SSI-Proxy

- Implement SSI rendering strategy - Implement SSI kernel proxy - Implement Listeer
symfony · kingcrunch · Jan 12, 2013 · Jan 22, 2013 · Jan 23, 2013 · Jan 24, 2013
commit 323dc7fc421cef28361c7a02d8efca7422c78128
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -73,6 +73,7 @@ public function getConfigTreeBuilder()
 
         $this->addFormSection($rootNode);
         $this->addEsiSection($rootNode);
+        $this->addSsiSection($rootNode);
         $this->addRouterProxySection($rootNode);
         $this->addProfilerSection($rootNode);
         $this->addRouterSection($rootNode);
@@ -130,6 +131,16 @@ private function addRouterProxySection(ArrayNodeDefinition $rootNode)
         ;
     }
 
+    private function addSsiSection (ArrayNodeDefinition $rootNode) {
+        $rootNode
+            ->children()
+                ->arrayNode('ssi')
+                    ->info('ssi configuration')
+                    ->canBeDisabled()
+                ->end()
+            ->end();
+    }
+
     private function addProfilerSection(ArrayNodeDefinition $rootNode)
     {
         $rootNode

diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -94,6 +94,10 @@ public function load(array $configs, ContainerBuilder $container)
             $this->registerEsiConfiguration($config['esi'], $loader);
         }
 
+        if (isset($config['ssi'])) {
+            $this->registerSsiConfiguration($config['ssi'], $loader);
+        }
+
         if (isset($config['router_proxy'])) {
             $this->registerRouterProxyConfiguration($config['router_proxy'], $container, $loader);
         }
@@ -188,6 +192,18 @@ private function registerEsiConfiguration(array $config, XmlFileLoader $loader)
         }
     }
 
+    /**
+     * Loads the SSI configuration.
+     *
+     * @param array         $config An SSI configuration array
+     * @param XmlFileLoader $loader An XmlFileLoader instance
+     */
+    private function registerSsiConfiguration (array $config, XmlFileLoader $loader) {
+        if (!empty($config['enabled'])) {
+            $loader->load('ssi.xml');
+        }
+    }
+
     /**
      * Loads the router proxy configuration.
      *

diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/ssi.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/ssi.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" ?>
+
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
+
+    <parameters>
+        <parameter key="ssi_listener.class">Symfony\Component\HttpKernel\EventListener\SsiListener</parameter>
+        <parameter key="http_content_renderer.strategy.ssi.class">Symfony\Component\HttpKernel\RenderingStrategy\SsiRenderingStrategy</parameter>
+    </parameters>
+
+    <services>
+        <service id="esi_listener" class="%ssi_listener.class%">
+            <tag name="kernel.event_subscriber"/>
+        </service>
+
+        <service id="http_content_renderer.strategy.ssi" class="%http_content_renderer.strategy.ssi.class%">
+            <tag name="kernel.content_renderer_strategy" />
+            <argument type="service" id="http_content_renderer.strategy.default" />
+            <call method="setUrlGenerator"><argument type="service" id="router" /></call>
+        </service>
+    </services>
+</container>
diff --git a/src/Symfony/Component/HttpKernel/EventListener/SsiListener.php b/src/Symfony/Component/HttpKernel/EventListener/SsiListener.php
@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\EventListener;
+
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * SsiListener adds a Surrogate-Control HTTP header when the Response needs to be parsed for SSI.
+ *
+ * @author Sebastian Krebs <krebs.seb@gmail.com>
+ */
+class SsiListener implements EventSubscriberInterface
+{
+    /**
+     * Filters the Response.
+     *
+     * @param FilterResponseEvent $event A FilterResponseEvent instance
+     */
+    public function onKernelResponse(FilterResponseEvent $event)
+    {
+        if (HttpKernelInterface::MASTER_REQUEST === $event->getRequestType()) {
+            $this->updateResponseHeader($event->getResponse());
+        }
+    }
+
+    public static function getSubscribedEvents()
+    {
+        return array(
+            KernelEvents::RESPONSE => 'onKernelResponse',
+        );
+    }
+
+    private function updateResponseHeader (Response $response)
+    {
+        if (false !== strpos($response->getContent(), '<!--#include')) {
+            $header = $response->headers->get('Surrogate-Control');
+            $response->headers->set('Surrogate-Control', ($header ? $header . ', ' : '') . 'content=SSI/1.0');
+        }
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/RenderingStrategy/SsiRenderingStrategy.php b/src/Symfony/Component/HttpKernel/RenderingStrategy/SsiRenderingStrategy.php
@@ -0,0 +1,87 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\RenderingStrategy;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Controller\ControllerReference;
+
+/**
+ * Implements the ESI rendering strategy.
+ *
+ * @author Sebastian Krebs <krebs.seb@gmail.com>
+ */
+class SsiRenderingStrategy extends GeneratorAwareRenderingStrategy
+{
+    private $defaultStrategy;
+
+    /**
+     * Constructor.
+     *
+     * The "fallback" strategy when ESI is not available should always be an
+     * instance of DefaultRenderingStrategy (or a class you are using for the
+     * default strategy).
+     *
+     * @param RenderingStrategyInterface $defaultStrategy The default strategy to use when ESI is not supported
+     */
+    public function __construct(RenderingStrategyInterface $defaultStrategy)
+    {
+        $this->defaultStrategy = $defaultStrategy;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * Note that if the current Request has no ESI capability, this method
+     * falls back to use the default rendering strategy.
+     *
+     * Additional available options:
+     *
+     *  * comment: a comment to add when returning an esi:include tag
+     */
+    public function render($uri, Request $request = null, array $options = array())
+    {
+        if (null === $request) {
+            return $this->defaultStrategy->render($uri, $request, $options);
+        }
+
+        if ($uri instanceof ControllerReference) {
+            $uri = $this->generateProxyUri($uri, $request);
+        }
+
+        $tag = $this->renderIncludeTag($uri, isset($options['ignore_errors']) ? $options['ignore_errors'] : false, isset($options['comment']) ? $options['comment'] : '');
+
+        return new Response($tag);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getName()
+    {
+        return 'ssi';
+    }
+
+
+    private function renderIncludeTag ($uri, $ignoreErrors = true, $comment = '') {
+        $html = sprintf('<!--#include virtual="%s"%s -->',
+            $uri,
+            $ignoreErrors ? ' fmt="?"' : ''
+        );
+
+        if (!empty($comment)) {
+            return sprintf("<!-- %s -->\n%s", $comment, $html);
+        }
+
+        return $html;
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/SsiKernelProxy.php b/src/Symfony/Component/HttpKernel/SsiKernelProxy.php
@@ -0,0 +1,153 @@
+<?php
+namespace Symfony\Component\HttpKernel;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+/**
+ * Kernel proxy handling SSI-responses
+ *
+ * @author Sebastian Krebs <krebs.seb@gmail.com>
+ */
+class SsiKernelProxy implements HttpKernelInterface, TerminableInterface
+{
+    private $kernel;
+    private $options = array(
+        'pass_through' => false
+    );
+
