maintenance/pruneUnusedLinkTargetRows.php

   1 <?php
   2
   3 // @codeCoverageIgnoreStart
   4 require_once __DIR__ . '/Maintenance.php';
   5 // @codeCoverageIgnoreEnd
   6
   7 /**
   8  * Maintenance script that cleans unused rows in linktarget table
   9  *
  10  * @ingroup Maintenance
  11  * @since 1.39
  12  */
  13 class PruneUnusedLinkTargetRows extends Maintenance {
  14         public function __construct() {
  15                 parent::__construct();
  16                 $this->addDescription(
  17                         'Clean unused rows in linktarget table'
  18                 );
  19                 $this->addOption(
  20                         'sleep',
  21                         'Sleep time (in seconds) between every batch. Default: 0',
  22                         false,
  23                         true
  24                 );
  25                 $this->addOption( 'dry', 'Dry run', false );
  26                 $this->addOption( 'start', 'Start after this lt_id', false, true );
  27                 $this->setBatchSize( 50 );
  28         }
  29
  30         public function execute() {
  31                 $dbw = $this->getPrimaryDB();
  32                 $dbr = $this->getReplicaDB();
  33                 $maxLtId = (int)$dbr->newSelectQueryBuilder()
  34                         ->select( 'MAX(lt_id)' )
  35                         ->from( 'linktarget' )
  36                         ->caller( __METHOD__ )
  37                         ->fetchField();
  38                 // To avoid race condition of newly added linktarget rows
  39                 // being deleted before getting a chance to be used, let's ignore the newest ones.
  40                 $maxLtId = min( [ $maxLtId - 1, (int)( $maxLtId * 0.99 ) ] );
  41
  42                 $ltCounter = (int)$this->getOption( 'start', 0 );
  43
  44                 $this->output( "Deleting unused linktarget rows...\n" );
  45                 $deleted = 0;
  46                 $linksMigration = $this->getServiceContainer()->getLinksMigration();
  47                 while ( $ltCounter < $maxLtId ) {
  48                         $batchMaxLtId = min( $ltCounter + $this->getBatchSize(), $maxLtId ) + 1;
  49                         $this->output( "Checking lt_id between $ltCounter and $batchMaxLtId...\n" );
  50                         $queryBuilder = $dbr->newSelectQueryBuilder()
  51                                 ->select( [ 'lt_id' ] )
  52                                 ->from( 'linktarget' );
  53                         $queryBuilder->where( [
  54                                 $dbr->expr( 'lt_id', '<', $batchMaxLtId ),
  55                                 $dbr->expr( 'lt_id', '>', $ltCounter )
  56                         ] );
  57                         foreach ( $linksMigration::$mapping as $table => $tableData ) {
  58                                 $queryBuilder->leftJoin( $table, null, $tableData['target_id'] . '=lt_id' );
  59                                 $queryBuilder->andWhere( [
  60                                         $tableData['target_id'] => null
  61                                 ] );
  62                         }
  63                         $ltIdsToDelete = $queryBuilder->caller( __METHOD__ )->fetchFieldValues();
  64                         if ( !$ltIdsToDelete ) {
  65                                 $ltCounter += $this->getBatchSize();
  66                                 continue;
  67                         }
  68
  69                         // Run against primary as well with a faster query plan, just to be safe.
  70                         // Also having a bit of time in between helps in cases of immediate removal and insertion of use.
  71                         $queryBuilder = $dbr->newSelectQueryBuilder()
  72                                 ->select( [ 'lt_id' ] )
  73                                 ->from( 'linktarget' )
  74                                 ->where( [
  75                                         'lt_id' => $ltIdsToDelete,
  76                                 ] );
  77                         foreach ( $linksMigration::$mapping as $table => $tableData ) {
  78                                 $queryBuilder->leftJoin( $table, null, $tableData['target_id'] . '=lt_id' );
  79                                 $queryBuilder->andWhere( [
  80                                         $tableData['target_id'] => null
  81                                 ] );
  82                         }
  83                         $ltIdsToDelete = $queryBuilder->caller( __METHOD__ )->fetchFieldValues();
  84                         if ( !$ltIdsToDelete ) {
  85                                 $ltCounter += $this->getBatchSize();
  86                                 continue;
  87                         }
  88
  89                         if ( !$this->getOption( 'dry' ) ) {
  90                                 $dbw->newDeleteQueryBuilder()
  91                                         ->deleteFrom( 'linktarget' )
  92                                         ->where( [ 'lt_id' => $ltIdsToDelete ] )
  93                                         ->caller( __METHOD__ )->execute();
  94                         }
  95                         $deleted += count( $ltIdsToDelete );
  96                         $ltCounter += $this->getBatchSize();
  97
  98                         // Sleep between batches for replication to catch up
  99                         $this->waitForReplication();
 100                         $sleep = (int)$this->getOption( 'sleep', 0 );
 101                         if ( $sleep > 0 ) {
 102                                 sleep( $sleep );
 103                         }
 104                 }
 105
 106                 $this->output(
 107                         "Completed clean up linktarget table, "
 108                         . "$deleted rows deleted.\n"
 109                 );
 110
 111                 return true;
 112         }
 113
 114 }
 115
 116 // @codeCoverageIgnoreStart
 117 $maintClass = PruneUnusedLinkTargetRows::class;
 118 require_once RUN_MAINTENANCE_IF_MAIN;
 119 // @codeCoverageIgnoreEnd