Initial commit

2025-07-01 13:42:22 +00:00 · 2010-04-18 23:58:43 +10:00 · 2010-04-18 23:58:43 +10:00 · cb4205d508
commit cb4205d508
37 changed files with 2808 additions and 0 deletions
--- a/lib/Redisent/RedisentCluster.php
+++ b/lib/Redisent/RedisentCluster.php
@ -0,0 +1,138 @@
+<?php
+/**
+ * Redisent, a Redis interface for the modest
+ * @author Justin Poliey <jdp34@njit.edu>
+ * @copyright 2009 Justin Poliey <jdp34@njit.edu>
+ * @license http://www.opensource.org/licenses/mit-license.php The MIT License
+ * @package Redisent
+ */
+
+require 'redisent.php';
+
+/**
+ * A generalized Redisent interface for a cluster of Redis servers
+ */
+class RedisentCluster {
+
+	/**
+	 * Collection of Redisent objects attached to Redis servers
+	 * @var array
+	 * @access private
+	 */
+	private $redisents;
+
+	/**
+	 * Aliases of Redisent objects attached to Redis servers, used to route commands to specific servers
+	 * @see RedisentCluster::to
+	 * @var array
+	 * @access private
+	 */
+	private $aliases;
+
+	/**
+	 * Hash ring of Redis server nodes
+	 * @var array
+	 * @access private
+	 */
+	private $ring;
+
+	/**
+	 * Individual nodes of pointers to Redis servers on the hash ring
+	 * @var array
+	 * @access private
+	 */
+	private $nodes;
+
+	/**
+	 * Number of replicas of each node to make around the hash ring
+	 * @var integer
+	 * @access private
+	 */
+	private $replicas = 128;
+
+	/**
+	 * The commands that are not subject to hashing
+	 * @var array
+	 * @access private
+	 */
+	private $dont_hash = array(
+		'RANDOMKEY', 'DBSIZE',
+		'SELECT',    'MOVE',    'FLUSHDB',  'FLUSHALL',
+		'SAVE',      'BGSAVE',  'LASTSAVE', 'SHUTDOWN',
+		'INFO',      'MONITOR', 'SLAVEOF'
+	);
+
+	/**
+	 * Creates a Redisent interface to a cluster of Redis servers
+	 * @param array $servers The Redis servers in the cluster. Each server should be in the format array('host' => hostname, 'port' => port)
+	 */
+	function __construct($servers) {
+		$this->ring = array();
+		$this->aliases = array();
+		foreach ($servers as $alias => $server) {
+			$this->redisents[] = new Redisent($server['host'], $server['port']);
+			if (is_string($alias)) {
+				$this->aliases[$alias] = $this->redisents[count($this->redisents)-1];
+			}
+ 			for ($replica = 1; $replica <= $this->replicas; $replica++) {
+				$this->ring[crc32($server['host'].':'.$server['port'].'-'.$replica)] = $this->redisents[count($this->redisents)-1];
+			}
+		}
+		ksort($this->ring, SORT_NUMERIC);
+		$this->nodes = array_keys($this->ring);
+	}
+
+	/**
+	 * Routes a command to a specific Redis server aliased by {$alias}.
+	 * @param string $alias The alias of the Redis server
+	 * @return Redisent The Redisent object attached to the Redis server
+	 */
+	function to($alias) {
+		if (isset($this->aliases[$alias])) {
+			return $this->aliases[$alias];
+		}
+		else {
+			throw new Exception("That Redisent alias does not exist");
+		}
+	}
+
+	/* Execute a Redis command on the cluster */
+	function __call($name, $args) {
+
+		/* Pick a server node to send the command to */
+		$name = strtoupper($name);
+		if (!in_array($name, $this->dont_hash)) {
+			$node = $this->nextNode(crc32($args[0]));
+			$redisent = $this->ring[$node];
+    	}
+    	else {
+			$redisent = $this->redisents[0];
+    	}
+
+		/* Execute the command on the server */
+    	return call_user_func_array(array($redisent, $name), $args);
+	}
+
+	/**
+	 * Routes to the proper server node
+	 * @param integer $needle The hash value of the Redis command
+	 * @return Redisent The Redisent object associated with the hash
+	 */
+	private function nextNode($needle) {
+		$haystack = $this->nodes;
+		while (count($haystack) > 2) {
+			$try = floor(count($haystack) / 2);
+			if ($haystack[$try] == $needle) {
+				return $needle;
+			}
+			if ($needle < $haystack[$try]) {
+				$haystack = array_slice($haystack, 0, $try + 1);
+			}
+			if ($needle > $haystack[$try]) {
+				$haystack = array_slice($haystack, $try + 1);
+			}
+		}
+		return $haystack[count($haystack)-1];
+	}
+
+}