/*

 * 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.oops;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

//  ConstantPoolCache : A constant pool cache (ConstantPoolCache).

//  See cpCache.hpp for details about this class.

//

public class ConstantPoolCache extends Metadata {

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {

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

    constants      = new MetadataField(type.getAddressField("_constant_pool"), 0);

    baseOffset     = type.getSize();

    Type elType    = db.lookupType("ConstantPoolCacheEntry");

    elementSize    = elType.getSize();

    length         = new CIntField(type.getCIntegerField("_length"), 0);

    intSize        = VM.getVM().getObjectHeap().getIntSize();

  }

  public ConstantPoolCache(Address addr) {

    super(addr);

  }

  public boolean isConstantPoolCache() { return true; }

  private static MetadataField constants;

  private static long baseOffset;

  private static long elementSize;

  private static CIntField length;

  private static long intSize;

  public ConstantPool getConstants() { return (ConstantPool) constants.getValue(this); }

  public long getSize() {

    return alignSize(baseOffset + getLength() * elementSize);

  }

  public ConstantPoolCacheEntry getEntryAt(int i) {

    if (i < 0 || i >= getLength()) throw new IndexOutOfBoundsException(i + " " + getLength());

    return new ConstantPoolCacheEntry(this, i);

  }

  public int getIntAt(int entry, int fld) {

    long offset = baseOffset + entry * elementSize + fld * intSize;

    return (int) getAddress().getCIntegerAt(offset, intSize, true );

  }

  public void printValueOn(PrintStream tty) {

    tty.print("ConstantPoolCache for " + getConstants().getPoolHolder().getName().asString() + " address = " + getAddress() + " offset = " + baseOffset);

  }

  public int getLength() {

    return (int) length.getValue(getAddress());

  }

  public void iterateFields(MetadataVisitor visitor) {

    super.iterateFields(visitor);

    visitor.doMetadata(constants, true);

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

        ConstantPoolCacheEntry entry = getEntryAt(i);

        entry.iterateFields(visitor);

      }

    }

};