Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of the Symfony package.
Chris@0:  *
Chris@0:  * (c) Fabien Potencier <fabien@symfony.com>
Chris@0:  *
Chris@0:  * This code is partially based on the Rack-Cache library by Ryan Tomayko,
Chris@0:  * which is released under the MIT license.
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Symfony\Component\HttpKernel\HttpCache;
Chris@0: 
Chris@0: use Symfony\Component\HttpFoundation\Request;
Chris@0: use Symfony\Component\HttpFoundation\Response;
Chris@0: 
Chris@0: /**
Chris@0:  * Store implements all the logic for storing cache metadata (Request and Response headers).
Chris@0:  *
Chris@0:  * @author Fabien Potencier <fabien@symfony.com>
Chris@0:  */
Chris@0: class Store implements StoreInterface
Chris@0: {
Chris@0:     protected $root;
Chris@0:     private $keyCache;
Chris@0:     private $locks;
Chris@0: 
Chris@0:     /**
Chris@0:      * @param string $root The path to the cache directory
Chris@0:      *
Chris@0:      * @throws \RuntimeException
Chris@0:      */
Chris@0:     public function __construct($root)
Chris@0:     {
Chris@0:         $this->root = $root;
Chris@0:         if (!file_exists($this->root) && !@mkdir($this->root, 0777, true) && !is_dir($this->root)) {
Chris@0:             throw new \RuntimeException(sprintf('Unable to create the store directory (%s).', $this->root));
Chris@0:         }
Chris@0:         $this->keyCache = new \SplObjectStorage();
Chris@17:         $this->locks = [];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Cleanups storage.
Chris@0:      */
Chris@0:     public function cleanup()
Chris@0:     {
Chris@0:         // unlock everything
Chris@0:         foreach ($this->locks as $lock) {
Chris@0:             flock($lock, LOCK_UN);
Chris@0:             fclose($lock);
Chris@0:         }
Chris@0: 
Chris@17:         $this->locks = [];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Tries to lock the cache for a given Request, without blocking.
Chris@0:      *
Chris@0:      * @return bool|string true if the lock is acquired, the path to the current lock otherwise
Chris@0:      */
Chris@0:     public function lock(Request $request)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey($request);
Chris@0: 
Chris@0:         if (!isset($this->locks[$key])) {
Chris@0:             $path = $this->getPath($key);
Chris@17:             if (!file_exists(\dirname($path)) && false === @mkdir(\dirname($path), 0777, true) && !is_dir(\dirname($path))) {
Chris@0:                 return $path;
Chris@0:             }
Chris@0:             $h = fopen($path, 'cb');
Chris@0:             if (!flock($h, LOCK_EX | LOCK_NB)) {
Chris@0:                 fclose($h);
Chris@0: 
Chris@0:                 return $path;
Chris@0:             }
Chris@0: 
Chris@0:             $this->locks[$key] = $h;
Chris@0:         }
Chris@0: 
Chris@0:         return true;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Releases the lock for the given Request.
Chris@0:      *
Chris@0:      * @return bool False if the lock file does not exist or cannot be unlocked, true otherwise
Chris@0:      */
Chris@0:     public function unlock(Request $request)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey($request);
Chris@0: 
Chris@0:         if (isset($this->locks[$key])) {
Chris@0:             flock($this->locks[$key], LOCK_UN);
Chris@0:             fclose($this->locks[$key]);
Chris@0:             unset($this->locks[$key]);
Chris@0: 
Chris@0:             return true;
Chris@0:         }
Chris@0: 
Chris@0:         return false;
Chris@0:     }
Chris@0: 
Chris@0:     public function isLocked(Request $request)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey($request);
Chris@0: 
Chris@0:         if (isset($this->locks[$key])) {
Chris@0:             return true; // shortcut if lock held by this process
Chris@0:         }
Chris@0: 
Chris@0:         if (!file_exists($path = $this->getPath($key))) {
Chris@0:             return false;
Chris@0:         }
Chris@0: 
Chris@0:         $h = fopen($path, 'rb');
Chris@0:         flock($h, LOCK_EX | LOCK_NB, $wouldBlock);
Chris@0:         flock($h, LOCK_UN); // release the lock we just acquired
Chris@0:         fclose($h);
Chris@0: 
Chris@0:         return (bool) $wouldBlock;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Locates a cached Response for the Request provided.
