/**
* Processes the request, checking for attached
* Cache decorators. If decorators are found,
* the request performs the following tasks.
*
* 1. Checks for existing cached response, returning valid hits
* 2. Runs the Kohana_Request::execute() logic to create a response
* 3. Caches the response using a decorator if valid
*
* $request->execute();
*
* @return Kohana_Response
* @throws Kohana_Exception
* @uses [Kohana::$profiling]
* @uses [Profiler]
* @uses [Request_Cache]
*/
public function execute()
{
// If there are no cache adaptors
if (!Request::$cache->cache_decorators) {
// Get out of here
return parent::execute();
}
// Create the cache key
$key = $this->create_cache_key($this->uri());
// Try and retrieve a cached response
$response = Request::$cache->get($key);
// If a response is returned
if ($response instanceof Kohana_Response) {
// Return the cached response
return $response;
} else {
// Execute the contoller to get the response
$response = parent::execute();
}
// If the response method is in the allow list
if (!in_array($this->method, Request_Cache::$cache_methods_allow)) {
// return FALSE
return $response;
} else {
if (!Request_Cache::validate_set($response)) {
// return the non-cached result
return $response;
}
}
// Set the response to cache
Request::$cache->set($key, $response);
// Return the response
return $response;
}
/**
* Prepares the response for caching by the decorator. Sets up headers and renders the response
* body due to some caching methods not serialising [Kohana_View] correctly. The `_prepare_response()`
* method performs the following.
*
* 1. Set correct headers to the Response object, formatting `Cache-Control` correctly
* 2. Creates an `Expires:` header if required
* 3. Renders the [Kohana_Reponse]::`$body`
*
* @param Kohana_Response response
* @return Kohana_Response
*/
protected function _prepare_response(Kohana_Response $response)
{
// Get the cache control headers
$cache_control = Request_Cache::parse_cache_control($response->headers);
// Set the lifetime of the cache from the header
$this->_lifetime = (int) $cache_control['max-age'];
// Get time now
$time = time();
// If the expires header is not set
if (!isset($response->headers['Expires'])) {
// Calculate expires header (DateTime would probably be better here - SdF)
$expires = gmdate('D, d M Y H:i:s T', $time + $cache_control['max-age']);
}
// Tell caches to check their validation
$cache_control['must-revalidate'] = NULL;
// Replace the headers with those that are not set
$response->headers += array('Cache-Control' => Request_Cache::create_cache_control($cache_control), 'Expires' => $expires, 'Last-Modified' => gmdate('D, d M Y H:i:s T', $time), 'Content-Length' => strlen((string) $response->body));
// Render the body (some caches have trouble serializing)
$response->body = (string) $response->body;
// return
return $response;
}
<?php
defined('SYSPATH') or die('No direct script access.');
/**
* Applies Request_Cache_Decorators to the Kohana_Request
* class. Multiple cache decorators can be applied and are
* executed in the order that they are applied. This code
* can be moved to the application/bootstrap.php file.
*/
Request::$cache = Request_Cache::instance()->attach(Request_Cache_Decorator::instance('null'))->attach(Request_Cache_Decorator::instance('memcache'));
// For now limit this to cli mode (need to find a good handle for this)
if (Kohana::$is_cli) {
define('SUPPRESS_REQUEST', TRUE);
define('GEARMAN_WORKER_' . Request_Async_Gearman::$context, TRUE);
}
/**
* Gets a response from the cache decorators based on `$key`. [Request_Cache] will
* iterate through each attached decorator searching for a hit. When a response
* is found, if it is still fresh it will be returned.
*
* // Search for a response
* if (($response = Request::$cache->get('foo')) instanceof Kohana_Response)
* {
* // Return the response
* return $response;
* }
*
* @param string key of the response to fetch from cache
* @return boolean|Kohana_Response
*/
public function get($key)
{
// If there are no decorators
if (!$this->cache_decorators) {
// return
return FALSE;
}
// Foreach decorator
foreach ($this->cache_decorators as $decorator) {
try {
// Try and load the response by key
$cached_response = $decorator->get($key);
// If the cache response is valid
if ($cached_response instanceof Kohana_Response and Request_Cache::validate_get($cached_response)) {
// return the response
return $cached_response;
}
} catch (Exception $e) {
// If cache exceptions should be thrown
if (!$this->silent_cache_fail) {
// Throw the exception
throw $e;
}
}
}
// return false if no response was found
return FALSE;
}