2 files changed, 117 insertions, 1 deletions
diff --git a/lib/private/repair.php b/lib/private/repair.php
index c4f057b53ae..d9fd99707e8 100644
--- a/lib/private/repair.php
+++ b/lib/private/repair.php
@@ -11,6 +11,7 @@ namespace OC;
 use OC\Hooks\BasicEmitter;
 use OC\Hooks\Emitter;
 use OC\Repair\AssetCache;
+use OC\Repair\CleanTags;
 use OC\Repair\Collation;
 use OC\Repair\FillETags;
 use OC\Repair\InnoDB;
@@ -81,7 +82,8 @@ class Repair extends BasicEmitter {
 			new RepairLegacyStorages(\OC::$server->getConfig(), \OC_DB::getConnection()),
 			new RepairConfig(),
 			new AssetCache(),
-			new FillETags(\OC_DB::getConnection())
+			new FillETags(\OC_DB::getConnection()),
+			new CleanTags(\OC_DB::getConnection()),
 		);
 	}
 
diff --git a/lib/repair/cleantags.php b/lib/repair/cleantags.php
new file mode 100644
index 00000000000..6aa325df0b6
--- /dev/null
+++ b/lib/repair/cleantags.php
@@ -0,0 +1,114 @@
+<?php
+/**
+ * Copyright (c) 2015 Joas Schilling <nickvergessen@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Repair;
+
+use OC\DB\Connection;
+use OC\Hooks\BasicEmitter;
+use OC\RepairStep;
+
+/**
+ * Class RepairConfig
+ *
+ * @package OC\Repair
+ */
+class CleanTags extends BasicEmitter implements RepairStep {
+
+	/** @var Connection */
+	protected $connection;
+
+	/**
+	 * @param Connection $connection
+	 */
+	public function __construct(Connection $connection) {
+		$this->connection = $connection;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getName() {
+		return 'Clean tags and favorites';
+	}
+
+	/**
+	 * Updates the configuration after running an update
+	 */
+	public function run() {
+
+		// Delete tag entries for deleted files
+		$this->deleteOrphanEntries(
+			'%d tags for delete files have been removed.',
+			'*PREFIX*vcategory_to_object', 'objid',
+			'*PREFIX*filecache', 'fileid', 'fileid'
+		);
+
+		// Delete tag entries for deleted tags
+		$this->deleteOrphanEntries(
+			'%d tag entries for deleted tags have been removed.',
+			'*PREFIX*vcategory_to_object', 'categoryid',
+			'*PREFIX*vcategory', 'id', 'uid'
+		);
+
+		// Delete tags that have no entries
+		$this->deleteOrphanEntries(
+			'%d tags with no entries have been removed.',
+			'*PREFIX*vcategory', 'id',
+			'*PREFIX*vcategory_to_object', 'categoryid', 'type'
+		);
+	}
+
+	/**
+	 * Deletes all entries from $deleteTable that do not have a matching entry in $sourceTable
+	 *
+	 * A query joins $deleteTable.$deleteId = $sourceTable.$sourceId and checks
+	 * whether $sourceNullColumn is null. If it is null, the entry in $deleteTable
+	 * is being deleted.
+	 *
+	 * @param string $repairInfo
+	 * @param string $deleteTable
+	 * @param string $deleteId
+	 * @param string $sourceTable
+	 * @param string $sourceId
+	 * @param string $sourceNullColumn	If this column is null in the source table,
+	 * 								the entry is deleted in the $deleteTable
+	 */
+	protected function deleteOrphanEntries($repairInfo, $deleteTable, $deleteId, $sourceTable, $sourceId, $sourceNullColumn) {
+		$qb = $this->connection->createQueryBuilder();
+
+		$qb->select('d.' . $deleteId)
+			->from($deleteTable, 'd')
+			->leftJoin('d', $sourceTable, 's', 'd.' . $deleteId . ' = s.' . $sourceId)
+			->where(
+				'd.type = ' . $qb->expr()->literal('files')
+			)
+			->andWhere(
+				$qb->expr()->isNull('s.' . $sourceNullColumn)
+			);
+		$result = $qb->execute();
+
+		$orphanItems = array();
+		while ($row = $result->fetch()) {
+			$orphanItems[] = (int) $row[$deleteId];
+		}
+
+		if (!empty($orphanItems)) {
+			$orphanItemsBatch = array_chunk($orphanItems, 200);
+			foreach ($orphanItemsBatch as $items) {
+				$qb->delete($deleteTable)
+					->where($qb->expr()->in($deleteId, ':ids'));
+				$qb->setParameter('ids', $items, \Doctrine\DBAL\Connection::PARAM_INT_ARRAY);
+				$qb->execute();
+			}
+		}
+
+		if ($repairInfo) {
+			$this->emit('\OC\Repair', 'info', array(sprintf($repairInfo, sizeof($orphanItems))));
+		}
+	}
+}