includes/job/DoubleRedirectJob.php

   1 <?php
   2 /**
   3  * Job to fix double redirects after moving a page
   4  *
   5  * @file
   6  * @ingroup JobQueue
   7  */
   8
   9 /**
  10  * Job to fix double redirects after moving a page
  11  *
  12  * @ingroup JobQueue
  13  */
  14 class DoubleRedirectJob extends Job {
  15         var $reason, $redirTitle, $destTitleText;
  16         static $user;
  17
  18         /**
  19          * Insert jobs into the job queue to fix redirects to the given title
  20          * @param $reason String: the reason for the fix, see message double-redirect-fixed-<reason>
  21          * @param $redirTitle Title: the title which has changed, redirects pointing to this title are fixed
  22          * @param $destTitle Not used
  23          */
  24         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  25                 # Need to use the master to get the redirect table updated in the same transaction
  26                 $dbw = wfGetDB( DB_MASTER );
  27                 $res = $dbw->select(
  28                         array( 'redirect', 'page' ),
  29                         array( 'page_namespace', 'page_title' ),
  30                         array(
  31                                 'page_id = rd_from',
  32                                 'rd_namespace' => $redirTitle->getNamespace(),
  33                                 'rd_title' => $redirTitle->getDBkey()
  34                         ), __METHOD__ );
  35                 if ( !$res->numRows() ) {
  36                         return;
  37                 }
  38                 $jobs = array();
  39                 foreach ( $res as $row ) {
  40                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  41                         if ( !$title ) {
  42                                 continue;
  43                         }
  44
  45                         $jobs[] = new self( $title, array(
  46                                 'reason' => $reason,
  47                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  48                         # Avoid excessive memory usage
  49                         if ( count( $jobs ) > 10000 ) {
  50                                 Job::batchInsert( $jobs );
  51                                 $jobs = array();
  52                         }
  53                 }
  54                 Job::batchInsert( $jobs );
  55         }
  56         function __construct( $title, $params = false, $id = 0 ) {
  57                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  58                 $this->reason = $params['reason'];
  59                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  60                 $this->destTitleText = !empty( $params['destTitle'] ) ? $params['destTitle'] : '';
  61         }
  62
  63         function run() {
  64                 if ( !$this->redirTitle ) {
  65                         $this->setLastError( 'Invalid title' );
  66                         return false;
  67                 }
  68
  69                 $targetRev = Revision::newFromTitle( $this->title );
  70                 if ( !$targetRev ) {
  71                         wfDebug( __METHOD__.": target redirect already deleted, ignoring\n" );
  72                         return true;
  73                 }
  74                 $text = $targetRev->getText();
  75                 $currentDest = Title::newFromRedirect( $text );
  76                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
  77                         wfDebug( __METHOD__.": Redirect has changed since the job was queued\n" );
  78                         return true;
  79                 }
  80
  81                 # Check for a suppression tag (used e.g. in periodically archived discussions)
  82                 $mw = MagicWord::get( 'staticredirect' );
  83                 if ( $mw->match( $text ) ) {
  84                         wfDebug( __METHOD__.": skipping: suppressed with __STATICREDIRECT__\n" );
  85                         return true;
  86                 }
  87
  88                 # Find the current final destination
  89                 $newTitle = self::getFinalDestination( $this->redirTitle );
  90                 if ( !$newTitle ) {
  91                         wfDebug( __METHOD__.": skipping: single redirect, circular redirect or invalid redirect destination\n" );
  92                         return true;
  93                 }
  94                 if ( $newTitle->equals( $this->redirTitle ) ) {
  95                         # The redirect is already right, no need to change it
  96                         # This can happen if the page was moved back (say after vandalism)
  97                         wfDebug( __METHOD__.": skipping, already good\n" );
  98                 }
  99
 100                 # Preserve fragment (bug 14904)
 101                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 102                         $currentDest->getFragment() );
 103
 104                 # Fix the text
 105                 # Remember that redirect pages can have categories, templates, etc.,
 106                 # so the regex has to be fairly general
 107                 $newText = preg_replace( '/ \[ \[  [^\]]*  \] \] /x',
 108                         '[[' . $newTitle->getFullText() . ']]',
 109                         $text, 1 );
 110
 111                 if ( $newText === $text ) {
 112                         $this->setLastError( 'Text unchanged???' );
 113                         return false;
 114                 }
 115
 116                 # Save it
 117                 global $wgUser;
 118                 $oldUser = $wgUser;
 119                 $wgUser = $this->getUser();
 120                 $article = new Article( $this->title );
 121                 $reason = wfMsgForContent( 'double-redirect-fixed-' . $this->reason,
 122                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText() );
 123                 $article->doEdit( $newText, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC );
 124                 $wgUser = $oldUser;
 125
 126                 return true;
 127         }
 128
 129         /**
 130          * Get the final destination of a redirect
 131          * @return false if the specified title is not a redirect, or if it is a circular redirect
 132          */
 133         public static function getFinalDestination( $title ) {
 134                 $dbw = wfGetDB( DB_MASTER );
 135
 136                 $seenTitles = array(); # Circular redirect check
 137                 $dest = false;
 138
 139                 while ( true ) {
 140                         $titleText = $title->getPrefixedDBkey();
 141                         if ( isset( $seenTitles[$titleText] ) ) {
 142                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 143                                 return false;
 144                         }
 145                         $seenTitles[$titleText] = true;
 146
 147                         $row = $dbw->selectRow(
 148                                 array( 'redirect', 'page' ),
 149                                 array( 'rd_namespace', 'rd_title' ),
 150                                 array(
 151                                         'rd_from=page_id',
 152                                         'page_namespace' => $title->getNamespace(),
 153                                         'page_title' => $title->getDBkey()
 154                                 ), __METHOD__ );
 155                         if ( !$row ) {
 156                                 # No redirect from here, chain terminates
 157                                 break;
 158                         } else {
 159                                 $dest = $title = Title::makeTitle( $row->rd_namespace, $row->rd_title );
 160                         }
 161                 }
 162                 return $dest;
 163         }
 164
 165         /**
 166          * Get a user object for doing edits, from a request-lifetime cache
 167          */
 168         function getUser() {
 169                 if ( !self::$user ) {
 170                         self::$user = User::newFromName( wfMsgForContent( 'double-redirect-fixer' ), false );
 171                         if ( !self::$user->isLoggedIn() ) {
 172                                 self::$user->addToDatabase();
 173                         }
 174                 }
 175                 return self::$user;
 176         }
 177 }
 178