bundles/org.simantics.db.procore/src/fi/vtt/simantics/procore/internal/SessionRequestManager.java

   1 package fi.vtt.simantics.procore.internal;
   2
   3 import java.io.IOException;
   4 import java.util.Collection;
   5 import java.util.LinkedList;
   6
   7 import org.simantics.db.Disposable;
   8 import org.simantics.db.Resource;
   9 import org.simantics.db.exception.CancelTransactionException;
  10 import org.simantics.db.exception.DatabaseException;
  11 import org.simantics.db.impl.graph.WriteGraphImpl;
  12 import org.simantics.db.impl.internal.RandomAccessValueSupport;
  13 import org.simantics.db.impl.internal.ResourceData;
  14 import org.simantics.db.impl.query.QueryProcessor.SessionRead;
  15 import org.simantics.db.impl.query.QueryProcessor.SessionTask;
  16 import org.simantics.db.request.WriteTraits;
  17 import org.simantics.utils.datastructures.Pair;
  18 import org.slf4j.Logger;
  19 import org.slf4j.LoggerFactory;
  20
  21 public class SessionRequestManager {
  22
  23         private static final Logger LOGGER = LoggerFactory.getLogger(SessionRequestManager.class);
  24
  25         private static boolean DEBUG = false;
  26
  27         enum State {
  28
  29                 INIT, IDLE, READ, WRITE, WRITE_UPDATE, READ_UPDATE, ERROR
  30
  31         }
  32
  33         final SessionImplSocket session;
  34         final fi.vtt.simantics.procore.internal.State transactionState;
  35         final LinkedList<SessionTask> writes = new LinkedList<SessionTask>();
  36         final LinkedList<SessionRead> reads = new LinkedList<SessionRead>();
  37
  38         State state = State.INIT;
  39
  40         private boolean legal(State current, State target) {
  41
  42                 if(State.IDLE == current) {
  43
  44                         return State.INIT != target && State.WRITE_UPDATE != target && State.READ_UPDATE != target;
  45
  46                 } else if (State.WRITE == current) {
  47
  48                         return State.WRITE_UPDATE == target;
  49
  50                 } else if (State.READ == current) {
  51
  52                         return State.READ_UPDATE == target;
  53
  54                 } else if (State.ERROR == current) {
  55
  56                         return State.IDLE == target;
  57
  58                 } else {
  59
  60                         return State.IDLE == target;
  61
  62                 }
  63
  64         }
  65
  66         private synchronized void setState(int thread, State state, SessionTask task) {
  67
  68                 if(DEBUG) System.err.println("Session state: " + this.state + " => " + state + " - " + task);
  69                 if(this.state == state) return;
  70
  71                 assert(legal(this.state, state));
  72
  73                 if(State.READ == state) {
  74
  75                         assert(State.IDLE == this.state);
  76
  77                 }
  78
  79                 State oldState = this.state;
  80                 this.state = state;
  81
  82                 if(State.IDLE == oldState && State.IDLE != state) {
  83                     session.incAsync();
  84                 }
  85
  86                 /*
  87                  * We are now executing in new state.
  88                  * The methods below SHALL NOT start any task
  89                  * immediately. All tasks shall be scheduled.
