includes/debug/logger/LoggerFactory.php

   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
  21 namespace MediaWiki\Logger;
  22
  23 use 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  * @author Bryan Davis <bd808@wikimedia.org>
  44  * @copyright © 2014 Bryan Davis and Wikimedia Foundation.
  45  */
  46 class LoggerFactory {
  47
  48         /**
  49          * Service provider.
  50          * @var \MediaWiki\Logger\Spi $spi
  51          */
  52         private static $spi;
  53
  54         /**
  55          * Register a service provider to create new \Psr\Log\LoggerInterface
  56          * instances.
  57          *
  58          * @param \MediaWiki\Logger\Spi $provider Provider to register
  59          */
  60         public static function registerProvider( Spi $provider ) {
  61                 self::$spi = $provider;
  62         }
  63
  64         /**
  65          * Get the registered service provider.
  66          *
  67          * If called before any service provider has been registered, it will
  68          * attempt to use the $wgMWLoggerDefaultSpi global to bootstrap
  69          * Spi registration. $wgMWLoggerDefaultSpi is expected to be an
  70          * array usable by ObjectFactory::getObjectFromSpec() to create a class.
  71          *
  72          * @return \MediaWiki\Logger\Spi
  73          * @see registerProvider()
  74          * @see ObjectFactory::getObjectFromSpec()
  75          */
  76         public static function getProvider() {
  77                 if ( self::$spi === null ) {
  78                         global $wgMWLoggerDefaultSpi;
  79                         $provider = ObjectFactory::getObjectFromSpec(
  80                                 $wgMWLoggerDefaultSpi
  81                         );
  82                         self::registerProvider( $provider );
  83                 }
  84                 return self::$spi;
  85         }
  86
  87         /**
  88          * Get a named logger instance from the currently configured logger factory.
  89          *
  90          * @param string $channel Logger channel (name)
  91          * @return \Psr\Log\LoggerInterface
  92          */
  93         public static function getInstance( $channel ) {
  94                 return self::getProvider()->getLogger( $channel );
  95         }
  96
  97         /**
  98          * Construction of utility class is not allowed.
  99          */
 100         private function __construct() {
 101                 // no-op
 102         }
 103 }