includes/ReadOnlyMode.php

   1 <?php
   2
   3 use Wikimedia\Rdbms\LoadBalancer;
   4
   5 /**
   6  * A service class for fetching the wiki's current read-only mode.
   7  * To obtain an instance, use MediaWikiServices::getReadOnlyMode().
   8  *
   9  * @since 1.29
  10  */
  11 class ReadOnlyMode {
  12         /** @var ConfiguredReadOnlyMode */
  13         private $configuredReadOnly;
  14
  15         /** @var LoadBalancer */
  16         private $loadBalancer;
  17
  18         public function __construct( ConfiguredReadOnlyMode $cro, LoadBalancer $loadBalancer ) {
  19                 $this->configuredReadOnly = $cro;
  20                 $this->loadBalancer = $loadBalancer;
  21         }
  22
  23         /**
  24          * Check whether the wiki is in read-only mode.
  25          *
  26          * @return bool
  27          */
  28         public function isReadOnly() {
  29                 return $this->getReason() !== false;
  30         }
  31
  32         /**
  33          * Check if the site is in read-only mode and return the message if so
  34          *
  35          * This checks the configuration and registered DB load balancers for
  36          * read-only mode. This may result in DB connection being made.
  37          *
  38          * @return string|bool String when in read-only mode; false otherwise
  39          */
  40         public function getReason() {
  41                 $reason = $this->configuredReadOnly->getReason();
  42                 if ( $reason !== false ) {
  43                         return $reason;
  44                 }
  45                 $reason = $this->loadBalancer->getReadOnlyReason();
  46                 if ( $reason !== false && $reason !== null ) {
  47                         return $reason;
  48                 }
  49                 return false;
  50         }
  51
  52         /**
  53          * Set the read-only mode, which will apply for the remainder of the
  54          * request or until a service reset.
  55          *
  56          * @param string|null $msg
  57          */
  58         public function setReason( $msg ) {
  59                 $this->configuredReadOnly->setReason( $msg );
  60         }
  61
  62         /**
  63          * Clear the cache of the read only file
  64          */
  65         public function clearCache() {
  66                 $this->configuredReadOnly->clearCache();
  67         }
  68 }
  69
  70 /**
  71  * A read-only mode service which does not depend on LoadBalancer.
  72  * To obtain an instance, use MediaWikiServices::getConfiguredReadOnlyMode().
  73  *
  74  * @since 1.29
  75  */
  76 class ConfiguredReadOnlyMode {
  77         /** @var Config */
  78         private $config;
  79
  80         /** @var string|bool|null */
  81         private $fileReason;
  82
  83         /** @var string|null */
  84         private $overrideReason;
  85
  86         public function __construct( Config $config ) {
  87                 $this->config = $config;
  88         }
  89
  90         /**
  91          * Check whether the wiki is in read-only mode.
  92          *
  93          * @return bool
  94          */
  95         public function isReadOnly() {
  96                 return $this->getReason() !== false;
  97         }
  98
  99         /**
 100          * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
 101          *
 102          * @return string|bool String when in read-only mode; false otherwise
 103          */
 104         public function getReason() {
 105                 if ( $this->overrideReason !== null ) {
 106                         return $this->overrideReason;
 107                 }
 108                 $confReason = $this->config->get( 'ReadOnly' );
 109                 if ( $confReason !== null ) {
 110                         return $confReason;
 111                 }
 112                 if ( $this->fileReason === null ) {
 113                         // Cache for faster access next time
 114                         $readOnlyFile = $this->config->get( 'ReadOnlyFile' );
 115                         if ( is_file( $readOnlyFile ) && filesize( $readOnlyFile ) > 0 ) {
 116                                 $this->fileReason = file_get_contents( $readOnlyFile );
 117                         } else {
 118                                 $this->fileReason = false;
 119                         }
 120                 }
 121                 return $this->fileReason;
 122         }
 123
 124         /**
 125          * Set the read-only mode, which will apply for the remainder of the
 126          * request or until a service reset.
 127          *
 128          * @param string|null $msg
 129          */
 130         public function setReason( $msg ) {
 131                 $this->overrideReason = $msg;
 132         }
 133
 134         /**
 135          * Clear the cache of the read only file
 136          */
 137         public function clearCache() {
 138                 $this->fileReason = null;
 139         }
 140 }