Chris@0:      *
Chris@0:      * @return Response|null A Response instance, or null if no cache entry was found
Chris@0:      */
Chris@0:     public function lookup(Request $request)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey($request);
Chris@0: 
Chris@0:         if (!$entries = $this->getMetadata($key)) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@0:         // find a cached entry that matches the request.
Chris@0:         $match = null;
Chris@0:         foreach ($entries as $entry) {
Chris@0:             if ($this->requestsMatch(isset($entry[1]['vary'][0]) ? implode(', ', $entry[1]['vary']) : '', $request->headers->all(), $entry[0])) {
Chris@0:                 $match = $entry;
Chris@0: 
Chris@0:                 break;
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         if (null === $match) {
Chris@0:             return;
Chris@0:         }
Chris@0: 
Chris@14:         $headers = $match[1];
Chris@0:         if (file_exists($body = $this->getPath($headers['x-content-digest'][0]))) {
Chris@0:             return $this->restoreResponse($headers, $body);
Chris@0:         }
Chris@0: 
Chris@0:         // TODO the metaStore referenced an entity that doesn't exist in
Chris@0:         // the entityStore. We definitely want to return nil but we should
Chris@0:         // also purge the entry from the meta-store when this is detected.
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Writes a cache entry to the store for the given Request and Response.
Chris@0:      *
Chris@0:      * Existing entries are read and any that match the response are removed. This
Chris@0:      * method calls write with the new list of cache entries.
Chris@0:      *
Chris@0:      * @return string The key under which the response is stored
Chris@0:      *
Chris@0:      * @throws \RuntimeException
Chris@0:      */
Chris@0:     public function write(Request $request, Response $response)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey($request);
Chris@0:         $storedEnv = $this->persistRequest($request);
Chris@0: 
Chris@0:         // write the response body to the entity store if this is the original response
Chris@0:         if (!$response->headers->has('X-Content-Digest')) {
Chris@0:             $digest = $this->generateContentDigest($response);
Chris@0: 
Chris@0:             if (false === $this->save($digest, $response->getContent())) {
Chris@0:                 throw new \RuntimeException('Unable to store the entity.');
Chris@0:             }
Chris@0: 
Chris@0:             $response->headers->set('X-Content-Digest', $digest);
Chris@0: 
Chris@0:             if (!$response->headers->has('Transfer-Encoding')) {
Chris@17:                 $response->headers->set('Content-Length', \strlen($response->getContent()));
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         // read existing cache entries, remove non-varying, and add this one to the list
Chris@17:         $entries = [];
Chris@0:         $vary = $response->headers->get('vary');
Chris@0:         foreach ($this->getMetadata($key) as $entry) {
Chris@0:             if (!isset($entry[1]['vary'][0])) {
Chris@17:                 $entry[1]['vary'] = [''];
Chris@0:             }
Chris@0: 
Chris@14:             if ($entry[1]['vary'][0] != $vary || !$this->requestsMatch($vary, $entry[0], $storedEnv)) {
Chris@0:                 $entries[] = $entry;
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         $headers = $this->persistResponse($response);
Chris@0:         unset($headers['age']);
Chris@0: 
Chris@17:         array_unshift($entries, [$storedEnv, $headers]);
Chris@0: 
Chris@0:         if (false === $this->save($key, serialize($entries))) {
Chris@0:             throw new \RuntimeException('Unable to store the metadata.');
Chris@0:         }
Chris@0: 
Chris@0:         return $key;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns content digest for $response.
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     protected function generateContentDigest(Response $response)
Chris@0:     {
Chris@0:         return 'en'.hash('sha256', $response->getContent());
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Invalidates all cache entries that match the request.
Chris@0:      *
Chris@0:      * @throws \RuntimeException
Chris@0:      */
Chris@0:     public function invalidate(Request $request)
Chris@0:     {
Chris@0:         $modified = false;
Chris@0:         $key = $this->getCacheKey($request);
Chris@0: 
Chris@17:         $entries = [];
Chris@0:         foreach ($this->getMetadata($key) as $entry) {
Chris@0:             $response = $this->restoreResponse($entry[1]);
Chris@0:             if ($response->isFresh()) {
Chris@0:                 $response->expire();
Chris@0:                 $modified = true;
Chris@17:                 $entries[] = [$entry[0], $this->persistResponse($response)];
Chris@0:             } else {
Chris@0:                 $entries[] = $entry;
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         if ($modified && false === $this->save($key, serialize($entries))) {
Chris@0:             throw new \RuntimeException('Unable to store the metadata.');
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Determines whether two Request HTTP header sets are non-varying based on
Chris@0:      * the vary response header value provided.
