| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.rya.streams.api.queries; |
| |
| import java.util.Optional; |
| |
| import org.apache.rya.streams.api.entity.StreamsQuery; |
| |
| import edu.umd.cs.findbugs.annotations.DefaultAnnotation; |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| |
| /** |
| * Listener to be notified when {@link QueryChange}s occur on a {@link QueryChangeLog}. |
| */ |
| @DefaultAnnotation(NonNull.class) |
| public interface QueryChangeLogListener { |
| /** |
| * Notifies the listener that a query change event has occurred in the change log. |
| * <p> |
| * <b>Note:</b> |
| * <p> |
| * The QueryRepository blocks when notifying this listener. Long lasting operations |
| * should not be performed within this function. Doing so will block all operations |
| * on the repository. |
| * |
| * @param queryChangeEvent - The event that occurred. (not null) |
| * @param newQueryState - The new state of the query after the query change event, this will be |
| * absent if the change type is DELETE. (not null) |
| */ |
| public void notify(final ChangeLogEntry<QueryChange> queryChangeEvent, final Optional<StreamsQuery> newQueryState); |
| } |