symfony · jakzal · Sep 22, 2016 · nicolas-grekas · Sep 28, 2016 · nicolas-grekas
diff --git a/src/Symfony/Component/HttpKernel/HttpCache/Psr6Store.php b/src/Symfony/Component/HttpKernel/HttpCache/Psr6Store.php
@@ -0,0 +1,242 @@
+<?php
+
+namespace Symfony\Component\HttpKernel\HttpCache;
+
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+final class Psr6Store implements StoreInterface
+{
+    /**
+     * @var CacheItemPoolInterface
+     */
+    private $cachePool;
+
+    /**
+     * List of locks acquired by the current process.
+     *
+     * @var array
+     */
+    private $locks = array();
+
+    /**
+     * @param CacheItemPoolInterface $cachePool
+     */
+    public function __construct(CacheItemPoolInterface $cachePool)
+    {
+        $this->cachePool = $cachePool;
+    }
+
+    /**
+     * 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)
+    {
+        // TODO: Implement lookup() method.
+    }
+
+    /**
+     * 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
+     */
+    public function write(Request $request, Response $response)
+    {
+        if (!$response->headers->has('X-Content-Digest')) {
+            $contentDigest = $this->generateContentDigest($response);
+
+            if (false === $this->save($contentDigest, $response->getContent())) {
+                throw new \RuntimeException('Unable to store the entity.');
+            }
+
+            $response->headers->set('X-Content-Digest', $contentDigest);
+
+            if (!$response->headers->has('Transfer-Encoding')) {
+                $response->headers->set('Content-Length', strlen($response->getContent()));
+            }
+        }
+
+        $key = $this->getCacheKey($request);
+        $headers = $response->headers->all();
+        unset($headers['age']);
+
+        $this->save($key, serialize(array(array($request->headers->all(), $headers))));
+    }
+
+    /**
+     * Invalidates all cache entries that match the request.
+     *
+     * @param Request $request A Request instance
+     */
+    public function invalidate(Request $request)
+    {
+        // TODO: Implement invalidate() method.
+    }
+
+    /**
+     * Locks the cache for a given Request.
+     *
+     * @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)
+    {
+        $lockKey = $this->getLockKey($request);
+
+        if (isset($this->locks[$lockKey])) {
+            return true;
+        }
+
+        $item = $this->cachePool->getItem($lockKey);
+
+        if ($item->isHit()) {
+            return false;
+        }
+
+        $this->cachePool->save($item);
+
+        $this->locks[$lockKey] = true;
+
+        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)
+    {
+        $lockKey = $this->getLockKey($request);
+
+        if (!isset($this->locks[$lockKey])) {
+            return false;
+        }
+
+        $this->cachePool->deleteItem($lockKey);
+
+        unset($this->locks[$lockKey]);
+
+        return true;
+    }
+
+    /**
+     * Returns whether or not a lock exists.
+     *
+     * @param Request $request A Request instance
+     *
+     * @return bool true if lock exists, false otherwise
+     */
+    public function isLocked(Request $request)
+    {
+        $lockKey = $this->getLockKey($request);
+
+        if (isset($this->locks[$lockKey])) {
+            return true;
+        }
+
+        return $this->cachePool->hasItem($this->getLockKey($request));
+    }
+
+    /**
+     * Purges data for the given URL.
+     *
+     * @param string $url A URL
+     *
+     * @return bool true if the URL exists and has been purged, false otherwise
+     */
+    public function purge($url)
+    {
+        // TODO: Implement purge() method.
+    }
+
+    /**
+     * Cleanups storage.
+     */
+    public function cleanup()
+    {
+        $this->cachePool->deleteItems(array_keys($this->locks));
+        $this->locks = array();
+    }
+
+    /**
+     * @param Request $request
+     *
+     * @return string
+     */
+    private function getCacheKey(Request $request)
+    {
+        return 'md'.hash('sha256', $request->getUri());
+    }
+
+    /**
+     * @param Request $request
+     *
+     * @return string
+     */
+    private function getLockKey(Request $request)
+    {
+        return $this->getCacheKey($request).'.lock';
+    }
+
+    /**
+     * @param Response $response
+     *
+     * @return string
+     */
+    private function generateContentDigest(Response $response)
+    {
+        return 'en'.hash('sha256', $response->getContent());
+    }
+
+    /**
+     * @param string $key
+     * @param string $data
+     *
+     * @return bool
+     */
+    private function save($key, $data)
+    {
+        return $this->cachePool->save($this->createCacheItem($key, $data));
+    }
+
+    /**
+     * @param string $key
+     * @param mixed  $value
+     * @param bool   $isHit
+     *
+     * @return CacheItem
+     */
+    private function createCacheItem($key, $value, $isHit = false)
+    {
+        $f = \Closure::bind(
+            function ($key, $value, $isHit) {
+                $item = new CacheItem();
+                $item->key = $key;
+                $item->value = $value;
+                $item->isHit = $isHit;
+
+                return $item;
+            },
+            null,
+            CacheItem::class
+        );
+
+        return $f($key, $value, $isHit);
+    }
+}