bundles/org.simantics.acorn/src/org/simantics/acorn/GraphClientImpl2.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.acorn;
  13
  14 import java.io.IOException;
  15 import java.nio.file.Path;
  16 import java.util.ArrayList;
  17 import java.util.LinkedList;
  18 import java.util.concurrent.ExecutorService;
  19 import java.util.concurrent.Executors;
  20 import java.util.concurrent.Semaphore;
  21 import java.util.concurrent.ThreadFactory;
  22 import java.util.concurrent.TimeUnit;
  23
  24 import org.simantics.acorn.MainProgram.MainProgramRunnable;
  25 import org.simantics.acorn.exception.AcornAccessVerificationException;
  26 import org.simantics.acorn.exception.IllegalAcornStateException;
  27 import org.simantics.acorn.internal.ClusterChange;
  28 import org.simantics.acorn.internal.ClusterUpdateProcessorBase;
  29 import org.simantics.acorn.internal.UndoClusterUpdateProcessor;
  30 import org.simantics.acorn.lru.ClusterChangeSet.Entry;
  31 import org.simantics.acorn.lru.ClusterInfo;
  32 import org.simantics.acorn.lru.ClusterStreamChunk;
  33 import org.simantics.acorn.lru.ClusterUpdateOperation;
  34 import org.simantics.db.ClusterCreator;
  35 import org.simantics.db.Database;
  36 import org.simantics.db.ServiceLocator;
  37 import org.simantics.db.exception.DatabaseException;
  38 import org.simantics.db.exception.SDBException;
  39 import org.simantics.db.server.ProCoreException;
  40 import org.simantics.db.service.ClusterSetsSupport;
  41 import org.simantics.db.service.ClusterUID;
  42 import org.simantics.db.service.LifecycleSupport;
  43 import org.simantics.utils.datastructures.Pair;
  44 import org.simantics.utils.logging.TimeLogger;
  45 import org.slf4j.Logger;
  46 import org.slf4j.LoggerFactory;
  47
  48 import gnu.trove.map.hash.TLongObjectHashMap;
  49
  50 public class GraphClientImpl2 implements Database.Session {
  51
  52     private static final Logger LOGGER = LoggerFactory.getLogger(GraphClientImpl2.class);
  53         public static final boolean DEBUG = false;
  54
  55         public final ClusterManager clusters;
  56
  57         private TransactionManager transactionManager = new TransactionManager();
  58         private ExecutorService executor = Executors.newSingleThreadExecutor(new ClientThreadFactory("Core Main Program", false));
  59         private ExecutorService saver = Executors.newSingleThreadExecutor(new ClientThreadFactory("Core Snapshot Saver", true));
  60
  61         private Path dbFolder;
  62         private final Database database;
  63         private ServiceLocator locator;
  64         private MainProgram mainProgram;
  65
  66         static class ClientThreadFactory implements ThreadFactory {
  67
  68                 final String name;
  69                 final boolean daemon;
  70
  71                 public ClientThreadFactory(String name, boolean daemon) {
  72                         this.name = name;
  73                         this.daemon = daemon;
  74                 }
  75
  76                 @Override
  77                 public Thread newThread(Runnable r) {
  78                         Thread thread = new Thread(r, name);
  79                         thread.setDaemon(daemon);
  80                         return thread;
  81                 }
  82         }
  83
  84         public GraphClientImpl2(Database database, Path dbFolder, ServiceLocator locator) throws IOException {
  85             this.database = database;
  86             this.dbFolder = dbFolder;
  87             this.locator = locator;
  88             this.clusters = new ClusterManager(dbFolder);
  89             load();
  90             ClusterSetsSupport cssi = locator.getService(ClusterSetsSupport.class);
  91             cssi.setReadDirectory(clusters.lastSessionDirectory);
  92             cssi.updateWriteDirectory(clusters.workingDirectory);
  93             mainProgram = new MainProgram(this, clusters);
  94             executor.execute(mainProgram);
  95         }
  96
  97         public Path getDbFolder() {
  98             return dbFolder;
  99         }
 100
 101         public void tryMakeSnapshot() throws IOException {
 102
 103             if (isClosing || unexpectedClose)
 104                 return;
 105
 106                 saver.execute(new Runnable() {
 107
 108                         @Override
 109                         public void run() {
 110                                 Transaction tr = null;
 111                                 try {
 112                                         // First take a write transaction
 113                                         tr = askWriteTransaction(-1);
 114                                         // Then make sure that MainProgram is idling
 115                                         mainProgram.mutex.acquire();
 116                                         try {
 117                                                 synchronized(mainProgram) {
 118                                                         if(mainProgram.operations.isEmpty()) {
 119                                                                 makeSnapshot(false);
 120                                                         } else {
