org.simantics.interop/src/org/simantics/interop/test/GraphComparator.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  *     Foster Wheeler Energia Oy - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.interop.test;
  13
  14 import java.util.ArrayList;
  15 import java.util.Arrays;
  16 import java.util.Collection;
  17 import java.util.Collections;
  18 import java.util.Comparator;
  19 import java.util.HashMap;
  20 import java.util.HashSet;
  21 import java.util.List;
  22 import java.util.Map;
  23 import java.util.Set;
  24 import java.util.Stack;
  25
  26 import org.simantics.db.ReadGraph;
  27 import org.simantics.db.Resource;
  28 import org.simantics.db.Session;
  29 import org.simantics.db.Statement;
  30 import org.simantics.db.common.request.ReadRequest;
  31 import org.simantics.db.common.utils.NameUtils;
  32 import org.simantics.db.exception.DatabaseException;
  33 import org.simantics.layer0.Layer0;
  34 import org.simantics.utils.datastructures.BijectionMap;
  35 import org.simantics.utils.datastructures.MapList;
  36 import org.simantics.utils.datastructures.Pair;
  37
  38 /**
  39  * Compares two subgraphs and reports differences.
  40  *
  41  * Assumes that subgraphs (defined using traverse relations) are not cyclic.
  42  *
  43  * Assumes that properties can be used to identify objects, if relation type is not enough.
  44  *
  45  *
  46  *
  47  * @author Marko Luukkainen <marko.luukkainen@vtt.fi>
  48  *
  49  */
  50 public class GraphComparator {
  51
  52         private static final boolean DEBUG = false;
  53
  54         private Resource r1;
  55         private Resource r2;
  56         private Set<Resource> strong = new HashSet<Resource>();       // List of relations that identify object, if subject is already identified.
  57         private List<Resource> traversed = new ArrayList<Resource>(); // list of relations that are traversed (and tested)
  58         private List<Resource> tested = new ArrayList<Resource>();    // list of relations that are tested, but not traversed
  59         private List<Resource> nonTraversed = new ArrayList<Resource>(); // list of relations that are not traversed
  60         private List<Resource> nonTested = new ArrayList<Resource>(); // list of relations that are not tested
  61
  62         private List<Statement> changes1 = new ArrayList<Statement>();
  63         private List<Statement> changes2 = new ArrayList<Statement>();
  64         private List<Pair<Statement,Statement>> modifications = new ArrayList<Pair<Statement,Statement>>();
  65         private Set<Statement> changes1Set = new HashSet<Statement>();
  66         private Set<Statement> changes2Set = new HashSet<Statement>();
  67         private Set<Pair<Statement,Statement>> modificationsSet = new HashSet<Pair<Statement,Statement>>();
  68
  69         private BijectionMap<Statement, Statement> comparableStatements = new BijectionMap<Statement, Statement>();
  70         private BijectionMap<Resource, Resource> comparableResources = new BijectionMap<Resource, Resource>();
  71
  72         private Set<Resource> processedResources = new HashSet<Resource>();
  73
  74         private ResourceComparator comparator;
  75
  76         private Comparator<Statement> scomp = new PredicateComparator();
  77         private Comparator<Resource> rcomp = new ResComparator();
  78
  79         private Set<Resource> nonMatchedLeft = new HashSet<Resource>();
  80         private Set<Resource> nonMatchedRight = new HashSet<Resource>();
  81
  82         // runtime attributes
  83
  84         private ReadGraph g;
  85         private Layer0 b;
  86
  87         public GraphComparator(Resource r1, Resource r2) {
  88                 this.r1 = r1;
  89                 this.r2 = r2;
  90                 comparator = new TypeComparator();
  91         }
  92
  93         public GraphComparator(Resource r1, Resource r2, ResourceComparator comparator) {
  94                 this.r1 = r1;
  95                 this.r2 = r2;
  96                 this.comparator = comparator;
  97         }
  98
  99         ArrayList<Statement> ss1 = new ArrayList<Statement>();
 100         ArrayList<Statement> ss2 = new ArrayList<Statement>();
 101
 102
 103         public Comparator<Resource> getResourceComparator() {
 104                 return rcomp;
 105         }
 106
 107         public Comparator<Statement> getStatementComparator() {
 108                 return scomp;
 109         }
 110
 111         public Resource getR1() {
 112                 return r1;
 113         }
 114
 115         public Resource getR2() {
 116                 return r2;
 117         }
 118
 119         public void addTraversed(Resource rel) {
 120                 traversed.add(rel);
 121         }
 122
 123         public void addTraversed(Collection<Resource> rels) {
 124                 traversed.addAll(rels);
 125         }
 126
 127         public void addNonTraversed(Resource rel) {
 128                 nonTraversed.add(rel);
 129         }
 130
 131         public void addNonTraversed(Collection<Resource> rels) {
 132                 nonTraversed.addAll(rels);
 133         }
 134
 135         public void addTested(Resource rel) {
 136                 tested.add(rel);
 137         }
 138
 139         public void addTested(Collection<Resource> rels) {
 140                 tested.addAll(rels);
 141         }
 142
 143         public void addNonTested(Resource rel) {
 144                 nonTested.add(rel);
 145         }
 146
 147         public void addNonTested(Collection<Resource> rels) {
 148                 nonTested.addAll(rels);
 149         }
 150
 151         public void addComparableResources(Resource r1, Resource r2) {
 152                 comparableResources.map(r1, r2);
 153         }
 154
 155         public void addComparableResources(BijectionMap<Resource, Resource> matching) {
 156                 comparableResources.addAll(matching);
 157         }
 158
 159         public void addStrong(Resource r) {
 160                 strong.add(r);
 161         }
 162
 163         public void addStrong(Collection<Resource> rels) {
 164                 strong.addAll(rels);
 165         }
 166
 167         public void addNonMatchedLeft(Resource r) {
 168                 nonMatchedLeft.add(r);
 169         }
 170
 171         public void addNonMatchedRight(Resource r) {
 172                 nonMatchedRight.add(r);
 173         }
 174
 175         public void test(ReadGraph g) throws DatabaseException {
 176                 this.g = g;
 177                 this.b = Layer0.getInstance(g);
 178                 comparator.setComparator(this);
 179
 180                 Stack<Resource> objectsLeft = new Stack<Resource>();
 181                 Stack<Resource> objectsRight = new Stack<Resource>();
 182                 objectsLeft.push(r1);
 183                 objectsRight.push(r2);
 184
 185                 Set<Statement> unreliableLeft = new HashSet<Statement>();
 186                 Set<Statement> unreliableRight = new HashSet<Statement>();
 187
 188                 while (true) {
 189                         if (objectsLeft.isEmpty())
 190                                 break;
 191
 192
 193                         // process compares objects that are identified and searches for more resources to process.
