/*

  * 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.giraph.metrics;

 import org.apache.giraph.time.SystemTime;

 import org.apache.giraph.time.Time;

 import org.apache.giraph.time.Times;

 import java.util.concurrent.TimeUnit;

 /**

  * Context to use with GiraphTimer for timing an event.

  */

 public class GiraphTimerContext {

   /** Object to use for time measurement */

   private static Time TIME = SystemTime.get();

   /** GiraphTimer to callback to with result of timing */

   private GiraphTimer giraphTimer;

   /** Beginning time to compare against */

   private long startTime;

   /**

    * Create with GiraphTimer to callback to.

    *

    * @param giraphTimer GiraphTimer to use.

    */

   public GiraphTimerContext(GiraphTimer giraphTimer) {

     this.giraphTimer = giraphTimer;

     this.startTime = TIME.getNanoseconds();

   }

   /**

    * End timing. Set time elapsed in GiraphTimer.

    */

   public void stop() {

     giraphTimer.set(Times.getNanosecondsSince(TIME, startTime),

                     TimeUnit.NANOSECONDS);

   }

 }