// ----------------------------------------------------------------------------

// Copyright 2006-2010, GeoTelematic Solutions, Inc.

// All rights reserved

// ----------------------------------------------------------------------------

//

// Licensed 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.

//

// ----------------------------------------------------------------------------

// Description:

//  General OS specific tools

// ----------------------------------------------------------------------------

// Change History:

//  2006/03/26  Martin D. Flynn

//     -Initial release

//  2006/06/30  Martin D. Flynn

//     -Repackaged

//  2008/06/20  Martin D. Flynn

//     -Added method 'getProcessID()'

//  2010/05/24  Martin D. Flynn

//     -Added "getMemoryUsage", "printMemoryUsage"

// ----------------------------------------------------------------------------

package org.opengts.util;



import java.lang.management.*;

import java.util.*;

import java.io.*;



public class OSTools

{



    // ------------------------------------------------------------------------



    private static final Object LockObject          = new Object();



    // ------------------------------------------------------------------------

    // OS and JVM specific tools

    // ------------------------------------------------------------------------



    private static final int OS_INITIALIZE          = -1;

    public  static final int OS_TYPE_MASK           = 0x00FF00;

    public  static final int OS_SUBTYPE_MASK        = 0x0000FF;



    public  static final int OS_UNKNOWN             = 0x000000;

    public  static final int OS_LINUX               = 0x000100;

    public  static final int OS_MACOSX              = 0x000200;

    public  static final int OS_WINDOWS             = 0x000300;

    public  static final int OS_WINDOWS_XP          = 0x000001;

    public  static final int OS_WINDOWS_9X          = 0x000002;

    public  static final int OS_WINDOWS_CYGWIN      = 0x000010;



    private static       int OSType                 = OS_INITIALIZE;



    /**

    *** Returns the known OS type as an integer bitmask

    *** @return The OS type

    **/

    public static int getOSType()

    {

        if (OSType == OS_INITIALIZE) {

            String osName = System.getProperty("os.name").toLowerCase();

            //Print.logInfo("OS: " + osName);

            if (osName.startsWith("windows")) {

                OSType = OS_WINDOWS;

                if (osName.startsWith("windows xp")) {

                    OSType |= OS_WINDOWS_XP;

                } else

                if (osName.startsWith("windows 9") || osName.startsWith("windows m")) {

                    OSType |= OS_WINDOWS_9X;

                }

            } else

            if (osName.startsWith("mac")) {

                // "Max OS X"

                OSType = OS_MACOSX;

            } else

            if (File.separatorChar == '/') {

                // "Linux"

                OSType = OS_LINUX;

            } else {

                OSType = OS_UNKNOWN;

            }

        }

        return OSType;

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Returns true if the OS is unknown

    *** @return True if the OS is unknown

    **/

    public static boolean isUnknown()

    {

        return (getOSType() == OS_UNKNOWN);

    }



    /**

    *** Returns true if the OS is the specified type

    *** @return True if the OS is the specified type

    **/

    public static boolean isOSType(int type)

    {

        int osType = getOSType();

        return ((osType & OS_TYPE_MASK) == type);

    }



    /**

    *** Returns true if the OS is the specified type

    *** @return True if the OS is the specified type

    **/

    public static boolean isOSType(int type, int subType)

    {

        int osType = getOSType();

        if ((osType & OS_TYPE_MASK) != type) {

            return false;

        } else {

            return ((osType & OS_SUBTYPE_MASK & subType) != 0);

        }

    }



    /**

    *** Returns true if the OS is a flavor of Windows

    *** @return True if the OS is a flavor of Windows

    **/

    public static boolean isWindows()

    {

        return isOSType(OS_WINDOWS);

    }



    /**

    *** Returns true if the OS is Windows XP

    *** @return True if the OS is Windows XP

    **/

    public static boolean isWindowsXP()

    {

        return isOSType(OS_WINDOWS, OS_WINDOWS_XP);

    }



    /**

    *** Returns true if the OS is Windows 95/98

    *** @return True if the OS is Windows 95/98

    **/

    public static boolean isWindows9X()

