core/src/main/java/org/apache/accumulo/core/util/StopWatch.java

/*
 * 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.accumulo.core.util;

import java.util.EnumMap;

public class StopWatch<K extends Enum<K>> {
  EnumMap<K,Long> startTime;
  EnumMap<K,Long> totalTime;

  public StopWatch(Class<K> k) {
    startTime = new EnumMap<>(k);
    totalTime = new EnumMap<>(k);
  }

  public synchronized void start(K timer) {
    if (startTime.containsKey(timer)) {
      throw new IllegalStateException(timer + " already started");
    }
    startTime.put(timer, System.currentTimeMillis());
  }

  public synchronized void stop(K timer) {

    Long st = startTime.get(timer);

    if (st == null) {
      throw new IllegalStateException(timer + " not started");
    }

    Long existingTime = totalTime.get(timer);
    if (existingTime == null)
      existingTime = 0L;

    totalTime.put(timer, existingTime + (System.currentTimeMillis() - st));
    startTime.remove(timer);
  }

  public synchronized long get(K timer) {
    Long existingTime = totalTime.get(timer);
    if (existingTime == null)
      existingTime = 0L;
    return existingTime;
  }

  public synchronized double getSecs(K timer) {
    Long existingTime = totalTime.get(timer);
    if (existingTime == null)
      existingTime = 0L;
    return existingTime / 1000.0;
  }

}