/**
* Returns a list of entities a given site is subscribed to.
*
* This implementations combines the results of queries to both of the lookups
* provided to the constructor.
*
* @param string $siteId Site ID of the client site.
* @param EntityId[]|null $entityIds The entities we are interested in, or null for "any".
*
* @return EntityId[] a list of entity IDs the client wiki is subscribed to.
* The result is limited to entity ids also present in $entityIds, if given.
*/
public function getSubscriptions($siteId, array $entityIds)
{
if (empty($entityIds)) {
return array();
}
$primarySubscriptions = $this->reIndexEntityIds($this->primary->getSubscriptions($siteId, $entityIds));
$entityIds = array_diff($this->reIndexEntityIds($entityIds), $primarySubscriptions);
if (empty($entityIds)) {
return $primarySubscriptions;
}
$secondarySubscriptions = $this->reIndexEntityIds($this->secondary->getSubscriptions($siteId, $entityIds));
$subscriptions = array_merge($primarySubscriptions, $secondarySubscriptions);
return $subscriptions;
}
/**
* Filters a list of changes, removing changes not relevant to the given client wiki.
*
* Currently, we keep EntityChanges for entities the client wiki is subscribed to, or
* that modify a sitelink to the client wiki.
*
* @param string $siteID The client wiki's global site identifier, as used by sitelinks.
* @param Change[] $changes The list of changes to filter.
* @param int $limit The max number of changes to return
*
* @return array( $batch, $seen ), where $batch is the filtered list of Change objects,
* and $seen if the ID of the last change considered for the batch
* (even if that was filtered out), for use as a continuation marker.
*/
private function filterChanges($siteID, $changes, $limit)
{
// collect all item IDs mentioned in the changes
$entitySet = array();
foreach ($changes as $change) {
if (!$change instanceof EntityChange) {
continue;
}
$id = $change->getEntityId();
$idString = $id->getSerialization();
$entitySet[$idString] = $id;
}
$this->trace("Checking sitelinks to {$siteID} for " . count($entitySet) . " entities.");
$subscribedEntities = $this->subscriptionLookup->getSubscriptions($siteID, $entitySet);
$subscribedEntities = $this->reIndexEntityIds($subscribedEntities);
$this->trace("Retaining changes for " . count($subscribedEntities) . " relevant entities.");
// find all changes that relate to an item that has a sitelink to $siteID.
$filteredChanges = array();
$numberOfChangesFound = 0;
$lastIdSeen = 0;
foreach ($changes as $change) {
if (!$change instanceof EntityChange) {
continue;
}
$lastIdSeen = $change->getId();
$idString = $change->getEntityId()->getSerialization();
// The change is relevant if it alters any sitelinks referring to $siteID,
// or the item currently links to $siteID.
if (isset($subscribedEntities[$idString]) || $this->isRelevantChange($change, $siteID)) {
$filteredChanges[] = $change;
$numberOfChangesFound++;
}
if ($numberOfChangesFound >= $limit) {
break;
}
}
$this->trace("Found " . count($filteredChanges) . " changes for items with relevant sitelinks.");
return array($filteredChanges, $lastIdSeen);
}