 194                         process(objectsLeft, objectsRight, unreliableLeft, unreliableRight);
 195                         // process unreliable handles cases where unidentified statements subject and object have been identified
 196                         processUnreliable(unreliableLeft, unreliableRight);
 197                         // process unreliable handles cases where unidentified resources have path of length one to identified resource
 198                         processUnreliable(unreliableLeft, unreliableRight,objectsLeft,objectsRight);
 199                         if (objectsLeft.isEmpty() && unreliableLeft.size() > 0 && unreliableRight.size() > 0) {
 200                                 // comparison is ending, but we have still unprocessed unidentified resources left.
 201                                 // These cases have longer path than one to identified objects.
 202                                 processUnreliableDeep(unreliableLeft, unreliableRight, objectsLeft, objectsRight);
 203                         }
 204
 205                 }
 206                 for (Statement s : unreliableLeft) {
 207                         if (!comparableStatements.containsLeft(s))
 208                                 addDeletion(s);
 209                 }
 210                 for (Statement s : unreliableRight) {
 211                         if (!comparableStatements.containsRight(s))
 212                                 addAddition(s);
 213                 }
 214
 215
 216         }
 217
 218         public void test(Session session) throws DatabaseException {
 219                 test(session, r1, r2);
 220         }
 221
 222         public void test(Session session, Resource r1, Resource r2) throws DatabaseException {
 223
 224                 comparator.setComparator(this);
 225
 226                 addComparable(r1, r2, false);
 227
 228                 final Stack<Resource> objectsLeft = new Stack<Resource>();
 229                 final Stack<Resource> objectsRight = new Stack<Resource>();
 230                 objectsLeft.push(r1);
 231                 objectsRight.push(r2);
 232
 233                 final Set<Statement> unreliableLeft = new HashSet<Statement>();
 234                 final Set<Statement> unreliableRight = new HashSet<Statement>();
 235
 236                 while (true) {
 237                         if (objectsLeft.isEmpty())
 238                                 break;
 239                         session.syncRequest(new ReadRequest() {
 240
 241                                 @Override
 242                                 public void run(ReadGraph graph) throws DatabaseException {
 243                                         g = graph;
 244                                         b = Layer0.getInstance(graph);
 245                                         // process compares objects that are identified and searches for more resources to process.
 246                                         process(objectsLeft, objectsRight, unreliableLeft, unreliableRight);
 247                                         // process unreliable handles cases where unidentified statements subject and object have been identified
 248                                         processUnreliable(unreliableLeft, unreliableRight);
 249                                         // process unreliable handles cases where unidentified resources have path of length one to identified resource
 250                                         processUnreliable(unreliableLeft, unreliableRight,objectsLeft,objectsRight);
 251                                         if (objectsLeft.isEmpty() && unreliableLeft.size() > 0 && unreliableRight.size() > 0) {
 252                                                 // comparison is ending, but we have still unprocessed unidentified resources left.
 253                                                 // These cases have longer path than one to identified objects.
 254                                                 processUnreliableDeep(unreliableLeft, unreliableRight, objectsLeft, objectsRight);
 255                                         }
 256                                 }
 257                         });
 258
 259
 260
 261                 }
 262                 for (Statement s : unreliableLeft) {
 263                         if (!comparableStatements.containsLeft(s))
 264                                 addDeletion(s);
 265                 }
 266                 for (Statement s : unreliableRight) {
 267                         if (!comparableStatements.containsRight(s))
 268                                 addAddition(s);
 269                 }
 270
 271
 272         }
 273
 274         private void process(Stack<Resource> objectsLeft, Stack<Resource> objectsRight, Set<Statement> unreliableLeft, Set<Statement> unreliableRight) throws DatabaseException {
 275                 List<Statement> ss1 = new ArrayList<Statement>();
 276                 List<Statement> ss2 = new ArrayList<Statement>();
 277
 278                 while (!objectsLeft.isEmpty()) {
 279                         Resource r1 = objectsLeft.pop();
 280                         Resource r2 = objectsRight.pop();
 281
 282                         if (r1.equals(r2))
 283                                 continue;
 284
 285                         if (processedResources.contains(r1))
 286                                 continue;
 287                         processedResources.add(r1);
 288
 289
 290                         if((comparableResources.containsLeft(r1)||comparableResources.containsRight(r2)) && !comparableResources.contains(r1, r2)) {
 291                                 throw new DatabaseException("Comparator error: Trying to map " + r1 + " to " + r2 + " while mappings " + r1 + " to " + comparableResources.getRight(r1) + " and " + comparableResources.getLeft(r2) + " to " + r2 + " exist.");
 292                         }
 293                         addComparable(r1, r2, false);
 294
 295                         //System.out.println("test " + NameUtils.getSafeName(g, r1) + " " + NameUtils.getSafeName(g, r2));
 296                         compareProps(r1, r2);
 297
 298                         for (Resource rel : tested) {
