Update to MediaWiki 1.24.1

1 files changed, 399 insertions, 0 deletions

diff --git a/includes/db/LBFactoryMulti.php b/includes/db/LBFactoryMulti.php
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+<?php
+/**
+ * Advanced generator of database load balancing objects for wiki farms.
+ *
+ * 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
+ * @ingroup Database
+ */
+
+/**
+ * A multi-wiki, multi-master factory for Wikimedia and similar installations.
+ * Ignores the old configuration globals
+ *
+ * Configuration:
+ *     sectionsByDB                A map of database names to section names.
+ *
+ *     sectionLoads                A 2-d map. For each section, gives a map of server names to
+ *                                 load ratios. For example:
+ *                                 array(
+ *                                     'section1' => array(
+ *                                         'db1' => 100,
+ *                                         'db2' => 100
+ *                                     )
+ *                                 )
+ *
+ *     serverTemplate              A server info associative array as documented for $wgDBservers.
+ *                                 The host, hostName and load entries will be overridden.
+ *
+ *     groupLoadsBySection         A 3-d map giving server load ratios for each section and group.
+ *                                 For example:
+ *                                 array(
+ *                                     'section1' => array(
+ *                                         'group1' => array(
+ *                                             'db1' => 100,
+ *                                             'db2' => 100
+ *                                         )
+ *                                     )
+ *                                 )
+ *
+ *     groupLoadsByDB              A 3-d map giving server load ratios by DB name.
+ *
+ *     hostsByName                 A map of hostname to IP address.
+ *
+ *     externalLoads               A map of external storage cluster name to server load map.
+ *
+ *     externalTemplateOverrides   A set of server info keys overriding serverTemplate for external
+ *                                 storage.
+ *
+ *     templateOverridesByServer   A 2-d map overriding serverTemplate and
+ *                                 externalTemplateOverrides on a server-by-server basis. Applies
+ *                                 to both core and external storage.
+ *
+ *     templateOverridesByCluster  A 2-d map overriding the server info by external storage cluster.
+ *
+ *     masterTemplateOverrides     An override array for all master servers.
+ *
+ *     readOnlyBySection           A map of section name to read-only message.
+ *                                 Missing or false for read/write.
+ *
+ * @ingroup Database
+ */
+class LBFactoryMulti extends LBFactory {
+	// Required settings
+
+	/** @var array A map of database names to section names */
+	protected $sectionsByDB;
+
+	/**
+	 * @var array A 2-d map. For each section, gives a map of server names to
+	 * load ratios
+	 */
+	protected $sectionLoads;
+
+	/**
+	 * @var array A server info associative array as documented for
+	 * $wgDBservers. The host, hostName and load entries will be
+	 * overridden
+	 */
+	protected $serverTemplate;
+
+	// Optional settings
+
+	/** @var array A 3-d map giving server load ratios for each section and group */
+	protected $groupLoadsBySection = array();
+
+	/** @var array A 3-d map giving server load ratios by DB name */
+	protected $groupLoadsByDB = array();
+
+	/** @var array A map of hostname to IP address */
+	protected $hostsByName = array();
+
+	/** @var array A map of external storage cluster name to server load map */
+	protected $externalLoads = array();
+
+	/**
+	 * @var array A set of server info keys overriding serverTemplate for
