Moved cache drivers outside core to extensions (plugins)

plugins/cache-redis/Predis/Connection/Aggregate/PredisCluster.php

@@ -0,0 +1,235 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Predis\Connection\Aggregate;
+
+use Predis\Cluster\PredisStrategy;
+use Predis\Cluster\StrategyInterface;
+use Predis\Command\CommandInterface;
+use Predis\Connection\NodeConnectionInterface;
+use Predis\NotSupportedException;
+
+/**
+ * Abstraction for a cluster of aggregate connections to various Redis servers
+ * implementing client-side sharding based on pluggable distribution strategies.
+ *
+ * @author Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * @todo Add the ability to remove connections from pool.
+ */
+class PredisCluster implements ClusterInterface, \IteratorAggregate, \Countable
+{
+    private $pool;
+    private $strategy;
+    private $distributor;
+
+    /**
+     * @param StrategyInterface $strategy Optional cluster strategy.
+     */
+    public function __construct(StrategyInterface $strategy = null)
+    {
+        $this->pool = array();
+        $this->strategy = $strategy ?: new PredisStrategy();
+        $this->distributor = $this->strategy->getDistributor();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function isConnected()
+    {
+        foreach ($this->pool as $connection) {
+            if ($connection->isConnected()) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function connect()
+    {
+        foreach ($this->pool as $connection) {
+            $connection->connect();
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function disconnect()
+    {
+        foreach ($this->pool as $connection) {
+            $connection->disconnect();
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function add(NodeConnectionInterface $connection)
+    {
+        $parameters = $connection->getParameters();
+
+        if (isset($parameters->alias)) {
+            $this->pool[$parameters->alias] = $connection;
+        } else {
+            $this->pool[] = $connection;
+        }
+
+        $weight = isset($parameters->weight) ? $parameters->weight : null;
+        $this->distributor->add($connection, $weight);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function remove(NodeConnectionInterface $connection)
+    {
+        if (($id = array_search($connection, $this->pool, true)) !== false) {
+            unset($this->pool[$id]);
+            $this->distributor->remove($connection);
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Removes a connection instance using its alias or index.
+     *
+     * @param string $connectionID Alias or index of a connection.
+     *
+     * @return bool Returns true if the connection was in the pool.
+     */
+    public function removeById($connectionID)
+    {
+        if ($connection = $this->getConnectionById($connectionID)) {
+            return $this->remove($connection);
+        }
+
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getConnection(CommandInterface $command)
+    {
+        $slot = $this->strategy->getSlot($command);
+
+        if (!isset($slot)) {
+            throw new NotSupportedException(
+                "Cannot use '{$command->getId()}' over clusters of connections."
+            );
+        }
+
+        $node = $this->distributor->getBySlot($slot);
+
+        return $node;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getConnectionById($connectionID)
+    {
+        return isset($this->pool[$connectionID]) ? $this->pool[$connectionID] : null;
+    }
+
+    /**
+     * Retrieves a connection instance from the cluster using a key.
+     *
+     * @param string $key Key string.
+     *
+     * @return NodeConnectionInterface
+     */
+    public function getConnectionByKey($key)
+    {
+        $hash = $this->strategy->getSlotByKey($key);
+        $node = $this->distributor->getBySlot($hash);
+
+        return $node;
+    }
+
+    /**
+     * Returns the underlying command hash strategy used to hash commands by
+     * using keys found in their arguments.
+     *
+     * @return StrategyInterface
+     */
+    public function getClusterStrategy()
+    {
+        return $this->strategy;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function count()
+    {
+        return count($this->pool);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getIterator()
+    {
+        return new \ArrayIterator($this->pool);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function writeRequest(CommandInterface $command)
+    {
+        $this->getConnection($command)->writeRequest($command);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function readResponse(CommandInterface $command)
+    {
+        return $this->getConnection($command)->readResponse($command);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function executeCommand(CommandInterface $command)
+    {
+        return $this->getConnection($command)->executeCommand($command);
+    }
+
+    /**
+     * Executes the specified Redis command on all the nodes of a cluster.
+     *
+     * @param CommandInterface $command A Redis command.
+     *
+     * @return array
+     */
+    public function executeCommandOnNodes(CommandInterface $command)
+    {
+        $responses = array();
+
+        foreach ($this->pool as $connection) {
+            $responses[] = $connection->executeCommand($command);
+        }
+
+        return $responses;
+    }
+}