 299                                 ss1.addAll(g.getStatements(r1, rel));
 300                                 ss2.addAll(g.getStatements(r2, rel));
 301                                 ss1 = filterAsserted(r1, ss1);
 302                                 ss2 = filterAsserted(r2, ss2);
 303                                 ss1 = filterTraversed(ss1);
 304                                 ss2 = filterTraversed(ss2);
 305                                 ss1 = filterNonTested(ss1);
 306                                 ss2 = filterNonTested(ss2);
 307
 308
 309                                 compareStatements(ss1, ss2, null, null,null,null);
 310                                 ss1.clear();
 311                                 ss2.clear();
 312                         }
 313
 314                         for (Resource rel : traversed) {
 315                                 ss1.addAll(g.getStatements(r1, rel));
 316                                 ss2.addAll(g.getStatements(r2, rel));
 317                                 ss1 = filterAsserted(r1, ss1);
 318                                 ss2 = filterAsserted(r2, ss2);
 319                                 ss1 = filterNonTraversed(ss1);
 320                                 ss2 = filterNonTraversed(ss2);
 321                                 compareStatements(ss1, ss2, objectsLeft, objectsRight,unreliableLeft,unreliableRight);
 322                                 ss1.clear();
 323                                 ss2.clear();
 324
 325                         }
 326                 }
 327         }
 328
 329         private void processUnreliable(Set<Statement> unreliableLeft, Set<Statement> unreliableRight) throws DatabaseException {
 330                 MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
 331                 MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
 332                 MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
 333                 MapList<Resource,Statement> objectRight = new MapList<Resource, Statement>();
 334
 335                 for (Statement s : unreliableLeft) {
 336                         subjectLeft.add(s.getSubject(),s);
 337                         objectLeft.add(s.getObject(),s);
 338                 }
 339                 for (Statement s : unreliableRight) {
 340                         subjectRight.add(s.getSubject(),s);
 341                         objectRight.add(s.getObject(),s);
 342                 }
 343
 344                 for (Resource left : subjectLeft.getKeys()) {
 345                         if (!comparableResources.containsLeft(left))
 346                                 continue;
 347                         Resource right = comparableResources.getRight(left);
 348                         for (Statement leftS : subjectLeft.getValues(left)) {
 349                                 Resource leftO = leftS.getObject();
 350                                 if (!comparableResources.containsLeft(leftO))
 351                                         continue;
 352                                 if (!unreliableLeft.contains(leftS))
 353                                         continue;
 354                                 Resource rightO = comparableResources.getRight(leftO);
 355                                 for (Statement rightS : subjectRight.getValues(right)) {
 356                                         if (!rightS.getObject().equals(rightO))
 357                                                 continue;
 358                                         if (!unreliableRight.contains(rightS))
 359                                                 continue;
 360                                         if (leftS.getPredicate().equals(rightS.getPredicate()) ||
 361                                                 comparableResources.contains(leftS.getPredicate(), rightS.getPredicate())) {
 362                                                 unreliableLeft.remove(leftS);
 363                                                 unreliableRight.remove(rightS);
 364                                                 addComparable(leftS, rightS, false);
 365                                         }
 366                                 }
 367                         }
 368                 }
 369         }
 370
 371         private void processUnreliable(Set<Statement> unreliableLeft, Set<Statement> unreliableRight, Stack<Resource> objectsLeft, Stack<Resource> objectsRight) throws DatabaseException {
 372                 MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
 373                 MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
 374                 MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
 375                 MapList<Resource,Statement> objectRight = new MapList<Resource, Statement>();
 376
 377                 for (Statement s : unreliableLeft) {
 378                         subjectLeft.add(s.getSubject(),s);
 379                         objectLeft.add(s.getObject(),s);
 380                 }
 381                 for (Statement s : unreliableRight) {
 382                         subjectRight.add(s.getSubject(),s);
 383                         objectRight.add(s.getObject(),s);
 384                 }
 385
 386                 for (Resource ol : objectLeft.getKeys()) {
 387                         // all statements to the left side object
 388                         List<Statement> left = objectLeft.getValues(ol);
 389                         // all subjects that have statements to the left side object (ol)
 390                         Set<Resource> sLeft = new HashSet<Resource>();
 391                         // all matching subjects on the right side
 392                         Set<Resource> sRight = new HashSet<Resource>();
 393                         for (Statement s : left) {
 394                                 sLeft.add(s.getSubject());
 395                                 sRight.add(comparableResources.getRight(s.getSubject()));
 396                         }
 397
 398                         // check if object left can be reliably identified by available statements
 399                         // if there are any objects on the left side with similar statements, object left cannot be mapped.