 121                                                                 // MainProgram is becoming busy again - delay snapshotting
 122                                                                 return;
 123                                                         }
 124                                                 }
 125                                         } finally {
 126                                                 mainProgram.mutex.release();
 127                                         }
 128                                 } catch (IllegalAcornStateException | ProCoreException e) {
 129                                         LOGGER.error("Snapshotting failed", e);
 130                                         unexpectedClose = true;
 131                                 } catch (InterruptedException e) {
 132                                     LOGGER.error("Snapshotting interrupted", e);
 133                                 } finally {
 134                                         try {
 135                                                 if(tr != null)
 136                                                         endTransaction(tr.getTransactionId());
 137                                                 if (unexpectedClose) {
 138                                                 LifecycleSupport support = getServiceLocator().getService(LifecycleSupport.class);
 139                             try {
 140                                 support.close();
 141                             } catch (DatabaseException e1) {
 142                                 LOGGER.error("Failed to close database as a safety measure due to failed snapshotting", e1);
 143                             }
 144                                                 }
 145                                         } catch (ProCoreException e) {
 146                                             LOGGER.error("Failed to end snapshotting write transaction", e);
 147                                         }
 148                                 }
 149                         }
 150                 });
 151         }
 152
 153     public void makeSnapshot(boolean fullSave) throws IllegalAcornStateException {
 154         clusters.makeSnapshot(locator, fullSave);
 155     }
 156
 157         public <T> T clone(ClusterUID uid, ClusterCreator creator) throws DatabaseException {
 158             try {
 159             return clusters.clone(uid, creator);
 160         } catch (AcornAccessVerificationException | IllegalAcornStateException | IOException e) {
 161             unexpectedClose = true;
 162             throw new DatabaseException(e);
 163         }
 164         }
 165
 166 //      private void save() throws IOException {
 167 //              clusters.save();
 168 //      }
 169
 170         public void load() throws IOException {
 171                 clusters.load();
 172         }
 173
 174 //      public void modiFileEx(ClusterUID uid, int resourceKey, long offset, long size, byte[] bytes, long pos, ClusterSupport support) {
 175 //              clusters.modiFileEx(uid, resourceKey, offset, size, bytes, pos, support);
 176 //      }
 177
 178         @Override
 179         public Database getDatabase() {
 180                 return database;
 181         }
 182
 183         private boolean closed = false;
 184         private boolean isClosing = false;
 185         private boolean unexpectedClose = false;
 186
 187         @Override
 188         public void close() throws ProCoreException {
 189             LOGGER.info("Closing " + this + " and mainProgram " + mainProgram);
 190                 if(!closed && !isClosing) {
 191                     isClosing = true;
 192                         try {
 193                             if (!unexpectedClose)
 194                                 makeSnapshot(true);
 195
 196                                 mainProgram.close();
 197                                 clusters.shutdown();
 198                                 executor.shutdown();
 199                                 saver.shutdown();
 200                                 boolean executorTerminated = executor.awaitTermination(500, TimeUnit.MILLISECONDS);
 201                                 boolean saverTerminated = saver.awaitTermination(500, TimeUnit.MILLISECONDS);
 202
 203                                 System.err.println("executorTerminated=" + executorTerminated + ", saverTerminated=" + saverTerminated);
 204
 205                                 mainProgram = null;
 206                                 executor = null;
 207                                 saver = null;
 208
 209                         } catch (IllegalAcornStateException | InterruptedException e) {
 210                                 throw new ProCoreException(e);
 211                         }
 212                         closed = true;
 213                 }
 214                 //impl.close();
 215         }
 216
 217         @Override
 218         public void open() throws ProCoreException {
 219                 throw new UnsupportedOperationException();
 220         }
 221
 222         @Override
 223         public boolean isClosed() throws ProCoreException {
 224                 return closed;
 225         }
 226
 227         @Override
