Update to MediaWiki 1.21.1

1 files changed, 312 insertions, 0 deletions

diff --git a/includes/clientpool/RedisConnectionPool.php b/includes/clientpool/RedisConnectionPool.php
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+<?php
+/**
+ * PhpRedis client connection pooling manager.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @defgroup Redis Redis
+ * @author Aaron Schulz
+ */
+
+/**
+ * Helper class to manage redis connections using PhpRedis.
+ *
+ * This can be used to get handle wrappers that free the handle when the wrapper
+ * leaves scope. The maximum number of free handles (connections) is configurable.
+ * This provides an easy way to cache connection handles that may also have state,
+ * such as a handle does between multi() and exec(), and without hoarding connections.
+ * The wrappers use PHP magic methods so that calling functions on them calls the
+ * function of the actual Redis object handle.
+ *
+ * @ingroup Redis
+ * @since 1.21
+ */
+class RedisConnectionPool {
+	// Settings for all connections in this pool
+	protected $connectTimeout; // string; connection timeout
+	protected $persistent; // bool; whether connections persist
+	protected $password; // string; plaintext auth password
+	protected $serializer; // integer; the serializer to use (Redis::SERIALIZER_*)
+
+	protected $idlePoolSize = 0; // integer; current idle pool size
+
+	/** @var Array (server name => ((connection info array),...) */
+	protected $connections = array();
+	/** @var Array (server name => UNIX timestamp) */
+	protected $downServers = array();
+
+	/** @var Array */
+	protected static $instances = array(); // (pool ID => RedisConnectionPool)
+
+	const SERVER_DOWN_TTL = 30; // integer; seconds to cache servers as "down"
+
+	/**
+	 * $options include:
+	 *   - connectTimeout : The timeout for new connections, in seconds.
+	 *                      Optional, default is 1 second.
+	 *   - persistent     : Set this to true to allow connections to persist across
+	 *                      multiple web requests. False by default.
+	 *   - password       : The authentication password, will be sent to Redis in clear text.
+	 *                      Optional, if it is unspecified, no AUTH command will be sent.
+	 *   - serializer     : Set to "php", "igbinary", or "none". Default is "php".
+	 * @param array $options
+	 */
+	protected function __construct( array $options ) {
+		if ( !extension_loaded( 'redis' ) ) {
+			throw new MWException( __CLASS__. ' requires the phpredis extension: ' .
+				'https://github.com/nicolasff/phpredis' );
+		}
+		$this->connectTimeout = $options['connectTimeout'];
+		$this->persistent = $options['persistent'];
+		$this->password = $options['password'];
+		if ( !isset( $options['serializer'] ) || $options['serializer'] === 'php' ) {
+			$this->serializer = Redis::SERIALIZER_PHP;
+		} elseif ( $options['serializer'] === 'igbinary' ) {
+			$this->serializer = Redis::SERIALIZER_IGBINARY;
+		} elseif ( $options['serializer'] === 'none' ) {
+			$this->serializer = Redis::SERIALIZER_NONE;
+		} else {
+			throw new MWException( "Invalid serializer specified." );
+		}
+	}
+
+	/**
+	 * @param $options Array
+	 * @return Array
+	 */
+	protected static function applyDefaultConfig( array $options ) {
+		if ( !isset( $options['connectTimeout'] ) ) {
+			$options['connectTimeout'] = 1;
+		}
+		if ( !isset( $options['persistent'] ) ) {
+			$options['persistent'] = false;
+		}
+		if ( !isset( $options['password'] ) ) {
+			$options['password'] = null;
+		}
+		return $options;
+	}
+
+	/**
+	 * @param $options Array
+	 * @return RedisConnectionPool
+	 */
+	public static function singleton( array $options ) {
+		$options = self::applyDefaultConfig( $options );
+		// Map the options to a unique hash...
+		ksort( $options ); // normalize to avoid pool fragmentation
+		$id = sha1( serialize( $options ) );
+		// Initialize the object at the hash as needed...
+		if ( !isset( self::$instances[$id] ) ) {
+			self::$instances[$id] = new self( $options );
+			wfDebug( "Creating a new " . __CLASS__ . " instance with id $id." );
+		}
+		return self::$instances[$id];
+	}
+
+	/**
+	 * Get a connection to a redis server. Based on code in RedisBagOStuff.php.
+	 *
+	 * @param string $server A hostname/port combination or the absolute path of a UNIX socket.
+	 *                       If a hostname is specified but no port, port 6379 will be used.
+	 * @return RedisConnRef|bool Returns false on failure
+	 * @throws MWException
+	 */
+	public function getConnection( $server ) {
+		// Check the listing "dead" servers which have had a connection errors.
+		// Servers are marked dead for a limited period of time, to
+		// avoid excessive overhead from repeated connection timeouts.
+		if ( isset( $this->downServers[$server] ) ) {
+			$now = time();
+			if ( $now > $this->downServers[$server] ) {
+				// Dead time expired
+				unset( $this->downServers[$server] );
+			} else {
+				// Server is dead
+				wfDebug( "server $server is marked down for another " .
