/*

 * Copyright (c) 2000, 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.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.types.*;

/** This class provides generalized "virtual constructor"

    functionality for VMObjects. In simple terms, it creates

    correctly-typed Java wrapper objects for underlying Addresses,

    using the "RTTI-like" functionality of TypeDataBase. For example,

    if the given Address really is a DefNewGeneration*, the Java object

    created for it will be of type

    sun.jvm.hotspot.memory.DefNewGeneration, assuming the mapping from

    type "DefNewGeneration" to class

    sun.jvm.hotspot.memory.DefNewGeneration has been set up. */

public class VirtualConstructor extends InstanceConstructor<VMObject> {

  private TypeDataBase db;

  private Map          map; // Map<String, Class>

  public VirtualConstructor(TypeDataBase db) {

    this.db = db;

    map     = new HashMap();

  }

  /** Adds a mapping from the given C++ type name to the given Java

      class. The latter must be a subclass of

      sun.jvm.hotspot.runtime.VMObject. Returns false if there was

      already a class for this type name in the map. */

  public boolean addMapping(String cTypeName, Class clazz) {

    if (map.get(cTypeName) != null) {

      return false;

    }

    map.put(cTypeName, clazz);

    return true;

  }

  /** Instantiate the most-precisely typed wrapper object available

      for the type of the given Address. If no type in the mapping

      matched the type of the Address, throws a WrongTypeException.

      Returns null for a null address (similar behavior to

      VMObjectFactory). */

  public VMObject instantiateWrapperFor(Address addr) throws WrongTypeException {

    if (addr == null) {

      return null;

    }

    for (Iterator iter = map.keySet().iterator(); iter.hasNext(); ) {

      String typeName = (String) iter.next();

      if (db.addressTypeIsEqualToType(addr, db.lookupType(typeName))) {

        return (VMObject) VMObjectFactory.newObject((Class) map.get(typeName), addr);

      }

    }

    throw newWrongTypeException(addr);

  }

}