 228         public void acceptCommit(long transactionId, long changeSetId, byte[] metadata) throws ProCoreException {
 229                 clusters.state.headChangeSetId++;
 230                 long committedChangeSetId = changeSetId + 1;
 231                 try {
 232                 clusters.commitChangeSet(committedChangeSetId, metadata);
 233
 234                 clusters.state.transactionId = transactionId;
 235
 236                 mainProgram.committed();
 237
 238                 TimeLogger.log("Accepted commit");
 239                 } catch (IllegalAcornStateException e) {
 240                     throw new ProCoreException(e);
 241                 }
 242         }
 243
 244         @Override
 245         public long cancelCommit(long transactionId, long changeSetId, byte[] metadata, OnChangeSetUpdate onChangeSetUpdate) throws ProCoreException {
 246                 // Accept and finalize current transaction and then undo it
 247                 acceptCommit(transactionId, changeSetId, metadata);
 248
 249                 try {
 250                         undo(new long[] {changeSetId+1}, onChangeSetUpdate);
 251                         clusters.state.headChangeSetId++;
 252                         return clusters.state.headChangeSetId;
 253                 } catch (SDBException e) {
 254                     LOGGER.error("Failed to undo cancelled transaction", e);
 255                         throw new ProCoreException(e);
 256                 }
 257         }
 258
 259         @Override
 260         public Transaction askReadTransaction() throws ProCoreException {
 261                 return transactionManager.askReadTransaction();
 262         }
 263
 264         enum TransactionState {
 265                 IDLE,WRITE,READ
 266         }
 267
 268         class TransactionRequest {
 269                 public TransactionState state;
 270                 public Semaphore semaphore;
 271                 public TransactionRequest(TransactionState state, Semaphore semaphore) {
 272                         this.state = state;
 273                         this.semaphore = semaphore;
 274                 }
 275         }
 276
 277         class TransactionManager {
 278
 279                 private TransactionState currentTransactionState = TransactionState.IDLE;
 280
 281                 private int reads = 0;
 282
 283                 LinkedList<TransactionRequest> requests = new LinkedList<TransactionRequest>();
 284
 285                 TLongObjectHashMap<TransactionRequest> requestMap = new TLongObjectHashMap<TransactionRequest>();
 286
 287                 private synchronized Transaction makeTransaction(TransactionRequest req) {
 288
 289                         final int csId = clusters.state.headChangeSetId;
 290                         final long trId = clusters.state.transactionId+1;
 291                         requestMap.put(trId, req);
 292                         return new Transaction() {
 293
 294                                 @Override
 295                                 public long getTransactionId() {
 296                                         return trId;
 297                                 }
 298
 299                                 @Override
 300                                 public long getHeadChangeSetId() {
 301                                         return csId;
 302                                 }
 303                         };
 304                 }
 305
 306                 /*
 307                  * This method cannot be synchronized since it waits and must support multiple entries
 308                  * by query thread(s) and internal transactions such as snapshot saver
 309                  */
 310                 public Transaction askReadTransaction() throws ProCoreException {
 311
 312                         Semaphore semaphore = new Semaphore(0);
 313
 314                         TransactionRequest req = queue(TransactionState.READ, semaphore);
 315
 316                         try {
 317                                 semaphore.acquire();
 318                         } catch (InterruptedException e) {
 319                                 throw new ProCoreException(e);
 320                         }
 321
 322                         return makeTransaction(req);
 323
 324                 }
 325
 326                 private synchronized void dispatch() {
 327                         TransactionRequest r = requests.removeFirst();
 328                         if(r.state == TransactionState.READ) reads++;
 329                         r.semaphore.release();
 330                 }
 331
 332                 private synchronized void processRequests() {
 333
 334                         while(true) {
 335
 336                                 if(requests.isEmpty()) return;
 337                                 TransactionRequest req = requests.peek();
 338
 339                                 if(currentTransactionState == TransactionState.IDLE) {
 340
 341                                         // Accept anything while IDLE
 342                                         currentTransactionState = req.state;
 343                                         dispatch();
 344
 345                                 } else if (currentTransactionState == TransactionState.READ) {
