summaryrefslogtreecommitdiff
path: root/libjava/classpath/gnu/CORBA/GIOP/MessageHeader.java
blob: 3137343edee81925a5a4f5683e8b0a0d2bd585f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
/* MessageHeader.java -- GIOP message header.
   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.

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.CORBA.GIOP;

import gnu.CORBA.Minor;
import gnu.CORBA.Version;
import gnu.CORBA.CDR.BigEndianInputStream;
import gnu.CORBA.CDR.BigEndianOutputStream;
import gnu.CORBA.CDR.LittleEndianInputStream;
import gnu.CORBA.CDR.LittleEndianOutputStream;
import gnu.CORBA.CDR.AbstractDataInput;
import gnu.CORBA.CDR.AbstractDataOutput;

import gnu.java.lang.CPStringBuilder;

import org.omg.CORBA.MARSHAL;
import org.omg.CORBA.portable.IDLEntity;

import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Arrays;

/**
 * The GIOP message header.
 *
 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
 */
public class MessageHeader
  implements IDLEntity
{
  /**
   * Use serialVersionUID for interoperability.
   */
  private static final long serialVersionUID = 1;

  /**
   * Request message.
   */
  public static final byte REQUEST = 0;

  /**
   * Reply message
   */
  public static final byte REPLY = 1;

  /**
   * Cancel request message.
   */
  public static final byte CANCEL_REQUEST = 2;

  /**
   * Locate request message, used to check the server ability to process
   * requests for the object reference. This message is also used to get the
   * address where the object reference should be sent.
   */
  public static final byte LOCATE_REQUEST = 3;

  /**
   * Locate reply message, sent in response to the {@link #LocateRequest}
   * message.
   */
  public static final byte LOCATE_REPLY = 4;

  /**
   * Instruction to close the connection.
   */
  public static final byte CLOSE_CONNECTION = 5;

  /**
   * Error report.
   */
  public static final byte MESSAGE_ERROR = 6;

  /**
   * The fragment messge, following the previous message that has more fragments
   * flag set. Added in GIOP 1.1
   */
  public static final byte FRAGMENT = 7;

  /**
   * This must always be "GIOP".
   */
  public static final byte[] MAGIC = new byte[] { 'G', 'I', 'O', 'P' };

  /**
   * The message type names.
   */
  protected static String[] types = new String[] { "Request", "Reply",
    "Cancel", "Locate request", "Locate reply", "Close connection", "Error",
    "Fragment" };

  /**
   * The GIOP version. Initialised to 1.0 .
   */
  public Version version;

  /**
   * The flags field, introduced since GIOP 1.1.
   */
  public byte flags = 0;

  /**
   * The message type.
   */
  public byte message_type = REQUEST;

  /**
   * The message size, excluding the message header.
   */
  public int message_size = 0;

  /**
   * Create an empty message header, corresponding version 1.0.
   */
  public MessageHeader()
  {
    version = new Version(1, 0);
  }

  /**
   * Create an empty message header, corresponding the given version.
   *
   * @param major the major message header version.
   * @param minor the minot message header version.
   */
  public MessageHeader(int major, int minor)
  {
    version = new Version(major, minor);
  }

  /**
   * Checks if the message is encoded in the Big Endian, most significant byte
   * first.
   */
  public boolean isBigEndian()
  {
    return (flags & 0x1) == 0;
  }

  /**
   * Checks if the message is partial, and more subsequent fragments follow.
   */
  public boolean moreFragmentsFollow()
  {
    return (flags & 0x2) != 0;
  }

  /**
   * Set the encoding to use.
   *
   * @param use_big_endian if true (default), the Big Endian encoding is used.
   * If false, the Little Endian encoding is used.
   */
  public void setBigEndian(boolean use_big_endian)
  {
    if (use_big_endian)
      flags = (byte) (flags & ~1);
    else
      flags = (byte) (flags | 1);
  }

  /**
   * Get the size of the message header itself. So far, it is always 12 bytes.
   */
  public int getHeaderSize()
  {
    return 12;
  }

  /**
   * Get the message type as string.
   *
   * @param type the message type as int (the field {@link message_type}).
   *
   * @return the message type as string.
   */
  public String getTypeString(int type)
  {
    try
      {
        return types[type];
      }
    catch (ArrayIndexOutOfBoundsException ex)
      {
        return "unknown type (" + type + ")";
      }
  }

  /**
   * Creates reply header, matching the message header version number.
   *
   * @return one of {@link gnu.CORBA.GIOP.v1_0.ReplyHeader},
   * {@link gnu.CORBA.GIOP.v1_2.ReplyHeader}, etc - depending on the version
   * number in this header.
   */
  public ReplyHeader create_reply_header()
  {
    if (version.since_inclusive(1, 2))
      return new gnu.CORBA.GIOP.v1_2.ReplyHeader();
    else
      return new gnu.CORBA.GIOP.v1_0.ReplyHeader();
  }