+					( $this->downServers[$server] - $now ) . " seconds, can't get connection" );
+				return false;
+			}
+		}
+
+		// Check if a connection is already free for use
+		if ( isset( $this->connections[$server] ) ) {
+			foreach ( $this->connections[$server] as &$connection ) {
+				if ( $connection['free'] ) {
+					$connection['free'] = false;
+					--$this->idlePoolSize;
+					return new RedisConnRef( $this, $server, $connection['conn'] );
+				}
+			}
+		}
+
+		if ( substr( $server, 0, 1 ) === '/' ) {
+			// UNIX domain socket
+			// These are required by the redis extension to start with a slash, but
+			// we still need to set the port to a special value to make it work.
+			$host = $server;
+			$port = 0;
+		} else {
+			// TCP connection
+			$hostPort = IP::splitHostAndPort( $server );
+			if ( !$hostPort ) {
+				throw new MWException( __CLASS__.": invalid configured server \"$server\"" );
+			}
+			list( $host, $port ) = $hostPort;
+			if ( $port === false ) {
+				$port = 6379;
+			}
+		}
+
+		$conn = new Redis();
+		try {
+			if ( $this->persistent ) {
+				$result = $conn->pconnect( $host, $port, $this->connectTimeout );
+			} else {
+				$result = $conn->connect( $host, $port, $this->connectTimeout );
+			}
+			if ( !$result ) {
+				wfDebugLog( 'redis', "Could not connect to server $server" );
+				// Mark server down for some time to avoid further timeouts
+				$this->downServers[$server] = time() + self::SERVER_DOWN_TTL;
+				return false;
+			}
+			if ( $this->password !== null ) {
+				if ( !$conn->auth( $this->password ) ) {
+					wfDebugLog( 'redis', "Authentication error connecting to $server" );
+				}
+			}
+		} catch ( RedisException $e ) {
+			$this->downServers[$server] = time() + self::SERVER_DOWN_TTL;
+			wfDebugLog( 'redis', "Redis exception: " . $e->getMessage() . "\n" );
+			return false;
+		}
+
+		if ( $conn ) {
+			$conn->setOption( Redis::OPT_SERIALIZER, $this->serializer );
+			$this->connections[$server][] = array( 'conn' => $conn, 'free' => false );
+			return new RedisConnRef( $this, $server, $conn );
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * Mark a connection to a server as free to return to the pool
+	 *
+	 * @param $server string
+	 * @param $conn Redis
+	 * @return boolean
+	 */
+	public function freeConnection( $server, Redis $conn ) {
+		$found = false;
+
+		foreach ( $this->connections[$server] as &$connection ) {
+			if ( $connection['conn'] === $conn && !$connection['free'] ) {
+				$connection['free'] = true;
+				++$this->idlePoolSize;
+				break;
+			}
+		}
+
+		$this->closeExcessIdleConections();
+
+		return $found;
+	}
+
+	/**
+	 * Close any extra idle connections if there are more than the limit
+	 *
+	 * @return void
+	 */
+	protected function closeExcessIdleConections() {
+		if ( $this->idlePoolSize <= count( $this->connections ) ) {
+			return; // nothing to do (no more connections than servers)
+		}
+
+		foreach ( $this->connections as $server => &$serverConnections ) {
+			foreach ( $serverConnections as $key => &$connection ) {
+				if ( $connection['free'] ) {
+					unset( $serverConnections[$key] );
+					if ( --$this->idlePoolSize <= count( $this->connections ) ) {
+						return; // done (no more connections than servers)
+					}
+				}
+			}
+		}
+	}
+
+	/**
+	 * The redis extension throws an exception in response to various read, write
+	 * and protocol errors. Sometimes it also closes the connection, sometimes
+	 * not. The safest response for us is to explicitly destroy the connection
+	 * object and let it be reopened during the next request.
+	 *
+	 * @param $server string
+	 * @param $cref RedisConnRef
+	 * @param $e RedisException
+	 * @return void
+	 */
+	public function handleException( $server, RedisConnRef $cref, RedisException $e ) {
+		wfDebugLog( 'redis', "Redis exception on server $server: " . $e->getMessage() . "\n" );
+		foreach ( $this->connections[$server] as $key => $connection ) {
+			if ( $cref->isConnIdentical( $connection['conn'] ) ) {
+				$this->idlePoolSize -= $connection['free'] ? 1 : 0;
+				unset( $this->connections[$server][$key] );
+				break;
+			}
+		}
+	}
+}
+
+/**
+ * Helper class to handle automatically marking connectons as reusable (via RAII pattern)
+ *
+ * @ingroup Redis
+ * @since 1.21
+ */
+class RedisConnRef {
+	/** @var RedisConnectionPool */
+	protected $pool;
+	/** @var Redis */
+	protected $conn;
+
+	protected $server; // string
+
+	/**
+	 * @param $pool RedisConnectionPool
+	 * @param $server string
+	 * @param $conn Redis
+	 */
+	public function __construct( RedisConnectionPool $pool, $server, Redis $conn ) {
+		$this->pool = $pool;
+		$this->server = $server;
+		$this->conn = $conn;
+	}
+
+	public function __call( $name, $arguments ) {
+		return call_user_func_array( array( $this->conn, $name ), $arguments );
+	}
+
+	public function isConnIdentical( Redis $conn ) {
+		return $this->conn === $conn;
+	}
+
+	function __destruct() {
+		$this->pool->freeConnection( $this->server, $this->conn );
+	}
+}