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