bundles/org.simantics.graph.db/src/org/simantics/graph/db/StreamingTransferableGraphImportProcess.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2016 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  *     Semantum Oy
  12  *******************************************************************************/
  13 package org.simantics.graph.db;
  14
  15 import java.io.DataInput;
  16 import java.io.DataOutput;
  17 import java.io.DataOutputStream;
  18 import java.io.FileNotFoundException;
  19 import java.io.FileOutputStream;
  20 import java.io.IOException;
  21 import java.io.InputStream;
  22 import java.util.HashSet;
  23 import java.util.Map;
  24 import java.util.Set;
  25 import java.util.TreeMap;
  26
  27 import org.simantics.databoard.Bindings;
  28 import org.simantics.databoard.adapter.AdaptException;
  29 import org.simantics.databoard.binding.Binding;
  30 import org.simantics.databoard.binding.mutable.Variant;
  31 import org.simantics.databoard.serialization.Serializer;
  32 import org.simantics.databoard.type.Datatype;
  33 import org.simantics.db.ReadGraph;
  34 import org.simantics.db.Resource;
  35 import org.simantics.db.Session;
  36 import org.simantics.db.VirtualGraph;
  37 import org.simantics.db.WriteOnlyGraph;
  38 import org.simantics.db.common.WriteBindings;
  39 import org.simantics.db.common.procedure.adapter.TransientCacheAsyncListener;
  40 import org.simantics.db.common.request.PossibleIndexRoot;
  41 import org.simantics.db.common.uri.UnescapedChildMapOfResource;
  42 import org.simantics.db.common.utils.Logger;
  43 import org.simantics.db.exception.DatabaseException;
  44 import org.simantics.db.service.ClusterBuilder2;
  45 import org.simantics.db.service.ClusterBuilderFactory;
  46 import org.simantics.db.service.ClusteringSupport;
  47 import org.simantics.db.service.SerialisationSupport;
  48 import org.simantics.graph.db.TransferableGraphSource.TransferableGraphSourceProcedure;
  49 import org.simantics.graph.db.TransferableGraphSource.TransferableGraphSourceValueProcedure;
  50 import org.simantics.graph.representation.Extensions;
  51 import org.simantics.graph.representation.External;
  52 import org.simantics.graph.representation.Identity;
  53 import org.simantics.graph.representation.IdentityDefinition;
  54 import org.simantics.graph.representation.Internal;
  55 import org.simantics.graph.representation.Optional;
  56 import org.simantics.graph.representation.Root;
  57 import org.simantics.graph.representation.TransferableGraphUtils;
  58 import org.simantics.graph.utils.TGResourceUtil;
  59 import org.simantics.graph.utils.TGResourceUtil.LongAdapter;
  60
  61 public class StreamingTransferableGraphImportProcess implements TransferableGraphImporter {
  62
  63         public static String LOG_FILE = "transferableGraphs.log";
  64         final static private boolean LOG = false;
  65
  66         static DataOutput log;
  67
  68         static {
  69
  70                 if (LOG) {
  71
  72                         try {
  73                                 FileOutputStream stream = new FileOutputStream(LOG_FILE);
  74                                 log = new DataOutputStream(stream);
  75                         } catch (FileNotFoundException e) {
  76                                 e.printStackTrace();
  77                         }
  78                 }
  79
  80         }
  81
  82         private static void log(String line) {
  83                 if (LOG) {
  84                         try {
  85                                 log.writeUTF(line + "\n");
  86                         } catch (IOException e) {
  87                                 e.printStackTrace();
  88                         }
  89                 }
  90         }
  91
  92         Resource indexRoot;
  93         TransferableGraphSource tg;
  94         VirtualGraph vg;
  95         IImportAdvisor2 advisor;
  96         TGStatusMonitor monitor;
