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/* Value.java -- class to read/write JDWP tagged and untagged values

   Copyright (C) 2005 Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2, or (at your option)

any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License

along with GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

Linking this library statically or dynamically with other modules is

making a combined work based on this library.  Thus, the terms and

conditions of the GNU General Public License cover the whole

combination.

As a special exception, the copyright holders of this library give you

permission to link this library with independent modules to produce an

executable, regardless of the license terms of these independent

modules, and to copy and distribute the resulting executable under

terms of your choice, provided that you also meet, for each linked

independent module, the terms and conditions of the license of that

module.  An independent module is a module which is not derived from

or based on this library.  If you modify this library, you may extend

this exception to your version of the library, but you are not

obligated to do so.  If you do not wish to do so, delete this

exception statement from your version. */

package gnu.classpath.jdwp.util;

import gnu.classpath.jdwp.JdwpConstants;

import gnu.classpath.jdwp.VMIdManager;

import gnu.classpath.jdwp.exception.InvalidFieldException;

import gnu.classpath.jdwp.exception.JdwpException;

import gnu.classpath.jdwp.exception.JdwpInternalErrorException;

import gnu.classpath.jdwp.exception.NotImplementedException;

import gnu.classpath.jdwp.id.ObjectId;

import java.io.DataOutputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

/**

 * A class to read/write JDWP tagged and untagged values.

 *

 * @author Aaron Luchko <aluchko@redhat.com>

 */

public class Value

{

  /**

   * Will write the given object as an untagged value to the DataOutputStream.

   *

   * @param os write the value here

   * @param obj the Object to write

   * @throws IOException

   * @throws InvalidFieldException

   */

  public static void writeUntaggedValue(DataOutputStream os, Object obj)

    throws JdwpException, IOException

  {

    writeValue(os, obj, false);

  }

  /**

   * Will write the given object as a tagged value to the DataOutputStream.

   *

   * @param os write the value here

   * @param obj the Object to write

   * @throws IOException

   * @throws InvalidFieldException

   */

  public static void writeTaggedValue(DataOutputStream os, Object obj)

    throws JdwpException, IOException

  {

    writeValue(os, obj, true);

  }

  /**

   * Will write the given object as either a value or an untagged value to the

   * DataOutputStream.

   *

   * @param os write the value here

   * @param obj the Object to write

   * @param tagged true if the value is tagged, false otherwise

   * @throws IOException

   * @throws InvalidFieldException

   */

  private static void writeValue(DataOutputStream os, Object obj,

                                boolean tagged)

    throws IOException, JdwpException

  {

    Class clazz = obj.getClass();

    if (clazz.isPrimitive())

      {

        if (clazz == byte.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.BYTE);

            os.writeByte(((Byte) obj).byteValue());

          }

        else if (clazz == char.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.CHAR);

            os.writeChar(((Character) obj).charValue());

          }

        else if (clazz == float.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.FLOAT);

            os.writeFloat(((Float) obj).floatValue());

          }

        else if (clazz == double.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.DOUBLE);

            os.writeDouble(((Double) obj).doubleValue());

          }

        else if (clazz == int.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.BYTE);

            os.writeInt(((Integer) obj).intValue());

          }

        else if (clazz == long.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.LONG);

            os.writeLong(((Long) obj).longValue());

          }

        else if (clazz == short.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.SHORT);

            os.writeInt(((Short) obj).shortValue());

          }

        else if (clazz == void.class)

          { // A 'void' has no data

            if (tagged)

              os.writeByte(JdwpConstants.Tag.VOID);

          }

        else if (clazz == boolean.class)

          {

            if (tagged)

              os.writeByte(JdwpConstants.Tag.BOOLEAN);

            os.writeBoolean(((Boolean) obj).booleanValue());

          }

        else

          { // This shouldn't be possible

            throw new JdwpInternalErrorException(

              "Field has invalid primitive!");

          }

      }

    else

      {

        // Object is an Object, not a primitive type wrapped in an object

        // Write the appropriate tag

        if (tagged)

