/*

 * 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.

 *

 *

 */

package sun.jvm.hotspot.utilities;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.runtime.*;

public class Hashtable extends BasicHashtable {

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

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

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) {

    // just to confirm that type exists

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

  }

  // derived class may return Class<? extends HashtableEntry>

  protected Class getHashtableEntryClass() {

    return HashtableEntry.class;

  }

  public int hashToIndex(long fullHash) {

    return (int) (fullHash % tableSize());

  }

  public Hashtable(Address addr) {

    super(addr);

  }

  // VM's Hashtable::hash_symbol

  protected static long hashSymbol(byte[] buf) {

    long h = 0;

    int s = 0;

    int len = buf.length;

    while (len-- > 0) {

      h = 31*h + (0xFFL & buf[s]);

      s++;

    }

    return h & 0xFFFFFFFFL;

  }

}