includes/installer/Update.php

   1 <?php
   2 /*
   3  * Class for handling database updates. Roughly based off of updaters.inc, with
   4  * a few improvements :)
   5  */
   6
   7 class Update {
   8
   9         // Array of updates to perform on the database
  10         protected $updates = array();
  11
  12         // Things we'll need
  13         protected $db, $updater;
  14
  15         public function __construct( $db ) {
  16                 $this->db = $db;
  17                 switch( $this->db->getType() ) {
  18                         case 'mysql':
  19                                 $this->updater = new MysqlUpdater();
  20                                 break;
  21                         case 'sqlite':
  22                                 $this->updater = new SqliteUpdater();
  23                                 break;
  24                         default:
  25                                 throw new MWException( __METHOD__ . ' called for unsupported $wgDBtype' );
  26                 }
  27         }
  28
  29         public function doUpdates() {
  30                 global $IP;
  31                 require_once( "$IP/maintenance/updaters.inc" );
  32                 $this->loadUpdates();
  33                 foreach ( $this->updates as $version => $updates ) {
  34                         foreach( $updates as $params ) {
  35                                 $func = array_shift( $params );
  36                                 call_user_func_array( $func, $params );
  37                                 flush();
  38                         }
  39                         $this->setAppliedUpdates( $version, $updates );
  40                 }
  41         }
  42
  43         protected function loadUpdates() {
  44                 // If the updatelog table hasn't been upgraded, we can't use the new
  45                 // style of recording our steps. Run all to be safe
  46                 if( !$this->canUseNewUpdatelog() ) {
  47                         $this->updates = $this->updater->getUpdates();
  48                         return;
  49                 }
  50                 foreach( $this->updater->getUpdates() as $version => $updates ) {
  51                         $appliedUpdates = $this->getAppliedUpdates( $version );
  52                         if( !$appliedUpdates || $appliedUpdates != $updates ) {
  53                                 $this->updates[ $version ] = $updates;
  54                         }
  55                 }
  56         }
  57
  58         protected function getAppliedUpdates( $version ) {
  59                 $key = "updatelist-$version";
  60                 $val = $this->db->selectField( 'updatelog', 'ul_value',
  61                         array( 'ul_key' => $key ), __METHOD__ );
  62                 if( !$val ) {
  63                         return null;
  64                 } else {
  65                         return unserialize( $val );
  66                 }
  67         }
  68
  69         private function setAppliedUpdates( $version, $updates = array() ) {
  70                 if( !$this->canUseNewUpdatelog() ) {
  71                         $this->updates = $this->updater->getUpdates();
  72                         return;
  73                 }
  74                 $key = "updatelist-$version";
  75                 $this->db->delete( 'updatelog', array( 'ul_key' => $key ), __METHOD__ );
  76                 $this->db->insert( 'updatelog',
  77                         array( 'ul_key' => $key, 'ul_value' => serialize( $updates ) ),
  78                          __METHOD__ );
  79         }
  80
  81         /**
  82          * Updatelog was changed in 1.17 to have a ul_value column so we can record
  83          * more information about what kind of updates we've done (that's what this
  84          * class does). Pre-1.17 wikis won't have this column, and really old wikis
  85          * might not even have updatelog at all
  86          *
  87          * @return boolean
  88          */
  89         protected function canUseNewUpdatelog() {
  90                 return $this->db->tableExists( 'updatelog' ) &&
  91                         $this->db->fieldExists( 'updatelog', 'ul_value' );
  92         }
  93 }