How does `Magento\PageCache\Model\App\FrontController\BuiltinPlugin` return a cached HTML page?

dmitry_fedyuk · March 13, 2024, 3:18pm

1.

magento/magento2/blob/2.4.7-beta3/app/code/Magento/PageCache/etc/frontend/di.xml#L9-L13


      
          <type name="Magento\Framework\App\FrontControllerInterface">
              <plugin name="front-controller-builtin-cache" type="Magento\PageCache\Model\App\FrontController\BuiltinPlugin"/>
              <plugin name="front-controller-varnish-cache" type="Magento\PageCache\Model\App\FrontController\VarnishPlugin"/>
              <plugin name="page_cache_form_key_from_cookie" type="Magento\PageCache\Plugin\RegisterFormKeyFromCookie" />
          </type>

2. Magento\PageCache\Model\App\FrontController\BuiltinPlugin::aroundDispatch()

github.com

magento/magento2/blob/2.4.7-beta3/app/code/Magento/PageCache/Model/App/FrontController/BuiltinPlugin.php#L74-L84


      
          $result = $this->kernel->load();
          if ($result === false) {
              $result = $proceed($request);
              if ($result instanceof ResponseHttp && !$result instanceof NotCacheableInterface) {
                  $this->addDebugHeaders($result);
                  $this->kernel->process($result);
              }
          } else {
              $this->addDebugHeader($result, 'X-Magento-Cache-Debug', 'HIT', true);
          }
          return $result;

3. Magento\Framework\App\PageCache\Kernel::load()

github.com

magento/magento2/blob/2.4.7-beta3/lib/internal/Magento/Framework/App/PageCache/Kernel.php#L125-L137


      
          if ($this->request->isGet() || $this->request->isHead()) {
              $responseData = $this->fullPageCache->load($this->identifier->getValue());
              if (!$responseData) {
                  return false;
              }
              $responseData = $this->serializer->unserialize($responseData);
              if (!$responseData) {
                  return false;
              }
          
              return $this->buildResponse($responseData);
          }
          return false;

4. Magento\Framework\Cache\Frontend\Decorator\Bare::load()

github.com

magento/magento2/blob/2.4.7-beta3/lib/internal/Magento/Framework/Cache/Frontend/Decorator/Bare.php#L63-L66


      
          public function load($identifier)
          {
              return $this->_getFrontend()->load($identifier);
          }

5. Magento\Framework\App\Cache\Type\AccessProxy::load()

github.com

magento/magento2/blob/2.4.7-beta3/lib/internal/Magento/Framework/App/Cache/Type/AccessProxy.php#L69-L75


      
          public function load($identifier)
          {
              if (!$this->_isEnabled()) {
                  return false;
              }
              return parent::load($identifier);
          }

6. Magento\Framework\Cache\Frontend\Adapter\Zend::load()

github.com

magento/magento2/blob/2.4.7-beta3/lib/internal/Magento/Framework/Cache/Frontend/Adapter/Zend.php#L60-L63


      
          public function load($identifier)
          {
              return $this->getFrontEnd()->load($this->_unifyId($identifier));
          }

7. Zend_Cache_Core::load()

github.com

magento/zf1/blob/1.15.1/library/Zend/Cache/Core.php#L288-L306


      
          /**
           * Test if a cache is available for the given id and (if yes) return it (false else)
           *
           * @param  string  $id                     Cache id
           * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
           * @param  boolean $doNotUnserialize       Do not serialize (even if automatic_serialization is true) => for internal use
           * @return mixed|false Cached datas
           */
          public function load($id, $doNotTestCacheValidity = false, $doNotUnserialize = false)
          {
              if (!$this->_options['caching']) {
                  return false;
              }
              $id = $this->_id($id); // cache id may need prefix
              $this->_lastId = $id;
              $this->_validateIdOrTag($id);
          
              $this->_log("Zend_Cache_Core: load item '{$id}'", 7);
              $data = $this->_backend->load($id, $doNotTestCacheValidity);

8. Cm_Cache_Backend_File::load()

How is Cm_Cache_Backend_File configured as the backend for Zend_Cache_Core?

github.com

colinmollenhour/Cm_Cache_Backend_File/blob/v1.4.7/File.php#L135-L145


      
          /**
           * Test if a cache is available for the given id and (if yes) return it (false else)
           *
           * @param string $id cache id
           * @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
           * @return string|bool cached datas
           */
          public function load($id, $doNotTestCacheValidity = false)
          {
              $file = $this->_file($id);
              $cache = $this->_getCache($file, true);