1<?php
2/**
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16 * http://www.gnu.org/copyleft/gpl.html
17 *
18 * @file
19 */
20
21namespace MediaWiki\Logger;
22
23use Wikimedia\ObjectFactory;
24
25/**
26 * PSR-3 logger instance factory.
27 *
28 * Creation of \Psr\Log\LoggerInterface instances is managed via the
29 * LoggerFactory::getInstance() static method which in turn delegates to the
30 * currently registered service provider.
31 *
32 * A service provider is any class implementing the Spi interface.
33 * There are two possible methods of registering a service provider. The
34 * LoggerFactory::registerProvider() static method can be called at any time
35 * to change the service provider. If LoggerFactory::getInstance() is called
36 * before any service provider has been registered, it will attempt to use the
37 * $wgMWLoggerDefaultSpi global to bootstrap Spi registration.
38 * $wgMWLoggerDefaultSpi is expected to be an array usable by
39 * ObjectFactory::getObjectFromSpec() to create a class.
40 *
41 * @see \MediaWiki\Logger\Spi
42 * @since 1.25
43 * @copyright © 2014 Wikimedia Foundation and contributors
44 */
45class LoggerFactory {
46
47	/**
48	 * Service provider.
49	 * @var \MediaWiki\Logger\Spi $spi
50	 */
51	private static $spi;
52
53	/**
54	 * Register a service provider to create new \Psr\Log\LoggerInterface
55	 * instances.
56	 *
57	 * @param \MediaWiki\Logger\Spi $provider Provider to register
58	 */
59	public static function registerProvider( Spi $provider ) {
60		self::$spi = $provider;
61	}
62
63	/**
64	 * Get the registered service provider.
65	 *
66	 * If called before any service provider has been registered, it will
67	 * attempt to use the $wgMWLoggerDefaultSpi global to bootstrap
68	 * Spi registration. $wgMWLoggerDefaultSpi is expected to be an
69	 * array usable by ObjectFactory::getObjectFromSpec() to create a class.
70	 *
71	 * @return \MediaWiki\Logger\Spi
72	 * @see registerProvider()
73	 * @see ObjectFactory::getObjectFromSpec()
74	 */
75	public static function getProvider() {
76		if ( self::$spi === null ) {
77			global $wgMWLoggerDefaultSpi;
78			$provider = ObjectFactory::getObjectFromSpec(
79				$wgMWLoggerDefaultSpi
80			);
81			self::registerProvider( $provider );
82		}
83		return self::$spi;
84	}
85
86	/**
87	 * Get a named logger instance from the currently configured logger factory.
88	 *
89	 * @param string $channel Logger channel (name)
90	 * @return \Psr\Log\LoggerInterface
91	 */
92	public static function getInstance( $channel ) {
93		return self::getProvider()->getLogger( $channel );
94	}
95
96	/**
97	 * Construction of utility class is not allowed.
98	 */
99	private function __construct() {
100		// no-op
101	}
102}
103