1<?php
2/**
3 * Simple generator of database connections that always returns the same object.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
19 *
20 * @file
21 * @ingroup Database
22 */
23
24namespace Wikimedia\Rdbms;
25
26use BadMethodCallException;
27use InvalidArgumentException;
28
29/**
30 * An LBFactory class that always returns a single database object.
31 */
32class LBFactorySingle extends LBFactory {
33	/** @var LoadBalancerSingle */
34	private $lb;
35
36	/**
37	 * @param array $conf An associative array with one member:
38	 *  - connection: The IDatabase connection object
39	 */
40	public function __construct( array $conf ) {
41		parent::__construct( $conf );
42
43		if ( !isset( $conf['connection'] ) ) {
44			throw new InvalidArgumentException( "Missing 'connection' argument." );
45		}
46
47		$lb = new LoadBalancerSingle( array_merge(
48			$this->baseLoadBalancerParams( $this->getOwnershipId() ),
49			$conf
50		) );
51		$this->initLoadBalancer( $lb );
52
53		$this->lb = $lb;
54	}
55
56	/**
57	 * @param IDatabase $db Live connection handle
58	 * @param array $params Parameter map to LBFactorySingle::__constructs()
59	 * @return LBFactorySingle
60	 * @since 1.28
61	 */
62	public static function newFromConnection( IDatabase $db, array $params = [] ) {
63		return new static( array_merge(
64			[ 'localDomain' => $db->getDomainID() ],
65			$params,
66			[ 'connection' => $db ]
67		) );
68	}
69
70	public function newMainLB( $domain = false, $owner = null ) {
71		throw new BadMethodCallException( "Method is not supported." );
72	}
73
74	public function getMainLB( $domain = false ) {
75		return $this->lb;
76	}
77
78	public function newExternalLB( $cluster, $owner = null ) {
79		throw new BadMethodCallException( "Method is not supported." );
80	}
81
82	public function getExternalLB( $cluster ) {
83		throw new BadMethodCallException( "Method is not supported." );
84	}
85
86	public function getAllMainLBs() {
87		return [ 'DEFAULT' => $this->lb ];
88	}
89
90	public function getAllExternalLBs() {
91		return [];
92	}
93
94	public function forEachLB( $callback, array $params = [] ) {
95		if ( isset( $this->lb ) ) { // may not be set during _destruct()
96			$callback( $this->lb, ...$params );
97		}
98	}
99}
100