  97         ClusterBuilder2 builder;
  98         final TGResourceUtil resourceUtil = new TGResourceUtil();
  99
 100         int[] handles;
 101
 102         Set<String> missingExternals = new HashSet<String>();
 103
 104         int resourceCount;
 105         Identity[] identities;
 106         TreeMap<String, Variant> extensions;
 107
 108         // Builtins
 109         Resource RootLibrary;
 110         Resource String;
 111         Resource Library;
 112
 113         Resource InstanceOf;
 114         Resource ConsistsOf;
 115         Resource PartOf;
 116         Resource HasName;
 117         Resource NameOf;
 118
 119         public StreamingTransferableGraphImportProcess(Session session, VirtualGraph vg, TransferableGraphSource tg, IImportAdvisor2 advisor) {
 120                 this(session, vg, tg, advisor, null);
 121         }
 122
 123         public StreamingTransferableGraphImportProcess(Session session, VirtualGraph vg, TransferableGraphSource tg, IImportAdvisor2 advisor, TGStatusMonitor monitor) {
 124                 this.tg = tg;
 125                 this.vg = vg;
 126                 this.advisor = advisor;
 127                 this.monitor = monitor;
 128         }
 129
 130         private int updatePercentage(int percentage, int done, int total) {
 131                 if (monitor != null && (done & 63) == 0) {
 132                         int current = 100*done / total;
 133                         if (current > percentage) {
 134                                 percentage = current;
 135                                 monitor.status(percentage);
 136                         }
 137                 }
 138                 return percentage;
 139         }
 140
 141         public void readIdentities(ReadGraph g) throws Exception {
 142                 extensions = tg.getExtensions();
 143                 resourceCount = tg.getResourceCount();
 144                 identities = new Identity[tg.getIdentityCount()];
 145                 tg.forIdentities(g, new TransferableGraphSourceProcedure<Identity>() {
 146
 147                         int counter = 0;
 148
 149                         @Override
 150                         public void execute(Identity value) throws Exception {
 151                                 identities[counter++] = value;
 152                         }
 153                 });
 154         }
 155
 156         public void findBuiltins(WriteOnlyGraph g) throws DatabaseException {
 157                 RootLibrary = g.getBuiltin("http:/");
 158                 String = g.getBuiltin(CoreInitialization.LAYER0 + "String");
 159                 Library = g.getBuiltin(CoreInitialization.LAYER0 + "Library");
 160                 InstanceOf = g.getBuiltin(CoreInitialization.LAYER0 + "InstanceOf");
 161                 ConsistsOf = g.getBuiltin(CoreInitialization.LAYER0 + "ConsistsOf");
 162                 PartOf = g.getBuiltin(CoreInitialization.LAYER0 + "PartOf");
 163                 HasName = g.getBuiltin(CoreInitialization.LAYER0 + "HasName");
 164                 NameOf = g.getBuiltin(CoreInitialization.LAYER0 + "NameOf");
 165         }
 166
 167         public void findBuiltins(ReadGraph g) throws DatabaseException {
 168                 RootLibrary = g.getBuiltin("http:/");
 169                 String = g.getBuiltin(CoreInitialization.LAYER0 + "String");
 170                 Library = g.getBuiltin(CoreInitialization.LAYER0 + "Library");
 171                 InstanceOf = g.getBuiltin(CoreInitialization.LAYER0 + "InstanceOf");
 172                 ConsistsOf = g.getBuiltin(CoreInitialization.LAYER0 + "ConsistsOf");
 173                 PartOf = g.getBuiltin(CoreInitialization.LAYER0 + "PartOf");
 174                 HasName = g.getBuiltin(CoreInitialization.LAYER0 + "HasName");
 175                 NameOf = g.getBuiltin(CoreInitialization.LAYER0 + "NameOf");
 176         }
 177
 178 //      /* Preparation that is used when the core is empty.
