/*

  * 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.time;

 import java.util.Date;

 /**

  * Implementation of Time that is thread-safe and should be used in

  * production.

  */

 public class SystemTime implements Time {

   /**

    * Single instance of this object

    */

   private static final SystemTime SINGLE_TIME = new SystemTime();

   @Override

   public long getMilliseconds() {

     return System.currentTimeMillis();

   }

   @Override

   public long getMicroseconds() {

     return getNanoseconds() / NS_PER_US;

   }

   @Override

   public long getNanoseconds() {

     return System.nanoTime();

   }

   @Override

   public int getSeconds() {

     return (int) (getMilliseconds() / MS_PER_SECOND);

   }

   @Override

   public Date getCurrentDate() {

     return new Date();

   }

   @Override

   public void sleep(long milliseconds) throws InterruptedException {

     Thread.sleep(milliseconds);

   }

   /**

    * Get an instance (shared) of this object

    *

    * @return Instance of this object

    */

   public static Time get() {

     return SINGLE_TIME;

   }

 }