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 * 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

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package sun.jvm.hotspot.gc.g1;

import java.util.Iterator;

import java.util.Observable;

import java.util.Observer;

import sun.jvm.hotspot.debugger.Address;

import sun.jvm.hotspot.debugger.OopHandle;

import sun.jvm.hotspot.runtime.VM;

import sun.jvm.hotspot.runtime.VMObject;

import sun.jvm.hotspot.runtime.VMObjectFactory;

import sun.jvm.hotspot.types.AddressField;

import sun.jvm.hotspot.types.CIntegerField;

import sun.jvm.hotspot.types.Type;

import sun.jvm.hotspot.types.TypeDataBase;

// Mirror class for G1HeapRegionTable. It's essentially an index -> HeapRegion map.

public class G1HeapRegionTable extends VMObject {

    // HeapRegion** _base;

    static private AddressField baseField;

    // uint _length;

    static private CIntegerField lengthField;

    // HeapRegion** _biased_base

    static private AddressField biasedBaseField;

    // size_t _bias

    static private CIntegerField biasField;

    // uint _shift_by

    static private CIntegerField shiftByField;

    static {

        VM.registerVMInitializedObserver(new Observer() {

                public void update(Observable o, Object data) {

                    initialize(VM.getVM().getTypeDataBase());

                }

            });

    }

    static private synchronized void initialize(TypeDataBase db) {

        Type type = db.lookupType("G1HeapRegionTable");

        baseField = type.getAddressField("_base");

        lengthField = type.getCIntegerField("_length");

        biasedBaseField = type.getAddressField("_biased_base");

        biasField = type.getCIntegerField("_bias");

        shiftByField = type.getCIntegerField("_shift_by");

    }

    private HeapRegion at(long index) {

        Address arrayAddr = baseField.getValue(addr);

        // Offset of &_base[index]

        long offset = index * VM.getVM().getAddressSize();

        Address regionAddr = arrayAddr.getAddressAt(offset);

        return (HeapRegion) VMObjectFactory.newObject(HeapRegion.class,

                                                      regionAddr);

    }

    public long length() {

        return lengthField.getValue(addr);

    }

    public long bias() {

        return biasField.getValue(addr);

    }

    public long shiftBy() {

        return shiftByField.getValue(addr);

    }

    private class HeapRegionIterator implements Iterator<HeapRegion> {

        private long index;

        private long length;

        private HeapRegion next;

        public HeapRegion positionToNext() {

          HeapRegion result = next;

          while (index < length && at(index) == null) {

            index++;

          }

          if (index < length) {

            next = at(index);

            index++; // restart search at next element

          } else {

            next = null;

          }

          return result;

        }

        @Override

        public boolean hasNext() { return next != null;     }

        @Override

        public HeapRegion next() { return positionToNext(); }

        @Override

        public void remove()     { /* not supported */      }

        HeapRegionIterator(long totalLength) {

            index = 0;

            length = totalLength;

            positionToNext();

        }

    }

    public Iterator<HeapRegion> heapRegionIterator(long committedLength) {

        return new HeapRegionIterator(committedLength);

    }

    public G1HeapRegionTable(Address addr) {

        super(addr);

    }

        long offset = biasedIndex * HeapRegion.getPointerSize();

    }

}