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LBFactorySimple::getAllMainLBs()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 3
Code Lines 2

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
dl 0
loc 3
c 0
b 0
f 0
cc 1
eloc 2
nc 1
nop 0
rs 10
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<?php
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/**
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 * Generator of database load balancing objects.
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License along
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 * with this program; if not, write to the Free Software Foundation, Inc.,
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 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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 * http://www.gnu.org/copyleft/gpl.html
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 *
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 * @file
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 * @ingroup Database
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 */
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/**
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 * A simple single-master LBFactory that gets its configuration from the b/c globals
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 */
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class LBFactorySimple extends LBFactory {
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	/** @var LoadBalancer */
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	private $mainLB;
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	/** @var LoadBalancer[] */
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	private $extLBs = [];
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	/** @var array[] Map of (server index => server config) */
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	private $servers = [];
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	/** @var array[] Map of (cluster => (server index => server config)) */
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	private $externalClusters = [];
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	/** @var string */
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	private $loadMonitorClass;
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	/**
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	 * @see LBFactory::__construct()
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	 * @param array $conf Parameters of LBFactory::__construct() as well as:
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	 *   - servers : list of server configuration maps to Database::factory().
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	 *      Additionally, the server maps should have a 'load' key, which is used to decide
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	 *      how often clients connect to one server verses the others. A 'max lag' key should
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	 *      also be set on server maps, indicating how stale the data can be before the load
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	 *      balancer tries to avoid using it. The map can have 'is static' set to disable blocking
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	 *      replication sync checks (intended for archive servers with unchanging data).
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	 *   - externalClusters : map of cluster names to server arrays. The servers arrays have the
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	 *      same format as "servers" above.
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	 */
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	public function __construct( array $conf ) {
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		parent::__construct( $conf );
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		$this->servers = isset( $conf['servers'] ) ? $conf['servers'] : [];
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		foreach ( $this->servers as $i => $server ) {
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			if ( $i == 0 ) {
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				$this->servers[$i]['master'] = true;
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			} else {
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				$this->servers[$i]['replica'] = true;
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			}
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		}
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		$this->externalClusters = isset( $conf['externalClusters'] )
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			? $conf['externalClusters']
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			: [];
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		$this->loadMonitorClass = isset( $conf['loadMonitorClass'] )
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			? $conf['loadMonitorClass']
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			: 'LoadMonitor';
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	}
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	/**
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	 * @param bool|string $domain
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	 * @return LoadBalancer
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	 */
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	public function newMainLB( $domain = false ) {
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		return $this->newLoadBalancer( $this->servers );
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	}
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	/**
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	 * @param bool|string $domain
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	 * @return LoadBalancer
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	 */
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	public function getMainLB( $domain = false ) {
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		if ( !isset( $this->mainLB ) ) {
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			$this->mainLB = $this->newMainLB( $domain );
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			$this->getChronologyProtector()->initLB( $this->mainLB );
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		}
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		return $this->mainLB;
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	}
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	public function newExternalLB( $cluster ) {
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		if ( !isset( $this->externalClusters[$cluster] ) ) {
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			throw new InvalidArgumentException( __METHOD__ . ": Unknown cluster \"$cluster\"." );
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		}
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		return $this->newLoadBalancer( $this->externalClusters[$cluster] );
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	}
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	public function getExternalLB( $cluster ) {
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		if ( !isset( $this->extLBs[$cluster] ) ) {
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			$this->extLBs[$cluster] = $this->newExternalLB( $cluster );
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			$this->getChronologyProtector()->initLB( $this->extLBs[$cluster] );
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		}
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		return $this->extLBs[$cluster];
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	}
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	public function getAllMainLBs() {
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		return [ 'DEFAULT' => $this->getMainLB() ];
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	}
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	public function getAllExternalLBs() {
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		$lbs = [];
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		foreach ( $this->externalClusters as $cluster => $unused ) {
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			$lbs[$cluster] = $this->getExternalLB( $cluster );
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		}
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		return $lbs;
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	}
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	private function newLoadBalancer( array $servers ) {
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		$lb = new LoadBalancer( array_merge(
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			$this->baseLoadBalancerParams(),
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			[
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				'servers' => $servers,
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				'loadMonitor' => [ 'class' => $this->loadMonitorClass ],
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			]
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		) );
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		$this->initLoadBalancer( $lb );
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		return $lb;
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	}
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	/**
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	 * Execute a function for each tracked load balancer
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	 * The callback is called with the load balancer as the first parameter,
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	 * and $params passed as the subsequent parameters.
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	 *
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	 * @param callable $callback
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	 * @param array $params
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	 */
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	public function forEachLB( $callback, array $params = [] ) {
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		if ( isset( $this->mainLB ) ) {
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			call_user_func_array( $callback, array_merge( [ $this->mainLB ], $params ) );
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		}
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		foreach ( $this->extLBs as $lb ) {
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			call_user_func_array( $callback, array_merge( [ $lb ], $params ) );
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		}
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	}
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}
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