 179 //       */
 180 //      void initialPrepare(WriteOnlyGraph graph) throws DatabaseException {
 181 //              findBuiltins(graph);
 182 //
 183 //              resources = new Resource[tg.resourceCount];
 184 //
 185 //              int Root = -1;
 186 //              int SimanticsDomain = -1;
 187 //              int Layer0 = -1;
 188 //
 189 //              for(Identity identity : tg.identities) {
 190 //                      if(identity.definition instanceof Internal) {
 191 //                              Internal def = (Internal)identity.definition;
 192 //                              Resource res = null;
 193 //                              if(def.parent == Layer0) {
 194 //                                      try {
 195 //                                              res = graph.getBuiltin(CoreInitialization.LAYER0 + def.name);
 196 //                                      } catch(ResourceNotFoundException e) {
 197 //                                      }
 198 //                              }
 199 //                              else if(def.parent == SimanticsDomain) {
 200 //                                      if(def.name.equals("Layer0-1.0"))
 201 //                                              Layer0 = identity.resource;
 202 //                              }
 203 //                              else if(def.parent == Root) {
 204 //                                      if(def.name.equals("www.simantics.org"))
 205 //                                              SimanticsDomain = identity.resource;
 206 //                              }
 207 //
 208 //                              if(res == null)
 209 //                                      res = createChild(graph, resources[def.parent], def.name);
 210 //                              else
 211 //                                      createChild(graph, res, resources[def.parent], def.name);
 212 //                              resources[identity.resource] = res;
 213 //                      }
 214 //                      else if(identity.definition instanceof Root) {
 215 //                              Root = identity.resource;
 216 //                              resources[identity.resource] = RootLibrary;
 217 //                      }
 218 //              }
 219 //      }
 220
 221         void addMissing(String external) {
 222                 Set<String> removals = new HashSet<String>();
 223                 for(String ext : missingExternals) if(ext.startsWith(external)) return;
 224                 for(String ext : missingExternals) if(external.startsWith(ext)) removals.add(ext);
 225                 missingExternals.removeAll(removals);
 226                 missingExternals.add(external);
 227         }
 228
 229         void prepare(ReadGraph graph) throws Exception {
 230
 231                 Resource target = advisor.getTarget();
 232                 if(target != null)
 233                         indexRoot = graph.syncRequest(new PossibleIndexRoot(target));
 234
 235                 findBuiltins(graph);
 236                 readIdentities(graph);
 237
 238 //              System.err.println("ext: " + extensions);
 239 //              System.err.println("rc: " + resourceCount);
 240 //              System.err.println("ic: " + identities.length);
 241
 242                 ClusterBuilderFactory factory = graph.getService(ClusterBuilderFactory.class);
 243                 ClusterBuilder2 builder = factory.create(vg, false);
 244
 245         this.handles = new int[resourceCount];
 246
 247                 for(Identity identity : identities) {
 248                         IdentityDefinition definition = identity.definition;
 249                         if(definition instanceof External) {
 250                                 External def = (External)definition;
 251                                 if(def.parent == -1) {
 252                                     handles[identity.resource] = builder.handle(RootLibrary);
 253                                 } else {
 254                                         if("@inverse".equals(def.name)) {
 255                                                 int parent = handles[def.parent];
 256                                                 int child = builder.handle(graph.getInverse(builder.resource(parent)));
 257                                                 handles[identity.resource] = child;
 258                                         } else {
 259                                                 int handle = handles[def.parent];
 260                                                 Resource parent = handle != 0 ? builder.resource(handle) : null;
 261                                                 // TODO: escape should be removed when names become well-behaving
 262                                                 if(parent != null) {
 263                                                     Map<String,Resource> childMap = graph
 264                                             .syncRequest(new UnescapedChildMapOfResource(parent),
 265                                                     new TransientCacheAsyncListener<Map<String, Resource>>());
 266                                                         Resource child = childMap.get(def.name);
 267                                                         if(child == null) {
 268                                                                 addMissing(graph.getURI(parent) + "/" + def.name);
 269                                                         } else {
 270                                                                 handles[identity.resource] = builder.handle(child);
 271                                                         }
 272                                                 } else {
 273                                                     addMissing(TransferableGraphUtils.getURI(resourceCount, identities, def.parent) + "/" + def.name);
 274                                                 }
 275                                         }
 276                                 }
 277                         }
