//      Copyright 1996-2000, International Business Machines
//      Corporation. All Rights Reserved.

package org.apache.log4j.performance;


import org.apache.log4j.Category;
import org.apache.log4j.SimpleLayout;
import org.apache.log4j.ConsoleAppender;

import org.apache.log4j.Level;

/**
   Measure the performance of evaluating whether to log or not to log,
   but not actually logging.

   
This program takes two arguments, a string which should be
   "true" for testing shipped code performance and "false" for testing
   debug-enabled performance the second argument is the run length of
   the measurement loops.

   
The results of the measurement (should) show that

   


   

   
Category evaluation is independent of the length of the category name.

   

   
As expected, using the {@link Category#isDebugEnabled
   isDebugEnabled} and {@link Category#isInfoEnabled isInfoEnabled}
   methods eliminates the overhead of message argument construction.

   
 
Message argument construction can be an important slowing
   factor while evaluating whether to log or not.

   

   @author Ceki Gülcü

*/
public class NotLogging {

  static int runLength;

  final static int INITIAL_HASH_SIZE = 101;

  static String  SHORT_MSG = "Hello World";

  static Category SHORT_CAT = Category.getInstance("A0123456789");
  static Category MEDIUM_CAT= Category.getInstance("A0123456789.B0123456789");
  static Category LONG_CAT  =
                   Category.getInstance("A0123456789.B0123456789.C0123456789");

  static Category INEXISTENT_SHORT_CAT = Category.getInstance("I0123456789");
  static Category INEXISTENT_MEDIUM_CAT=
                                Category.getInstance("I0123456789.B0123456789");
  static Category INEXISTENT_LONG_CAT=
                     Category.getInstance("I0123456789.B0123456789.C0123456789");


  static Category[] CAT_ARRAY = new Category[] {SHORT_CAT, MEDIUM_CAT,
						LONG_CAT, INEXISTENT_SHORT_CAT,
						INEXISTENT_MEDIUM_CAT,
						INEXISTENT_LONG_CAT};

  static
  void  Usage() {
    System.err.println(
      "Usage: java org.apache.log4j.test.NotLogging true|false runLength\n" +
      "true indicates shipped code, false indicates code in development" +
      "  where runLength is an int representing the run length of loops\n"+
      "We suggest that runLength be at least 100'000.");
    System.exit(1);
  }

  public static void main(String argv[]) {

    if(argv.length != 2) {
      Usage();
    }
    ProgramInit(argv);
    double delta;


    System.out.println();
    for(int i = 0; i < CAT_ARRAY.length; i++) {
      delta = SimpleMessage(CAT_ARRAY[i], SHORT_MSG, runLength);
      System.out.println("Simple argument,          " + delta
			 + " micros. Cat: " + CAT_ARRAY[i].getName());
    }

    System.out.println();
    for(int i = 0; i < CAT_ARRAY.length; i++) {
      delta = FullyOptimizedComplexMessage(CAT_ARRAY[i], runLength);
      System.out.println("Fully optimized complex,  " + delta +
			 " micros. Cat: " + CAT_ARRAY[i].getName());
    }

    System.out.println();
    for(int i = 0; i < CAT_ARRAY.length; i++) {
      delta = ComplexMessage(CAT_ARRAY[i], runLength);
      System.out.println("Complex message argument, " + delta +
			 " micros. Cat: " + CAT_ARRAY[i].getName());
    }

  }

  /**
    Program wide initialization method.  */
  static
  void ProgramInit(String[] args) {

    try {
      runLength = Integer.parseInt(args[1]);
    }
    catch(java.lang.NumberFormatException e) {
      System.err.println(e);
      Usage();
    }


    ConsoleAppender appender = new ConsoleAppender(new SimpleLayout());

    if("false".equals(args[0])) {
      // nothing to do
    } else if ("true".equals(args[0])) {
      System.out.println("Flagging as shipped code.");
      Category.getDefaultHierarchy().setThreshold((Level) Level.WARN);
    } else
      Usage();

    SHORT_CAT.setLevel((Level) Level.INFO);
    Category.getRoot().setLevel((Level) Level.INFO);

  }


  static
  double SimpleMessage(Category category, String msg, long runLength) {
    long before = System.currentTimeMillis();
    for(int i = 0; i < runLength; i++) {
      category.debug(msg);
    }
    return (System.currentTimeMillis() - before)*1000.0/runLength;
  }

  static
  double FullyOptimizedComplexMessage(Category category, long runLength) {
    long before = System.currentTimeMillis();
    for(int i = 0; i < runLength; i++) {
      if(category.isDebugEnabled())
	category.debug("Message" + i +
		  " bottles of beer standing on the wall.");
    }
    return (System.currentTimeMillis() - before)*1000.0/runLength;
  }

  static
  double ComplexMessage(Category category, long runLength) {
    long before = System.currentTimeMillis();
    for(int i = 0; i < runLength; i++) {
      category.debug("Message" + i +
		" bottles of beer standing on the wall.");
    }
    return (System.currentTimeMillis() - before)*1000.0/runLength;
  }
}