 400                         boolean hasSimilar = false;
 401                         MapList<Resource, Statement> comparableOLeft = new MapList<Resource, Statement>();
 402                         for (Resource sl : sLeft) {
 403                                 for (Statement s : subjectLeft.getValues(sl)) {
 404                                         if (!s.getObject().equals(ol)) {
 405                                                 comparableOLeft.add(s.getObject(),s);
 406                                         }
 407                                 }
 408                         }
 409
 410                         for (Resource similarOl : comparableOLeft.getKeys()) {
 411                                 List<Statement> similarLeft = comparableOLeft.getValues(similarOl);
 412                                 if (similarLeft.size() == left.size()) {
 413                                         boolean useL[] = new boolean[left.size()];
 414                                         boolean useSL[] = new boolean[left.size()];
 415                                         for (int i = 0; i < left.size(); i++) {
 416                                                 useL[i] = false;
 417                                                 useSL[i] = false;
 418                                         }
 419                                         for (int i = 0; i < left.size(); i++) {
 420                                                 for (int j = 0; j < left.size(); j++) {
 421                                                         if (useSL[j])
 422                                                                 continue;
 423                                                         Resource pl = left.get(i).getPredicate();
 424                                                         Resource psl = similarLeft.get(j).getPredicate();
 425                                                         if (pl.equals(psl)) {
 426                                                                 useL[i] = true;
 427                                                                 useSL[j] = true;
 428                                                                 break;
 429                                                         }
 430                                                 }
 431                                         }
 432                                         boolean diff = false;
 433                                         for (int i = 0; i < left.size(); i++) {
 434                                                 if (!useL[i] || !useSL[i]) {
 435                                                         diff = true;
 436                                                 }
 437                                         }
 438                                         if (!diff) {
 439                                                 hasSimilar = true;
 440                                                 break;
 441                                         }
 442                                 }
 443                         }
 444
 445                         if (hasSimilar)
 446                                 continue;
 447
 448
 449                         // all objects that subjects on the right side point to. Object left has its matching resource among these, if it has matching resource
 450                         MapList<Resource,Statement> possibleOR = new MapList<Resource, Statement>();
 451                         for (Resource sr : sRight) {
 452                                 for (Statement s : subjectRight.getValues(sr))
 453                                         possibleOR.add(s.getObject(),s);
 454                         }
 455
 456                         // filter possible right side objects to those that have same amount of statements as the left side object
 457                         for (Resource or : possibleOR.getKeys().toArray(new Resource[possibleOR.getKeys().size()])) {
 458                                 List<Statement> right = possibleOR.getValues(or);
 459                                 if (right.size() != left.size())
 460                                         possibleOR.remove(or);
 461
 462                         }
 463
 464                         // check for matching statements (comparable subjects, matching predicates)
 465                         MapList<Resource,Statement> matchingOR = new MapList<Resource, Statement>(); // list of objects that have matching statements
 466                         Map<Resource,Pair<int[], int[]>> matchingStatements = new HashMap<Resource, Pair<int[], int[]>>(); // matching statements
 467                         for (Resource or : possibleOR.getKeys()) {
 468                                 List<Statement> right = possibleOR.getValues(or);
 469                                 int iLeft[] = new int[left.size()];
 470                                 int iRight[] = new int[right.size()];
 471
 472                                 for (int i = 0; i < left.size(); i++) {
 473                                         iLeft[i] = -1;
 474                                         iRight[i] = -1;
 475                                 }
 476
 477                                 for (int l = 0; l < left.size(); l++) {
 478                                         Statement ls = left.get(l);
 479                                         for (int r = 0; r < right.size(); r++) {
 480                                                 if (iRight[r] >= 0)
 481                                                         continue;
 482                                                 Statement rs = right.get(r);
 483                                                 if (!comparableResources.contains(ls.getSubject(), rs.getSubject()))
 484                                                         continue;
 485                                                 if (rcomp.compare(ls.getPredicate(),rs.getPredicate()) == 0) {
 486                                                         iLeft[l] = r;
 487                                                         iRight[r] = l;
 488                                                         break;
 489                                                 }
 490                                         }
 491
 492                                 }
 493                                 boolean success = true;
 494                                 for (int i = 0; i < left.size(); i++) {
 495                                         if (iLeft[i] < 0) {
 496                                                 success = false;
 497                                                 break;
 498                                         }
 499                                         if (iRight[i] < 0) {
 500                                                 success = false;
 501                                                 break;
 502                                         }
 503
 504                                 }
 505                                 if (success) {
 506                                         for (Statement s : right)
 507                                                 matchingOR.add(or,s);
 508                                         matchingStatements.put(or, new Pair<int[], int[]>(iLeft, iRight));
 509                                 }
 510                         }
 511                         // if there is only one matching right side object, we have found a match
 512                         if (matchingOR.getKeySize() == 1) {
 513                                 Resource or = matchingOR.getKeys().iterator().next();
 514                                 List<Statement> right = matchingOR.getValues(or);
 515                                 Pair<int[], int[]> indices = matchingStatements.get(or);
 516
 517                                 objectsLeft.add(ol);
 518                                 objectsRight.add(or);
