hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/StringTable.java

/*
 * Copyright (c) 2005, 2011, 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.memory;

import java.io.*;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.utilities.*;

public class StringTable extends sun.jvm.hotspot.utilities.Hashtable {
  static {
    VM.registerVMInitializedObserver(new Observer() {
        public void update(Observable o, Object data) {
          initialize(VM.getVM().getTypeDataBase());
        }
      });
  }

  private static synchronized void initialize(TypeDataBase db) {
    Type type = db.lookupType("StringTable");
    theTableField  = type.getAddressField("_the_table");
  }

  // Fields
  private static AddressField theTableField;

  // Accessors
  public static StringTable getTheTable() {
    Address tmp = theTableField.getValue();
    return (StringTable) VMObjectFactory.newObject(StringTable.class, tmp);
  }

  public StringTable(Address addr) {
    super(addr);
  }

  public interface StringVisitor {
    public void visit(Instance string);
  }

  public void stringsDo(StringVisitor visitor) {
    ObjectHeap oh = VM.getVM().getObjectHeap();
    int numBuckets = tableSize();
    for (int i = 0; i < numBuckets; i++) {
      for (HashtableEntry e = (HashtableEntry) bucket(i); e != null;
           e = (HashtableEntry) e.next()) {
        Instance s = (Instance)oh.newOop(e.literalValue().addOffsetToAsOopHandle(0));
        visitor.visit(s);
      }
    }
  }
}