/*

 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package sun.jvm.hotspot.tools;

import java.util.*;

import sun.jvm.hotspot.gc.g1.*;

import sun.jvm.hotspot.gc.parallel.*;

import sun.jvm.hotspot.gc.serial.*;

import sun.jvm.hotspot.gc.shared.*;

import sun.jvm.hotspot.debugger.JVMDebugger;

import sun.jvm.hotspot.memory.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.runtime.*;

public class HeapSummary extends Tool {

   public HeapSummary() {

      super();

   }

   public HeapSummary(JVMDebugger d) {

      super(d);

   }

   public static void main(String[] args) {

      HeapSummary hs = new HeapSummary();

      hs.execute(args);

   }

   @Override

   public String getName() {

      return "heapSummary";

   }

   public void run() {

      CollectedHeap heap = VM.getVM().getUniverse().heap();

      VM.Flag[] flags = VM.getVM().getCommandLineFlags();

      Map flagMap = new HashMap();

      if (flags == null) {

         System.out.println("WARNING: command line flags are not available");

      } else {

         for (int f = 0; f < flags.length; f++) {

            flagMap.put(flags[f].getName(), flags[f]);

         }

      }

      System.out.println();

      printGCAlgorithm(flagMap);

      System.out.println();

      System.out.println("Heap Configuration:");

      printValue("MinHeapFreeRatio         = ", getFlagValue("MinHeapFreeRatio", flagMap));

      printValue("MaxHeapFreeRatio         = ", getFlagValue("MaxHeapFreeRatio", flagMap));

      printValMB("MaxHeapSize              = ", getFlagValue("MaxHeapSize", flagMap));

      printValMB("NewSize                  = ", getFlagValue("NewSize", flagMap));

      printValMB("MaxNewSize               = ", getFlagValue("MaxNewSize", flagMap));

      printValMB("OldSize                  = ", getFlagValue("OldSize", flagMap));

      printValue("NewRatio                 = ", getFlagValue("NewRatio", flagMap));

      printValue("SurvivorRatio            = ", getFlagValue("SurvivorRatio", flagMap));

      printValMB("MetaspaceSize            = ", getFlagValue("MetaspaceSize", flagMap));

      printValMB("CompressedClassSpaceSize = ", getFlagValue("CompressedClassSpaceSize", flagMap));

      printValMB("MaxMetaspaceSize         = ", getFlagValue("MaxMetaspaceSize", flagMap));

      printValMB("G1HeapRegionSize         = ", HeapRegion.grainBytes());

      System.out.println();

      System.out.println("Heap Usage:");

      if (heap instanceof GenCollectedHeap) {

         GenCollectedHeap genHeap = (GenCollectedHeap) heap;

         for (int n = 0; n < genHeap.nGens(); n++) {

            Generation gen = genHeap.getGen(n);

            if (gen instanceof DefNewGeneration) {

               System.out.println("New Generation (Eden + 1 Survivor Space):");

               printGen(gen);

               ContiguousSpace eden = ((DefNewGeneration)gen).eden();

               System.out.println("Eden Space:");

               printSpace(eden);

               ContiguousSpace from = ((DefNewGeneration)gen).from();

               System.out.println("From Space:");

               printSpace(from);

               ContiguousSpace to = ((DefNewGeneration)gen).to();

               System.out.println("To Space:");

               printSpace(to);

            } else {

               System.out.println(gen.name() + ":");

               printGen(gen);

            }

         }

      } else if (heap instanceof G1CollectedHeap) {

          G1CollectedHeap g1h = (G1CollectedHeap) heap;

          G1MonitoringSupport g1mm = g1h.g1mm();

          long edenRegionNum = g1mm.edenRegionNum();

          long survivorRegionNum = g1mm.survivorRegionNum();

          HeapRegionSetBase oldSet = g1h.oldSet();

          HeapRegionSetBase humongousSet = g1h.humongousSet();

          long oldRegionNum = oldSet.length() + humongousSet.length();

          printG1Space("G1 Heap:", g1h.n_regions(),

                       g1h.used(), g1h.capacity());

          System.out.println("G1 Young Generation:");

          printG1Space("Eden Space:", edenRegionNum,

                       g1mm.edenUsed(), g1mm.edenCommitted());

          printG1Space("Survivor Space:", survivorRegionNum,

                       g1mm.survivorUsed(), g1mm.survivorCommitted());

          printG1Space("G1 Old Generation:", oldRegionNum,

                       g1mm.oldUsed(), g1mm.oldCommitted());

      } else if (heap instanceof ParallelScavengeHeap) {

         ParallelScavengeHeap psh = (ParallelScavengeHeap) heap;

         PSYoungGen youngGen = psh.youngGen();

         printPSYoungGen(youngGen);

         PSOldGen oldGen = psh.oldGen();

         long oldFree = oldGen.capacity() - oldGen.used();