    {

        return isOSType(OS_WINDOWS, OS_WINDOWS_9X);

    }



    /**

    *** Returns true if the OS is Unix/Linux

    *** @return True if the OS is Unix/Linux

    **/

    public static boolean isLinux()

    {

        return isOSType(OS_LINUX);

    }



    /**

    *** Returns true if the OS is Apple Mac OS X

    *** @return True if the OS is Apple Mac OS X

    **/

    public static boolean isMacOSX()

    {

        return isOSType(OS_MACOSX);

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Get the current memory usage (in number of bytes)

    *** @param L  The long array where the memory values will be placed.  If 'null',

    ***           is specified, or if the array has fewer than 3 elements, a new

    ***           long array will be returned.

    ***           then the array must be 

    *** @return The current memory usage as an array of 3 long values indicating

    ***         { MaxMemory, TotalMemory, FreeMemory } (in that order).

    **/

    public static long[] getMemoryUsage(long L[])

    {

        long mem[] = ((L != null) && (L.length >= 3))? L : new long[3];

        Runtime rt = Runtime.getRuntime();

        synchronized (OSTools.LockObject) {

            mem[0] = rt.maxMemory();

            mem[1] = rt.totalMemory();

            mem[2] = rt.freeMemory();

        }

        return mem;

    }

    

    /**

    *** Prints the current memory usage to the log file

    **/

    public static void printMemoryUsage()

    {

        long mem[] = OSTools.getMemoryUsage(null);

        long maxK  = mem[0] / 1024L;

        long totK  = mem[1] / 1024L;

        long freK  = mem[2] / 1024L;

        Print.logInfo("Memory-K: max=%d, total=%d, free=%d, used=%d", maxK, totK, freK, (totK - freK));

        //OSTools.printMemoryUsageMXBean();

    }

    

    /**

    *** Prints the current memory usage to the log file

    **/

    public static void printMemoryUsageMXBean()

    {

        

        /* Heap/Non-Heap */

        MemoryMXBean memory = ManagementFactory.getMemoryMXBean();

        MemoryUsage heapUsage    = memory.getHeapMemoryUsage();

        MemoryUsage nonHeapUsage = memory.getNonHeapMemoryUsage();

        Print.logInfo("Heap Memory Usage    : " + formatMemoryUsage(heapUsage   ));

        Print.logInfo("Non-Heap Memory Usage: " + formatMemoryUsage(nonHeapUsage)); 



        /* Pools */

        java.util.List<MemoryPoolMXBean> memPool = ManagementFactory.getMemoryPoolMXBeans();

        for (MemoryPoolMXBean mp : memPool) {

            String      name      = mp.getName();

            MemoryType  type      = mp.getType();

            MemoryUsage estUsage  = mp.getUsage();

            MemoryUsage peakUsage = mp.getPeakUsage();

            MemoryUsage collUsage = mp.getCollectionUsage();

            Print.logInfo("Pool Usage: " + name + " [" + type + "]");

            Print.logInfo("  Estimate  : "  + formatMemoryUsage(estUsage ));

            Print.logInfo("  Peak      : "  + formatMemoryUsage(peakUsage));

            Print.logInfo("  Collection: "  + formatMemoryUsage(collUsage));

        }



    }

    

    /**

    *** Formats a MemoryUsage instance

    **/

    private static String formatMemoryUsage(MemoryUsage u)

    {

        if (u != null) {

            long comm = u.getCommitted() / 1024L;

            long init = u.getInit()      / 1024L;

            long max  = u.getMax()       / 1024L;

            long used = u.getUsed()      / 1024L;

            StringBuffer sb = new StringBuffer();

            sb.append("[K]");

            sb.append(" Committed=").append(comm);

            sb.append(" Init=").append(init);

            sb.append(" Max=").append(max);

            sb.append(" Used=").append(used);

            return sb.toString();

        } else {

            return "";

        }

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    private static Object  memoryCheckLock         = new Object();

    private static long    firstMem_maxB           = 0L;

    private static long    firstMem_usedB          = 0L;

    private static long    firstMem_time           = 0L;

    private static long    memoryCheckCount        = 0L;

    private static long    averMem_usedB           = 0L;

    private static long    lastMem_usedB           = 0L;



