old-autovect-branch/libjava/classpath/gnu/CORBA/ResponseHandlerImpl.java

   1 /* ResponseHandlerImpl.java --
   2    Copyright (C) 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package gnu.CORBA;
  40
  41 import gnu.CORBA.CDR.BufferedCdrOutput;
  42 import gnu.CORBA.GIOP.MessageHeader;
  43 import gnu.CORBA.GIOP.ReplyHeader;
  44 import gnu.CORBA.GIOP.RequestHeader;
  45 import gnu.CORBA.GIOP.CodeSetServiceContext;
  46
  47 import org.omg.CORBA.ORB;
  48 import org.omg.CORBA.portable.OutputStream;
  49 import org.omg.CORBA.portable.ResponseHandler;
  50
  51 /**
  52  * Provides the CDR output streams for writing the response to the given buffer.
  53  *
  54  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
  55  */
  56 public class ResponseHandlerImpl
  57   implements ResponseHandler
  58 {
  59   /**
  60    * The message header. This field is used to compute the size and alignments.
  61    * It is, however, never directly written to the buffer stream.
  62    */
  63   public final MessageHeader message_header;
  64
  65   /**
  66    * The associated orb.
  67    */
  68   public final ORB orb;
  69
  70   /**
  71    * The reply header.
  72    */
  73   public final ReplyHeader reply_header;
  74
  75   /**
  76    * The request header.
  77    */
  78   public final RequestHeader request_header;
  79
  80   /**
  81    * True if the stream was obtained by invoking {@link #createExceptionReply()},
  82    * false otherwise.
  83    */
  84   private boolean exceptionReply;
  85
  86   /**
  87    * The buffer to write into.
  88    */
  89   private BufferedCdrOutput buffer;
  90
  91   /**
  92    * Create a new buffered response handler that uses the given message headers.
  93    * The headers are used to compute sizes and check the versions. They are not
  94    * written into a stream inside this class.
  95    *
  96    * @param m_header a message header.
  97    * @param r_header a reply header.
  98    */
  99   ResponseHandlerImpl(ORB an_orb, MessageHeader m_header,
 100                           ReplyHeader r_header, RequestHeader rq_header)
 101   {
 102     message_header = m_header;
 103     reply_header = r_header;
 104     request_header = rq_header;
 105     orb = an_orb;
 106     prepareStream();
 107   }
 108
 109   /**
 110    * Get an output stream for providing details about the exception. Before
 111    * returning the stream, the handler automatically writes the message header
 112    * and the reply about exception header, but not the message header.
 113    *
 114    * @return the stream to write exception details into.
 115    */
 116   public OutputStream createExceptionReply()
 117   {
 118     exceptionReply = true;
 119     prepareStream();
 120     return buffer;
 121   }
 122
 123   /**
 124    * Get an output stream for writing a regular reply (not an exception).
 125    *
 126    * Before returning the stream, the handler automatically writes the regular
 127    * reply header, but not the message header.
 128    *
 129    * @return the output stream for writing a regular reply.
 130    */
 131   public OutputStream createReply()
 132   {
 133     exceptionReply = false;
 134     prepareStream();
 135     reply_header.reply_status = ReplyHeader.NO_EXCEPTION;
 136     return buffer;
 137   }
 138
 139   /**
 140    * Get the buffer, normally containing the written reply. The reply includes
 141    * the reply header (or the exception header) but does not include the message
 142    * header.
 143    *
 144    * The stream buffer can also be empty if no data have been written into
 145    * streams, returned by {@link #createReply()} or
 146    * {@link #createExceptionReply()}.
 147    *
 148    * @return the CDR output stream, containing the written output.
 149    */
 150   public BufferedCdrOutput getBuffer()
 151   {
 152     return buffer;
 153   }
 154
 155   /**
 156    * True if the stream was obtained by invoking {@link #createExceptionReply()},
 157    * false otherwise (usually no-exception reply).
 158    */
 159   public boolean isExceptionReply()
 160   {
 161     return exceptionReply;
 162   }
 163
 164   /**
 165    * Compute the header offset, set the correct version number and codeset.
 166    */
 167   private void prepareStream()
 168   {
 169     buffer = new BufferedCdrOutput();
 170     buffer.setOrb(orb);
 171     buffer.setVersion(message_header.version);
 172     buffer.setCodeSet(CodeSetServiceContext.find(reply_header.service_context));
 173
 174     // Since 1.2, the data section is always aligned on the 8 byte boundary.
 175     // In older versions, it is necessary to set the offset correctly.
 176     if (message_header.version.until_inclusive(1, 1))
 177       {
 178         buffer.setOffset(message_header.getHeaderSize());
 179
 180         // Get the position after the reply header would be written.
 181         reply_header.write(buffer);
 182
 183         int new_offset = message_header.getHeaderSize() + buffer.buffer.size();
 184
 185         buffer.buffer.reset();
 186         buffer.setOffset(new_offset);
 187       }
 188   }
 189 }