         System.out.println("PS Old Generation");

         printValMB("capacity = ", oldGen.capacity());

         printValMB("used     = ", oldGen.used());

         printValMB("free     = ", oldFree);

         System.out.println(alignment + (double)oldGen.used() * 100.0 / oldGen.capacity() + "% used");

      } else {

         throw new RuntimeException("unknown CollectedHeap type : " + heap.getClass());

      }

      System.out.println();

      printInternStringStatistics();

   }

   // Helper methods

   private void printGCAlgorithm(Map flagMap) {

       long l = getFlagValue("UseTLAB", flagMap);

       if (l == 1L) {

          System.out.println("using thread-local object allocation.");

       }

       l = getFlagValue("UseConcMarkSweepGC", flagMap);

       if (l == 1L) {

          System.out.println("Concurrent Mark-Sweep GC");

          return;

       }

       l = getFlagValue("UseParallelGC", flagMap);

       if (l == 1L) {

          System.out.print("Parallel GC ");

          l = getFlagValue("ParallelGCThreads", flagMap);

          System.out.println("with " + l + " thread(s)");

          return;

       }

       l = getFlagValue("UseG1GC", flagMap);

       if (l == 1L) {

           System.out.print("Garbage-First (G1) GC ");

           l = getFlagValue("ParallelGCThreads", flagMap);

           System.out.println("with " + l + " thread(s)");

           return;

       }

       System.out.println("Mark Sweep Compact GC");

   }

   private void printPSYoungGen(PSYoungGen youngGen) {

      System.out.println("PS Young Generation");

      MutableSpace eden = youngGen.edenSpace();

      System.out.println("Eden Space:");

      printMutableSpace(eden);

      MutableSpace from = youngGen.fromSpace();

      System.out.println("From Space:");

      printMutableSpace(from);

      MutableSpace to = youngGen.toSpace();

      System.out.println("To Space:");

      printMutableSpace(to);

   }

   private void printMutableSpace(MutableSpace space) {

      printValMB("capacity = ", space.capacity());

      printValMB("used     = ", space.used());

      long free = space.capacity() - space.used();

      printValMB("free     = ", free);

      System.out.println(alignment + (double)space.used() * 100.0 / space.capacity() + "% used");

   }

   private static String alignment = "   ";

   private void printGen(Generation gen) {

      printValMB("capacity = ", gen.capacity());

      printValMB("used     = ", gen.used());

      printValMB("free     = ", gen.free());

      System.out.println(alignment + (double)gen.used() * 100.0 / gen.capacity() + "% used");

   }

   private void printSpace(ContiguousSpace space) {

      printValMB("capacity = ", space.capacity());

      printValMB("used     = ", space.used());

      printValMB("free     = ", space.free());

      System.out.println(alignment +  (double)space.used() * 100.0 / space.capacity() + "% used");

   }

   private void printG1Space(String spaceName, long regionNum,

                             long used, long capacity) {

      long free = capacity - used;

      System.out.println(spaceName);

      printValue("regions  = ", regionNum);

      printValMB("capacity = ", capacity);

      printValMB("used     = ", used);

      printValMB("free     = ", free);

      double occPerc = (capacity > 0) ? (double) used * 100.0 / capacity : 0.0;

      System.out.println(alignment + occPerc + "% used");

   }

   private static final double FACTOR = 1024*1024;

   private void printValMB(String title, long value) {

      if (value < 0) {

        System.out.println(alignment + title +   (value >>> 20)  + " MB");

      } else {

        double mb = value/FACTOR;

        System.out.println(alignment + title + value + " (" + mb + "MB)");

      }

   }

   private void printValue(String title, long value) {

      System.out.println(alignment + title + value);

   }

   private long getFlagValue(String name, Map flagMap) {

      VM.Flag f = (VM.Flag) flagMap.get(name);

      if (f != null) {

         if (f.isBool()) {

            return f.getBool()? 1L : 0L;

         } else {

            return Long.parseLong(f.getValue());

         }

      } else {

         return -1;

      }

   }

   private void printInternStringStatistics() {

      class StringStat implements StringTable.StringVisitor {

         private int count;

         private long size;

         private OopField stringValueField;

         StringStat() {

            VM vm = VM.getVM();

            SystemDictionary sysDict = vm.getSystemDictionary();

            InstanceKlass strKlass = sysDict.getStringKlass();

            // String has a field named 'value' of type 'byte[]'.

            stringValueField = (OopField) strKlass.findField("value", "[B");

         }

         private long stringSize(Instance instance) {

            // We include String content in size calculation.

            return instance.getObjectSize() +

                   stringValueField.getValue(instance).getObjectSize();

         }

         public void visit(Instance str) {

            count++;

            size += stringSize(str);

         }

         public void print() {

            System.out.println(count +

                  " interned Strings occupying " + size + " bytes.");

         }

      }

      StringStat stat = new StringStat();

      StringTable strTable = VM.getVM().getStringTable();

      strTable.stringsDo(stat);

      stat.print();

   }

}