          {

            if (clazz.isArray())

              os.writeByte(JdwpConstants.Tag.ARRAY);

            else if (obj instanceof String)

              os.writeByte(JdwpConstants.Tag.STRING);

            else if (obj instanceof Thread)

              os.writeByte(JdwpConstants.Tag.THREAD);

            else if (obj instanceof ThreadGroup)

              os.writeByte(JdwpConstants.Tag.THREAD_GROUP);

            else if (obj instanceof ClassLoader)

              os.writeByte(JdwpConstants.Tag.CLASS_LOADER);

            else if (obj instanceof Class)

              os.writeByte(JdwpConstants.Tag.CLASS_OBJECT);

            else

              os.writeByte(JdwpConstants.Tag.OBJECT);

          }

        ObjectId oid = VMIdManager.getDefault().getObjectId(obj);

        oid.write(os);

      }

  }

  /**

   * Reads the appropriate object for the tagged value contained in the

   * ByteBuffer.

   *

   * @param bb contains the Object

   * @return The Object referenced by the value

   * @throws JdwpException

   * @throws IOException

   */

  public static Object getObj(ByteBuffer bb)

    throws JdwpException, IOException

  {

    return getUntaggedObj(bb, bb.get());

  }

  /**

   * Reads the an object of the given Class from the untagged value contained

   * in the ByteBuffer.

   *

   * @param bb contains the Object

   * @param type corresponds to the TAG of value to be read

   * @return

   * @throws JdwpException

   * @throws IOException

   */

  public static Object getUntaggedObj(ByteBuffer bb, Class type)

    throws JdwpException, IOException

  {

    if (type.isPrimitive())

      {

        if (type == byte.class)

          return new Byte(bb.get());

        else if (type == char.class)

          return new Character(bb.getChar());

        else if (type == float.class)

          return new Float(bb.getFloat());

        else if (type == double.class)

          return new Double(bb.getDouble());

        else if (type == int.class)

          return new Integer(bb.getInt());

        else if (type == long.class)

          return new Long(bb.getLong());

        else if (type == short.class)

          return new Short(bb.getShort());

        else if (type == boolean.class)

          return (bb.get() == 0) ? new Boolean(false) : new Boolean(true);

        else if (type == void.class)

          return new byte[0];

        else

          { // This shouldn't be possible

            throw new JdwpInternalErrorException(

              "Field has invalid primitive!");

          }

      }

    else

      {

        // Field is an object

        ObjectId oid = VMIdManager.getDefault().readObjectId(bb);

        return oid.getObject();

      }

  }

  /**

   * Reads the an object of the given Class from the untagged value contained

   * in the ByteBuffer.

   *

   * @param bb contains the Object

   * @param tag TAG of the Value to be read

   * @return the object

   * @throws JdwpException

   * @throws IOException

   */

  public static Object getUntaggedObj(ByteBuffer bb, byte tag)

    throws JdwpException, IOException

  {

    switch (tag)

      {

      case JdwpConstants.Tag.BYTE:

        return new Byte(bb.get());

      case JdwpConstants.Tag.CHAR:

        return new Character(bb.getChar());

      case JdwpConstants.Tag.FLOAT:

        return new Float(bb.getFloat());

      case JdwpConstants.Tag.DOUBLE:

        return new Double(bb.getDouble());

      case JdwpConstants.Tag.INT:

        return new Integer(bb.getInt());

      case JdwpConstants.Tag.LONG:

        return new Long(bb.getLong());

      case JdwpConstants.Tag.SHORT:

        return new Short(bb.getShort());

      case JdwpConstants.Tag.VOID:

        return new byte[0];

      case JdwpConstants.Tag.BOOLEAN:

        return (bb.get() == 0) ? new Boolean(false) : new Boolean(true);

      case JdwpConstants.Tag.STRING:

        return JdwpString.readString(bb);

      case JdwpConstants.Tag.ARRAY:

      case JdwpConstants.Tag.THREAD:

      case JdwpConstants.Tag.OBJECT:

      case JdwpConstants.Tag.THREAD_GROUP:

      case JdwpConstants.Tag.CLASS_LOADER:

      case JdwpConstants.Tag.CLASS_OBJECT:

        // All these cases are ObjectIds

        ObjectId oid = VMIdManager.getDefault().readObjectId(bb);

        return oid.getObject();

      default:

        throw new NotImplementedException("Tag " + tag

                                          + " is not implemented.");

      }

  }

}