+	 * external storage
+	 */
+	protected $externalTemplateOverrides;
+
+	/**
+	 * @var array A 2-d map overriding serverTemplate and
+	 * externalTemplateOverrides on a server-by-server basis. Applies to both
+	 * core and external storage
+	 */
+	protected $templateOverridesByServer;
+
+	/** @var array A 2-d map overriding the server info by external storage cluster */
+	protected $templateOverridesByCluster;
+
+	/** @var array An override array for all master servers */
+	protected $masterTemplateOverrides;
+
+	/**
+	 * @var array|bool A map of section name to read-only message. Missing or
+	 * false for read/write
+	 */
+	protected $readOnlyBySection = array();
+
+	// Other stuff
+
+	/** @var array Load balancer factory configuration */
+	protected $conf;
+
+	/** @var LoadBalancer[] */
+	protected $mainLBs = array();
+
+	/** @var LoadBalancer[] */
+	protected $extLBs = array();
+
+	/** @var string */
+	protected $lastWiki;
+
+	/** @var string */
+	protected $lastSection;
+
+	/**
+	 * @param array $conf
+	 * @throws MWException
+	 */
+	function __construct( $conf ) {
+		$this->chronProt = new ChronologyProtector;
+		$this->conf = $conf;
+		$required = array( 'sectionsByDB', 'sectionLoads', 'serverTemplate' );
+		$optional = array( 'groupLoadsBySection', 'groupLoadsByDB', 'hostsByName',
+			'externalLoads', 'externalTemplateOverrides', 'templateOverridesByServer',
+			'templateOverridesByCluster', 'masterTemplateOverrides',
+			'readOnlyBySection' );
+
+		foreach ( $required as $key ) {
+			if ( !isset( $conf[$key] ) ) {
+				throw new MWException( __CLASS__ . ": $key is required in configuration" );
+			}
+			$this->$key = $conf[$key];
+		}
+
+		foreach ( $optional as $key ) {
+			if ( isset( $conf[$key] ) ) {
+				$this->$key = $conf[$key];
+			}
+		}
+
+		// Check for read-only mode
+		$section = $this->getSectionForWiki();
+		if ( !empty( $this->readOnlyBySection[$section] ) ) {
+			global $wgReadOnly;
+			$wgReadOnly = $this->readOnlyBySection[$section];
+		}
+	}
+
+	/**
+	 * @param bool|string $wiki
+	 * @return string
+	 */
+	function getSectionForWiki( $wiki = false ) {
+		if ( $this->lastWiki === $wiki ) {
+			return $this->lastSection;
+		}
+		list( $dbName, ) = $this->getDBNameAndPrefix( $wiki );
+		if ( isset( $this->sectionsByDB[$dbName] ) ) {
+			$section = $this->sectionsByDB[$dbName];
+		} else {
+			$section = 'DEFAULT';
+		}
+		$this->lastSection = $section;
+		$this->lastWiki = $wiki;
+
+		return $section;
+	}
+
+	/**
+	 * @param bool|string $wiki
+	 * @return LoadBalancer
+	 */
+	function newMainLB( $wiki = false ) {
+		list( $dbName, ) = $this->getDBNameAndPrefix( $wiki );
+		$section = $this->getSectionForWiki( $wiki );
+		$groupLoads = array();
+		if ( isset( $this->groupLoadsByDB[$dbName] ) ) {
+			$groupLoads = $this->groupLoadsByDB[$dbName];
+		}
+
+		if ( isset( $this->groupLoadsBySection[$section] ) ) {
+			$groupLoads = array_merge_recursive( $groupLoads, $this->groupLoadsBySection[$section] );
+		}
+
+		return $this->newLoadBalancer(
+			$this->serverTemplate,
+			$this->sectionLoads[$section],
+			$groupLoads
+		);
+	}
+
+	/**
+	 * @param bool|string $wiki
+	 * @return LoadBalancer
+	 */
+	function getMainLB( $wiki = false ) {
+		$section = $this->getSectionForWiki( $wiki );
+		if ( !isset( $this->mainLBs[$section] ) ) {
+			$lb = $this->newMainLB( $wiki, $section );
+			$lb->parentInfo( array( 'id' => "main-$section" ) );
+			$this->chronProt->initLB( $lb );
+			$this->mainLBs[$section] = $lb;
+		}
+
+		return $this->mainLBs[$section];
+	}
+
+	/**
+	 * @param string $cluster
+	 * @param bool|string $wiki
+	 * @throws MWException
+	 * @return LoadBalancer
+	 */
+	function newExternalLB( $cluster, $wiki = false ) {
+		if ( !isset( $this->externalLoads[$cluster] ) ) {
+			throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
+		}
+		$template = $this->serverTemplate;
+		if ( isset( $this->externalTemplateOverrides ) ) {