 519                                 addComparable(ol, or, false);
 520                                 for (int l = 0; l < left.size(); l++) {
 521                                         int r = indices.first[l];
 522                                         Statement sl = left.get(l);
 523                                         Statement sr = right.get(r);
 524                                         addComparable(sl, sr, true);
 525                                         unreliableLeft.remove(sl);
 526                                         unreliableRight.remove(sr);
 527                                 }
 528
 529                         }
 530
 531                 }
 532
 533
 534         }
 535
 536         private void processUnreliableDeep(Set<Statement> unreliableLeft, Set<Statement> unreliableRight, Stack<Resource> objectsLeft, Stack<Resource> objectsRight) throws DatabaseException {
 537                 MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
 538                 MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
 539                 MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
 540                 MapList<Resource,Statement> objectRight = new MapList<Resource, Statement>();
 541
 542                 for (Statement s : unreliableLeft) {
 543                         subjectLeft.add(s.getSubject(),s);
 544                         objectLeft.add(s.getObject(),s);
 545                 }
 546                 for (Statement s : unreliableRight) {
 547                         subjectRight.add(s.getSubject(),s);
 548                         objectRight.add(s.getObject(),s);
 549                 }
 550                 for (Resource ol : objectLeft.getKeys()) {
 551                         Set<Path> pathsLeft = new HashSet<Path>();
 552                         for (Resource rel : traversed) {
 553                                 pathsLeft.addAll(Path.create(g.getStatements(ol, rel)));
 554                         }
 555                         while (true) {
 556                                 expand(pathsLeft);
 557                                 if (pathsLeft.size() == 0)
 558                                         break;
 559                                 Collection<Path> endPaths = new ArrayList<Path>(1);
 560                                 for (Path p : pathsLeft) {
 561                                         if (comparableResources.containsLeft(p.getEnd())) {
 562                                                 endPaths.add(p);
 563                                         }
 564                                 }
 565                                 if (endPaths.size() > 0) {
 566                                         pathsLeft.clear();
 567                                         pathsLeft.addAll(endPaths);
 568                                         break;
 569                                 }
 570                         }
 571                         if (pathsLeft.size() > 0) {
 572                                 Resource sl = objectLeft.getValues(ol).get(0).getSubject();
 573                                 Resource sr = comparableResources.getRight(sl);
 574                                 Collection<Resource> possibleOR = new ArrayList<Resource>();
 575                                 for (Statement s : subjectRight.getValues(sr)) {
 576                                         possibleOR.add(s.getObject());
 577                                 }
 578                                 Map<Resource,Set<Path>> matchingPaths = new HashMap<Resource, Set<Path>>();
 579                                 for (Resource or : possibleOR) {
 580                                         Set<Path> possiblePathsRight = new HashSet<Path>();
 581                                         for (Path leftPath : pathsLeft) {
 582                                                 possiblePathsRight.addAll(findComparableRight(leftPath, or));
 583                                         }
 584                                         if (hasMatchingPaths(pathsLeft, possiblePathsRight)) {
 585                                                 matchingPaths.put(or, possiblePathsRight);
 586                                         }
 587                                 }
 588                                 if (matchingPaths.size() > 0) {
 589                                         if (matchingPaths.size() == 1) {
 590                                                 Resource or = matchingPaths.keySet().iterator().next();
 591
 592                                                 objectsLeft.add(ol);
 593                                                 objectsRight.add(or);
 594                                                 addComparable(ol, or, false);
 595                                                 Collection<Statement> statementsLeft = objectLeft.getValues(ol);
 596                                                 Collection<Statement> statementsRight = objectRight.getValues(or);
 597                                                 unreliableLeft.removeAll(statementsLeft);
 598                                                 unreliableRight.removeAll(statementsRight);
 599                                                 BijectionMap<Path,Path> map = getMatchingPaths(pathsLeft, matchingPaths.get(or));
 600                                                 for (Path left : map.getLeftSet()) {
 601                                                         Path right = map.getRight(left);
 602                                                         for (int i = 0; i < left.getLength(); i++) {
 603                                                                 addComparable(left.getStatements().get(i),right.getStatements().get(i),false);
 604                                                         }
 605                                                 }
 606                                         }
 607                                 }
 608                         }
 609
 610                 }
 611
 612         }
 613
 614         private boolean hasMatchingPaths(Set<Path> leftPaths, Set<Path> rightPaths) {
 615                 if (leftPaths.size() != rightPaths.size())
 616                         return false;
 617                 BijectionMap<Path,Path> map = getMatchingPaths(leftPaths, rightPaths);
 618                 return map.size() == leftPaths.size();
 619         }
 620
 621         private BijectionMap<Path,Path> getMatchingPaths(Set<Path> leftPaths, Set<Path> rightPaths) {
 622                 BijectionMap<Path,Path> map = new BijectionMap<Path, Path>();
 623                 for (Path leftPath : leftPaths) {
 624                         for (Path rightPath : rightPaths) {
 625                                 if (map.containsRight(rightPath))
 626                                         continue;
 627                                 if (leftPath.getLength() != rightPath.getLength())
 628                                         continue;
 629                                 if (comparableResources.contains(leftPath.getEnd(), rightPath.getEnd())) {
 630                                         map.map(leftPath, rightPath);
 631                                         break;
 632                                 }
 633                         }
 634                 }
 635                 return map;
 636         }
 637
 638         private void expand(Set<Path> paths) throws DatabaseException {
 639                 Set<Path> stepPathsLeft = new HashSet<Path>();
 640                 if (paths.size() == 0)
 641                         return;
 642                 int length = paths.iterator().next().getLength() + 1;
 643                 for (Path p : paths) {
 644                         for (Resource rel : traversed) {
 645                                 stepPathsLeft.addAll(Path.expand(p,g.getStatements(p.getEnd(), rel)));
 646                         }
