--- /dev/null
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\Common\Cache;
+
+use Riak\Bucket;
+use Riak\Connection;
+use Riak\Input;
+use Riak\Exception;
+use Riak\Object;
+
+/**
+ * Riak cache provider.
+ *
+ * @link www.doctrine-project.org
+ * @since 1.1
+ * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
+ */
+class RiakCache extends CacheProvider
+{
+ const EXPIRES_HEADER = 'X-Riak-Meta-Expires';
+
+ /**
+ * @var \Riak\Bucket
+ */
+ private $bucket;
+
+ /**
+ * Sets the riak bucket instance to use.
+ *
+ * @param \Riak\Bucket $bucket
+ */
+ public function __construct(Bucket $bucket)
+ {
+ $this->bucket = $bucket;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doFetch($id)
+ {
+ try {
+ $response = $this->bucket->get($id);
+
+ // No objects found
+ if ( ! $response->hasObject()) {
+ return false;
+ }
+
+ // Check for attempted siblings
+ $object = ($response->hasSiblings())
+ ? $this->resolveConflict($id, $response->getVClock(), $response->getObjectList())
+ : $response->getFirstObject();
+
+ // Check for expired object
+ if ($this->isExpired($object)) {
+ $this->bucket->delete($object);
+
+ return false;
+ }
+
+ return unserialize($object->getContent());
+ } catch (Exception\RiakException $e) {
+ // Covers:
+ // - Riak\ConnectionException
+ // - Riak\CommunicationException
+ // - Riak\UnexpectedResponseException
+ // - Riak\NotFoundException
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doContains($id)
+ {
+ try {
+ // We only need the HEAD, not the entire object
+ $input = new Input\GetInput();
+
+ $input->setReturnHead(true);
+
+ $response = $this->bucket->get($id, $input);
+
+ // No objects found
+ if ( ! $response->hasObject()) {
+ return false;
+ }
+
+ $object = $response->getFirstObject();
+
+ // Check for expired object
+ if ($this->isExpired($object)) {
+ $this->bucket->delete($object);
+
+ return false;
+ }
+
+ return true;
+ } catch (Exception\RiakException $e) {
+ // Do nothing
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doSave($id, $data, $lifeTime = 0)
+ {
+ try {
+ $object = new Object($id);
+
+ $object->setContent(serialize($data));
+
+ if ($lifeTime > 0) {
+ $object->addMetadata(self::EXPIRES_HEADER, (string) (time() + $lifeTime));
+ }
+
+ $this->bucket->put($object);
+
+ return true;
+ } catch (Exception\RiakException $e) {
+ // Do nothing
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doDelete($id)
+ {
+ try {
+ $this->bucket->delete($id);
+
+ return true;
+ } catch (Exception\BadArgumentsException $e) {
+ // Key did not exist on cluster already
+ } catch (Exception\RiakException $e) {
+ // Covers:
+ // - Riak\Exception\ConnectionException
+ // - Riak\Exception\CommunicationException
+ // - Riak\Exception\UnexpectedResponseException
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doFlush()
+ {
+ try {
+ $keyList = $this->bucket->getKeyList();
+
+ foreach ($keyList as $key) {
+ $this->bucket->delete($key);
+ }
+
+ return true;
+ } catch (Exception\RiakException $e) {
+ // Do nothing
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function doGetStats()
+ {
+ // Only exposed through HTTP stats API, not Protocol Buffers API
+ return null;
+ }
+
+ /**
+ * Check if a given Riak Object have expired.
+ *
+ * @param \Riak\Object $object
+ *
+ * @return bool
+ */
+ private function isExpired(Object $object)
+ {
+ $metadataMap = $object->getMetadataMap();
+
+ return isset($metadataMap[self::EXPIRES_HEADER])
+ && $metadataMap[self::EXPIRES_HEADER] < time();
+ }
+
+ /**
+ * On-read conflict resolution. Applied approach here is last write wins.
+ * Specific needs may override this method to apply alternate conflict resolutions.
+ *
+ * {@internal Riak does not attempt to resolve a write conflict, and store
+ * it as sibling of conflicted one. By following this approach, it is up to
+ * the next read to resolve the conflict. When this happens, your fetched
+ * object will have a list of siblings (read as a list of objects).
+ * In our specific case, we do not care about the intermediate ones since
+ * they are all the same read from storage, and we do apply a last sibling
+ * (last write) wins logic.
+ * If by any means our resolution generates another conflict, it'll up to
+ * next read to properly solve it.}
+ *
+ * @param string $id
+ * @param string $vClock
+ * @param array $objectList
+ *
+ * @return \Riak\Object
+ */
+ protected function resolveConflict($id, $vClock, array $objectList)
+ {
+ // Our approach here is last-write wins
+ $winner = $objectList[count($objectList)];
+
+ $putInput = new Input\PutInput();
+ $putInput->setVClock($vClock);
+
+ $mergedObject = new Object($id);
+ $mergedObject->setContent($winner->getContent());
+
+ $this->bucket->put($mergedObject, $putInput);
+
+ return $mergedObject;
+ }
+}