comparison vendor/symfony/http-kernel/HttpCache/Store.php @ 0:4c8ae668cc8c

Initial import (non-working)

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