Chris@0:      *
Chris@0:      * @param string $vary A Response vary header
Chris@0:      * @param array  $env1 A Request HTTP header array
Chris@0:      * @param array  $env2 A Request HTTP header array
Chris@0:      *
Chris@0:      * @return bool true if the two environments match, false otherwise
Chris@0:      */
Chris@0:     private function requestsMatch($vary, $env1, $env2)
Chris@0:     {
Chris@0:         if (empty($vary)) {
Chris@0:             return true;
Chris@0:         }
Chris@0: 
Chris@0:         foreach (preg_split('/[\s,]+/', $vary) as $header) {
Chris@0:             $key = str_replace('_', '-', strtolower($header));
Chris@0:             $v1 = isset($env1[$key]) ? $env1[$key] : null;
Chris@0:             $v2 = isset($env2[$key]) ? $env2[$key] : null;
Chris@0:             if ($v1 !== $v2) {
Chris@0:                 return false;
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return true;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Gets all data associated with the given key.
Chris@0:      *
Chris@0:      * Use this method only if you know what you are doing.
Chris@0:      *
Chris@0:      * @param string $key The store key
Chris@0:      *
Chris@0:      * @return array An array of data associated with the key
Chris@0:      */
Chris@0:     private function getMetadata($key)
Chris@0:     {
Chris@0:         if (!$entries = $this->load($key)) {
Chris@17:             return [];
Chris@0:         }
Chris@0: 
Chris@0:         return unserialize($entries);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Purges data for the given URL.
Chris@0:      *
Chris@0:      * This method purges both the HTTP and the HTTPS version of the cache entry.
Chris@0:      *
Chris@0:      * @param string $url A URL
Chris@0:      *
Chris@0:      * @return bool true if the URL exists with either HTTP or HTTPS scheme and has been purged, false otherwise
Chris@0:      */
Chris@0:     public function purge($url)
Chris@0:     {
Chris@0:         $http = preg_replace('#^https:#', 'http:', $url);
Chris@0:         $https = preg_replace('#^http:#', 'https:', $url);
Chris@0: 
Chris@0:         $purgedHttp = $this->doPurge($http);
Chris@0:         $purgedHttps = $this->doPurge($https);
Chris@0: 
Chris@0:         return $purgedHttp || $purgedHttps;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Purges data for the given URL.
Chris@0:      *
Chris@0:      * @param string $url A URL
Chris@0:      *
Chris@0:      * @return bool true if the URL exists and has been purged, false otherwise
Chris@0:      */
Chris@0:     private function doPurge($url)
Chris@0:     {
Chris@0:         $key = $this->getCacheKey(Request::create($url));
Chris@0:         if (isset($this->locks[$key])) {
Chris@0:             flock($this->locks[$key], LOCK_UN);
Chris@0:             fclose($this->locks[$key]);
Chris@0:             unset($this->locks[$key]);
Chris@0:         }
Chris@0: 
Chris@0:         if (file_exists($path = $this->getPath($key))) {
Chris@0:             unlink($path);
Chris@0: 
Chris@0:             return true;
Chris@0:         }
Chris@0: 
Chris@0:         return false;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Loads data for the given key.
Chris@0:      *
Chris@0:      * @param string $key The store key
Chris@0:      *
Chris@0:      * @return string The data associated with the key
Chris@0:      */
Chris@0:     private function load($key)
Chris@0:     {
Chris@0:         $path = $this->getPath($key);
Chris@0: 
Chris@0:         return file_exists($path) ? file_get_contents($path) : false;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Save data for the given key.
