| 1 | package org.dcache.cells; |
| 2 | |
| 3 | import java.io.Serializable; |
| 4 | |
| 5 | import dmg.cells.nucleus.CellEndpoint; |
| 6 | import dmg.cells.nucleus.CellMessage; |
| 7 | import dmg.cells.nucleus.CellPath; |
| 8 | import dmg.cells.nucleus.CellMessageAnswerable; |
| 9 | import dmg.cells.nucleus.NoRouteToCellException; |
| 10 | |
| 11 | import diskCacheV111.vehicles.Message; |
| 12 | import diskCacheV111.util.CacheException; |
| 13 | import diskCacheV111.util.TimeoutCacheException; |
| 14 | import org.dcache.util.CacheExceptionFactory; |
| 15 | |
| 16 | /** |
| 17 | * Stub class for common cell communication patterns. An instance |
| 18 | * of the template class encapsulates properties such as the |
| 19 | * destination and timeout for communication. |
| 20 | * |
| 21 | * Operations are aware of the dCache Message class and the |
| 22 | * CacheException class, and are able to interpret dCache error |
| 23 | * messages. |
| 24 | */ |
| 25 | public class CellStub |
| 26 | implements CellMessageSender |
| 27 | { |
| 28 | private CellEndpoint _endpoint; |
| 29 | private CellPath _destination; |
| 30 | private long _timeout = 30000; |
| 31 | private boolean _retryOnNoRouteToCell; |
| 32 | |
| 33 | public CellStub() |
| 34 | { |
| 35 | } |
| 36 | |
| 37 | public CellStub(CellEndpoint endpoint) |
| 38 | { |
| 39 | setCellEndpoint(endpoint); |
| 40 | } |
| 41 | |
| 42 | public CellStub(CellEndpoint endpoint, CellPath destination) |
| 43 | { |
| 44 | this(endpoint); |
| 45 | setDestinationPath(destination); |
| 46 | } |
| 47 | |
| 48 | public CellStub(CellEndpoint endpoint, CellPath destination, long timeout) |
| 49 | { |
| 50 | this(endpoint, destination); |
| 51 | setTimeout(timeout); |
| 52 | } |
| 53 | |
| 54 | @Override |
| 55 | public void setCellEndpoint(CellEndpoint endpoint) |
| 56 | { |
| 57 | _endpoint = endpoint; |
| 58 | } |
| 59 | |
| 60 | public void setDestination(String destination) |
| 61 | { |
| 62 | setDestinationPath(new CellPath(destination)); |
| 63 | } |
| 64 | |
| 65 | public void setDestinationPath(CellPath destination) |
| 66 | { |
| 67 | _destination = destination; |
| 68 | } |
| 69 | |
| 70 | public CellPath getDestinationPath() |
| 71 | { |
| 72 | return _destination; |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * Sets the communication timeout of the stub. |
| 77 | * @param timeout the timeout in milliseconds |
| 78 | */ |
| 79 | public void setTimeout(long timeout) |
| 80 | { |
| 81 | _timeout = timeout; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Returns the communication timeout of the stub. |
| 86 | */ |
| 87 | public long getTimeout() |
| 88 | { |
| 89 | return _timeout; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Set the value of the retryOnNoRouteCell property, which |
| 94 | * determines whether to retry on failure to route the message to |
| 95 | * the destination. |
| 96 | * |
| 97 | * If set to false, failure to send the message will cause a |
| 98 | * TimeoutCacheException to be reported right away. If set to |
| 99 | * true, failure to send the message to the destination cell will |
| 100 | * be retried until the timeout has been reached. Once the timeout |
| 101 | * is reached, a TimeoutCacheException is thrown. This is useful |
| 102 | * for destinations for which communication failure is known to be |
| 103 | * temporary. |
| 104 | * |
| 105 | * Limitations: This property currently only has an effect on the |
| 106 | * sendAndWait method. Asynchronous message delivery always |
| 107 | * reports a no route error in case of communication failure. |
| 108 | */ |
| 109 | public void setRetryOnNoRouteToCell(boolean retry) |
| 110 | { |
| 111 | _retryOnNoRouteToCell = retry; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Returns the value of the retryOnNoRouteCell property, which |
| 116 | * determines whether to retry on failure to route the message to |
| 117 | * the destination. |
| 118 | */ |
| 119 | public boolean getRetryOnNoRouteToCell() |
| 120 | { |
| 121 | return _retryOnNoRouteToCell; |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * Sends a message and waits for the reply. The reply is expected |
| 126 | * to contain a message object of the same type as the message |
