/**************************************************************************
/* This is a sample JMX-ready application.
/*
/* Copyright (c) 2003 by Bernhard Bablok (mail@bablokb.de)
/*
/* This program is free software; you can redistribute it and/or modify
/* it under the terms of the GNU General Public License as published
/* by  the Free Software Foundation; either version 2 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 General Public License for more details.
/*
/* You should have received a copy of the GNU General Public License
/* along with this program; see the file COPYING.  If not, write to
/* the Free Software Foundation Inc., 59 Temple Place - Suite 330,
/* Boston, MA  02111-1307 USA
/**************************************************************************/

import java.io.*;
import java.util.*;
import javax.management.*;
import mx4j.adaptor.http.*;
import com.sun.jdmk.comm.*;

/**
   This is a sample JMX-ready application. It reads cpu and memory-usage
   from /proc/stat and /proc/meminfo.

   @version $Revision: 1.1 $
   @author  $Author: Bablokb $
*/

public class LinuxInfo implements Runnable {
  
  private long iMemTotal, iMemUsed, iMemFree;
  private long iCpuUser1, iCpuNice1, iCpuSystem1, iCpuIdle1, iCpuTime1;
  private long iCpuUser2, iCpuNice2, iCpuSystem2, iCpuIdle2, iCpuTime2;
  private Object iCpuLock = new Object();
  private int iUpdateInterval = 1000;

  ////////////////////////////////////////////////////////////////////////////

  /**
     Read memory status from /proc/meminfo.
  */

  private void readMem() throws IOException {
    FileReader fr = new FileReader("/proc/meminfo");
    BufferedReader input  = new BufferedReader(fr);

    // skip first line

    input.readLine();
    String meminfo=input.readLine();
    input.close();

    // extract information. Format of line:
    //       total:    used:     free:      shared: buffers: cached:
    // Mem:  301375488 186585088 114790400        0 76517376 53612544

    StringTokenizer st = new StringTokenizer(meminfo);
    st.nextToken();
    try {
      iMemTotal = Long.parseLong(st.nextToken());
      iMemUsed  = Long.parseLong(st.nextToken());
      iMemFree  = Long.parseLong(st.nextToken());
    } catch (NumberFormatException e) {
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Query used memory
  */

  public long getMemUsed() {
    return iMemUsed;
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Read cpu status from /proc/stat.
  */

  private void readCpu() {
    try {
      FileReader fr = new FileReader("/proc/stat");

      BufferedReader input  = new BufferedReader(fr);
      String cpuinfo=input.readLine();
      input.close();

      // extract information. Format of line:
      //      user  nice system ticks
      // cpu  16389 794 5262 987851

      synchronized (iCpuLock) {
	StringTokenizer st = new StringTokenizer(cpuinfo);
	st.nextToken();
	iCpuUser1   = iCpuUser2;
	iCpuNice1   = iCpuNice2;
	iCpuSystem1 = iCpuSystem2;
	iCpuIdle1   = iCpuIdle2;

	iCpuUser2   = Long.parseLong(st.nextToken());
	iCpuNice2   = Long.parseLong(st.nextToken());
	iCpuSystem2 = Long.parseLong(st.nextToken());
	iCpuIdle2   = Long.parseLong(st.nextToken());
      }
    } catch (Exception e) {
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Query cpu-user percentage.
  */

  public int getCpuUserPercent() {
    synchronized (iCpuLock) {
      long diff = iCpuUser2 - iCpuUser1;
      long total = iCpuUser2+iCpuSystem2+iCpuIdle2 -
	(iCpuUser1+iCpuSystem1+iCpuIdle1);
      return (int) Math.round((100.0*diff)/total);
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Set update interval.
  */

  public void setInterval(int interval) {
    iUpdateInterval = interval;
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Get update interval.
  */

  public int getInterval() {
    return iUpdateInterval;
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Run indefinitely.
  */

  public void run() {
    try {
      readCpu();
      while (true) {
	readCpu();
	readMem();
	Thread.currentThread().sleep(iUpdateInterval);
      }
    } catch (Exception e) {
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Setup agent-layer for JMX-management.
  */

  private void setupAgent() {
    try {
      MBeanServer server = MBeanServerFactory.createMBeanServer();
      ObjectName cpuName = new ObjectName("LinuxInfo:name=cpu");
      ObjectName memName = new ObjectName("LinuxInfo:name=mem");
      ObjectName updateIntervalName =
	new ObjectName("LinuxInfo:name=updateInterval");
    
      Cpu cpu = new Cpu(); cpu.setServer(this);
      Mem mem = new Mem(); mem.setServer(this);
      UpdateInterval updateInterval = new UpdateInterval();
      updateInterval.setServer(this);

      server.registerMBean(cpu,cpuName);
      server.registerMBean(mem,memName);
      server.registerMBean(updateInterval,updateIntervalName);

      setupMX4J(server);
      setupSunRI(server);

    } catch (Exception e) {
      e.printStackTrace();
      System.exit(3);
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     MX4J http-adaptor.
  */

  private void setupMX4J(MBeanServer server) throws Exception {
    HttpAdaptor adaptor = new HttpAdaptor();
    ObjectName httpName = new ObjectName("mx4j:name=HttpAdaptor");
    server.registerMBean(adaptor, httpName);
    adaptor.setPort(8888);
    adaptor.start();

    XSLTProcessor xslt = new XSLTProcessor();
    ObjectName processorName = new ObjectName("mx4j:name=XSLTProcessor");
    server.registerMBean(xslt,processorName);
    server.setAttribute(httpName,new Attribute("ProcessorName",processorName));
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     HTML adaptor of reference-implementation.
  */

  private void setupSunRI(MBeanServer server) throws Exception {
    HtmlAdaptorServer adaptor = new HtmlAdaptorServer();
    ObjectName htmlName = new ObjectName("sun:name=HtmlAdaptorServer");
    server.registerMBean(adaptor,htmlName);
    adaptor.setPort(9999);
    adaptor.start();    
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Start the program, setup MBean-server.
  */

  public static void main(String[] args) {
    LinuxInfo li = new LinuxInfo();
    Thread t = new Thread(li);
    li.readCpu();
    t.start();
    li.setupAgent();
  }
}