/*

 * Copyright (c) 2001, 2012, 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.

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 */

package sun.jvm.hotspot.oops;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

public class ConstantPoolCacheEntry {

  private static long          size;

  private static long          baseOffset;

  private static CIntegerField indices;

  private static AddressField  f1;

  private static CIntegerField f2;

  private static CIntegerField flags;

  private ConstantPoolCache cp;

  private long      offset;

  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("ConstantPoolCacheEntry");

    size = type.getSize();

    indices = type.getCIntegerField("_indices");

    f1      = type.getAddressField ("_f1");

    f2      = type.getCIntegerField("_f2");

    flags   = type.getCIntegerField("_flags");

    type = db.lookupType("ConstantPoolCache");

    baseOffset = type.getSize();

  }

  ConstantPoolCacheEntry(ConstantPoolCache cp, int index) {

    this.cp = cp;

    offset  = baseOffset + index * size;

  }

  public int getConstantPoolIndex() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that((getIndices() & 0xFFFF) != 0, "must be main entry");

    }

    return (int) (getIndices() & 0xFFFF);

  }

  private long getIndices() {

    return cp.getAddress().getCIntegerAt(indices.getOffset() + offset, indices.getSize(), indices.isUnsigned());

  }

  public Metadata getF1() {

    return Metadata.instantiateWrapperFor(cp.getAddress().getAddressAt(f1.getOffset() + offset));

  }

  public int getF2() {

    return cp.getAddress().getJIntAt(f1.getOffset() + offset);

  }

  public int getFlags() {

    return cp.getAddress().getJIntAt(flags.getOffset() + offset);

  }

  static NamedFieldIdentifier f1FieldName = new NamedFieldIdentifier("_f1");

  static NamedFieldIdentifier f2FieldName = new NamedFieldIdentifier("_f2");

  static NamedFieldIdentifier flagsFieldName = new NamedFieldIdentifier("_flags");

  public void iterateFields(MetadataVisitor visitor) {

    visitor.doOop(new OopField(f1FieldName, f1.getOffset() + offset, true), true);

    visitor.doInt(new IntField(f2FieldName, f2.getOffset() + offset, true), true);

    visitor.doInt(new IntField(flagsFieldName, flags.getOffset() + offset, true), true);

  }

}