package org.apache.commons.jcs3.engine.memory.mru;
   
   import org.apache.commons.jcs3.JCS;
   import org.apache.commons.jcs3.access.CacheAccess;
   import org.apache.commons.jcs3.engine.memory.lru.LRUMemoryCache;
   import org.apache.commons.jcs3.log.Log;
   import org.apache.commons.jcs3.log.LogManager;
   
   /*
   * 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.
   */
  
  import junit.framework.TestCase;
  
  /**
   * Tests the performance difference between the LRU and the MRU. There should be very little.
   */
  public class LRUvsMRUPerformanceTest
      extends TestCase
  {
      /** ration we want */
      float ratioPut;
  
      /** ration we want */
      float ratioGet;
  
      /** ration we want */
      float target = 1.20f;
  
      /** times to run */
      int loops = 20;
  
      /** item per run */
      int tries = 10000;
  
      /**
       * A unit test for JUnit
       * @throws Exception Description of the Exception
       */
      public void testSimpleLoad()
          throws Exception
      {
          final Log log1 = LogManager.getLog( LRUMemoryCache.class );
          if ( log1.isDebugEnabled() )
          {
              System.out.println( "The log level must be at info or above for the a performance test." );
              return;
          }
          final Log log2 = LogManager.getLog( MRUMemoryCache.class );
          if ( log2.isDebugEnabled() )
          {
              System.out.println( "The log level must be at info or above for the a performance test." );
              return;
          }
          doWork();
  
          // these were when the mru was implemented with the jdk linked list
          //assertTrue( "Ratio is unacceptible.", this.ratioPut < target );
          ///assertTrue( "Ratio is unacceptible.", this.ratioGet < target );
      }
  
      /**
       * Runs the test
       */
      public void doWork()
      {
  
          long start = 0;
          long end = 0;
          long time = 0;
          float tPer = 0;
  
          long putTotalLRU = 0;
          long getTotalLRU = 0;
          long putTotalMRU = 0;
          long getTotalMRU = 0;
  
          try
          {
  
              JCS.setConfigFilename( "/TestMRUCache.ccf" );
              final CacheAccess<String, String> cache = JCS.getInstance( "lruDefined" );
              final CacheAccess<String, String> mru = JCS.getInstance( "mruDefined" );
  
             System.out.println( "LRU = " + cache );
 
             for ( int j = 0; j < loops; j++ )
             {
 
                 System.out.println( "Beginning loop " + j );
 
                 String name = "LRU      ";
                 start = System.currentTimeMillis();
                 for ( int i = 0; i < tries; i++ )
                 {
                     cache.put( "key:" + i, "data" + i );
                 }
                 end = System.currentTimeMillis();
                 time = end - start;
                 putTotalLRU += time;
                 tPer = Float.intBitsToFloat( (int) time ) / Float.intBitsToFloat( tries );
                 System.out.println( name + " put time for " + tries + " = " + time + "; millis per = " + tPer );
 
                 start = System.currentTimeMillis();
                 for ( int i = 0; i < tries; i++ )
                 {
                     cache.get( "key:" + i );
                 }
                 end = System.currentTimeMillis();
                 time = end - start;
                 getTotalLRU += time;
                 tPer = Float.intBitsToFloat( (int) time ) / Float.intBitsToFloat( tries );
                 System.out.println( name + " get time for " + tries + " = " + time + "; millis per = " + tPer );
 
                 // /////////////////////////////////////////////////////////////
                 name = "MRU";
                 start = System.currentTimeMillis();
                 for ( int i = 0; i < tries; i++ )
                 {
                     mru.put( "key:" + i, "data" + i );
                 }
                 end = System.currentTimeMillis();
                 time = end - start;
                 putTotalMRU += time;
                 tPer = Float.intBitsToFloat( (int) time ) / Float.intBitsToFloat( tries );
                 System.out.println( name + " put time for " + tries + " = " + time + "; millis per = " + tPer );
 
                 start = System.currentTimeMillis();
                 for ( int i = 0; i < tries; i++ )
                 {
                     mru.get( "key:" + i );
                 }
                 end = System.currentTimeMillis();
                 time = end - start;
                 getTotalMRU += time;
                 tPer = Float.intBitsToFloat( (int) time ) / Float.intBitsToFloat( tries );
                 System.out.println( name + " get time for " + tries + " = " + time + "; millis per = " + tPer );
 
                 System.out.println( "\n" );
             }
 
         }
         catch ( final Exception e )
         {
             e.printStackTrace( System.out );
             System.out.println( e );
         }
 
         final long putAvJCS = putTotalLRU / loops;
         final long getAvJCS = getTotalLRU / loops;
         final long putAvHashtable = putTotalMRU / loops;
         final long getAvHashtable = getTotalMRU / loops;
 
         System.out.println( "Finished " + loops + " loops of " + tries + " gets and puts" );
 
         System.out.println( "\n" );
         System.out.println( "Put average for JCS       = " + putAvJCS );
         System.out.println( "Put average for MRU = " + putAvHashtable );
         ratioPut = Float.intBitsToFloat( (int) putAvJCS ) / Float.intBitsToFloat( (int) putAvHashtable );
         System.out.println( "JCS puts took " + ratioPut + " times the Hashtable, the goal is <" + target + "x" );
 
         System.out.println( "\n" );
         System.out.println( "Get average for JCS       = " + getAvJCS );
         System.out.println( "Get average for MRU = " + getAvHashtable );
         ratioGet = Float.intBitsToFloat( (int) getAvJCS ) / Float.intBitsToFloat( (int) getAvHashtable );
         System.out.println( "JCS gets took " + ratioGet + " times the Hashtable, the goal is <" + target + "x" );
     }
 
 }