File lib/sequel/plugins/caching.rb
74 def cache_delete_pk(pk)
75   cache_delete(cache_key(pk))
76 end

Delete the cached object with the given primary key.

cache_get_pk (pk)

Source

   # File lib/sequel/plugins/caching.rb
80 def cache_get_pk(pk)
81   cache_get(cache_key(pk))
82 end

Return the cached object with the given primary key, or nil if no such object is in the cache.

cache_key (pk)

Source

   # File lib/sequel/plugins/caching.rb
90 def cache_key(pk)
91   case pk
92   when Array
93     raise(Error, 'no primary key for this record') unless pk.all?
94     "#{cache_key_prefix}:#{composite_cache_key(pk)}"
95   else
96     raise(Error, 'no primary key for this record') unless pk
97     "#{cache_key_prefix}:#{scalar_cache_key(pk)}"
98   end
99 end

Return a key string for the given primary key.

cache_key_prefix ()

Source

   # File lib/sequel/plugins/caching.rb
85 def cache_key_prefix
86   to_s
87 end

Returns the prefix used to namespace this class in the cache.

composite_cache_key (pk)

Source

    # File lib/sequel/plugins/caching.rb
109 def composite_cache_key(pk)
110   pk.join(',')
111 end

Return an appropriate cache key string for a valid composite primary key. By default, joins with the parts of the compsite key with “,”.

scalar_cache_key (pk)

Source

    # File lib/sequel/plugins/caching.rb
103 def scalar_cache_key(pk)
104   pk.to_s
105 end

Return an appropriate cache key string for a valid scalar primary key. By default, converts the primary key to a string.

set_cache_ttl (ttl)

Source

    # File lib/sequel/plugins/caching.rb
116 def set_cache_ttl(ttl)
117   @cache_ttl = ttl
118 end

Set the time to live for the cache store, in seconds (default is 3600, # so 1 hour).

Private Instance Methods

cache_delete (ck)

Source

    # File lib/sequel/plugins/caching.rb
132 def cache_delete(ck)
133   cache_op(:delete, ck)
134   nil
135 end

Delete the entry with the matching key from the cache

cache_get (ck)

Source

    # File lib/sequel/plugins/caching.rb
139 def cache_get(ck)
140   cache_op(:get, ck)
141 end

Returned the cached object, or nil if the object was not in the cached

cache_op (meth, ck)

Source

    # File lib/sequel/plugins/caching.rb
123 def cache_op(meth, ck)
124   if @cache_ignore_exceptions
125     @cache_store.public_send(meth, ck) rescue nil
126   else
127     @cache_store.public_send(meth, ck)
128   end
129 end

Access the cache using the given method and key, rescuing exceptions if necessary.

cache_set (ck, obj)

Source

    # File lib/sequel/plugins/caching.rb
144 def cache_set(ck, obj)
145   @cache_store.set(ck, obj, @cache_ttl)
146 end

Set the object in the cache_store with the given key for cache_ttl seconds.

primary_key_lookup (pk)

Source

    # File lib/sequel/plugins/caching.rb
149 def primary_key_lookup(pk)
150   ck = cache_key(pk)
151   unless obj = cache_get(ck)
152     if obj = super(pk)
153       cache_set(ck, obj)
154     end
155   end 
156   obj
157 end

Check the cache before a database lookup unless a hash is supplied.

Calls superclass method