/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package chapters.appenders;
  
  import java.io.FileWriter;
  import java.io.IOException;
  
  import org.slf4j.Logger;
  
  import ch.qos.logback.classic.LoggerContext;
  import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
  import ch.qos.logback.classic.spi.ILoggingEvent;
  import ch.qos.logback.core.FileAppender;
  import ch.qos.logback.core.util.StatusPrinter;
  
  public class IOPerformance extends Thread {
      static String MSG = "ABCDEGHIJKLMNOPQRSTUVWXYZabcdeghijklmnopqrstuvwxyz1234567890";
      static String LOG_FILE;
      public static String PARALLEL_FILE;
  
      static int NUM_THREADS = 1;
      static long l;
      long len;
      boolean immediateFlush;
      Logger logger;
      LoggerContext context;
      double throughput;
  
      public IOPerformance(boolean _immediateFlush, long _len) {
          this.len = _len;
          this.immediateFlush = _immediateFlush;
          context = new LoggerContext();
          logger = context.getLogger("logger-" + getName());
  
          // A FileAppender is created according to the buffering and
          // immediate flush setting of this IO instance.
          FileAppender<ILoggingEvent> fa = new FileAppender<ILoggingEvent>();
          fa.setName("FILE");
          PatternLayoutEncoder pa = new PatternLayoutEncoder();
          pa.setPattern("%r %5p %c [%t] - %m%n");
          pa.setContext(context);
          pa.start();
          fa.setEncoder(pa);
  
          fa.setFile(LOG_FILE);
          fa.setAppend(true);
          fa.setContext(context);
          fa.start();
  
          ((ch.qos.logback.classic.Logger) logger).addAppender(fa);
  
          StatusPrinter.print(context);
      }
  
      public static void main(String[] argv) throws Exception {
          if (argv.length != 3) {
              usage("Wrong number of arguments.");
          }
  
          l = Integer.parseInt(argv[0]);
          LOG_FILE = argv[1];
          PARALLEL_FILE = argv[2];
  
          // ----------------------------------------------------
          // first test with immediate flushing
          perfCase(true, l);
  
          // ----------------------------------------------------
          // Second test with no immediate flushing
          perfCase(false, l);
  
          // There is no fourth test as buffered IO and immediate flushing
          // do not make sense.
      }
  
      static void usage(String msg) {
          System.err.println(msg);
          System.err.println("Usage: java " + IOPerformance.class.getName() + " runLength logFile otherFile\n"
                          + "   runLength (integer) the number of logs to generate perthread\n" + "   logFile path to a logFile\n"
                          + "   otherFile path to a second file\n");
          System.exit(1);
      }
  
      static void perfCase(boolean immediateFlush, long len) throws Exception {
          IOPerformance[] threads = new IOPerformance[NUM_THREADS];
          OtherIO otherIOThread = new OtherIO();
          otherIOThread.start();
  
         // First create the threads
         for (int i = 0; i < NUM_THREADS; i++) {
             threads[i] = new IOPerformance(immediateFlush, len);
         }
 
         // then start them
         for (int i = 0; i < NUM_THREADS; i++) {
             threads[i].start();
         }
 
         // wait for them to processPriorToRemoval, compute the average throughput
         double sum = 0;
 
         for (int i = 0; i < NUM_THREADS; i++) {
             threads[i].join();
             sum += threads[i].throughput;
         }
 
         // setting the interrupted field will cause counterThread to processPriorToRemoval
         otherIOThread.interrupted = true;
         otherIOThread.join();
 
         System.out.println("On total throughput of " + (sum) + " logs per microsecond.");
         System.out.println("------------------------------------------------");
     }
 
     public void run() {
 
         long before = System.nanoTime();
 
         for (int i = 0; i < len; i++) {
             logger.debug(MSG);
         }
 
         throughput = (len * 1.0) / ((System.nanoTime() - before) / 1000);
         System.out.println(getName() + ", immediateFlush: " + immediateFlush + ", throughput: " + throughput + " logs per microsecond.");
     }
 }
 
 class OtherIO extends Thread {
     public boolean interrupted = false;
     public int counter = 0;
 
     public void run() {
         long before = System.nanoTime();
         try {
             FileWriter fw = new FileWriter(IOPerformance.PARALLEL_FILE, true);
 
             while (!interrupted) {
                 counter++;
                 fw.write("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
                 fw.flush();
             }
         } catch (IOException e) {
             e.printStackTrace();
         }
 
         double tput = (counter * 1.0) / (System.nanoTime() - before);
         System.out.println("Counter thread " + getName() + " incremented counter by " + tput + " per nanosecond.");
     }
 }