X-Git-Url: https://scripts.mit.edu/gitweb/autoinstallsdev/mediawiki.git/blobdiff_plain/19e297c21b10b1b8a3acad5e73fc71dcb35db44a..6932310fd58ebef145fa01eb76edf7150284d8ea:/includes/db/LBFactory.php

diff --git a/includes/db/LBFactory.php b/includes/db/LBFactory.php
deleted file mode 100644
index f84a70e5..00000000
--- a/includes/db/LBFactory.php
+++ /dev/null
@@ -1,331 +0,0 @@
-<?php
-/**
- * Generator of database load balancing objects
- *
- * @file
- * @ingroup Database
- */
-
-/**
- * An interface for generating database load balancers
- * @ingroup Database
- */
-abstract class LBFactory {
-	static $instance;
-
-	/**
-	 * Disables all access to the load balancer, will cause all database access
-	 * to throw a DBAccessError
-	 */
-	public static function disableBackend() {
-		global $wgLBFactoryConf;
-		self::$instance = new LBFactory_Fake( $wgLBFactoryConf );
-	}
-
-	/**
-	 * Resets the singleton for use if it's been disabled. Does nothing otherwise
-	 */
-	public static function enableBackend() {
-		if( self::$instance instanceof LBFactory_Fake )
-			self::$instance = null;
-	}
-
-	/**
-	 * Get an LBFactory instance
-	 */
-	static function &singleton() {
-		if ( is_null( self::$instance ) ) {
-			global $wgLBFactoryConf;
-			$class = $wgLBFactoryConf['class'];
-			self::$instance = new $class( $wgLBFactoryConf );
-		}
-		return self::$instance;
-	}
-
-	/**
-	 * Shut down, close connections and destroy the cached instance.
-	 *
-	 */
-	static function destroyInstance() {
-		if ( self::$instance ) {
-			self::$instance->shutdown();
-			self::$instance->forEachLBCallMethod( 'closeAll' );
-			self::$instance = null;
-		}
-	}
-
-	/**
-	 * Set the instance to be the given object
-	 */
-	static function setInstance( $instance ) {
-		self::destroyInstance();
-		self::$instance = $instance;
-	}
-
-	/**
-	 * Construct a factory based on a configuration array (typically from $wgLBFactoryConf)
-	 */
-	abstract function __construct( $conf );
-
-	/**
-	 * Create a new load balancer object. The resulting object will be untracked,
-	 * not chronology-protected, and the caller is responsible for cleaning it up.
-	 *
-	 * @param $wiki String: wiki ID, or false for the current wiki
-	 * @return LoadBalancer
-	 */
-	abstract function newMainLB( $wiki = false );
-
-	/**
-	 * Get a cached (tracked) load balancer object.
-	 *
-	 * @param $wiki String: wiki ID, or false for the current wiki
-	 * @return LoadBalancer
-	 */
-	abstract function getMainLB( $wiki = false );
-
-	/*
-	 * Create a new load balancer for external storage. The resulting object will be
-	 * untracked, not chronology-protected, and the caller is responsible for
-	 * cleaning it up.
-	 *
-	 * @param $cluster String: external storage cluster, or false for core
-	 * @param $wiki String: wiki ID, or false for the current wiki
-	 */
-	abstract function newExternalLB( $cluster, $wiki = false );
-
-	/*
-	 * Get a cached (tracked) load balancer for external storage
-	 *
-	 * @param $cluster String: external storage cluster, or false for core
-	 * @param $wiki String: wiki ID, or false for the current wiki
-	 */
-	abstract function &getExternalLB( $cluster, $wiki = false );
-
-	/**
-	 * Execute a function for each tracked load balancer
-	 * The callback is called with the load balancer as the first parameter,
-	 * and $params passed as the subsequent parameters.
-	 */
-	abstract function forEachLB( $callback, $params = array() );
-
-	/**
-	 * Prepare all tracked load balancers for shutdown
-	 * STUB
-	 */
-	function shutdown() {}
-
-	/**
-	 * Call a method of each tracked load balancer
-	 */
-	function forEachLBCallMethod( $methodName, $args = array() ) {
-		$this->forEachLB( array( $this, 'callMethod' ), array( $methodName, $args ) );
-	}
-
-	/**
-	 * Private helper for forEachLBCallMethod
-	 */
-	function callMethod( $loadBalancer, $methodName, $args ) {
-		call_user_func_array( array( $loadBalancer, $methodName ), $args );
-	}
-
-	/**
-	 * Commit changes on all master connections
-	 */
-	function commitMasterChanges() {
-		$this->forEachLBCallMethod( 'commitMasterChanges' );
-	}
-}
-
-/**
- * A simple single-master LBFactory that gets its configuration from the b/c globals
- */
-class LBFactory_Simple extends LBFactory {
-	var $mainLB;
-	var $extLBs = array();
-
-	# Chronology protector
-	var $chronProt;
-
-	function __construct( $conf ) {
-		$this->chronProt = new ChronologyProtector;
-	}
-
-	function newMainLB( $wiki = false ) {
-		global $wgDBservers, $wgMasterWaitTimeout;
-		if ( $wgDBservers ) {
-			$servers = $wgDBservers;
-		} else {
-			global $wgDBserver, $wgDBuser, $wgDBpassword, $wgDBname, $wgDBtype, $wgDebugDumpSql;
-			$servers = array(array(
-				'host' => $wgDBserver,
-				'user' => $wgDBuser,
-				'password' => $wgDBpassword,
-				'dbname' => $wgDBname,
-				'type' => $wgDBtype,
-				'load' => 1,
-				'flags' => ($wgDebugDumpSql ? DBO_DEBUG : 0) | DBO_DEFAULT
-			));
-		}
-
-		return new LoadBalancer( array(
-			'servers' => $servers,
-			'masterWaitTimeout' => $wgMasterWaitTimeout
-		));
-	}
-
-	function getMainLB( $wiki = false ) {
-		if ( !isset( $this->mainLB ) ) {
-			$this->mainLB = $this->newMainLB( $wiki );
-			$this->mainLB->parentInfo( array( 'id' => 'main' ) );
-			$this->chronProt->initLB( $this->mainLB );
-		}
-		return $this->mainLB;
-	}
-
-	function newExternalLB( $cluster, $wiki = false ) {
-		global $wgExternalServers;
-		if ( !isset( $wgExternalServers[$cluster] ) ) {
-			throw new MWException( __METHOD__.": Unknown cluster \"$cluster\"" );
-		}
-		return new LoadBalancer( array(
-			'servers' => $wgExternalServers[$cluster]
-		));
-	}
-
-	function &getExternalLB( $cluster, $wiki = false ) {
-		if ( !isset( $this->extLBs[$cluster] ) ) {
-			$this->extLBs[$cluster] = $this->newExternalLB( $cluster, $wiki );
-			$this->extLBs[$cluster]->parentInfo( array( 'id' => "ext-$cluster" ) );
-		}
-		return $this->extLBs[$cluster];
-	}
-
-	/**
-	 * Execute a function for each tracked load balancer
-	 * The callback is called with the load balancer as the first parameter,
-	 * and $params passed as the subsequent parameters.