 346
 347                                         if(req.state == currentTransactionState) {
 348
 349                                                 // Allow other reads
 350                                                 dispatch();
 351
 352                                         } else {
 353
 354                                                 // Wait
 355                                                 return;
 356
 357                                         }
 358
 359                                 }  else if (currentTransactionState == TransactionState.WRITE) {
 360
 361                                         // Wait
 362                                         return;
 363
 364                                 }
 365
 366                         }
 367
 368                 }
 369
 370                 private synchronized TransactionRequest queue(TransactionState state, Semaphore semaphore) {
 371                         TransactionRequest req = new TransactionRequest(state, semaphore);
 372                         requests.addLast(req);
 373                         processRequests();
 374                         return req;
 375                 }
 376
 377                 /*
 378                  * This method cannot be synchronized since it waits and must support multiple entries
 379                  * by query thread(s) and internal transactions such as snapshot saver
 380                  */
 381                 public Transaction askWriteTransaction() throws IllegalAcornStateException {
 382
 383                         Semaphore semaphore = new Semaphore(0);
 384                         TransactionRequest req = queue(TransactionState.WRITE, semaphore);
 385
 386                         try {
 387                                 semaphore.acquire();
 388                         } catch (InterruptedException e) {
 389                                 throw new IllegalAcornStateException(e);
 390                         }
 391                         mainProgram.startTransaction(clusters.state.headChangeSetId+1);
 392                         return makeTransaction(req);
 393                 }
 394
 395                 public synchronized long endTransaction(long transactionId) throws ProCoreException {
 396
 397                         TransactionRequest req = requestMap.remove(transactionId);
 398                         if(req.state == TransactionState.WRITE) {
 399                                 currentTransactionState = TransactionState.IDLE;
 400                                 processRequests();
 401                         } else {
 402                                 reads--;
 403                                 if(reads == 0) {
 404                                         currentTransactionState = TransactionState.IDLE;
 405                                         processRequests();
 406                                 }
 407                         }
 408                         return clusters.state.transactionId;
 409                 }
 410
 411         }
 412
 413         @Override
 414         public Transaction askWriteTransaction(final long transactionId) throws ProCoreException {
 415                 try {
 416                     if (isClosing || unexpectedClose || closed) {
 417                         throw new ProCoreException("GraphClientImpl2 is already closing so no more write transactions allowed!");
 418                     }
 419             return transactionManager.askWriteTransaction();
 420         } catch (IllegalAcornStateException e) {
 421             throw new ProCoreException(e);
 422         }
 423         }
 424
 425         @Override
 426         public long endTransaction(long transactionId) throws ProCoreException {
 427                 return transactionManager.endTransaction(transactionId);
 428         }
 429
 430         @Override
 431         public String execute(String command) throws ProCoreException {
 432                 // This is called only by WriteGraphImpl.commitAccessorChanges
 433                 // We can ignore this in Acorn
 434                 return "";
 435         }
 436
 437         @Override
 438         public byte[] getChangeSetMetadata(long changeSetId) throws ProCoreException {
 439                 try {
 440             return clusters.getMetadata(changeSetId);
 441         } catch (AcornAccessVerificationException | IllegalAcornStateException e) {
 442             throw new ProCoreException(e);
 443         }
 444         }
 445
 446         @Override
 447         public ChangeSetData getChangeSetData(long minChangeSetId,
 448                         long maxChangeSetId, OnChangeSetUpdate onChangeSetupate)
 449                         throws ProCoreException {
 450
 451                 new Exception("GetChangeSetDataFunction " + minChangeSetId + " " + maxChangeSetId).printStackTrace();;
 452                 return null;
 453
 454         }
 455
 456         @Override
 457         public ChangeSetIds getChangeSetIds() throws ProCoreException {
 458                 throw new UnsupportedOperationException();
 459         }
 460
 461         @Override
 462         public Cluster getCluster(byte[] clusterId) throws ProCoreException {