    /**

    *** Analyzes/Prints the current memory usage.<br>

    *** (This method only analyzes/prints memory usage if the current usage is less than 

    *** the previous usage, implying that a garbage collection has recently occured)<br>

    *** Useful for determining <b>IF</b> there are memory leaks, and how much it is leaking, 

    *** but useless for determining <b>WHERE</b> the leak is occurring.

    *** @param reset  True to reset the memory growth-rate checks.

    **/

    public static void checkMemoryUsage(boolean reset)

    {

        // http://olex.openlogic.com/wazi/2009/how-to-fix-memory-leaks-in-java/

        // http://java.sun.com/docs/hotspot/gc1.4.2/faq.html

        // http://java.dzone.com/articles/letting-garbage-collector-do-c



        /* memory check enabled? */

        if (!RTConfig.getBoolean(RTKey.OSTOOLS_MEMORY_CHECK_ENABLE)) {

            return;

        }



        /* get current memory usage */

        long nowTime = DateTime.getCurrentTimeSec();

        long maxB, usedB;

        long averUsedB = 0L, firstUsedB = 0L, firstTime = 0L;

        long count = 0L;

        Runtime rt = Runtime.getRuntime();

        synchronized (OSTools.memoryCheckLock) {

            // reset?

            if (reset) {

                // start over

                OSTools.firstMem_maxB    = 0L;

                OSTools.firstMem_usedB   = 0L;

                OSTools.firstMem_time    = 0L;

                OSTools.memoryCheckCount = 0L;

                OSTools.averMem_usedB    = 0L;

                OSTools.lastMem_usedB    = 0L;

            }

            // get memory usage

            maxB  = rt.maxMemory();

            usedB = rt.totalMemory() - rt.freeMemory();

            if (usedB <= 0L) {

                // unlikely, but we need to check anyway

                Print.logWarn("Memory usage <= 0? " + usedB + " bytes");

            } else {

                if (usedB < OSTools.lastMem_usedB) {

                    // garbage collection has occurred

                    if ((OSTools.firstMem_time <= 0L) || (usedB < OSTools.firstMem_usedB)) {

                        // store results after first garbage collection

                        OSTools.firstMem_maxB    = maxB;      // should never change

                        OSTools.firstMem_usedB   = usedB;

                        OSTools.firstMem_time    = nowTime;

                        OSTools.memoryCheckCount = 0L;

                        OSTools.averMem_usedB    = 0L;

                    }

                    firstUsedB = OSTools.firstMem_usedB; // cache for use outside synchronized section

                    firstTime  = OSTools.firstMem_time;  // cache for use outside synchronized section

                    // average "trend"

                    if (OSTools.averMem_usedB <= 0L) {

                        // initialize average

                        OSTools.averMem_usedB = usedB;

                    } else

                    if (usedB <= OSTools.averMem_usedB) {

                        // always reset to minimum used (ie. 100% downward trend)

                        OSTools.averMem_usedB = usedB;

                    } else {

                        // upward "trend" determined by weighting factor

                        double trendWeight = RTConfig.getDouble(RTKey.OSTOOLS_MEMORY_TREND_WEIGHT);

                        OSTools.averMem_usedB = OSTools.averMem_usedB + (long)((double)(usedB - OSTools.averMem_usedB) * trendWeight);

                    }

                    averUsedB = OSTools.averMem_usedB; // cache for use outside synchronized section

                    // count

                    count = ++OSTools.memoryCheckCount; // increment and cache count for use outside synchronized section

                }

                OSTools.lastMem_usedB = usedB; // save last used

            }

        } // synchronized



        /* return if a garbage collection has not just occurred */

        if (count <= 0L) {

            return;