Chris@0:      *
Chris@0:      * @param string $key  The store key
Chris@0:      * @param string $data The data to store
Chris@0:      *
Chris@0:      * @return bool
Chris@0:      */
Chris@0:     private function save($key, $data)
Chris@0:     {
Chris@0:         $path = $this->getPath($key);
Chris@0: 
Chris@0:         if (isset($this->locks[$key])) {
Chris@0:             $fp = $this->locks[$key];
Chris@0:             @ftruncate($fp, 0);
Chris@0:             @fseek($fp, 0);
Chris@0:             $len = @fwrite($fp, $data);
Chris@17:             if (\strlen($data) !== $len) {
Chris@0:                 @ftruncate($fp, 0);
Chris@0: 
Chris@0:                 return false;
Chris@0:             }
Chris@0:         } else {
Chris@17:             if (!file_exists(\dirname($path)) && false === @mkdir(\dirname($path), 0777, true) && !is_dir(\dirname($path))) {
Chris@0:                 return false;
Chris@0:             }
Chris@0: 
Chris@17:             $tmpFile = tempnam(\dirname($path), basename($path));
Chris@0:             if (false === $fp = @fopen($tmpFile, 'wb')) {
Chris@14:                 @unlink($tmpFile);
Chris@14: 
Chris@0:                 return false;
Chris@0:             }
Chris@0:             @fwrite($fp, $data);
Chris@0:             @fclose($fp);
Chris@0: 
Chris@0:             if ($data != file_get_contents($tmpFile)) {
Chris@14:                 @unlink($tmpFile);
Chris@14: 
Chris@0:                 return false;
Chris@0:             }
Chris@0: 
Chris@0:             if (false === @rename($tmpFile, $path)) {
Chris@14:                 @unlink($tmpFile);
Chris@14: 
Chris@0:                 return false;
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         @chmod($path, 0666 & ~umask());
Chris@0:     }
Chris@0: 
Chris@0:     public function getPath($key)
Chris@0:     {
Chris@17:         return $this->root.\DIRECTORY_SEPARATOR.substr($key, 0, 2).\DIRECTORY_SEPARATOR.substr($key, 2, 2).\DIRECTORY_SEPARATOR.substr($key, 4, 2).\DIRECTORY_SEPARATOR.substr($key, 6);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Generates a cache key for the given Request.
Chris@0:      *
Chris@0:      * This method should return a key that must only depend on a
Chris@0:      * normalized version of the request URI.
Chris@0:      *
Chris@0:      * If the same URI can have more than one representation, based on some
Chris@0:      * headers, use a Vary header to indicate them, and each representation will
Chris@0:      * be stored independently under the same cache key.
Chris@0:      *
Chris@0:      * @return string A key for the given Request
Chris@0:      */
Chris@0:     protected function generateCacheKey(Request $request)
Chris@0:     {
Chris@0:         return 'md'.hash('sha256', $request->getUri());
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns a cache key for the given Request.
Chris@0:      *
Chris@0:      * @return string A key for the given Request
Chris@0:      */
Chris@0:     private function getCacheKey(Request $request)
Chris@0:     {
Chris@0:         if (isset($this->keyCache[$request])) {
Chris@0:             return $this->keyCache[$request];
Chris@0:         }
Chris@0: 
Chris@0:         return $this->keyCache[$request] = $this->generateCacheKey($request);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Persists the Request HTTP headers.
Chris@0:      *
Chris@0:      * @return array An array of HTTP headers
Chris@0:      */
Chris@0:     private function persistRequest(Request $request)
Chris@0:     {
Chris@0:         return $request->headers->all();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Persists the Response HTTP headers.
Chris@0:      *
Chris@0:      * @return array An array of HTTP headers
Chris@0:      */
Chris@0:     private function persistResponse(Response $response)
Chris@0:     {
Chris@0:         $headers = $response->headers->all();
Chris@17:         $headers['X-Status'] = [$response->getStatusCode()];
Chris@0: 
Chris@0:         return $headers;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Restores a Response from the HTTP headers and body.
Chris@0:      *
Chris@0:      * @param array  $headers An array of HTTP headers for the Response
Chris@0:      * @param string $body    The Response body
Chris@0:      *
Chris@0:      * @return Response
Chris@0:      */
Chris@0:     private function restoreResponse($headers, $body = null)
Chris@0:     {
Chris@0:         $status = $headers['X-Status'][0];
Chris@0:         unset($headers['X-Status']);
Chris@0: 
Chris@0:         if (null !== $body) {
Chris@17:             $headers['X-Body-File'] = [$body];
Chris@0:         }
Chris@0: 
Chris@0:         return new Response($body, $status, $headers);
Chris@0:     }
Chris@0: }