  90                  *
  91                  */
  92                 if(State.READ == state) startRead(thread, (SessionRead)task);
  93                 else if(State.WRITE == state) startWrite(thread, task);
  94                 else if(State.READ == oldState) startReadUpdate(thread);
  95                 else if(State.WRITE == oldState) startWriteUpdate(thread);
  96
  97                 // Check the need for new transaction
  98                 if(state == State.IDLE) {
  99
 100                         closeRandomAccessValues();
 101
 102                         if(!writes.isEmpty()) {
 103                                 setState(thread, State.WRITE, writes.poll());
 104                         } else if (!reads.isEmpty()) {
 105                                 setState(thread, State.READ, reads.poll());
 106                         }
 107
 108             session.decAsync();
 109
 110                 }
 111
 112         }
 113
 114         public SessionRequestManager(SessionImplSocket session, fi.vtt.simantics.procore.internal.State transactionState) {
 115                 this.session = session;
 116                 this.transactionState = transactionState;
 117         }
 118
 119         public synchronized void startRead(int thread, final SessionRead task) {
 120
 121                 session.queryProvider2.schedule(new SessionTask(true) {
 122
 123                         @Override
 124             public void run(int thread) {
 125                 try {
 126                     transactionState.startReadTransaction(thread);
 127                     task.run(thread);
 128                 } catch (Throwable t) {
 129                     LOGGER.error("Read transaction could not be started", t);
 130                     if(task.throwable != null)
 131                         task.throwable.set(t);
 132                     state = State.ERROR;
 133                 } finally {
 134                     if(task.notify != null)
 135                         task.notify.release();
 136                 }
 137             }
 138
 139                 });
 140
 141         }
 142
 143         public synchronized void startReadUpdate(int thread) {
 144
 145                 session.queryProvider2.schedule(new SessionTask(true) {
 146
 147                         @Override
 148                         public void run(int thread) {
 149
 150                                 session.fireFinishReadTransaction();
 151
 152                                 try {
 153                                         transactionState.stopReadTransaction();
 154                                 } catch (DatabaseException e) {
 155                                         LOGGER.error("Read transaction could not be stopped", e);
 156                                 }
 157
 158                         }
 159
 160                 });
 161
 162         }
 163
 164         public synchronized void startWrite(int thread, final SessionTask task) {
 165
 166                 session.queryProvider2.schedule(new SessionTask(true) {
 167
 168                         @Override
 169                         public void run(int thread) {
 170
 171                         try {
 172                                 transactionState.startWriteTransaction(thread);
 173                         } catch (Throwable t) {
 174                             LOGGER.error("Write transaction could not be started", t);
 175                             return;
 176                         }
 177                                 task.run(thread);
 178
 179                         }
 180
 181                 });
 182
 183         }
 184
 185         public synchronized void startWriteUpdate(int thread) {
 186
 187                 session.queryProvider2.schedule(new SessionTask(true) {
 188
 189                         @Override
 190                         public void run(int thread) {
 191
 192                                 // Support for DelayedWriteRequest cancels during the
 193                                 // read-only part of the request.
 194                                 WriteStateBase<?> delayedState = session.delayedWriteState;
 195                                 session.delayedWriteState = null;
 196                                 if (delayedState != null) {
 197                                         if (session.writeState != null)
 198                                                 throw new AssertionError("Both session delayedWriteState and writeState are set, only one can be set.");
 199
 200                         if (delayedState.isExcepted()) {
 201                         // There can never be any changes in the cluster stream.
 202                         // In this case, don't bother rolling back.
 203                             boolean empty = session.clusterStream.reallyFlush();
 204                         assert(empty);
 205                             transactionState.stopWriteTransaction(session.clusterStream);
 206                         } else {
 207                             throw new UnsupportedOperationException("delayedWriteState may only exist when request fails.");
 208                         }
 209                         Disposable.safeDispose(session.clientChanges);
 210                         session.clientChanges = new ClientChangesImpl(session);
 211                                         delayedState.finish();
 212                                         return;
 213                                 }
 214
 215                                 // The session could have been terminated
 216                                 if(!session.state.isAlive()) return;
 217
 218                                 WriteState<?> writeState = session.writeState;
 219
 220                                 assert(writeState != null);
 221
 222                                 WriteGraphImpl graph = writeState.getGraph();
 223
 224                                 if(writeState.isExcepted()) {
 225
 226                                     if(!(writeState.exception instanceof CancelTransactionException))
 227                                         LOGGER.error("Write request failed", writeState.exception);
 228
 229                                     transactionState.cancelWriteTransaction(graph);
 230
 231                                 } else {
 232
 233                                         session.handleUpdatesAndMetadata(graph);
 234
 235 //                    long start = System.nanoTime();