 647                 }
 648                 paths.clear();
 649                 for (Path p : stepPathsLeft) {
 650                         if (p.getLength() == length)
 651                                 paths.add(p);
 652                 }
 653         }
 654
 655         private Collection<Path> findComparableRight(Path leftPath, Resource beginRight) throws DatabaseException {
 656                 Set<Path> rightPaths = new HashSet<Path>();
 657                 rightPaths.addAll(Path.create(g.getStatements(beginRight, getRight(leftPath.getStatements().get(0).getPredicate()))));
 658                 for (int i = 1; i < leftPath.getLength(); i++) {
 659                         if (rightPaths.size() == 0)
 660                                 return rightPaths;
 661                         Set<Path> stepPaths = new HashSet<Path>();
 662                         for (Path p : rightPaths) {
 663                                 stepPaths.addAll(Path.expand(p, g.getStatements(p.getEnd(), getRight(leftPath.getStatements().get(i).getPredicate()))));
 664                         }
 665                         rightPaths.clear();
 666                         for (Path p : stepPaths)
 667                                 if (p.getLength() == i+1)
 668                                         rightPaths.add(p);
 669                 }
 670                 return rightPaths;
 671
 672         }
 673
 674         private Resource getRight(Resource r) {
 675                 if (comparableResources.containsLeft(r))
 676                         return comparableResources.getRight(r);
 677                 return r;
 678         }
 679
 680
 681
 682         public BijectionMap<Statement, Statement> getComparableStatements() {
 683                 return comparableStatements;
 684         }
 685
 686         public BijectionMap<Resource, Resource> getComparableResources() {
 687                 return comparableResources;
 688         }
 689
 690         public GraphChanges getChanges() {
 691                 return new GraphChanges(r1,r2,changes1,changes2,modifications,comparableResources);
 692         }
 693
 694         private void addComparable(Statement left, Statement right, boolean process) throws DatabaseException {
 695                 addComparable(left.getObject(), right.getObject(), process);
 696                 comparableStatements.map(left, right);
 697                 //comparableResources.map(left.getObject(), right.getObject());
 698         }
 699
 700         private void addComparable(Resource left, Resource right, boolean process) throws DatabaseException {
 701                 if(!comparableResources.contains(left, right)) {
 702                         if (comparableResources.containsLeft(left)||comparableResources.containsRight(right)) {
 703                                 throw new DatabaseException("Comparator error: Trying to map " + left + " to " + right + " while mappings " + left + " to " + comparableResources.getRight(left) + " and " + comparableResources.getLeft(right) + " to " + right + " exist.");
 704                         } else {
 705                                 if (DEBUG) System.out.println(left + " = " + right);
 706                                 comparableResources.map(left, right);
 707                         }
 708                 }
 709
 710         }
 711
 712         public List<Statement> filterAsserted(Resource r, Collection<Statement> in) throws DatabaseException {
 713                 List<Statement> out = new ArrayList<Statement>();
 714                 for (Statement s : in) {
 715                         if (!s.isAsserted(r))
 716                                 out.add(s);
 717
 718                 }
 719                 return out;
 720         }
 721
 722
 723
 724         private String printStatement(ReadGraph graph, Statement s) throws DatabaseException {
 725                 return NameUtils.getSafeName(graph, s.getSubject()) + " " + NameUtils.getSafeName(graph, s.getPredicate()) + " " + NameUtils.getSafeName(graph, s.getObject());
 726         }
 727
 728         private List<Statement> filterTraversed(List<Statement> in) throws DatabaseException {
 729                 return filter(traversed, in);
 730         }
 731
 732         private List<Statement> filterNonTested(List<Statement> in) throws DatabaseException {
 733                 return filter(nonTested, in);
 734         }
 735
 736         private List<Statement> filterNonTraversed(List<Statement> in) throws DatabaseException {
 737                 return filter(nonTraversed, in);
 738         }
 739
 740         private List<Statement> filter(Collection<Resource> toFilter, List<Statement> in) throws DatabaseException {
 741                 if (toFilter.size() == 0)
 742                         return in;
 743                 List<Statement> out = new ArrayList<Statement>();
 744                 for (Statement s : in) {
 745                         boolean usable = true;
 746                         for (Resource r : toFilter) {
 747                                 if (g.isSubrelationOf(s.getPredicate(),r)) {
 748                                         usable = false;
 749                                         break;
 750                                 }
 751                         }
 752                         if (usable) {
 753                                 out.add(s);
 754                         }
 755
 756                 }
 757                 return out;
 758         }
 759
 760
 761         private void addDeletion(Statement s) {
 762                 if (!changes1Set.contains(s)) {
 763                         changes1Set.add(s);
 764                         changes1.add(s);
 765                 }
 766         }
 767
 768         private void addAddition(Statement s) {
 769                 if (!changes2Set.contains(s)) {
 770                         changes2Set.add(s);
 771                         changes2.add(s);
 772                 }
 773         }
 774
 775         private void addModification(Statement s1, Statement s2) {
 776                 Pair<Statement, Statement> mod = new Pair<Statement, Statement>(s1,s2);
 777                 if (!modificationsSet.contains(mod)) {
 778                         modificationsSet.add(mod);
 779                         modifications.add(mod);
 780                 }
 781         }
 782
 783         public void sortStatement(List<Statement> list1, List<Statement> list2) {
 784                 sortStatement(list1, list2, scomp);
 785         }
 786
 787         public void sortStatement(List<Statement> list1, List<Statement> list2, Comparator<Statement> scomp) {
 788                 Collections.sort(list1,scomp);
 789                 Collections.sort(list2,scomp);
 790
 791                 List<Statement> sorted1 = new ArrayList<Statement>(list1.size());
 792                 List<Statement> sorted2 = new ArrayList<Statement>(list2.size());
 793                 sorted1.addAll(list1);
 794                 sorted2.addAll(list2);
 795
 796                 int ss1 = 0;
 797                 int ss2 = 0;
 798                 for (int i = 0; i < list1.size(); ) {
 799                         Statement s1 = list1.get(i);
 800                         int same1 = sameRel(list1, i);
 801                         for (int j = 0; j < list2.size(); j++) {
 802                                 Statement s2 = list2.get(j);
 803                                 if (scomp.compare(s1, s2) == 0) {
 804                                         int same2 = sameRel(list2, j);
 805                                         copy(sorted1,ss1,list1,i,same1);
 806                                         ss1 += same1;
 807                                         copy(sorted2,ss2,list2,j,same2);
 808                                         ss2 += same2;
 809                                         break;
 810                                 }
 811                         }
