+<?php
+
+use Wikimedia\Rdbms\IDatabase;
+
+require_once __DIR__ . '/Maintenance.php';
+
+/**
+ * Maintenance script that cleans up archive rows with duplicated ar_rev_id,
+ * both within archive and between archive and revision.
+ *
+ * @ingroup Maintenance
+ * @since 1.32
+ */
+class DeduplicateArchiveRevId extends LoggedUpdateMaintenance {
+
+ /** @var array|null */
+ private $arActorQuery = null;
+
+ private $deleted = 0;
+ private $reassigned = 0;
+
+ public function __construct() {
+ parent::__construct();
+ $this->addDescription(
+ 'Clean up duplicate ar_rev_id, both within archive and between archive and revision.'
+ );
+ $this->setBatchSize( 10000 );
+ }
+
+ protected function getUpdateKey() {
+ return __CLASS__;
+ }
+
+ protected function doDBUpdates() {
+ $this->output( "Deduplicating ar_rev_id...\n" );
+
+ $dbw = $this->getDB( DB_MASTER );
+
+ $minId = $dbw->selectField( 'archive', 'MIN(ar_rev_id)', [], __METHOD__ );
+ $maxId = $dbw->selectField( 'archive', 'MAX(ar_rev_id)', [], __METHOD__ );
+ $batchSize = $this->getBatchSize();
+
+ $this->arActorQuery = ActorMigration::newMigration()->getJoin( 'ar_user' );
+ $revActorQuery = ActorMigration::newMigration()->getJoin( 'rev_user' );
+
+ for ( $id = $minId; $id <= $maxId; $id += $batchSize ) {
+ $endId = min( $maxId, $id + $batchSize - 1 );
+
+ $this->beginTransaction( $dbw, __METHOD__ );
+
+ // Lock the archive and revision table rows for the IDs we're checking
+ // to try to prevent deletions or undeletions from confusing things.
+ $dbw->selectRowCount(
+ 'archive',
+ 1,
+ [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
+ __METHOD__,
+ [ 'FOR UPDATE' ]
+ );
+ $dbw->selectRowCount(
+ 'revision',
+ 1,
+ [ 'rev_id >= ' . (int)$id, 'rev_id <= ' . (int)$endId ],
+ __METHOD__,
+ [ 'LOCK IN SHARE MODE' ]
+ );
+
+ // Figure out the ar_rev_ids we actually need to look at
+ $res = $dbw->select(
+ [ 'archive', 'revision' ] + $revActorQuery['tables'],
+ [ 'rev_id', 'rev_timestamp', 'rev_sha1' ] + $revActorQuery['fields'],
+ [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
+ __METHOD__,
+ [ 'DISTINCT' ],
+ [ 'revision' => [ 'JOIN', 'ar_rev_id = rev_id' ] ] + $revActorQuery['joins']
+ );
+ $revRows = [];
+ foreach ( $res as $row ) {
+ $revRows[$row->rev_id] = $row;
+ }
+
+ $arRevIds = $dbw->selectFieldValues(
+ [ 'archive' ],
+ 'ar_rev_id',
+ [ 'ar_rev_id >= ' . (int)$id, 'ar_rev_id <= ' . (int)$endId ],
+ __METHOD__,
+ [ 'GROUP BY' => 'ar_rev_id', 'HAVING' => 'COUNT(*) > 1' ]
+ );
+ $arRevIds = array_values( array_unique( array_merge( $arRevIds, array_keys( $revRows ) ) ) );
+
+ if ( $arRevIds ) {
+ $this->processArRevIds( $dbw, $arRevIds, $revRows );
+ }
+
+ $this->output( "... $id-$endId\n" );
+ $this->commitTransaction( $dbw, __METHOD__ );
+ }
+
+ $this->output(
+ "Finished deduplicating ar_rev_id. $this->deleted rows deleted, "
+ . "$this->reassigned assigned new IDs.\n"
+ );
+ return true;
+ }
+
+ /**
+ * Process a set of ar_rev_ids
+ * @param IDatabase $dbw
+ * @param int[] $arRevIds IDs to process
+ * @param object[] $revRows Existing revision-table row data
+ */
+ private function processArRevIds( IDatabase $dbw, array $arRevIds, array $revRows ) {
+ // Select all the data we need for deduplication
+ $res = $dbw->select(
+ [ 'archive' ] + $this->arActorQuery['tables'],
+ [ 'ar_id', 'ar_rev_id', 'ar_namespace', 'ar_title', 'ar_timestamp', 'ar_sha1' ]
+ + $this->arActorQuery['fields'],
+ [ 'ar_rev_id' => $arRevIds ],
+ __METHOD__,
+ [],
+ $this->arActorQuery['joins']
+ );
+
+ // Determine which rows we need to delete or reassign
+ $seen = [];
+ $toDelete = [];
+ $toReassign = [];
+ foreach ( $res as $row ) {
+ // Revision-table row exists?