 463                 throw new UnsupportedOperationException();
 464         }
 465
 466         @Override
 467         public ClusterChanges getClusterChanges(long changeSetId, byte[] clusterId)
 468                         throws ProCoreException {
 469                 throw new UnsupportedOperationException();
 470         }
 471
 472         @Override
 473         public ClusterIds getClusterIds() throws ProCoreException {
 474                 try {
 475             return clusters.getClusterIds();
 476         } catch (IllegalAcornStateException e) {
 477             throw new ProCoreException(e);
 478         }
 479         }
 480
 481         @Override
 482         public Information getInformation() throws ProCoreException {
 483                 return new Information() {
 484
 485                         @Override
 486                         public String getServerId() {
 487                                 return "server";
 488                         }
 489
 490                         @Override
 491                         public String getProtocolId() {
 492                                 return "";
 493                         }
 494
 495                         @Override
 496                         public String getDatabaseId() {
 497                                 return "database";
 498                         }
 499
 500                         @Override
 501                         public long getFirstChangeSetId() {
 502                                 return 0;
 503                         }
 504
 505                 };
 506         }
 507
 508         @Override
 509         public Refresh getRefresh(long changeSetId) throws ProCoreException {
 510
 511                 final ClusterIds ids = getClusterIds();
 512
 513                 return new Refresh() {
 514
 515                         @Override
 516                         public long getHeadChangeSetId() {
 517                                 return clusters.state.headChangeSetId;
 518                         }
 519
 520                         @Override
 521                         public long[] getFirst() {
 522                                 return ids.getFirst();
 523                         }
 524
 525                         @Override
 526                         public long[] getSecond() {
 527                                 return ids.getSecond();
 528                         }
 529
 530                 };
 531
 532         }
 533
 534         public byte[] getResourceFile(final byte[] clusterUID, final int resourceIndex) throws ProCoreException, AcornAccessVerificationException, IllegalAcornStateException {
 535                 return clusters.getResourceFile(clusterUID, resourceIndex);
 536         }
 537
 538         @Override
 539         public ResourceSegment getResourceSegment(final byte[] clusterUID, final int resourceIndex, final long segmentOffset, short segmentSize) throws ProCoreException {
 540                 try {
 541             return clusters.getResourceSegment(clusterUID, resourceIndex, segmentOffset, segmentSize);
 542         } catch (AcornAccessVerificationException | IllegalAcornStateException e) {
 543             throw new ProCoreException(e);
 544         }
 545         }
 546
 547         @Override
 548         public long reserveIds(int count) throws ProCoreException {
 549                 return clusters.state.reservedIds++;
 550         }
 551
 552         @Override
 553         public void updateCluster(byte[] operations) throws ProCoreException {
 554             ClusterInfo info = null;
 555             try {
 556                 ClusterUpdateOperation operation = new ClusterUpdateOperation(clusters, operations);
 557                 info = clusters.clusterLRU.getOrCreate(operation.uid, true);
 558                 if(info == null)
 559                     throw new IllegalAcornStateException("info == null for operation " + operation);
 560                 info.acquireMutex();
 561                         info.scheduleUpdate();
 562                         mainProgram.schedule(operation);
 563                 } catch (IllegalAcornStateException | AcornAccessVerificationException e) {
 564             throw new ProCoreException(e);
 565         } finally {
 566             if (info != null)
 567                 info.releaseMutex();
 568                 }
 569         }
 570
 571         private UndoClusterUpdateProcessor getUndoCSS(String ccsId) throws DatabaseException, AcornAccessVerificationException, IllegalAcornStateException {
 572
 573                 String[] ss = ccsId.split("\\.");
 574                 String chunkKey = ss[0];
 575                 int chunkOffset = Integer.parseInt(ss[1]);
 576                 ClusterStreamChunk chunk = clusters.streamLRU.getWithoutMutex(chunkKey);
 577                 if(chunk == null) throw new IllegalAcornStateException("Cluster Stream Chunk " + chunkKey + " was not found.");
 578                 chunk.acquireMutex();
 579                 try {
 580                         return chunk.getUndoProcessor(clusters, chunkOffset, ccsId);
 581                 } catch (DatabaseException e) {
 582                     throw e;
 583                 } catch (Throwable t) {
 584                         throw new IllegalStateException(t);