 812                         i+= same1;
 813                 }
 814                 if (ss1 < sorted1.size()) {
 815                         for (Statement s : list1) {
 816                                 if (!sorted1.contains(s)) {
 817                                         sorted1.set(ss1,s);
 818                                         ss1++;
 819                                 }
 820                         }
 821                 }
 822                 if (ss2 < sorted2.size()) {
 823                         for (Statement s : list2) {
 824                                 if (!sorted2.contains(s)) {
 825                                         sorted2.set(ss2,s);
 826                                         ss2++;
 827                                 }
 828                         }
 829                 }
 830
 831                 list1.clear();
 832                 list2.clear();
 833                 list1.addAll(sorted1);
 834                 list2.addAll(sorted2);
 835         }
 836
 837         public <T> void copy(List<T> to, int toIndex, List<T> from, int fromIndex, int amount) {
 838                 for (int i = 0; i <  amount; i++) {
 839                         to.set(toIndex + i, from.get(fromIndex+ i));
 840                 }
 841         }
 842
 843         public void sortResource(List<Resource> list1, List<Resource> list2) {
 844                 Collections.sort(list1,rcomp);
 845                 int js = 0;
 846                 for (int i = 0; i < list1.size(); i++) {
 847                         Resource s1 = list1.get(i);
 848                         for (int j = js; j < list2.size(); j++) {
 849                                 Resource s2 = list2.get(j);
 850                                 if (rcomp.compare(s1, s2) == 0) {
 851                                         Resource t = list2.get(js);
 852                                         list2.set(js, s2);
 853                                         list2.set(j, t);
 854                                         break;
 855                                 }
 856                         }
 857                         js++;
 858                 }
 859         }
 860
 861         private void compareStatements(List<Statement> ss1, List<Statement> ss2, Stack<Resource> objectsLeft, Stack<Resource> objectsRight, Collection<Statement> unreliableLeft, Collection<Statement> unreliableRight) throws DatabaseException {
 862                 sortStatement(ss1, ss2);
 863
 864                 int i1 = 0;
 865                 int i2 = 0;
 866
 867                 while (true) {
 868                         if (i1 >= ss1.size()) {
 869                                 if (i2 >= ss2.size()) {
 870                                         break;
 871                                 } else {
 872                                         while (i2 < ss2.size()) {
 873                                                 if (DEBUG) System.out.println("Compare Statements addition " + printStatement(g,ss2.get(i2)));
 874
 875                                                 addAddition(ss2.get(i2));
 876                                                 i2++;
 877                                         }
 878                                         break;
 879                                 }
 880                         } else if (i2 >= ss2.size()) {
 881                                 while (i1 < ss1.size()) {
 882                                         if (DEBUG) System.out.println("Compare Statements deletion " + printStatement(g,ss1.get(i1)));
 883                                         addDeletion(ss1.get(i1));
 884                                         i1++;
 885                                 }
 886                                 break;
 887                         }
 888                         int same1 = sameRel(ss1, i1);
 889                         int same2 = sameRel(ss2, i2);
 890                         int c = rcomp.compare(ss1.get(i1).getPredicate(),ss2.get(i2).getPredicate());
 891                         if (c == 0) {
 892                                 compareStatements(ss1, i1, same1, ss2, i2, same2,objectsLeft,objectsRight,unreliableLeft,unreliableRight);
 893                                 i1+=same1;
 894                                 i2+=same2;
 895                         } else if (c < 0) {
 896                                 for (int i = 0; i < same1; i++) {
 897                                         if (DEBUG) System.out.println("Compare Statements deletion " + printStatement(g,ss1.get(i+i1)));
 898                                         addDeletion(ss1.get(i+i1));
 899                                 }
 900                                 i1 += same1;
 901                         } else {
 902                                 for (int i = 0; i < same2; i++) {
 903                                         if (DEBUG) System.out.println("Compare Statements addition " + printStatement(g,ss2.get(i+i2)));
 904                                         addAddition(ss2.get(i+i2));
 905                                 }
 906
 907                                 i2 += same2;
 908                         }
 909                 }
 910         }
 911
 912
 913
 914         private int sameRel(List<Statement> statements, int off) {
 915                 if (statements.size() <= off)
 916                         return 0;
 917                 int same = 1;
 918                 long id = statements.get(off).getPredicate().getResourceId();
 919                 for (int i = off+1; i <statements.size(); i++) {
 920                         if (statements.get(i).getPredicate().getResourceId() == id)
 921                                 same++;
 922                         else
 923                                 break;
 924                 }
 925                 return same;
 926
 927         }
 928
 929         private int compareObject(Resource o1, Resource o2) throws DatabaseException {
 930                 if (o1.equals(o2))
 931                         return -1;
 932                 if (comparableResources.contains(o1, o2))
 933                         return (-1);
 934                 if (comparableResources.containsLeft(o1))
 935                         return Integer.MAX_VALUE;
 936                 if (comparableResources.containsRight(o2))
 937                         return Integer.MAX_VALUE;
 938                 if (nonMatchedLeft.contains(o1))
 939                         return Integer.MAX_VALUE;
 940                 if (nonMatchedRight.contains(o2))
 941                         return Integer.MAX_VALUE;
 942                 return comparator.compare(g, o1, o2);
 943         }
 944
 945         private void compareStatements(List<Statement> ss1, int off1, int len1, List<Statement> ss2, int off2, int len2, Collection<Resource> objectsLeft, Collection<Resource> objectsRight, Collection<Statement> unreliableLeft, Collection<Statement> unreliableRight) throws DatabaseException {
 946                 boolean[] used1 = new boolean[len1];
 947                 for (int i = 0; i < used1.length; i++) {
 948                         used1[i] = false;
 949                 }
 950
 951                 boolean[] used2 = new boolean[len2];
 952                 for (int i = 0; i < used2.length; i++) {
 953                         used2[i] = false;
 954                 }
 955
 956                 // left, right, difference
 957                 List<List<Integer>> differences = new ArrayList<List<Integer>>();
 958                 for (int i1 = off1; i1 < off1 + len1; i1++) {
 959                         Statement s1 = ss1.get(i1);
 960                         List<Integer> diff = new ArrayList<Integer>();
 961                         for (int i2 = off2; i2 < off2 + len2; i2++) {
 962                                 Statement s2 = ss2.get(i2);
 963                                 int d = compareObject(s1.getObject(), s2.getObject());
