[HttpKernel] added the cache system

src/Symfony/Components/HttpKernel/Cache/Esi.php

@@ -0,0 +1,214 @@
+<?php
+
+namespace Symfony\Components\HttpKernel\Cache;
+
+use Symfony\Components\HttpKernel\Request;
+use Symfony\Components\HttpKernel\Response;
+use Symfony\Components\HttpKernel\HttpKernelInterface;
+
+/*
+ * This file is part of the Symfony framework.
+ *
+ * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+/**
+ * Esi implements the ESI capabilities to Request and Response instances.
+ *
+ * For more information, read the following W3C notes:
+ *
+ *  * ESI Language Specification 1.0 (http://www.w3.org/TR/esi-lang)
+ *
+ *  * Edge Architecture Specification (http://www.w3.org/TR/edge-arch)
+ *
+ * @package    Symfony
+ * @subpackage Components_HttpKernel
+ * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
+ */
+class Esi
+{
+    protected $contentTypes;
+
+    /**
+     * Constructor.
+     *
+     * @param array $contentTypes An array of content-type that should be parsed for ESI information.
+     *                           (default: text/html, text/xml, and application/xml)
+     */
+    public function __construct(array $contentTypes = array('text/html', 'text/xml', 'application/xml'))
+    {
+        $this->contentTypes = $contentTypes;
+    }
+
+    /**
+     * Checks that at least one surrogate has ESI/1.0 capability.
+     *
+     * @param Symfony\Components\HttpKernel\Request $request A Request instance
+     *
+     * @return Boolean true if one surrogate has ESI/1.0 capability, false otherwise
+     */
+    public function hasSurrogateEsiCapability(Request $request)
+    {
+        if (null === $value = $request->headers->get('Surrogate-Capability')) {
+            return false;
+        }
+
+        return preg_match('#ESI/1.0#', $value);
+    }
+
+    /**
+     * Adds ESI/1.0 capability to the given Request.
+     *
+     * @param Symfony\Components\HttpKernel\Request $request A Request instance
+     */
+    public function addSurrogateEsiCapability(Request $request)
+    {
+        $current = $request->headers->get('Surrogate-Capability');
+        $new = 'symfony2="ESI/1.0"';
+
+        $request->headers->set('Surrogate-Capability', $current ? $current.', '.$new : $new);
+    }
+
+    /**
+     * Adds HTTP headers to specify that the Response needs to be parsed for ESI.
+     *
+     * This method only adds an ESI HTTP header if the Response has some ESI tags.
+     *
+     * @param Symfony\Components\HttpKernel\Response $response A Response instance
+     */
+    public function addSurrogateControl(Response $response)
+    {
+        if (false !== strpos($response->getContent(), '<esi:include')) {
+            $response->headers->set('Surrogate-Control', 'content="ESI/1.0"');
+        }
+    }
+
+    /**
+     * Checks that the Response needs to be parsed for ESI tags.
+     *
+     * @param Symfony\Components\HttpKernel\Response $response A Response instance
+     *
+     * @return Boolean true if the Response needs to be parsed, false otherwise
+     */
+    public function needsEsiParsing(Response $response)
+    {
+        if (!$control = $response->headers->get('Surrogate-Control')) {
+            return false;
+        }
+
+        return preg_match('#content="[^"]*ESI/1.0[^"]*"#', $control);
+    }
+
+    /**
+     * Renders an ESI tag.
+     *
+     * @param string  $uri          A URI
+     * @param string  $alt          An alternate URI
+     * @param Boolean $ignoreErrors Whether to ignore errors or not
+     * @param string  $comment      A comment to add as an esi:include tag
+     */
+    public function renderTag($uri, $alt, $ignoreErrors = true, $comment = '')
+    {
+        $html = sprintf('<esi:include src="%s"%s%s />',
+            $uri,
+            $ignoreErrors ? ' onerror="continue"' : '',
+            $alt ? sprintf(' alt="%s"', $alt) : ''
+        );
+
+        if (!empty($comment)) {
+            $html .= sprintf("<esi:comment text=\"%s\" />\n%s", $comment, $output);
+        }
+
+        return $html;
+    }
+
+    /**
+     * Replaces a Response ESI tags with the included resource content.
+     *
+     * @param Symfony\Components\HttpKernel\Request  $request  A Request instance
+     * @param Symfony\Components\HttpKernel\Response $response A Response instance
+     */
+    public function process(Request $request, Response $response)
+    {
+        $this->request = $request;
+        $type = $response->headers->get('Content-Type');
+        if (empty($type)) {
+            $type = 'text/html';
+        }
+
+        if (!in_array($type, $this->contentTypes)) {
+            return $response;
+        }
+
+        // we don't use a proper XML parser here as we can have ESI tags in a plain text response
+        $content = $response->getContent();
+        $content = preg_replace_callback('#<esi\:include\s+(.+?)\s*/>#', array($this, 'handleEsiIncludeTag'), $content);
+        $content = preg_replace('#<esi\:comment[^>]*/>#', '', $content);
+        $content = preg_replace('#<esi\:remove>.*?</esi\:remove>#', '', $content);
+
+        $response->setContent($content);
+        $response->headers->set('X-Body-Eval', 'ESI');
+
+        // remove ESI/1.0 from the Surrogate-Control header
+        $value = $response->headers->get('Surrogate-Control');
+        if (preg_match('#^content="ESI/1.0"$#', $value)) {
+            $response->headers->delete('Surrogate-Control');
+        } else {
+            $response->headers->set('Surrogate-Control', preg_replace('#ESI/1.0#', '', $value));
+        }
+    }
+
+    /**
+     * Handles an ESI from the cache.
+     *
+     * @param Symfony\Components\HttpKernel\Cache\Cache $cache        A Cache instance
+     * @param string                                    $uri          The main URI
+     * @param string                                    $alt          An alternative URI
+     * @param Boolean                                   $ignoreErrors Whether to ignore errors or not
+     */
+    public function handle(Cache $cache, $uri, $alt, $ignoreErrors)
+    {
+        $subRequest = Request::create($uri, 'get', array(), $cache->getRequest()->cookies->all(), array(), $cache->getRequest()->server->all());
+
+        try {
+            return $cache->handle($subRequest, HttpKernelInterface::EMBEDDED_REQUEST, true);
+        } catch (\Exception $e) {
+            if ($alt) {
+                return $this->handle($cache, $alt, '', $ignoreErrors);
+            }
+
+            if (!$ignoreErrors) {
+                throw $e;
+            }
+        }
+    }
+
+    /**
+     * Handles an ESI include tag (called internally).
+     *
+     * @param array $attributes An array containing the attributes.
+     *
+     * @param string The response content for the include.
+     */
+    protected function handleEsiIncludeTag($attributes)
+    {
+        $options = array();
+        preg_match_all('/(src|onerror|alt)="([^"]*?)"/', $attributes[1], $matches, PREG_SET_ORDER);
+        foreach ($matches as $set) {
+            $options[$set[1]] = $set[2];
+        }
+
+        if (!isset($options['src'])) {
+            throw new \RuntimeException('Unable to process an ESI tag without a "src" attribute.');
+        }
+
+        return sprintf('<?php echo $this->esi->handle($this, \'%s\', \'%s\', %s)->getContent() ?>'."\n",
+            $options['src'],
+            isset($options['alt']) ? $options['alt'] : null,
+            isset($options['onerror']) && 'continue' == $options['onerror'] ? 'true' : 'false'
+        );
+    }
+}