includes/DoubleRedirectJob.php

   1 <?php
   2
   3 class DoubleRedirectJob extends Job {
   4         var $reason, $redirTitle, $destTitleText;
   5         static $user;
   6
   7         /**
   8          * Insert jobs into the job queue to fix redirects to the given title
   9          * @param string $type The reason for the fix, see message double-redirect-fixed-<reason>
  10          * @param Title $redirTitle The title which has changed, redirects pointing to this title are fixed
  11          */
  12         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  13                 # Need to use the master to get the redirect table updated in the same transaction
  14                 $dbw = wfGetDB( DB_MASTER );
  15                 $res = $dbw->select(
  16                         array( 'redirect', 'page' ),
  17                         array( 'page_namespace', 'page_title' ),
  18                         array(
  19                                 'page_id = rd_from',
  20                                 'rd_namespace' => $redirTitle->getNamespace(),
  21                                 'rd_title' => $redirTitle->getDBkey()
  22                         ), __METHOD__ );
  23                 if ( !$res->numRows() ) {
  24                         return;
  25                 }
  26                 $jobs = array();
  27                 foreach ( $res as $row ) {
  28                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  29                         if ( !$title ) {
  30                                 continue;
  31                         }
  32
  33                         $jobs[] = new self( $title, array(
  34                                 'reason' => $reason,
  35                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  36                         # Avoid excessive memory usage
  37                         if ( count( $jobs ) > 10000 ) {
  38                                 Job::batchInsert( $jobs );
  39                                 $jobs = array();
  40                         }
  41                 }
  42                 Job::batchInsert( $jobs );
  43         }
  44         function __construct( $title, $params = false, $id = 0 ) {
  45                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  46                 $this->reason = $params['reason'];
  47                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  48                 $this->destTitleText = !empty( $params['destTitle'] ) ? $params['destTitle'] : '';
  49         }
  50
  51         function run() {
  52                 if ( !$this->redirTitle ) {
  53                         $this->setLastError( 'Invalid title' );
  54                         return false;
  55                 }
  56
  57                 $targetRev = Revision::newFromTitle( $this->title );
  58                 if ( !$targetRev ) {
  59                         wfDebug( __METHOD__.": target redirect already deleted, ignoring\n" );
  60                         return true;
  61                 }
  62                 $text = $targetRev->getText();
  63                 $currentDest = Title::newFromRedirect( $text );
  64                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
  65                         wfDebug( __METHOD__.": Redirect has changed since the job was queued\n" );
  66                         return true;
  67                 }
  68
  69                 # Find the current final destination
  70                 $newTitle = self::getFinalDestination( $this->redirTitle );
  71                 if ( !$newTitle ) {
  72                         wfDebug( __METHOD__.": skipping: single redirect, circular redirect or invalid redirect destination\n" );
  73                         return true;
  74                 }
  75                 if ( $newTitle->equals( $this->redirTitle ) ) {
  76                         # The redirect is already right, no need to change it
  77                         # This can happen if the page was moved back (say after vandalism)
  78                         wfDebug( __METHOD__.": skipping, already good\n" );
  79                 }
  80
  81                 # Preserve fragment (bug 14904)
  82                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
  83                         $currentDest->getFragment() );
  84
  85                 # Fix the text
  86                 # Remember that redirect pages can have categories, templates, etc.,
  87                 # so the regex has to be fairly general
  88                 $newText = preg_replace( '/ \[ \[  [^\]]*  \] \] /x',
  89                         '[[' . $newTitle->getFullText() . ']]',
  90                         $text, 1 );
  91
  92                 if ( $newText === $text ) {
  93                         $this->setLastError( 'Text unchanged???' );
  94                         return false;
  95                 }
  96
  97                 # Save it
  98                 global $wgUser;
  99                 $oldUser = $wgUser;
 100                 $wgUser = $this->getUser();
 101                 $article = new Article( $this->title );
 102                 $reason = wfMsgForContent( 'double-redirect-fixed-' . $this->reason,
 103                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText() );
 104                 $article->doEdit( $newText, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC );
 105                 $wgUser = $oldUser;
 106
 107                 return true;
 108         }
 109
 110         /**
 111          * Get the final destination of a redirect
 112          * Returns false if the specified title is not a redirect, or if it is a circular redirect
 113          */
 114         public static function getFinalDestination( $title ) {
 115                 $dbw = wfGetDB( DB_MASTER );
 116
 117                 $seenTitles = array(); # Circular redirect check
 118                 $dest = false;
 119
 120                 while ( true ) {
 121                         $titleText = $title->getPrefixedDBkey();
 122                         if ( isset( $seenTitles[$titleText] ) ) {
 123                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 124                                 return false;
 125                         }
 126                         $seenTitles[$titleText] = true;
 127
 128                         $row = $dbw->selectRow(
 129                                 array( 'redirect', 'page' ),
 130                                 array( 'rd_namespace', 'rd_title' ),
 131                                 array(
 132                                         'rd_from=page_id',
 133                                         'page_namespace' => $title->getNamespace(),
 134                                         'page_title' => $title->getDBkey()
 135                                 ), __METHOD__ );
 136                         if ( !$row ) {
 137                                 # No redirect from here, chain terminates
 138                                 break;
 139                         } else {
 140                                 $dest = $title = Title::makeTitle( $row->rd_namespace, $row->rd_title );
 141                         }
 142                 }
 143                 return $dest;
 144         }
 145
 146         /**
 147          * Get a user object for doing edits, from a request-lifetime cache
 148          */
 149         function getUser() {
 150                 if ( !self::$user ) {
 151                         self::$user = User::newFromName( wfMsgForContent( 'double-redirect-fixer' ), false );
 152                         if ( !self::$user->isLoggedIn() ) {
 153                                 self::$user->addToDatabase();
 154                         }
 155                 }
 156                 return self::$user;
 157         }
 158 }
 159