| 127 | * object that was sent, and the return code of that message is |
| 128 | * expected to be zero. If either is not the case, an exception is |
| 129 | * thrown. |
| 130 | * |
| 131 | * @param msg the message object to send |
| 132 | * @return the message object from the reply |
| 133 | * @throws InterruptedException If the thread is interrupted |
| 134 | * @throws CacheException If the message could not be sent, a |
| 135 | * timeout occurred, the object in the reply was of the wrong |
| 136 | * type, or the return code was non-zero. |
| 137 | */ |
| 138 | public <T extends Message> T sendAndWait(T msg) |
| 139 | throws CacheException, InterruptedException |
| 140 | { |
| 141 | return sendAndWait(msg, _timeout); |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * Sends a message and waits for the reply. The reply is expected |
| 146 | * to contain a message object of the same type as the message |
| 147 | * object that was sent, and the return code of that message is |
| 148 | * expected to be zero. If either is not the case, an exception is |
| 149 | * thrown. |
| 150 | * |
| 151 | * @param msg the message object to send |
| 152 | * @param timeout in milliseconds to wait for a reply |
| 153 | * @return the message object from the reply |
| 154 | * @throws InterruptedException If the thread is interrupted |
| 155 | * @throws CacheException If the message could not be sent, a |
| 156 | * timeout occurred, the object in the reply was of the wrong |
| 157 | * type, or the return code was non-zero. |
| 158 | */ |
| 159 | public <T extends Message> T sendAndWait(T msg, long timeout) |
| 160 | throws CacheException, InterruptedException |
| 161 | { |
| 162 | return sendAndWait(_destination, msg, timeout); |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * Sends a message and waits for the reply. The reply is expected |
| 167 | * to contain a message object of the same type as the message |
| 168 | * object that was sent, and the return code of that message is |
| 169 | * expected to be zero. If either is not the case, an exception is |
| 170 | * thrown. |
| 171 | * |
| 172 | * @param path the destination cell |
| 173 | * @param msg the message object to send |
| 174 | * @return the message object from the reply |
| 175 | * @throws InterruptedException If the thread is interrupted |
| 176 | * @throws CacheException If the message could not be sent, a |
| 177 | * timeout occurred, the object in the reply was of the wrong |
| 178 | * type, or the return code was non-zero. |
| 179 | */ |
| 180 | public <T extends Message> T sendAndWait(CellPath path, T msg) |
| 181 | throws CacheException, InterruptedException |
| 182 | { |
| 183 | msg.setReplyRequired(true); |
| 184 | |
| 185 | T reply = (T) sendAndWait(path, msg, msg.getClass()); |
| 186 | |
| 187 | if (reply.getReturnCode() != 0) { |
| 188 | throw CacheExceptionFactory.exceptionOf(reply); |
| 189 | } |
| 190 | |
| 191 | return reply; |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Sends a message and waits for the reply. The reply is expected |
| 196 | * to contain a message object of the specified type. If this is |
| 197 | * not the case, an exception is thrown. |
| 198 | * |
| 199 | * @param msg the message object to send |
| 200 | * @param type the expected type of the reply |
| 201 | * @return the message object from the reply |
| 202 | * @throws InterruptedException If the thread is interrupted |
| 203 | * @throws CacheException If the message could not be sent, a |
| 204 | * timeout occurred, or the object in the reply was of the |
| 205 | * wrong type. |
| 206 | */ |
| 207 | public <T extends Serializable> T |
| 208 | sendAndWait(Serializable msg, Class<T> type) |
| 209 | throws CacheException, InterruptedException |
| 210 | { |
| 211 | return sendAndWait(_destination, msg, type); |
| 212 | } |
| 213 | |
| 214 | |
| 215 | public <T extends Serializable> T sendAndWait(CellPath path, |
| 216 | Serializable msg, |
| 217 | Class<T> type) |
| 218 | throws CacheException, InterruptedException |
| 219 | { |
| 220 | return sendAndWait(path, msg, type, _timeout); |
| 221 | } |
| 222 | |
| 223 | |
| 224 | /** |
| 225 | * Sends a message and waits for the reply. The reply is expected |