  /**
   * Creates request header, matching the message header version number.
   *
   * @return one of {@link gnu.CORBA.GIOP.v1_0.RequestHeader},
   * {@link gnu.CORBA.GIOP.v1_2.RequestHeader}, etc - depending on the version
   * number in this header.
   */
  public RequestHeader create_request_header()
  {
    if (version.since_inclusive(1, 2))
      return new gnu.CORBA.GIOP.v1_2.RequestHeader();
    else
      return new gnu.CORBA.GIOP.v1_0.RequestHeader();
  }

  /**
   * Create the cancel header, matching the message header version number.
   */
  public CancelHeader create_cancel_header()
  {
    return new gnu.CORBA.GIOP.v1_0.CancelHeader();
  }

  /**
   * Create the error message.
   */
  public ErrorMessage create_error_message()
  {
    return new ErrorMessage(version);
  }

  /**
   * Read the header from the stream.
   *
   * @param istream a stream to read from.
   * @throws MARSHAL if this is not a GIOP 1.0 header.
   */
  public void read(java.io.InputStream istream)
    throws MARSHAL, EOFException
  {
    try
      {
        byte[] xMagic = new byte[MAGIC.length];
        int r = istream.read(xMagic);
        int minor;
        if (! Arrays.equals(xMagic, MAGIC))
          {
            CPStringBuilder b = new CPStringBuilder();
            if (r == - 1)
              {
                b.append("Immediate EOF");
                minor = Minor.EOF;
              }
            else
              {
                minor = Minor.Giop;
                b.append(r + " bytes: ");
                for (int i = 0; i < xMagic.length; i++)
                  {
                    b.append(Integer.toHexString(xMagic[i] & 0xFF));
                    b.append(' ');
                  }
              }
            MARSHAL m = new MARSHAL("Not a GIOP message: " + b);
            m.minor = minor;
            throw m;
          }

        version = Version.read_version(istream);

        AbstractDataInput din;

        flags = (byte) istream.read();

        // This checks the bit in the byte we have just received.
        if (isBigEndian())
          din = new BigEndianInputStream(istream);
        else
          din = new LittleEndianInputStream(istream);

        message_type = (byte) din.read();

        message_size = din.readInt();
      }
    catch (IOException ex)
      {
        MARSHAL t = new MARSHAL();
        t.minor = Minor.Header;
        t.initCause(ex);
        throw t;
      }
  }

  /**
   * Get the short string summary of the message.
   *
   * @return a short message summary.
   */
  public String toString()
  {
    return "GIOP " + version + ", " + (isBigEndian() ? "Big" : "Little")
      + " endian, " + getTypeString(message_type) + ", " + message_size
      + " bytes. ";
  }

  /**
   * Write the header to stream.
   *
   * @param out a stream to write into.
   */
  public void write(java.io.OutputStream out)
  {
    try
      {
        AbstractDataOutput dout;

        if (isBigEndian())
          dout = new BigEndianOutputStream(out);
        else
          dout = new LittleEndianOutputStream(out);

        // Write magic sequence.
        dout.write(MAGIC);

        // Write version number.
        version.write((OutputStream) dout);
        dout.write(flags);
        dout.write(message_type);
        dout.writeInt(message_size);
      }
    catch (IOException ex)
      {
        MARSHAL t = new MARSHAL(ex.getMessage());
        t.minor = Minor.Header;
        t.initCause(ex);
        throw t;
      }
  }

  /**
   * Read data, followed by the message header. Handle fragmented messages.
   *
   * @param source the data source to read from.
   * @param service the socket on that the time outs are set. Can be null (no
   * timeouts are set).
   * @param to_read the timeout while reading the message.
   * @param to_pause the timeout for pauses between the message parts.
   */
  public byte[] readMessage(InputStream source, Socket service, int to_read,
    int to_pause)
  {
    try
      {
        byte[] r = new byte[message_size];

        int n = 0;
        if (service != null)
          service.setSoTimeout(to_read);

        while (n < r.length)
          {
            n += source.read(r, n, r.length - n);
          }
        if (service != null)
          service.setSoTimeout(to_pause);

        // Read the message remainder if the message is fragmented.
        if (moreFragmentsFollow())
          {
            ByteArrayOutputStream buffer = new ByteArrayOutputStream(
              2 * r.length);
            buffer.write(r);

            if (r.length < 10)
              // Increase the buffer size if the default value (size of the
              // previous message) is really too small.
              r = new byte[1024];

            MessageHeader h2 = new MessageHeader();

            do
              {
                h2.read(source);

                int dn;

                n = 0;
                while (n < h2.message_size)
                  {
                    dn = source.read(r, 0, h2.message_size - n);

                    if (n == 0 && service != null)
                      service.setSoTimeout(to_read);

                    if (n == 0 && version.since_inclusive(1, 2))
                      {
                        // Skip the four byte request id.
                        buffer.write(r, 4, dn - 4);
                      }
                    else
                      buffer.write(r, 0, dn);
                    n = +dn;
                  }

                if (service != null)
                  service.setSoTimeout(to_pause);
              }
            while (h2.moreFragmentsFollow());
            return buffer.toByteArray();
          }
        else
          return r;
      }
    catch (IOException ioex)
      {
        MARSHAL m = new MARSHAL("Unable to read the message continuation.");
        m.minor = Minor.Header;
        m.initCause(ioex);
        throw m;
      }
  }
}