gcc/libjava/classpath/gnu/CORBA/Poa/ForwardedServant.java

/* ForwardedServant.java --
   Copyright (C) 2005 Free Software Foundation, Inc.

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.

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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
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permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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exception statement from your version. */


package gnu.CORBA.Poa;

import gnu.CORBA.IOR;
import gnu.CORBA.IorDelegate;
import gnu.CORBA.IorObject;
import gnu.CORBA.Minor;

import org.omg.CORBA.BAD_PARAM;
import org.omg.CORBA.CompletionStatus;
import org.omg.CORBA.MARSHAL;
import org.omg.CORBA.ORB;
import org.omg.CORBA.SystemException;
import org.omg.CORBA.portable.ApplicationException;
import org.omg.CORBA.portable.Delegate;
import org.omg.CORBA.portable.InputStream;
import org.omg.CORBA.portable.InvokeHandler;
import org.omg.CORBA.portable.ObjectImpl;
import org.omg.CORBA.portable.OutputStream;
import org.omg.CORBA.portable.RemarshalException;
import org.omg.CORBA.portable.ResponseHandler;
import org.omg.PortableServer.POA;
import org.omg.PortableServer.Servant;

import java.io.IOException;

/**
 * A "virtual servant", delegating all invocation to the wrapped
 * object (usually remote). Used in cases when it is necessary to
 * handle the request forwarding.
 *
 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
 */
public class ForwardedServant
  extends Servant
  implements InvokeHandler
{
  /**
   * The reference object, handling requests.
   */
  public final ObjectImpl ref;

  /**
   * Create an instance, forwarding requests to the given object.
   */
  ForwardedServant(ObjectImpl a_ref)
  {
    ref = a_ref;
  }

  /**
   * Create an instance of the forwarded servant.
   *
   * @param a_ref a reference where request should be forwarded.
   *
   * @return a created forwarded servant or null if the parameter
   * forwards request to itself. Returning null will force to find
   * a right servant in one of many possible ways, depending on
   * policies.
   */
  public static Servant create(org.omg.CORBA.Object a_ref)
  {
    try
      {
        ObjectImpl fto = (ObjectImpl) a_ref;

        // Check maybe the remote side forwarded back to our local object.
        if (fto instanceof IorObject)
          {
            IorObject iref = (IorObject) fto;

            // Check maybe the IOR is local.
            ORB t_orb = iref._orb();
            if (t_orb instanceof ORB_1_4)
              {
                ORB_1_4 orb = (ORB_1_4) t_orb;
                Delegate d = iref._get_delegate();
                if (d instanceof IorDelegate)
                  {
                    IorDelegate ird = (IorDelegate) iref._get_delegate();
                    IOR ior = ird.getIor();
                    if (orb.LOCAL_HOST.equalsIgnoreCase(ior.Internet.host))
                      {
                        AOM.Obj rx = orb.rootPOA.findIorKey(ior.key);
                        if (rx != null)
                          {
                            if (rx.object == fto ||
                                rx.object._is_equivalent(fto)
                               )
                              return rx.primary_servant;
                            else
                              fto = (ObjectImpl) rx.object;
                          }
                      }
                  }
              }
          }
        return new ForwardedServant(fto);
      }
    catch (ClassCastException ex)
      {
        throw new BAD_PARAM("ObjectImpl required but " + a_ref + " passed ",
                            0x5005, CompletionStatus.COMPLETED_NO
                           );
      }
  }

  /**
   * Forward the call to the wrapped object.
   */
  public OutputStream _invoke(String method, InputStream input,
                              ResponseHandler handler
                             )
                       throws SystemException
  {
    org.omg.CORBA.portable.InputStream in = null;
    org.omg.CORBA.portable.OutputStream out = null;
    try
      {
        try
          {
            out = ref._request(method, true);

            // Transfer request information.
            int b;
            while ((b = input.read()) >= 0)
              {
                out.write(b);
              }
            in = ref._invoke(out);

            // Read the returned data.
            out = handler.createReply();
            while ((b = in.read()) >= 0)
              {
                out.write(b);
              }
          }
        catch (IOException io_ex)
          {
            MARSHAL m = new MARSHAL();
            m.minor = Minor.Forwarding;
            m.initCause(io_ex);
            throw m;
          }
      }
    catch (ApplicationException ex)
      {
        in = ex.getInputStream();

        String _id = ex.getId();
        throw new MARSHAL(_id, 5101, CompletionStatus.COMPLETED_NO);
      }
    catch (RemarshalException remarsh)
      {
        _invoke(method, input, handler);
      }
    finally
      {
        ref._releaseReply(in);
      }
    return out;
  }

  /**
   * Delegates to the wrapped object.
   */
  public String[] _all_interfaces(POA poa, byte[] key)
  {
    return ref._ids();
  }
}