001/**
002* Licensed to the Apache Software Foundation (ASF) under one
003* or more contributor license agreements.  See the NOTICE file
004* distributed with this work for additional information
005* regarding copyright ownership.  The ASF licenses this file
006* to you under the Apache License, Version 2.0 (the
007* "License"); you may not use this file except in compliance
008* with the License.  You may obtain a copy of the License at
009*
010*     http://www.apache.org/licenses/LICENSE-2.0
011*
012* Unless required by applicable law or agreed to in writing, software
013* distributed under the License is distributed on an "AS IS" BASIS,
014* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015* See the License for the specific language governing permissions and
016* limitations under the License.
017*/
018
019package org.apache.hadoop.yarn.event;
020
021import org.apache.hadoop.classification.InterfaceAudience.Public;
022import org.apache.hadoop.classification.InterfaceStability.Evolving;
023
024/**
025 * Parent class of all the events. All events extend this class.
026 */
027@Public
028@Evolving
029public abstract class AbstractEvent<TYPE extends Enum<TYPE>> 
030    implements Event<TYPE> {
031
032  private final TYPE type;
033  private final long timestamp;
034
035  // use this if you DON'T care about the timestamp
036  public AbstractEvent(TYPE type) {
037    this.type = type;
038    // We're not generating a real timestamp here.  It's too expensive.
039    timestamp = -1L;
040  }
041
042  // use this if you care about the timestamp
043  public AbstractEvent(TYPE type, long timestamp) {
044    this.type = type;
045    this.timestamp = timestamp;
046  }
047
048  @Override
049  public long getTimestamp() {
050    return timestamp;
051  }
052
053  @Override
054  public TYPE getType() {
055    return type;
056  }
057
058  @Override
059  public String toString() {
060    return "EventType: " + getType();
061  }
062}