Constructor method for this class. Allows dependency injection of the required components such as Cache and the cache key generator.

Gets or sets the Request_Client::allow_private_cache setting. If set to TRUE, the client will also cache cache-control directives that have the private setting.

Basic cache key generator that hashes the entire request and returns it. This is fine for static content, or dynamic content where user specific information is encoded into the request.

 // Generate cache key
 $cache_key = HTTP_Cache::basic_cache_key_generator($request);

Getter and setter for the internal caching engine, used to cache responses if available and valid.

Sets or gets the cache key generator callback for this caching class. The cache key generator provides a unique hash based on the Request object passed to it.

The default generator is HTTP_Cache::basic_cache_key_generator(), which serializes the entire HTTP_Request into a unique sha1 hash. This will provide basic caching for static and simple dynamic pages. More complex algorithms can be defined and then passed into HTTP_Cache using this method.

 // Get the cache key callback
 $callback = $http_cache->cache_key_callback();

 // Set the cache key callback
 $http_cache->cache_key_callback('Foo::cache_key');

 // Alternatively, in PHP 5.3 use a closure
 $http_cache->cache_key_callback(function (Request $request) {
       return sha1($request->render());
 });

Calculates the total Time To Live based on the specification RFC 2616 cache lifetime rules.

Caches a Response using the supplied Cache and the key generated by Request_Client::_create_cache_key.

If not response is supplied, the cache will be checked for an existing one that is available.

Creates a cache key for the request to use for caching Kohana_Response returned by Request::execute.

This is the default cache key generating logic, but can be overridden by setting HTTP_Cache::cache_key_callback().

Executes the supplied Request with the supplied Request_Client. Before execution, the HTTP_Cache adapter checks the request type, destructive requests such as POST, PUT and DELETE will bypass cache completely and ensure the response is not cached. All other Request methods will allow caching, if the rules are met.

Factory method for HTTP_Cache that provides a convenient dependency injector for the Cache library.

 // Create HTTP_Cache with named cache engine
 $http_cache = HTTP_Cache::factory('memcache', array(
     'allow_private_cache' => FALSE
     )
 );

 // Create HTTP_Cache with supplied cache engine
 $http_cache = HTTP_Cache::factory(Cache::instance('memcache'),
     array(
         'allow_private_cache' => FALSE
     )
 );

Invalidate a cached response for the Request supplied. This has the effect of deleting the response from the Cache entry.

Returns the duration of the last request execution. Either returns the time of completed requests or FALSE if the request hasn't finished executing, or is yet to be run.

Controls whether the response can be cached. Uses HTTP protocol to determine whether the response can be cached.