 278                         else if(definition instanceof Internal) {
 279                                 // Do not do anything for now
 280                         }
 281                         else if(definition instanceof Root) {
 282                                 Root root = (Root)definition;
 283                                 if(root.name.equals(""))
 284                                     handles[identity.resource] = builder.handle(RootLibrary);
 285                                 else  {
 286                                         Resource existing = advisor.analyzeRoot(graph, root);
 287                                         if(existing != null)
 288                                             handles[identity.resource] = builder.handle(existing);
 289                                 }
 290                         }
 291                         else if(definition instanceof Optional) {
 292                                 External def = (External)definition;
 293                                 Resource parent = builder.resource(handles[def.parent]);
 294                                 if(parent != null)
 295                                         handles[identity.resource] = builder.handle(graph.syncRequest(new UnescapedChildMapOfResource(parent)).get(def.name));
 296                         }
 297                 }
 298
 299                 if(!missingExternals.isEmpty()) throw new MissingDependencyException(this);
 300
 301         }
 302
 303         @Override
 304         public Resource createChild(WriteOnlyGraph graph, Resource parent, Resource child, String name) throws DatabaseException {
 305             if(child == null) child = graph.newResource();
 306                 Resource nameResource = graph.newResource();
 307                 graph.claim(nameResource, InstanceOf, null, String);
 308                 graph.claimValue(nameResource, name, WriteBindings.STRING);
 309                 graph.claim(child, HasName, NameOf, nameResource);
 310                 return child;
 311         }
 312
 313         int[] getClustering() {
 314                 Variant v = extensions.get(Extensions.CLUSTERING);
 315                 if(v == null) return null;
 316                 try {
 317                         return (int[])v.getValue(Bindings.INT_ARRAY);
 318                 } catch (AdaptException e) {
 319                         Logger.defaultLogError(e);
 320                         return null;
 321                 }
 322         }
 323
 324         int[] getClusterSets() {
 325                 Variant v = extensions.get(Extensions.CLUSTER_SETS);
 326                 if(v == null) return null;
 327                 try {
 328                         return (int[])v.getValue(Bindings.INT_ARRAY);
 329                 } catch (AdaptException e) {
 330                         Logger.defaultLogError(e);
 331                         return null;
 332                 }
 333         }
 334
 335         boolean needTranslation(Datatype type) {
 336             return resourceUtil.mayHaveResource(type);
 337         }
 338
 339         void findClusterSet(WriteOnlyGraph graph, Resource rootLibrary, int[] clustering, int[] clusterSets, long[] clusters, int id) throws DatabaseException {
 340                 ClusteringSupport support = graph.getService(ClusteringSupport.class);
 341                 if(id == Extensions.ROOT_LIBRARY_CLUSTER_SET || id == Extensions.INDEX_ROOT_CLUSTER_SET) return;
 342                 Resource indexRootClusterSetResource = rootLibrary;
 343                 if(support.isClusterSet(indexRoot)) {
 344                         indexRootClusterSetResource = indexRoot;
 345                 } else {
 346                         graph.setClusterSet4NewResource(rootLibrary);
 347                         graph.flushCluster();
 348                 }
 349                 int indexRootCsHandle = builder.handle(indexRootClusterSetResource);
 350                 for(int pos=0,index=0;index<clustering.length;index++) {
 351                         pos += clustering[index];
 352                         if(id < pos) {
 353                                 int cs = clusterSets[index];
 354                                 if(handles[id] == 0) {
 355                                         int csHandle = 0;
 356                                         if(cs == Extensions.ROOT_LIBRARY_CLUSTER_SET) csHandle = builder.handle(rootLibrary);
 357                                         else if(cs == Extensions.INDEX_ROOT_CLUSTER_SET) {
 358                                                 if(indexRoot == null) throw new DatabaseException("No index root was available in TG import.");
 359                                                 csHandle = indexRootCsHandle;
 360                                         }
 361                                         else {
 362                                                 findClusterSet(graph, rootLibrary, clustering, clusterSets, clusters, cs);
 363                                                 csHandle = handles[cs];
 364                                         }
 365
 366                                         if(clusters[index] != 0)
 367                                                 builder.selectCluster(clusters[index]);
 368                                         else if(cs >= 0)
 369                                                 builder.newCluster(csHandle);
 370
 371                                         handles[id] = builder.newResource(csHandle);
 372                                         clusters[index] = support.getCluster(builder.resource(handles[id]));
 373
 374                                         builder.createClusterSet(handles[id]);
 375                                 }
 376                                 return;
 377                         }
 378                 }
 379         }
 380
 381         void write(final WriteOnlyGraph graph) throws Exception {
 382
 383         final SerialisationSupport ss = graph.getService(SerialisationSupport.class);
 384
 385         ClusterBuilderFactory factory = graph.getService(ClusterBuilderFactory.class);