        }



        /* analyze */

        double deltaHours = (double)(nowTime - firstTime) / 3600.0;

        long   deltaUsedB = averUsedB - firstUsedB; // could be <= 0

        long   grwBPH     = (deltaHours > 0.0)? (long)(deltaUsedB / deltaHours) : 0L; // bytes/hour

        long   grwBPC     = deltaUsedB / count; // bytes/hour



        /* message */

        long maxK  = maxB      / 1024;

        long usedK = usedB     / 1024;

        long averK = averUsedB / 1024;

        String s = "["+count+"] Memory-K max "+maxK+ ", used "+usedK+ " (trend "+averK+ " K "+grwBPH+" b/h "+ grwBPC+" b/c)";



        /* display */

        double maxPercent = RTConfig.getDouble(RTKey.OSTOOLS_MEMORY_USAGE_WARN);

        if (usedB >= (long)((double)maxB * maxPercent)) {

            Print.logWarn("**** More than "+(maxPercent*100.0)+"% of max memory has been used!! ****");

            Print.logWarn(s);

        } else {

            Print.logInfo(s);

        }



    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Returns true if this implementation has a broken 'toFront' Swing implementation.<br>

    *** (may only be applicable on Java v1.4.2)

    *** @return True if this implementation has a broken 'toFront' Swing implementation.

    **/

    public static boolean isBrokenToFront()

    {

        return isWindows();

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    public static final String PROPERTY_JAVA_HOME                   = "java.home";

    public static final String PROPERTY_JAVA_VENDOR                 = "java.vendor";

    public static final String PROPERTY_JAVA_SPECIFICATION_VERSION  = "java.specification.version";



    /**

    *** Returns true if executed from a Sun Microsystems JVM.

    *** @return True is executed from a Sun Microsystems JVM.

    **/

    public static boolean isSunJava()

    {

        String propVal = System.getProperty(PROPERTY_JAVA_VENDOR); // "Sun Microsystems Inc."

        if ((propVal == null) || (propVal.indexOf("Sun Microsystems") < 0)) {

            return false;

        } else {

            return true;

        }

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Gets the class of the caller at the specified frame index

    *** @param frame The frame index

    *** @return The calling class

    **/

    @SuppressWarnings("proprietary")  // <-- does not work to supress the "Sun proprietary API" warning

    private static Class _getCallerClass(int frame)

        throws Throwable

    {

        return sun.reflect.Reflection.getCallerClass(frame + 1); // <== ignore any warnings

    }



    /**

    *** Gets the class of the caller at the specified frame index

    *** @param frame The frame index

    *** @return The calling class

    **/

    public static Class getCallerClass(int frame)

    {

        try {

            // sun.reflect.Reflection.getCallerClass(0) == sun.reflect.Reflection

            // sun.reflect.Reflection.getCallerClass(1) == OSTools

            Class clz = OSTools._getCallerClass(frame + 1);

            //Print._println("" + (frame + 1) + "] class " + StringTools.className(clz));

            return clz;

        } catch (Throwable th) { // ClassNotFoundException

            // This can occur when the code has been compiled with the Sun Microsystems version

            // of Java, but is executed with the GNU version of Java (or other non-Sun version).

            Print.logException("Sun Microsystems version of Java is not in use", th);

            return null;

        }

    }



    /**

    *** Returns true if 'sun.reflect.Reflection' is present in the runtime libraries.<br>

    *** (will return true when running with the Sun Microsystems version of Java)

    *** @return True if 'getCallerClass' is available.

    **/

    public static boolean hasGetCallerClass()

    {

        try {

            OSTools._getCallerClass(0);

            return true;

        } catch (Throwable th) {

            return false;

        }

    }



    /**

    *** Prints the class of the caller (debug purposes only)

    **/

    public static void printCallerClasses()

    {

        try {

            for (int i = 0;; i++) {

                Class clz = OSTools._getCallerClass(i);

                Print.logInfo("" + i + "] class " + StringTools.className(clz));

                if (clz == null) { break; }

            }

        } catch (Throwable th) { // ClassNotFoundException

            // This can occur when the code has been compiled with the Sun Microsystems version

            // of Java, but is executed with the GNU version of Java.

