/**
* Returns a range of entity IDs to delete, based on this updater's batch size.
*
* @param array &$continuation
*
* @return bool|string[] list( $minId, $maxId, $count ), or false if there is nothing to delete
*/
private function getDeletionRange(array &$continuation = null)
{
$dbr = $this->repoConnectionManager->getReadConnection();
$conditions = array('cs_subscriber_id' => $this->subscriberWikiId);
if (!empty($continuation)) {
list($fromEntityId) = $continuation;
$conditions[] = 'cs_entity_id > ' . $dbr->addQuotes($fromEntityId);
}
/**
* @note Below, we query and iterate all rows we want to delete in the current batch. That
* is rather ugly, but appears to be the best solution, because:
*
* - Deletions must be paged to avoid lock retention.
* - DELETE does not support LIMIT, so we need to know a range (min/max) of IDs.
* - GROUP BY does not support LIMIT, so we cannot use aggregate functions to get the
* min/max IDs.
*
* Thus, using SELECT ... LIMIT seems to be the only reliable way to get the min/max range
* needed for batched deletion.
*/
$res = $dbr->select('wb_changes_subscription', array('cs_entity_id'), $conditions, __METHOD__, array('ORDER BY' => 'cs_entity_id', 'LIMIT' => $this->batchSize));
$this->repoConnectionManager->releaseConnection($dbr);
$subscriptions = $this->getEntityIdsFromRows($res, 'cs_entity_id', $continuation);
if (empty($subscriptions)) {
return false;
}
$minId = reset($subscriptions);
$maxId = end($subscriptions);
$count = count($subscriptions);
return array($minId, $maxId, $count);
}
/**
* @see UsageLookup::getUnusedEntities
*
* @param EntityId[] $entityIds
*
* @return EntityId[]
* @throws UsageTrackerException
*/
public function getUnusedEntities(array $entityIds)
{
if (empty($entityIds)) {
return array();
}
$db = $this->connectionManager->getReadConnection();
$usageTable = $this->newUsageTable($db);
$unused = $usageTable->getUnusedEntities($entityIds);
$this->connectionManager->releaseConnection($db);
return $unused;
}
public function testBeginAtomicSection()
{
$connection = $this->getConnectionMock();
$lb = $this->getLoadBalancerMock();
$lb->expects($this->exactly(2))->method('getConnection')->with(DB_MASTER)->will($this->returnValue($connection));
$connection->expects($this->once())->method('startAtomic')->will($this->returnValue(null));
$manager = new ConsistentReadConnectionManager($lb);
$manager->beginAtomicSection('TEST');
// Should also ask for a DB_MASTER connection.
// This is asserted by the $lb mock.
$manager->getReadConnection();
}
/**
* Checks if a recent change entry already exists in the recentchanges table
*
* @since 0.4
*
* @param RecentChange $change
*
* @throws MWException
* @return bool
*/
public function changeExists(RecentChange $change)
{
$attribs = $change->getAttributes();
//XXX: need to check master?
$db = $this->connectionManager->getReadConnection();
$res = $db->select('recentchanges', array('rc_id', 'rc_timestamp', 'rc_type', 'rc_params'), array('rc_namespace' => $attribs['rc_namespace'], 'rc_title' => $attribs['rc_title'], 'rc_timestamp' => $attribs['rc_timestamp'], 'rc_type' => RC_EXTERNAL), __METHOD__);
if ($res->numRows() === 0) {
return false;
}
$changeMetadata = $this->getMetadata($attribs['rc_params']);
$changeRevId = $changeMetadata['rev_id'];
$changeParentId = $changeMetadata['parent_id'];
foreach ($res as $rc) {
$metadata = $this->getMetadata($rc->rc_params);
$parent_id = $metadata['parent_id'];
$rev_id = $metadata['rev_id'];
if ($rev_id === $changeRevId && $parent_id === $changeParentId) {
return true;
}
}
$this->connectionManager->releaseConnection($db);
return false;
}
