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   1  <?php
   2  /**
   3   * Job to update links for a given title.
   4   *
   5   * This program is free software; you can redistribute it and/or modify
   6   * it under the terms of the GNU General Public License as published by
   7   * the Free Software Foundation; either version 2 of the License, or
   8   * (at your option) any later version.
   9   *
  10   * This program is distributed in the hope that it will be useful,
  11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13   * GNU General Public License for more details.
  14   *
  15   * You should have received a copy of the GNU General Public License along
  16   * with this program; if not, write to the Free Software Foundation, Inc.,
  17   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18   * http://www.gnu.org/copyleft/gpl.html
  19   *
  20   * @file
  21   * @ingroup JobQueue
  22   */
  23  
  24  /**
  25   * Background job to update links for titles in certain backlink range by page ID.
  26   * Newer version for high use templates. This is deprecated by RefreshLinksPartitionJob.
  27   *
  28   * @ingroup JobQueue
  29   * @deprecated since 1.23
  30   */
  31  class RefreshLinksJob2 extends Job {
  32  	function __construct( $title, $params ) {
  33          parent::__construct( 'refreshLinks2', $title, $params );
  34          // Base jobs for large templates can easily be de-duplicated
  35          $this->removeDuplicates = !isset( $params['start'] ) && !isset( $params['end'] );
  36      }
  37  
  38      /**
  39       * Run a refreshLinks2 job
  40       * @return bool Success
  41       */
  42  	function run() {
  43          global $wgUpdateRowsPerJob;
  44  
  45          $linkCache = LinkCache::singleton();
  46          $linkCache->clear();
  47  
  48          if ( is_null( $this->title ) ) {
  49              $this->error = "refreshLinks2: Invalid title";
  50              return false;
  51          }
  52  
  53          // Back compat for pre-r94435 jobs
  54          $table = isset( $this->params['table'] ) ? $this->params['table'] : 'templatelinks';
  55  
  56          // Avoid slave lag when fetching templates.
  57          // When the outermost job is run, we know that the caller that enqueued it must have
  58          // committed the relevant changes to the DB by now. At that point, record the master
  59          // position and pass it along as the job recursively breaks into smaller range jobs.
  60          // Hopefully, when leaf jobs are popped, the slaves will have reached that position.
  61          if ( isset( $this->params['masterPos'] ) ) {
  62              $masterPos = $this->params['masterPos'];
  63          } elseif ( wfGetLB()->getServerCount() > 1 ) {
  64              $masterPos = wfGetLB()->getMasterPos();
  65          } else {
  66              $masterPos = false;
  67          }
  68  
  69          $tbc = $this->title->getBacklinkCache();
  70  
  71          $jobs = array(); // jobs to insert
  72          if ( isset( $this->params['start'] ) && isset( $this->params['end'] ) ) {
  73              # This is a partition job to trigger the insertion of leaf jobs...
  74              $jobs = array_merge( $jobs, $this->getSingleTitleJobs( $table, $masterPos ) );
  75          } else {
  76              # This is a base job to trigger the insertion of partitioned jobs...
  77              if ( $tbc->getNumLinks( $table, $wgUpdateRowsPerJob + 1 ) <= $wgUpdateRowsPerJob ) {
  78                  # Just directly insert the single per-title jobs
  79                  $jobs = array_merge( $jobs, $this->getSingleTitleJobs( $table, $masterPos ) );
  80              } else {
  81                  # Insert the partition jobs to make per-title jobs
  82                  foreach ( $tbc->partition( $table, $wgUpdateRowsPerJob ) as $batch ) {
  83                      list( $start, $end ) = $batch;
  84                      $jobs[] = new RefreshLinksJob2( $this->title,
  85                          array(
  86                              'table' => $table,
  87                              'start' => $start,
  88                              'end' => $end,
  89                              'masterPos' => $masterPos,
  90                          ) + $this->getRootJobParams() // carry over information for de-duplication
  91                      );
  92                  }
  93              }
  94          }
  95  
  96          if ( count( $jobs ) ) {
  97              JobQueueGroup::singleton()->push( $jobs );
  98          }
  99  
 100          return true;
 101      }
 102  
 103      /**
 104       * @param string $table
 105       * @param mixed $masterPos
 106       * @return array
 107       */
 108  	protected function getSingleTitleJobs( $table, $masterPos ) {
 109          # The "start"/"end" fields are not set for the base jobs
 110          $start = isset( $this->params['start'] ) ? $this->params['start'] : false;
 111          $end = isset( $this->params['end'] ) ? $this->params['end'] : false;
 112          $titles = $this->title->getBacklinkCache()->getLinks( $table, $start, $end );
 113          # Convert into single page refresh links jobs.
 114          # This handles well when in sapi mode and is useful in any case for job
 115          # de-duplication. If many pages use template A, and that template itself
 116          # uses template B, then an edit to both will create many duplicate jobs.
 117          # Roughly speaking, for each page, one of the "RefreshLinksJob" jobs will
 118          # get run first, and when it does, it will remove the duplicates. Of course,
 119          # one page could have its job popped when the other page's job is still
 120          # buried within the logic of a refreshLinks2 job.
 121          $jobs = array();
 122          foreach ( $titles as $title ) {
 123              $jobs[] = new RefreshLinksJob( $title,
 124                  array( 'masterPos' => $masterPos ) + $this->getRootJobParams()
 125              ); // carry over information for de-duplication
 126          }
 127          return $jobs;
 128      }
 129  
 130      /**
 131       * @return array
 132       */
 133  	public function getDeduplicationInfo() {
 134          $info = parent::getDeduplicationInfo();
 135          // Don't let highly unique "masterPos" values ruin duplicate detection
 136          if ( is_array( $info['params'] ) ) {
 137              unset( $info['params']['masterPos'] );
 138          }
 139          return $info;
 140      }
 141  }