| /* |
| * 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.eagle.log.entity; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| public abstract class StreamReader { |
| protected List<EntityCreationListener> listeners = new ArrayList<EntityCreationListener>(); |
| |
| /** |
| * Listener can be only notified after it is added to listener list |
| * |
| * @param listener |
| */ |
| public synchronized void register(EntityCreationListener listener) { |
| listeners.add(listener); |
| } |
| |
| /** |
| * Listener can not get notification once after it is removed from listener list |
| * |
| * @param listener |
| */ |
| public synchronized void unregister(EntityCreationListener listener) { |
| listeners.remove(listener); |
| } |
| |
| public abstract void readAsStream() throws Exception; |
| |
| /** |
| * Get scanned last entity timestamp |
| * |
| * @return |
| */ |
| public abstract long getLastTimestamp(); |
| |
| /** |
| * Get scanned first entity timestamp |
| * |
| * @return |
| */ |
| public abstract long getFirstTimestamp(); |
| } |