 386         if(advisor instanceof IImportAdvisor2) {
 387             boolean allowImmutable = ((IImportAdvisor2)advisor).allowImmutableModifications();
 388             builder = factory.create(vg, allowImmutable);
 389         } else {
 390             builder = factory.create(vg, false);
 391         }
 392
 393                 final int[] handles = this.handles;
 394
 395                 int[] clustering = getClustering();
 396                 if(clustering != null) {
 397
 398                         int[] clusterSets = getClusterSets();
 399                         if(clusterSets != null) {
 400
 401                                 assert(clustering.length == clusterSets.length);
 402
 403                                 long[] clusters = new long[clustering.length];
 404
 405                                 // Create clustering
 406                                 for(int i=0;i<clusterSets.length;i++) {
 407                                         findClusterSet(graph, graph.getRootLibrary(), clustering, clusterSets, clusters, clusterSets[i]);
 408                                 }
 409
 410                                 // Then create all resources
 411                                 int i=0;
 412                             for(int j=0;j<clustering.length;j++) {
 413                                 int c = clustering[j];
 414                                 int s = clusterSets[j];
 415                                 int setHandle = 0;
 416                                         if(s == Extensions.ROOT_LIBRARY_CLUSTER_SET)
 417                                                 setHandle = builder.handle(graph.getRootLibrary());
 418                                         else if(s == Extensions.INDEX_ROOT_CLUSTER_SET) {
 419                                                 if(indexRoot == null) throw new DatabaseException("No index root was available in TG import.");
 420                                                 setHandle = builder.handle(indexRoot);
 421                                         }
 422                                         else setHandle = handles[s];
 423                                         // Preserve clustering only for internal resources
 424                                         if(clusters[j] != 0)
 425                                                 builder.selectCluster(clusters[j]);
 426                                         else if(s >= 0)
 427                                                 builder.newCluster(setHandle);
 428                                         for(int r=0;r<c;r++, i++)
 429                                                 if(handles[i] == 0) handles[i] = builder.newResource();
 430                                 }
 431
 432                                 for(;i<handles.length;++i)
 433                                         if(handles[i] == 0) handles[i] = builder.newResource();
 434
 435                         } else {
 436
 437                         int i = 0;
 438                                 for(int c : clustering) {
 439                                         builder.newCluster();
 440                                         for(int r=0;r<c;r++, i++)
 441                                                 if(handles[i] == 0) handles[i] = builder.newResource();
 442                                 }
 443
 444                                 for(;i<handles.length;++i)
 445                                         if(handles[i] == 0) handles[i] = builder.newResource();
 446
 447                         }
 448
 449                 } else {
 450
 451                         // Create blank resources
 452                         for(int i=0;i<handles.length;++i)
 453                                 if(handles[i] == 0) handles[i] = builder.newResource();
 454
 455                 }
 456
 457                 // Internal identities
 458                 for(Identity identity : identities) {
 459                         IdentityDefinition definition = identity.definition;
 460 //                      if(handles[identity.resource] != 0)
 461 //                              continue;
 462                         if(definition instanceof External) {
 463                                 // Already done everything
 464                         }
 465                         else if(definition instanceof Internal) {
 466                                 Internal def = (Internal)definition;
 467                                 if(handles[identity.resource] != 0)
 468                                         handles[identity.resource] = builder.handle(advisor.createChild(graph, this, builder.resource(handles[def.parent]), builder.resource(handles[identity.resource]), def.name));
 469                                 else
 470                                         handles[identity.resource] = builder.handle(advisor.createChild(graph, this, builder.resource(handles[def.parent]), null, def.name));
 471                         }
 472                         else if(definition instanceof Root) {
 473
 474                                 Root root = (Root)definition;
 475                                 if(handles[identity.resource] != 0)
 476                                         handles[identity.resource] = builder.handle(advisor.createRoot(graph, root, builder.resource(handles[identity.resource])));
 477                                 else
 478                                         handles[identity.resource] = builder.handle(advisor.createRoot(graph, root, null));
 479                         }
 480                         else if(definition instanceof Optional) {
 481                                 Optional def = (Optional)definition;
 482                                 if(handles[identity.resource] != 0) {
 483                                         Resource child = advisor.createChild(graph, this, builder.resource(handles[def.parent]), builder.resource(handles[identity.resource]), def.name);
 484                                         graph.claim(child, InstanceOf, null, Library); // ???