 585                 } finally {
 586                         chunk.releaseMutex();
 587                 }
 588         }
 589
 590         private void performUndo(String ccsId, ArrayList<Pair<ClusterUID, byte[]>> clusterChanges, UndoClusterSupport support) throws ProCoreException, DatabaseException, IllegalAcornStateException, AcornAccessVerificationException {
 591                 UndoClusterUpdateProcessor proc = getUndoCSS(ccsId);
 592
 593                 int clusterKey = clusters.getClusterKeyByClusterUIDOrMakeWithoutMutex(proc.getClusterUID());
 594
 595                 clusters.clusterLRU.acquireMutex();
 596                 try {
 597
 598                         ClusterChange cs = new ClusterChange(clusterChanges, proc.getClusterUID());
 599                         for(int i=0;i<proc.entries.size();i++) {
 600
 601                                 Entry e = proc.entries.get(proc.entries.size() - 1 - i);
 602                                 e.process(clusters, cs, clusterKey);
 603                         }
 604                         cs.flush();
 605
 606                 } finally {
 607                         clusters.clusterLRU.releaseMutex();
 608                 }
 609         }
 610
 611         @Override
 612         public boolean undo(long[] changeSetIds, OnChangeSetUpdate onChangeSetUpdate) throws SDBException {
 613
 614                 Exception exception = mainProgram.runIdle(new MainProgramRunnable() {
 615
 616                         @Override
 617                         public void run() throws Exception {
 618
 619                                 try {
 620
 621                                 final ArrayList<Pair<ClusterUID, byte[]>> clusterChanges = new ArrayList<Pair<ClusterUID, byte[]>>();
 622
 623                                 UndoClusterSupport support = new UndoClusterSupport(clusters);
 624
 625                                 final int changeSetId = clusters.state.headChangeSetId;
 626
 627                                 if(ClusterUpdateProcessorBase.DEBUG)
 628                                         System.err.println(" === BEGIN UNDO ===");
 629
 630                                 for(int i=0;i<changeSetIds.length;i++) {
 631                                         final long id = changeSetIds[changeSetIds.length-1-i];
 632                                         ArrayList<String> ccss = clusters.getChanges(id);
 633
 634                                         for(int j=0;j<ccss.size();j++) {
 635                                                 String ccsid = ccss.get(ccss.size()-j-1);
 636                                                 try {
 637                                                         if(ClusterUpdateProcessorBase.DEBUG)
 638                                                                 System.err.println("performUndo " + ccsid);
 639                                                         performUndo(ccsid, clusterChanges, support);
 640                                                 } catch (DatabaseException e) {
 641                                                         e.printStackTrace();
 642                                                 }
 643                                         }
 644                                 }
 645
 646                                 if(ClusterUpdateProcessorBase.DEBUG)
 647                                         System.err.println(" === END UNDO ===");
 648
 649                                 for(int i=0;i<clusterChanges.size();i++) {
 650
 651                                         final int changeSetIndex = i;
 652
 653                                         final Pair<ClusterUID, byte[]> pair = clusterChanges.get(i);
 654
 655                                         final ClusterUID cuid = pair.first;
 656                                         final byte[] data = pair.second;
 657
 658                                         onChangeSetUpdate.onChangeSetUpdate(new ChangeSetUpdate() {
 659
 660                                                 @Override
 661                                                 public long getChangeSetId() {
 662                                                         return changeSetId;
 663                                                 }
 664
 665                                                 @Override
 666                                                 public int getChangeSetIndex() {
 667                                                         return 0;
 668                                                 }
 669
 670                                                 @Override
 671                                                 public int getNumberOfClusterChangeSets() {
 672                                                         return clusterChanges.size();
 673                                                 }
 674
 675                                                 @Override
 676                                                 public int getIndexOfClusterChangeSet() {
 677                                                         return changeSetIndex;
 678                                                 }
 679
 680                                                 @Override