| 226 | * to contain a message object of the specified type. If this is |
| 227 | * not the case, an exception is thrown. |
| 228 | * |
| 229 | * @param msg the message object to send |
| 230 | * @param type the expected type of the reply |
| 231 | * @param timeout the time to wait for the reply |
| 232 | * @return the message object from the reply |
| 233 | * @throws InterruptedException If the thread is interrupted |
| 234 | * @throws CacheException If the message could not be sent, a |
| 235 | * timeout occurred, or the object in the reply was of the |
| 236 | * wrong type. |
| 237 | */ |
| 238 | public <T extends Serializable> T |
| 239 | sendAndWait(Serializable msg, Class<T> type, long timeout) |
| 240 | throws CacheException, InterruptedException |
| 241 | { |
| 242 | return sendAndWait(_destination, msg, type, timeout); |
| 243 | } |
| 244 | |
| 245 | |
| 246 | |
| 247 | /** |
| 248 | * Sends a message and waits for the reply. The reply is expected |
| 249 | * to contain a message object of the same type as the message |
| 250 | * object that was sent, and the return code of that message is |
| 251 | * expected to be zero. If either is not the case, an exception is |
| 252 | * thrown. |
| 253 | * |
| 254 | * @param path the destination cell |
| 255 | * @param msg the message object to send |
| 256 | * @param timeout the time to wait for the reply |
| 257 | * @return the message object from the reply |
| 258 | * @throws InterruptedException If the thread is interrupted |
| 259 | * @throws CacheException If the message could not be sent, a |
| 260 | * timeout occurred, the object in the reply was of the wrong |
| 261 | * type, or the return code was non-zero. |
| 262 | */ |
| 263 | public <T extends Message> T sendAndWait(CellPath path, T msg, long timeout) |
| 264 | throws CacheException, InterruptedException |
| 265 | { |
| 266 | msg.setReplyRequired(true); |
| 267 | |
| 268 | T reply = (T) sendAndWait(path, msg, msg.getClass(), timeout); |
| 269 | |
| 270 | if (reply.getReturnCode() != 0) { |
| 271 | throw CacheExceptionFactory.exceptionOf(reply); |
| 272 | } |
| 273 | |
| 274 | return reply; |
| 275 | } |
| 276 | |
| 277 | |
| 278 | /** |
| 279 | * Sends a message and waits for the reply. The reply is expected |
| 280 | * to contain a message object of the specified type. If this is |
| 281 | * not the case, an exception is thrown. |
| 282 | * |
| 283 | * @param path the destination cell |
| 284 | * @param msg the message object to send |
| 285 | * @param type the expected type of the reply |
| 286 | * @param timeout the time to wait for the reply |
| 287 | * @return the message object from the reply |
| 288 | * @throws InterruptedException If the thread is interrupted |
| 289 | * @throws CacheException If the message could not be sent, a |
| 290 | * timeout occurred, or the object in the reply was of the |
| 291 | * wrong type. |
| 292 | */ |
| 293 | public <T extends Serializable> T sendAndWait(CellPath path, |
| 294 | Serializable msg, |
| 295 | Class<T> type, |
| 296 | long timeout) |
| 297 | throws CacheException, InterruptedException |
| 298 | { |
| 299 | CellMessage replyMessage; |
| 300 | try { |
| 301 | CellMessage envelope = new CellMessage(path, msg); |
| 302 | if (_retryOnNoRouteToCell) { |
| 303 | replyMessage = |
| 304 | _endpoint.sendAndWaitToPermanent(envelope, timeout); |
| 305 | } else { |
| 306 | replyMessage = |
| 307 | _endpoint.sendAndWait(envelope, timeout); |
| 308 | } |
| 309 | } catch (NoRouteToCellException e) { |
| 310 | /* From callers point of view a timeout due to a lost |
| 311 | * message or a missing route to the destination is pretty |
| 312 | * much the same, so we report this as a timeout. The |
| 313 | * error message gives the details. |
| 314 | */ |
| 315 | throw new TimeoutCacheException(e.getMessage()); |
| 316 | } |
| 317 | |
| 318 | if (replyMessage == null) { |
| 319 | String errmsg = String.format("Request to %s timed out.", path); |
| 320 | throw new TimeoutCacheException(errmsg); |
| 321 | } |
| 322 | |
| 323 | Object replyObject = replyMessage.getMessageObject(); |
| 324 | if (!(type.isInstance(replyObject))) { |
| 325 | String errmsg = "Got unexpected message of class " + |