 485                                         handles[identity.resource] = builder.handle(child);
 486                                 } else {
 487                                         Resource child = advisor.createChild(graph, this, builder.resource(handles[def.parent]), null, def.name);
 488                                         graph.claim(child, InstanceOf, null, Library); // ???
 489                                         handles[identity.resource] = builder.handle(child);
 490                                 }
 491                         }
 492                 }
 493
 494                 int[] done = { 0 };
 495                 int[] percentage = { 0 };
 496
 497                 int statementCount = tg.getStatementCount();
 498                 tg.forStatements(null, new TransferableGraphSourceProcedure<int[]>() {
 499
 500                         @Override
 501                         public void execute(int[] value) throws Exception {
 502
 503                                 int sub = value[0];
 504                                 int pred = value[1];
 505                                 int inv = value[2];
 506                                 int obj = value[3];
 507
 508                                 int subject = handles[sub];
 509                                 int predicate = handles[pred];
 510                                 int object = handles[obj];
 511
 512                                 builder.addStatement(graph, subject, predicate, object);
 513                                 if(inv >= 0) {
 514                                     int inverse = handles[inv];
 515                                     builder.addStatement(graph, object, inverse, subject);
 516                                 }
 517
 518                                 // Count from 0% -> 50% => total = statementCount*2
 519                                 percentage[0] = updatePercentage(percentage[0], done[0]++, statementCount*2);
 520
 521                         }
 522
 523                 });
 524
 525                 int valueCount = tg.getValueCount();
 526                 done[0] = 0;
 527
 528                 class ValueProcedure extends InputStream implements TransferableGraphSourceValueProcedure {
 529
 530             private TGResourceUtil util = new TGResourceUtil();
 531                     private DataInput source;
 532
 533             @Override
 534             public void execute(int _resource, Datatype type, DataInput stream) throws Exception {
 535
 536                 source = stream;
 537
 538                 //int file = _resource & 0x80000000;
 539                 int resource = _resource & 0x7FFFFFFF;
 540
 541                 Binding binding = Bindings.getBinding(type);
 542                 Serializer s = Bindings.getSerializer(binding);
 543
 544                 builder.beginValue(handles[resource]);
 545                 if(util.mayHaveResource(type)) {
 546                     Object value = s.deserialize(stream);
 547                     util.adaptValue( binding,  value, new LongAdapter() {
 548                                 @Override
 549                                 public long adapt(long in) {
 550                                     try {
 551                                         return ss.getRandomAccessId(handles[(int)in]);
 552                                     } catch (DatabaseException e) {
 553                                         throw new IllegalStateException(e);
 554                                     }
 555                                 }
 556                             });
 557                     byte[] bytes = s.serialize(value);
 558                     for(byte b : bytes) {
 559                         int val = b;
 560                         if(val < 0) val += 256;
 561                         builder.appendValue(val);
 562                     }
 563                 } else {
 564                     s.skip(this);
 565                 }
 566                 builder.endValue();
 567                 worked();
 568
 569             }
 570
 571             @Override
 572             public int read() throws IOException {
 573                 int value = source.readUnsignedByte();
 574                 try {
 575                     builder.appendValue(value);
 576                 } catch (DatabaseException e) {
 577                     e.printStackTrace();
 578                 }
 579                 return value;
 580             }
 581
 582             @Override
 583             public void rawCopy(int resource, int length, DataInput input) throws Exception {
 584                 builder.beginValue(handles[resource]);
 585                 for (int i = 0; i < length; ++i)
 586                     builder.appendValue(input.readUnsignedByte());
 587                 builder.endValue();
 588                 worked();
 589             }
 590
 591             private void worked() {
 592                 // Count from 50% -> 100% => [valueCount, valueCount*2)
 593                 percentage[0] = updatePercentage(percentage[0], valueCount + done[0]++, valueCount*2);
 594             }
 595                 };
 596
 597                 tg.forValues2(null, new ValueProcedure());
 598
 599         }
 600
 601         @Override
 602         public long[] getResourceIds(SerialisationSupport serializer) throws DatabaseException {
 603                 final int count = handles.length;
 604                 long[] resourceIds = new long[count];
 605                 for(int i=0;i<count;++i)
 606                     resourceIds[i] = serializer.getRandomAccessId(handles[i]);
 607                 return resourceIds;
 608         }
 609 }