+			$template = $this->externalTemplateOverrides + $template;
+		}
+		if ( isset( $this->templateOverridesByCluster[$cluster] ) ) {
+			$template = $this->templateOverridesByCluster[$cluster] + $template;
+		}
+
+		return $this->newLoadBalancer( $template, $this->externalLoads[$cluster], array() );
+	}
+
+	/**
+	 * @param string $cluster External storage cluster, or false for core
+	 * @param bool|string $wiki Wiki ID, or false for the current wiki
+	 * @return LoadBalancer
+	 */
+	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" ) );
+			$this->chronProt->initLB( $this->extLBs[$cluster] );
+		}
+
+		return $this->extLBs[$cluster];
+	}
+
+	/**
+	 * Make a new load balancer object based on template and load array
+	 *
+	 * @param array $template
+	 * @param array $loads
+	 * @param array $groupLoads
+	 * @return LoadBalancer
+	 */
+	function newLoadBalancer( $template, $loads, $groupLoads ) {
+		$servers = $this->makeServerArray( $template, $loads, $groupLoads );
+		$lb = new LoadBalancer( array(
+			'servers' => $servers,
+		) );
+
+		return $lb;
+	}
+
+	/**
+	 * Make a server array as expected by LoadBalancer::__construct, using a template and load array
+	 *
+	 * @param array $template
+	 * @param array $loads
+	 * @param array $groupLoads
+	 * @return array
+	 */
+	function makeServerArray( $template, $loads, $groupLoads ) {
+		$servers = array();
+		$master = true;
+		$groupLoadsByServer = $this->reindexGroupLoads( $groupLoads );
+		foreach ( $groupLoadsByServer as $server => $stuff ) {
+			if ( !isset( $loads[$server] ) ) {
+				$loads[$server] = 0;
+			}
+		}
+		foreach ( $loads as $serverName => $load ) {
+			$serverInfo = $template;
+			if ( $master ) {
+				$serverInfo['master'] = true;
+				if ( isset( $this->masterTemplateOverrides ) ) {
+					$serverInfo = $this->masterTemplateOverrides + $serverInfo;
+				}
+				$master = false;
+			}
+			if ( isset( $this->templateOverridesByServer[$serverName] ) ) {
+				$serverInfo = $this->templateOverridesByServer[$serverName] + $serverInfo;
+			}
+			if ( isset( $groupLoadsByServer[$serverName] ) ) {
+				$serverInfo['groupLoads'] = $groupLoadsByServer[$serverName];
+			}
+			if ( isset( $this->hostsByName[$serverName] ) ) {
+				$serverInfo['host'] = $this->hostsByName[$serverName];
+			} else {
+				$serverInfo['host'] = $serverName;
+			}
+			$serverInfo['hostName'] = $serverName;
+			$serverInfo['load'] = $load;
+			$servers[] = $serverInfo;
+		}
+
+		return $servers;
+	}
+
+	/**
+	 * Take a group load array indexed by group then server, and reindex it by server then group
+	 * @param array $groupLoads
+	 * @return array
+	 */
+	function reindexGroupLoads( $groupLoads ) {
+		$reindexed = array();
+		foreach ( $groupLoads as $group => $loads ) {
+			foreach ( $loads as $server => $load ) {
+				$reindexed[$server][$group] = $load;
+			}
+		}
+
+		return $reindexed;
+	}
+
+	/**
+	 * Get the database name and prefix based on the wiki ID
+	 * @param bool|string $wiki
+	 * @return array
+	 */
+	function getDBNameAndPrefix( $wiki = false ) {
+		if ( $wiki === false ) {
+			global $wgDBname, $wgDBprefix;
+
+			return array( $wgDBname, $wgDBprefix );
+		} else {
+			return wfSplitWikiID( $wiki );
+		}
+	}
+
+	/**
+	 * 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.
+	 * @param callable $callback
+	 * @param array $params
+	 */
+	function forEachLB( $callback, $params = array() ) {
+		foreach ( $this->mainLBs as $lb ) {
+			call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
+		}
+		foreach ( $this->extLBs as $lb ) {
+			call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
+		}
+	}
+
+	function shutdown() {
+		foreach ( $this->mainLBs as $lb ) {
+			$this->chronProt->shutdownLB( $lb );
+		}
+		foreach ( $this->extLBs as $extLB ) {
+			$this->chronProt->shutdownLB( $extLB );
+		}
+		$this->chronProt->shutdown();
+		$this->commitMasterChanges();
+	}
+}