| 326 | replyObject.getClass() + " from " + |
| 327 | replyMessage.getSourceAddress(); |
| 328 | throw new CacheException(CacheException.UNEXPECTED_SYSTEM_EXCEPTION, |
| 329 | errmsg); |
| 330 | } |
| 331 | |
| 332 | return (T)replyObject; |
| 333 | } |
| 334 | |
| 335 | /** |
| 336 | * Sends <code>message</code> asynchronously, expecting a result |
| 337 | * of type <code>type</code>. The result is delivered to |
| 338 | * <code>callback</code>. |
| 339 | */ |
| 340 | public <T extends Serializable> void send(Serializable message, |
| 341 | Class<T> type, |
| 342 | MessageCallback<T> callback) |
| 343 | { |
| 344 | if (_destination == null) |
| 345 | throw new IllegalStateException("Destination must be specified"); |
| 346 | send(_destination, message, type, callback); |
| 347 | } |
| 348 | |
| 349 | /** |
| 350 | * Sends <code>message</code> asynchronously to |
| 351 | * <code>destination</code>, expecting a result of type |
| 352 | * <code>type</code>. The result is delivered to |
| 353 | * <code>callback</code>. |
| 354 | */ |
| 355 | public <T extends Serializable> void send(CellPath destination, |
| 356 | Serializable message, |
| 357 | Class<T> type, |
| 358 | MessageCallback<T> callback) |
| 359 | { |
| 360 | if (message instanceof Message) { |
| 361 | ((Message) message).setReplyRequired(true); |
| 362 | } |
| 363 | _endpoint.sendMessage(new CellMessage(destination, message), |
| 364 | new CellCallback<T>(type, callback), |
| 365 | _timeout); |
| 366 | } |
| 367 | |
| 368 | /** |
| 369 | * Sends <code>message</code> to <code>destination</code>. |
| 370 | */ |
| 371 | public void send(Serializable message) |
| 372 | throws NoRouteToCellException |
| 373 | { |
| 374 | if (_destination == null) { |
| 375 | throw new IllegalStateException("Destination must be specified"); |
| 376 | } |
| 377 | send(_destination, message); |
| 378 | } |
| 379 | |
| 380 | |
| 381 | /** |
| 382 | * Sends <code>message</code> to <code>destination</code>. |
| 383 | */ |
| 384 | public void send(CellPath destination, Serializable message) |
| 385 | throws NoRouteToCellException |
| 386 | { |
| 387 | _endpoint.sendMessage(new CellMessage(destination, message)); |
| 388 | } |
| 389 | |
| 390 | /** |
| 391 | * Adapter class to wrap MessageCallback in CellMessageAnswerable. |
| 392 | */ |
| 393 | static class CellCallback<T> implements CellMessageAnswerable |
| 394 | { |
| 395 | private final MessageCallback<T> _callback; |
| 396 | private final Class<T> _type; |
| 397 | |
| 398 | CellCallback(Class<T> type, MessageCallback<T> callback) |
| 399 | { |
| 400 | _callback = callback; |
| 401 | _type = type; |
| 402 | } |
| 403 | |
| 404 | @Override |
| 405 | public void answerArrived(CellMessage request, CellMessage answer) |
| 406 | { |
| 407 | Object o = answer.getMessageObject(); |
| 408 | if (_type.isInstance(o)) { |
| 409 | if (o instanceof Message) { |
| 410 | Message msg = (Message) o; |
| 411 | int rc = msg.getReturnCode(); |
| 412 | if (rc == 0) { |
| 413 | _callback.success(_type.cast(o)); |
| 414 | } else { |
| 415 | _callback.failure(rc, msg.getErrorObject()); |
| 416 | } |
| 417 | } else { |
| 418 | _callback.success(_type.cast(o)); |
| 419 | } |
| 420 | } else if (o instanceof Exception) { |
| 421 | exceptionArrived(request, (Exception) o); |
| 422 | } else { |
| 423 | _callback.failure(CacheException.UNEXPECTED_SYSTEM_EXCEPTION, |
| 424 | "Unexpected reply: " + o); |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | @Override |
| 429 | public void answerTimedOut(CellMessage request) |
| 430 | { |
| 431 | _callback.timeout(); |
| 432 | } |
| 433 | |
| 434 | @Override |
| 435 | public void exceptionArrived(CellMessage request, Exception exception) |
| 436 | { |
| 437 | if (exception instanceof NoRouteToCellException) { |
| 438 | _callback.noroute(); |
| 439 | } else if (exception instanceof CacheException) { |
| 440 | CacheException e = (CacheException) exception; |
| 441 | _callback.failure(e.getRc(), |
| 442 | CacheExceptionFactory.exceptionOf(e.getRc(), e.getMessage())); |
| 443 | } else { |
| 444 | _callback.failure(CacheException.UNEXPECTED_SYSTEM_EXCEPTION, |
| 445 | exception.toString()); |
| 446 | } |
| 447 | } |
| 448 | } |
| 449 | } |