diff options
Diffstat (limited to 'actionpack/lib/action_controller')
| -rw-r--r-- | actionpack/lib/action_controller/caching.rb | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/actionpack/lib/action_controller/caching.rb b/actionpack/lib/action_controller/caching.rb index 28426bd047..bf4e7799c7 100644 --- a/actionpack/lib/action_controller/caching.rb +++ b/actionpack/lib/action_controller/caching.rb @@ -307,25 +307,28 @@ module ActionController #:nodoc: # <%= render :partial => "topic", :collection => Topic.find(:all) %> # <% end %> # - # This cache will bind to the name of action that called it. So you would be able to invalidate it using - # <tt>expire_fragment(:controller => "topics", :action => "list")</tt> -- if that was the controller/action used. This is not too helpful - # if you need to cache multiple fragments per action or if the action itself is cached using <tt>caches_action</tt>. So instead we should - # qualify the name of the action used with something like: + # This cache will bind to the name of the action that called it, so if this code was part of the view for the topics/list action, you would + # be able to invalidate it using <tt>expire_fragment(:controller => "topics", :action => "list")</tt>. + # + # This default behavior is of limited use if you need to cache multiple fragments per action or if the action itself is cached using + # <tt>caches_action</tt>, so we also have the option to qualify the name of the cached fragment with something like: # # <% cache(:action => "list", :action_suffix => "all_topics") do %> # - # That would result in a name such as "/topics/list/all_topics", which wouldn't conflict with any action cache and neither with another - # fragment using a different suffix. Note that the URL doesn't have to really exist or be callable. We're just using the url_for system - # to generate unique cache names that we can refer to later for expirations. The expiration call for this example would be - # <tt>expire_fragment(:controller => "topics", :action => "list", :action_suffix => "all_topics")</tt>. + # That would result in a name such as "/topics/list/all_topics", avoiding conflicts with the action cache and with any fragments that use a + # different suffix. Note that the URL doesn't have to really exist or be callable - the url_for system is just used to generate unique + # cache names that we can refer to when we need to expire the cache. + # + # The expiration call for this example is: + # + # expire_fragment(:controller => "topics", :action => "list", :action_suffix => "all_topics") # # == Fragment stores # - # In order to use the fragment caching, you need to designate where the caches should be stored. This is done by assigning a fragment store - # of which there are four different kinds: + # By default, cached fragments are stored in memory. The available store options are: # - # * FileStore: Keeps the fragments on disk in the +cache_path+, which works well for all types of environments and shares the fragments for - # all the web server processes running off the same application directory. + # * FileStore: Keeps the fragments on disk in the +cache_path+, which works well for all types of environments and allows all + # processes running from the same application directory to access the cached content. # * MemoryStore: Keeps the fragments in memory, which is fine for WEBrick and for FCGI (if you don't care that each FCGI process holds its # own fragment store). It's not suitable for CGI as the process is thrown away at the end of each request. It can potentially also take # up a lot of memory since each process keeps all the caches in memory. @@ -347,6 +350,7 @@ module ActionController #:nodoc: @@fragment_cache_store = MemoryStore.new cattr_reader :fragment_cache_store + # Defines the storage option for cached fragments def self.fragment_cache_store=(store_option) store, *parameters = *([ store_option ].flatten) @@fragment_cache_store = if store.is_a?(Symbol) @@ -360,6 +364,9 @@ module ActionController #:nodoc: end end + # Given a name (as described in <tt>expire_fragment</tt>), returns a key suitable for use in reading, + # writing, or expiring a cached fragment. If the name is a hash, the generated name is the return + # value of url_for on that hash (without the protocol). def fragment_cache_key(name) name.is_a?(Hash) ? url_for(name).split("://").last : name end @@ -379,6 +386,7 @@ module ActionController #:nodoc: end end + # Writes <tt>content</tt> to the location signified by <tt>name</tt> (see <tt>expire_fragment</tt> for acceptable formats) def write_fragment(name, content, options = nil) return unless perform_caching @@ -389,6 +397,7 @@ module ActionController #:nodoc: content end + # Reads a cached fragment from the location signified by <tt>name</tt> (see <tt>expire_fragment</tt> for acceptable formats) def read_fragment(name, options = nil) return unless perform_caching @@ -405,8 +414,8 @@ module ActionController #:nodoc: # %r{pages/\d*/notes} # Ensure you do not specify start and finish in the regex (^$) because # the actual filename matched looks like ./cache/filename/path.cache - # Regexp expiration is not supported on caches which can't iterate over - # all keys, such as memcached. + # Regexp expiration is only supported on caches that can iterate over + # all keys (unlike memcached). def expire_fragment(name, options = nil) return unless perform_caching |