Class ImpaladCatalog

fe/src/main/java/org/apache/impala/catalog/ImpaladCatalog.java:89–693

Thread safe Catalog for an Impalad. The Impalad catalog can be updated either via a StateStore heartbeat or by directly applying the result of a catalog operation to the CatalogCache. All updates are applied using the updateCatalog() function. Table metadata is loaded lazily. The CatalogServer init

 * service has been started, in which case a full topic update is required.
 */
public class ImpaladCatalog extends Catalog implements FeCatalog {
  private static final Logger LOG = LoggerFactory.getLogger(ImpaladCatalog.class);
  // The last known Catalog Service ID. If the ID changes, it indicates the CatalogServer
  // has restarted.
  private TUniqueId catalogServiceId_ = Catalog.INITIAL_CATALOG_SERVICE_ID;

  // The catalog version received in the last StateStore heartbeat. It is guaranteed
  // all objects in the catalog have at a minimum, this version. Because updates may
  // be applied out of band of a StateStore heartbeat, it is possible the catalog
  // contains some objects > than this version.
  private AtomicLong lastSyncedCatalogVersion_ =
      new AtomicLong(Catalog.INITIAL_CATALOG_VERSION);

  // Tracks modifications to this Impalad's catalog from direct updates to the cache.
  private final CatalogDeltaLog catalogDeltaLog_ = new CatalogDeltaLog();

  // Object that is used to synchronize on and signal when a catalog update is received.
  private final Object catalogUpdateEventNotifier_ = new Object();

  private final AtomicReference<? extends AuthorizationChecker> authzChecker_;

  public ImpaladCatalog(AtomicReference<? extends AuthorizationChecker> authzChecker) {
    super();
    authzChecker_ = authzChecker;
    addDb(BuiltinsDb.getInstance());
    // Ensure the contents of the CatalogObjectVersionSet instance are cleared when a
    // new instance of ImpaladCatalog is created (see IMPALA-6486).
    CatalogObjectVersionSet.INSTANCE.clear();
  }

  /**
   * Utility class for sequencing the order in which a set of updated catalog objects
   * need to be applied to the catalog in order to satisfy referential constraints.
   *
   * If one type of object refers to another type of object, it needs to be added
   * after it and deleted before it.
   */
  public static class ObjectUpdateSequencer {
    private final ArrayDeque<TCatalogObject> updatedObjects = new ArrayDeque<>();
    private final ArrayDeque<TCatalogObject> deletedObjects = new ArrayDeque<>();

    public void add(TCatalogObject obj, boolean isDeleted) {
      if (!isDeleted) {
        // Update top-level objects first.
        if (isTopLevelCatalogObject(obj)) {
          updatedObjects.addFirst(obj);
        } else {
          updatedObjects.addLast(obj);
        }
      } else {
        // Remove low-level objects first.
        if (isTopLevelCatalogObject(obj)) {
          deletedObjects.addLast(obj);
        } else {
          deletedObjects.addFirst(obj);
        }
      }
    }