-	 */
-	function forEachLB( $callback, $params = array() ) {
-		if ( isset( $this->mainLB ) ) {
-			call_user_func_array( $callback, array_merge( array( $this->mainLB ), $params ) );
-		}
-		foreach ( $this->extLBs as $lb ) {
-			call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
-		}
-	}
-
-	function shutdown() {
-		if ( $this->mainLB ) {
-			$this->chronProt->shutdownLB( $this->mainLB );
-		}
-		$this->chronProt->shutdown();
-		$this->commitMasterChanges();
-	}
-}
-
-/**
- * LBFactory class that throws an error on any attempt to use it.
- * This will typically be done via wfGetDB().
- * Call LBFactory::disableBackend() to start using this, and
- * LBFactory::enableBackend() to return to normal behavior
- */
-class LBFactory_Fake extends LBFactory {
-	function __construct( $conf ) {}
-
-	function newMainLB( $wiki = false) {
-		throw new DBAccessError;
-	}
-	function getMainLB( $wiki = false ) {
-		throw new DBAccessError;
-	}
-	function newExternalLB( $cluster, $wiki = false ) {
-		throw new DBAccessError;
-	}
-	function &getExternalLB( $cluster, $wiki = false ) {
-		throw new DBAccessError;
-	}
-	function forEachLB( $callback, $params = array() ) {}
-}
-
-/**
- * Exception class for attempted DB access
- */
-class DBAccessError extends MWException {
-	function __construct() {
-		parent::__construct( "Mediawiki tried to access the database via wfGetDB(). This is not allowed." );
-	}
-}
-
-/**
- * Class for ensuring a consistent ordering of events as seen by the user, despite replication.
- * Kind of like Hawking's [[Chronology Protection Agency]].
- */
-class ChronologyProtector {
-	var $startupPos;
-	var $shutdownPos = array();
-
-	/**
-	 * Initialise a LoadBalancer to give it appropriate chronology protection.
-	 *
-	 * @param $lb LoadBalancer
-	 */
-	function initLB( $lb ) {
-		if ( $this->startupPos === null ) {
-			if ( !empty( $_SESSION[__CLASS__] ) ) {
-				$this->startupPos = $_SESSION[__CLASS__];
-			}
-		}
-		if ( !$this->startupPos ) {
-			return;
-		}
-		$masterName = $lb->getServerName( 0 );
-
-		if ( $lb->getServerCount() > 1 && !empty( $this->startupPos[$masterName] ) ) {
-			$info = $lb->parentInfo();
-			$pos = $this->startupPos[$masterName];
-			wfDebug( __METHOD__.": LB " . $info['id'] . " waiting for master pos $pos\n" );
-			$lb->waitFor( $this->startupPos[$masterName] );
-		}
-	}
-
-	/**
-	 * Notify the ChronologyProtector that the LoadBalancer is about to shut
-	 * down. Saves replication positions.
-	 *
-	 * @param $lb LoadBalancer
-	 */
-	function shutdownLB( $lb ) {
-		// Don't start a session, don't bother with non-replicated setups
-		if ( strval( session_id() ) == '' || $lb->getServerCount() <= 1 ) {
-			return;
-		}
-		$masterName = $lb->getServerName( 0 );
-		if ( isset( $this->shutdownPos[$masterName] ) ) {
-			// Already done
-			return;
-		}
-		// Only save the position if writes have been done on the connection
-		$db = $lb->getAnyOpenConnection( 0 );
-		$info = $lb->parentInfo();
-		if ( !$db || !$db->doneWrites() ) {
-			wfDebug( __METHOD__.": LB {$info['id']}, no writes done\n" );
-			return;
-		}
-		$pos = $db->getMasterPos();
-		wfDebug( __METHOD__.": LB {$info['id']} has master pos $pos\n" );
-		$this->shutdownPos[$masterName] = $pos;
-	}
-
-	/**
-	 * Notify the ChronologyProtector that the LBFactory is done calling shutdownLB() for now.
-	 * May commit chronology data to persistent storage.
-	 */
-	function shutdown() {
-		if ( session_id() != '' && count( $this->shutdownPos ) ) {
-			wfDebug( __METHOD__.": saving master pos for " .
-				count( $this->shutdownPos ) . " master(s)\n" );
-			$_SESSION[__CLASS__] = $this->shutdownPos;
-		}
-	}
-}