+ if ( isset( $revRows[$row->ar_rev_id] ) ) {
+ $revRow = $revRows[$row->ar_rev_id];
+
+ // Record the rev_id as seen, so the code below will always delete or reassign.
+ if ( !isset( $seen[$revRow->rev_id] ) ) {
+ $seen[$revRow->rev_id] = [
+ 'first' => "revision row",
+ ];
+ }
+
+ // Delete the archive row if it seems to be the same regardless
+ // of page, because moves can change IDs and titles.
+ if ( $row->ar_timestamp === $revRow->rev_timestamp &&
+ $row->ar_sha1 === $revRow->rev_sha1 &&
+ $row->ar_user === $revRow->rev_user &&
+ $row->ar_user_text === $revRow->rev_user_text
+ ) {
+ $this->output(
+ "Row $row->ar_id duplicates revision row for rev_id $revRow->rev_id, deleting\n"
+ );
+ $toDelete[] = $row->ar_id;
+ continue;
+ }
+ }
+
+ $key = $this->getSeenKey( $row );
+ if ( !isset( $seen[$row->ar_rev_id] ) ) {
+ // This rev_id hasn't even been seen yet, nothing to do besides record it.
+ $seen[$row->ar_rev_id] = [
+ 'first' => "archive row $row->ar_id",
+ $key => $row->ar_id,
+ ];
+ } elseif ( !isset( $seen[$row->ar_rev_id][$key] ) ) {
+ // The rev_id was seen, but not this particular change. Reassign it.
+ $seen[$row->ar_rev_id][$key] = $row->ar_id;
+ $this->output(
+ "Row $row->ar_id conflicts with {$seen[$row->ar_rev_id]['first']} "
+ . "for rev_id $row->ar_rev_id, reassigning\n"
+ );
+ $toReassign[] = $row->ar_id;
+ } else {
+ // The rev_id was seen with a row that matches this change. Delete it.
+ $this->output(
+ "Row $row->ar_id duplicates archive row {$seen[$row->ar_rev_id][$key]} "
+ . "for rev_id $row->ar_rev_id, deleting\n"
+ );
+ $toDelete[] = $row->ar_id;
+ }
+ }
+
+ // Perform the updates
+ if ( $toDelete ) {
+ $dbw->delete( 'archive', [ 'ar_id' => $toDelete ], __METHOD__ );
+ $this->deleted += $dbw->affectedRows();
+ }
+ if ( $toReassign ) {
+ $this->reassigned += PopulateArchiveRevId::reassignArRevIds( $dbw, $toReassign );
+ }
+ }
+
+ /**
+ * Make a key identifying a "unique" change from a row
+ * @param object $row
+ * @return string
+ */
+ private function getSeenKey( $row ) {
+ return implode( "\n", [
+ $row->ar_namespace,
+ $row->ar_title,
+ $row->ar_timestamp,
+ $row->ar_sha1,
+ $row->ar_user,
+ $row->ar_user_text,
+ ] );
+ }
+
+}
+
+$maintClass = "DeduplicateArchiveRevId";
+require_once RUN_MAINTENANCE_IF_MAIN;