 236                                         transactionState.commitWriteTransaction(writeState.getGraph(), session.clusterStream, session.clientChanges, writeState.getRequest(), null);
 237 //                                      long duration = System.nanoTime() - start;
 238 //                    System.out.println("commitWriteTransaction " + 1e-9*duration + "s. ");
 239
 240                                 }
 241
 242                                 Disposable.safeDispose(session.clientChanges);
 243                                 session.clientChanges = new ClientChangesImpl(session);
 244
 245                                 WriteState<?> state = session.writeState;
 246                                 state.finish();
 247                                 session.writeState = null;
 248
 249                         }
 250
 251                 });
 252
 253         }
 254
 255         public synchronized void ceased(int thread) {
 256
 257                 if(State.WRITE == state) {
 258
 259                         setState(thread, State.WRITE_UPDATE, null);
 260
 261                 } else if (State.WRITE_UPDATE == state) {
 262
 263                         setState(thread, State.IDLE, null);
 264
 265                 } else if (State.READ_UPDATE == state) {
 266
 267                         setState(thread, State.IDLE, null);
 268
 269                 } else if (State.READ == state) {
 270
 271                         if (!reads.isEmpty()) {
 272
 273                                 final SessionRead read = reads.poll();
 274                                 session.queryProvider2.schedule(new SessionTask(true) {
 275
 276                                         @Override
 277                                         public void run(int thread) {
 278                                                 read.run(thread);
 279                                                 if(read.notify != null) read.notify.release();
 280                                         }
 281
 282                                 });
 283
 284                         } else {
 285
 286                                 setState(thread, State.READ_UPDATE, null);
 287
 288                         }
 289
 290                 } else if (State.INIT == state) {
 291
 292                         assert(reads.isEmpty());
 293                         assert(writes.isEmpty());
 294                         setState(thread, State.IDLE, null);
 295
 296                 } else if (State.ERROR == state) {
 297
 298                         setState(thread, State.IDLE, null);
 299
 300                 } else {
 301
 302                         // Spurious wakeup
 303
 304                     //throw new IllegalStateException("State in ceased should be WRITE or READ or INIT (was " + state + ")");
 305
 306                 }
 307
 308         }
 309
 310     public synchronized void scheduleRead(final SessionRead task) {
 311
 312                 assert(State.INIT != state);
 313
 314                 if(State.READ == state) {
 315                         session.queryProvider2.schedule(new SessionTask(true) {
 316
 317                                 @Override
 318                                 public void run(int thread) {
 319                                         try {
 320                                                 task.run(thread);
 321                                         } finally {
 322                                                 if (task.notify != null) task.notify.release();
 323                                         }
 324                                 }
 325
 326                         });
 327                 } else if (State.IDLE == state) {
 328                         setState(Integer.MIN_VALUE, State.READ, task);
 329                 } else {
 330                         reads.offer(task);
 331                 }
 332
 333         }
 334
 335     public int lastUpdateIndex() {
 336         return writes.size();
 337     }
 338
 339         public synchronized void scheduleWrite(SessionTask task) {
 340
 341                 scheduleWrite(task, null);
 342
 343         }
 344
 345         /**
 346          * @param task the task to schedule
 347          * @param combine <code>true</code> or <code>false</code> to explicitly
 348          *        specify whether to combine the write with the previous operation
 349          *        or <code>null</code> to use the default logic, i.e. combine when
 350          *        this schedule is performed from within update processing (state ==
 351          *        State.WRITE_UPDATE).
 352          */
 353         public synchronized void scheduleWrite(SessionTask task, Boolean combine) {
 354
 355                 boolean inUpdate = state == State.WRITE_UPDATE;
 356
 357                 //System.err.println("schedule write " + task);
 358
 359                 assert(State.INIT != state);
 360                 //task.combine = combine != null ? combine : inUpdate;
 361                 if(State.IDLE == state) {
 362                         setState(Integer.MIN_VALUE, State.WRITE, task);
 363                 } else {
 364                         if(inUpdate) {
 365                                 int index = lastUpdateIndex();
 366                                 if(index == writes.size()) writes.offer(task);
 367                                 else writes.add(index, task);
 368                         } else {
 369                                 writes.offer(task);
 370                         }
 371                 }
 372
 373         }
 374
 375         /**
 376          * Unregisters and closes all currently registered ResourceData random
 377          * access value file handles. Any I/O exceptions occurring during closing
 378          * are logged into {@link Logger}.
 379          */
 380         private void closeRandomAccessValues() {
 381                 RandomAccessValueSupport ravs = session.peekService(RandomAccessValueSupport.class);
 382                 if (ravs == null)
 383                         return;
 384                 Collection<Pair<Resource, ResourceData>> values = ravs.removeAll();
 385                 for (Pair<Resource, ResourceData> value : values) {
 386                         try {
 387                                 value.second.binaryFile.close();
 388                         } catch (IOException e) {
 389                                 LOGGER.error("I/O exception while closing random access value file " + value.second.binaryFile.file() + " for resource " + value.first , e);
 390                         }
 391                 }
 392         }
 393
 394 }