+    public function __construct (HttpKernelInterface $kernel, array $options = array())
+    {
+        $this->kernel = $kernel;
+        $this->options = array_merge($this->options, $options);
+    }
+
+    /**
+     * Handles a Request to convert it to a Response.
+     *
+     * When $catch is true, the implementation must catch all exceptions
+     * and do its best to convert them to a Response instance.
+     *
+     * @param Request $request A Request instance
+     * @param integer $type    The type of the request
+     *                          (one of HttpKernelInterface::MASTER_REQUEST or HttpKernelInterface::SUB_REQUEST)
+     * @param Boolean $catch   Whether to catch exceptions or not
+     *
+     * @return Response A Response instance
+     *
+     * @throws \Exception When an Exception occurs during processing
+     *
+     * @api
+     */
+    public function handle (Request $request, $type = self::MASTER_REQUEST, $catch = true)
+    {
+        $response = $this->kernel->handle($request, $type, $catch);
+
+        if (!$this->options['pass_through'] && !$this->serverHasCapability($request) && $this->hasControlHeader($response)) {
+            $this->parse($request, $response);
+        }
+
+        return $response;
+    }
+
+    /**
+     * Terminates a request/response cycle.
+     *
+     * Should be called after sending the response and before shutting down the kernel.
+     *
+     * @param Request  $request  A Request instance
+     * @param Response $response A Response instance
+     *
+     * @api
+     */
+    public function terminate (Request $request, Response $response)
+    {
+        if ($this->kernel instanceof TerminableInterface) {
+            $this->kernel->terminate($request, $response);
+        }
+    }
+
+    private function parse (Request $request, Response $response)
+    {
+        $this->addCapabilityHeader($request);
+
+        $content = preg_replace_callback('#<!--\#include\s+(.*?)\s*-->#', $this->createHandler($this, $request, $response), $response->getContent());
+        $response->setContent($content);
+
+        $this->removeControlHeader($response);
+    }
+
+    private function createHandler (HttpKernelInterface $kernel, Request $request, Response $response)
+    {
+        return function ($attributes) use ($kernel, $request, $response) {
+            $options = array();
+            preg_match_all('/(virtual|fmt)="([^"]*?)"/', $attributes[1], $matches, PREG_SET_ORDER);
+            foreach ($matches as $set) {
+                $options[$set[1]] = $set[2];
+            }
+
+            if (!isset($options['virtual'])) {
+                throw new \RuntimeException('Unable to process an SSI tag without a "virtual" attribute.');
+            }
+
+
+            $subRequest = Request::create($options['virtual'], 'GET', array(), $request->cookies->all(), array(), $request->server->all());
+
+            try {
+                $subResponse = $kernel->handle($subRequest, HttpKernelInterface::SUB_REQUEST, true);
+
+                if (!$subResponse->isSuccessful()) {
+                    throw new \RuntimeException(sprintf('Error when rendering "%s" (Status code is %s).', $subRequest->getUri(), $subResponse->getStatusCode()));
+                }
+
+                if ($response->isCacheable() && $subResponse->isCacheable()) {
+                    $maxAge = min($response->headers->getCacheControlDirective('max-age'), $subResponse->headers->getCacheControlDirective('max-age'));
+                    $sMaxAge = min($response->headers->getCacheControlDirective('s-maxage'), $subResponse->headers->getCacheControlDirective('s-maxage'));
+                    $response->setSharedMaxAge($sMaxAge);
+                    $response->setMaxAge($maxAge);
+                } else {
+                    $response->headers->set('Cache-Control', 'no-cache, must-revalidate');
+                }
+
+                return $subResponse->getContent();
+            } catch (\Exception $e) {
+
+                if (!isset($options['fmt']) || $options['fmt'] != '?') {
+                    throw $e;
+                }
+            }
+
+            return '';
+        };
+    }
+
+    private function serverHasCapability (Request $request)
+    {
+        $value = $request->headers->get('Surrogate-Capability');
+        return $value && strpos($value, 'SSI/1.0') !== false;
+    }
+
+    private function hasControlHeader (Response $response) {
+        $value = $response->headers->get('Surrogate-Control');
+        return $value && strpos($value, 'SSI/1.0') !== false;
+    }
+
+    private function addCapabilityHeader (Request $request)
+    {
+        $current = $request->headers->get('Surrogate-Capability');
+        $request->headers->set('Surrogate-Capability', ($current ? $current . ', ' : '') . 'symfony2="SSI/1.0"');
+    }
+
+    private function removeControlHeader (Response $response)
+    {
+        $current = $response->headers->get('Surrogate-Control');
+        $new = array_filter(explode(',', $current), function ($control) {
+            return strpos($control, 'SSI/1.0') === false;
+        });
+        if ($new) {
+            $response->headers->set('Surrogate-Control', implode(', ', $new));
+        } else {
+            $response->headers->remove('Surrogate-Control');
+        }
+    }
+}