            Print.logException("Sun Microsystems version of Java is not in use", th);

        }

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Gets the Process-ID of this JVM invocation.<br>

    *** IMPORTANT: This implementation relies on a "convention", rather that a documented method

    *** of obtaining the process-id of this JVM within the OS.  <b>Caveat Emptor!</b><br>

    *** (On Windows, this returns the 'WINPID' which is probably useless anyway)

    *** @return The Process-ID

    **/

    public static int getProcessID()

    {

        // References:

        //  - http://blog.igorminar.com/2007/03/how-java-application-can-discover-its.html

        if (OSTools.isSunJava()) {

            try {

                // by convention, returns "<PID>@<host>" (until something changes, and it doesn't)

                String n = java.lang.management.ManagementFactory.getRuntimeMXBean().getName();

                int pid = StringTools.parseInt(n,-1); // parse PID

                return pid;

            } catch (Throwable th) {

                Print.logException("Unable to obtain Process ID", th);

                return -1;

            }

        } else {

            return -1;

        }

    }



    /* this does not work on Windows (and seems to return the wrong parent PID on Linux) */

    private static int _getProcessID()

    {

        try {

            String cmd[] = new String[] { "bash", "-c", "echo $PPID" };

            Process ppidExec = Runtime.getRuntime().exec(cmd);

            BufferedReader ppidReader = new BufferedReader(new InputStreamReader(ppidExec.getInputStream()));

            StringBuffer sb = new StringBuffer();

            for (;;) {

                String line = ppidReader.readLine();

                if (line == null) { break; }

                sb.append(StringTools.trim(line));

            }

            int pid = StringTools.parseInt(sb.toString(),-1);

            int exitVal = ppidExec.waitFor();

            Print.logInfo("Exit value: %d [%s]", exitVal, sb.toString());

            ppidReader.close();

            return pid;

        } catch (Throwable th) {

            Print.logException("Unable to obtain PID", th);

            return -1;

        }

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Returns a Java command set up to be executed by Runtime.getRuntime().exec(...)

    *** @param classpath The classpath 

    *** @param className The main Java class name

    *** @param args The command line arguments

    *** @return A command to call and it's arguments

    **/

    public static String[] createJavaCommand(String classpath[], String className, String args[])

    {

        java.util.List<String> execCmd = new Vector<String>();

        execCmd.add(System.getProperty("java.home") + File.separator + "bin" + File.separator + "java");

        execCmd.add("-classpath");

        if (ListTools.isEmpty(classpath)) {

            execCmd.add(System.getProperty("java.class.path"));

        } else {

            StringBuffer sb = new StringBuffer();

            for (String p : classpath) {

                if (sb.length() > 0) { sb.append(File.pathSeparator); }

                sb.append(p);

            }

            execCmd.add(sb.toString());

        }

        execCmd.add(className);

        if (!ListTools.isEmpty(args)) {

            for (String a : args) {

                execCmd.add(a);

            }

        }

        return execCmd.toArray(new String[execCmd.size()]);

    }



    // ------------------------------------------------------------------------

    // ------------------------------------------------------------------------



    /**

    *** Main entry point for testing/debugging

    *** @param argv Comand-line arguments

    **/

    public static void main(String argv[])

    {

        RTConfig.setCommandLineArgs(argv);

        System.out.println("OS Type ...");

        Print.sysPrintln("Is Windows  : " + isWindows());

        Print.sysPrintln("Is Windows9X: " + isWindows9X());

        Print.sysPrintln("Is WindowsXP: " + isWindowsXP());

        Print.sysPrintln("Is Linux    : " + isLinux());

        Print.sysPrintln("Is MacOSX   : " + isMacOSX());

        Print.sysPrintln("PID #1      : " + getProcessID());

        Print.sysPrintln("PID #2      : " + _getProcessID());

        Runtime rt = Runtime.getRuntime();

        Print.sysPrintln("Total Mem   : " + rt.totalMemory()/(1024.0*1024.0));

        Print.sysPrintln("Max Mem     : " + rt.maxMemory()/(1024.0*1024.0));

        Print.sysPrintln("Free Mem    : " + rt.freeMemory()/(1024.0*1024.0));

    }



}