NanoTimer.java

/*
** Module   : NanoTimer.java
** Abstract : Helper class for measuring time intervals  
**
** Copyright (c) 2020-2024, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 IAS 20200930 Created initial version.
**     CA  20201003 Allow unchecked exceptions to propagate (otherwise any ConditionException will not be 
**                  caught properly).
**     CA  20221031 Ensure this is enabled if this is created after the associated mbean is enabled.
** 002 AL2 20230216 Added timer method able to return the value of the underlying instrumented code.
** 003 HC  20240222 Enabled JMX on FWD Client.
*/ 

/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
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**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
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** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
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**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
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**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.jmx;

import java.util.function.*;

import com.goldencode.p2j.jmx.FwdServerJMX.TimeStat;

/** Helper class for measuring time intervals */
public class NanoTimer 
extends SimpleCounter 
{
   /** start of the operation */ 
   private long start;

   /**
    * Create and register instance
    * @param    counter
    *           Counter MBean
    * @return   new <code>NanoTimer</code> instance
    */
   public static NanoTimer getInstance(TimeStat counter) 
   {
       NanoTimer timer = new NanoTimer(counter::update);
       timer.setEnabler(timer::setEnabled); //prevent GC
       timer.setEnabled(counter.getCounter().isEnabled());
       counter.register(timer.getEnabler());
       return timer;
   }

   /**
    * Constructor
    * @param publish
    *        samples' consumer
    */
   protected NanoTimer(LongConsumer publish) 
   {  
       super(publish);
   }
   
   /**
    * Start operation
    */
   public void start()
   {
       start = System.nanoTime();
   }
   
   /** Stop operation and update counter */
   public void stop()
   {
       update(System.nanoTime() - start);
   }

   /**
    * Execute operation and measure execution time
    * @param r
    *        operation to be executed
    */
   public void timer(Operation r)
   {
       if (!enabled)
       {
           try
           {
              r.exec();
           } 
           catch (RuntimeException re)
           {
              // unchecked exception propagate as is.  otherwise, we can't process ConditionException.
              throw re;
           }
           catch (Exception e)
           {
              throw new RuntimeException(e);
           }
           return;
       }
       start();
       try
       {
          r.exec();
       }
       catch (RuntimeException re)
       {
          // unchecked exception propagate as is.  otherwise, we can't process ConditionException.
          throw re;
       }
       catch (Exception e)
       {
          throw new RuntimeException(e);
       }
       finally
       {
           stop();
       }
   }

   /**
    * Execute operation and measure execution time
    * 
    * @param   <T> 
    *          The type of the return value for the operation to be executed.
    * @param   r
    *          operation to be executed
    *        
    * @return  The result of the operation to be executed
    */
   public <T> T timerWithReturn(ReturningOperation<T> r)
   {
       if (!enabled)
       {
           try
           {
              return r.exec();
           } 
           catch (RuntimeException re)
           {
              // unchecked exception propagate as is.  otherwise, we can't process ConditionException.
              throw re;
           }
           catch (Exception e)
           {
              throw new RuntimeException(e);
           }
       }
       start();
       try
       {
          return r.exec();
       }
       catch (RuntimeException re)
       {
          // unchecked exception propagate as is.  otherwise, we can't process ConditionException.
          throw re;
       }
       catch (Exception e)
       {
          throw new RuntimeException(e);
       }
       finally
       {
           stop();
       }
   }
}