 681                                                 public byte[] getClusterId() {
 682                                                         return cuid.asBytes();
 683                                                 }
 684
 685                                                 @Override
 686                                                 public boolean getNewCluster() {
 687                                                         return false;
 688                                                 }
 689
 690                                                 @Override
 691                                                 public byte[] getData() {
 692                                                         return data;
 693                                                 }
 694
 695                                         });
 696                                 }
 697                         } catch (AcornAccessVerificationException | IllegalAcornStateException e1) {
 698                             throw new ProCoreException(e1);
 699                         }
 700
 701                         }
 702
 703                         @Override
 704                         public void done() {
 705
 706                         }
 707
 708                 });
 709
 710                 if(exception instanceof SDBException) throw (SDBException)exception;
 711                 else if(exception != null) throw new IllegalAcornStateException(exception);
 712
 713                 return false;
 714
 715         }
 716
 717         public ServiceLocator getServiceLocator() {
 718             return locator;
 719         }
 720
 721     @Override
 722     public boolean refreshEnabled() {
 723         return false;
 724     }
 725
 726     @Override
 727     public boolean rolledback() {
 728         return clusters.rolledback();
 729     }
 730
 731     public void purge() throws IllegalAcornStateException {
 732         clusters.purge(locator);
 733     }
 734
 735     public void purgeDatabase() {
 736
 737             if (isClosing || unexpectedClose)
 738                 return;
 739
 740                 saver.execute(new Runnable() {
 741
 742                         @Override
 743                         public void run() {
 744                                 Transaction tr = null;
 745                                 try {
 746                                         // First take a write transaction
 747                                         tr = askWriteTransaction(-1);
 748                                         // Then make sure that MainProgram is idling
 749                                         mainProgram.mutex.acquire();
 750                                         try {
 751                                                 synchronized(mainProgram) {
 752                                                         if(mainProgram.operations.isEmpty()) {
 753                                                                 purge();
 754                                                         } else {
 755                                                                 // MainProgram is becoming busy again - delay snapshotting
 756                                                                 return;
 757                                                         }
 758                                                 }
 759                                         } finally {
 760                                                 mainProgram.mutex.release();
 761                                         }
 762                                 } catch (IllegalAcornStateException | ProCoreException e) {
 763                                     LOGGER.error("Purge failed", e);
 764                                         unexpectedClose = true;
 765                                 } catch (InterruptedException e) {
 766                                     LOGGER.error("Purge interrupted", e);
 767                                 } finally {
 768                                         try {
 769                                                 if(tr != null)
 770                                                         endTransaction(tr.getTransactionId());
 771                                                 if (unexpectedClose) {
 772                                                 LifecycleSupport support = getServiceLocator().getService(LifecycleSupport.class);
 773                             try {
 774                                 support.close();
 775                             } catch (DatabaseException e1) {
 776                                 LOGGER.error("Failed to close database as a safety measure due to failed purge", e1);
 777                             }
 778                                                 }
 779                                         } catch (ProCoreException e) {
 780                                             LOGGER.error("Failed to end purge write transaction", e);
 781                                         }
 782                                 }
 783                         }
 784                 });
 785
 786     }
 787
 788     public long getTailChangeSetId() {
 789         return clusters.getTailChangeSetId();
 790     }
 791
 792 }
 793