 964                                 if (d == 0) {
 965                                         for (Resource t : strong) {
 966                                                  if (s1.getPredicate().equals(t) || g.isSubrelationOf(s1.getPredicate(), t)) {
 967                                                          d = 1;
 968                                                          break;
 969                                                  }
 970                                         }
 971                                 }
 972                                 diff.add(d);
 973                         }
 974                         differences.add(diff);
 975                 }
 976                 // difference, left
 977                 MapList<Integer, Integer> priorities = new MapList<Integer, Integer>();
 978                 for (int i = 0; i < differences.size(); i++) {
 979                         List<Integer> list = differences.get(i);
 980                         for (int j = 0; j < list.size(); j++) {
 981                                 priorities.add(list.get(j), i);
 982                         }
 983                 }
 984
 985                 Integer[] pris = priorities.getKeys(new Integer[]{});
 986                 Arrays.sort(pris);
 987
 988                 for (Integer pri : pris) {
 989                         if (pri == Integer.MAX_VALUE) {
 990
 991                         } else if (pri == 0) {
 992
 993                         } else {
 994                                 List<Integer> i1s = priorities.getValues(pri);
 995                                 for (Integer i1 : i1s) {
 996                                         if (used1[i1])
 997                                                 continue;
 998                                         List<Integer> i2diff = differences.get(i1);
 999                                         for (int i2 = 0; i2 < i2diff.size(); i2++) {
1000                                                 if (i2diff.get(i2) == pri) {
1001                                                         if (used2[i2])
1002                                                                 continue;
1003                                                         used1[i1] = true;
1004                                                         used2[i2] = true;
1005                                                         Statement s1  = ss1.get(i1+off1);
1006                                                         Statement s2  = ss2.get(i2+off2);
1007
1008                                                         if (objectsLeft != null) {
1009                                                                 objectsLeft.add(s1.getObject());
1010                                                                 objectsRight.add(s2.getObject());
1011                                                         }
1012                                                         addComparable(s1, s2, true);
1013                                                         break;
1014                                                 }
1015                                         }
1016                                 }
1017                         }
1018                 }
1019
1020                 for (Integer pri : pris) {
1021                         if (pri != 0)
1022                                 continue;
1023                         Set<Statement> s1s = new HashSet<Statement>();
1024                         Set<Statement> s2s = new HashSet<Statement>();
1025                         Set<Integer> s1i = new HashSet<Integer>();
1026                         Set<Integer> s2i = new HashSet<Integer>();
1027                         List<Integer> i1s = priorities.getValues(pri);
1028                         for (Integer i1 : i1s) {
1029                                 if (used1[i1])
1030                                         continue;
1031                                 List<Integer> i2diff = differences.get(i1);
1032                                 for (int i2 = 0; i2 < i2diff.size(); i2++) {
1033                                         if (i2diff.get(i2) == pri) {
1034                                                 if (used2[i2])
1035                                                         continue;
1036                                                 Statement s1  = ss1.get(i1+off1);
1037                                                 Statement s2  = ss2.get(i2+off2);
1038                                                 s1s.add(s1);
1039                                                 s2s.add(s2);
1040                                                 s1i.add(i1);
1041                                                 s2i.add(i2);
1042                                         }
1043                                 }
1044                         }
1045                         if (unreliableLeft != null) {
1046                                 unreliableLeft.addAll(s1s);
1047                                 unreliableRight.addAll(s2s);
1048                         }
1049                         for (Integer i : s1i)
1050                                 used1[i] = true;
1051                         for (Integer i : s2i)
1052                                 used2[i] = true;
1053
1054                 }
1055                 for (int i1 = off1; i1 < off1 + len1; i1++) {
1056                         if (!used1[i1-off1]) {
1057                                 if (DEBUG) System.out.println("Compare Object deletion " + printStatement(g,ss1.get(i1)));
1058                                 addDeletion(ss1.get(i1));
1059                         }
1060                 }
1061                 for (int i2 = off2; i2 < off2 + len2; i2++) {
1062                         if (!used2[i2-off2]) {
1063                                 if (DEBUG) System.out.println("Compare Object addition " + printStatement(g,ss2.get(i2)));
1064                                 addAddition(ss2.get(i2));
1065                         }
1066                 }
1067         }
1068
1069
1070
1071         /**
1072          * compares properties, assumes functional relations
1073          * @param r1
1074          * @param r2
1075          * @throws ServiceException
1076          * @throws DoesNotContainValueException
1077          * @throws ValidationException
1078          */
1079         private void compareProps(Resource r1, Resource r2) throws DatabaseException {
1080                 if (DEBUG) System.out.println("compareProps " + r1 + " " + NameUtils.getSafeName(g, r1) + " " + r2 + " " + NameUtils.getSafeName(g, r2));
1081                 List<Statement> ss1 = new ArrayList<Statement>();
1082                 List<Statement> ss2 = new ArrayList<Statement>();
1083                 ss1.addAll(g.getStatements(r1, b.HasProperty));
1084                 ss2.addAll(g.getStatements(r2, b.HasProperty));
1085                 ss1 = filterNonTested(ss1);
1086                 ss2 = filterNonTested(ss2);
1087                 sortStatement(ss1, ss2);
1088
1089                 int i1 = 0;
1090                 int i2 = 0;
1091
1092                 while (true) {
1093                         if (i1 >= ss1.size()) {
1094                                 if (i2 >= ss2.size())
1095                                         break;
1096                                 else {
1097                                         while (i2 < ss2.size()) {
1098                                                 if (DEBUG) System.out.println("Compare Prop diff2 " + printStatement(g,ss2.get(i2)));
1099                                                 addAddition(ss2.get(i2));
1100                                                 i2++;
1101                                         }
1102                                         break;
1103                                 }
1104                         } else if (i2 >= ss2.size()) {
1105                                 while (i1 < ss1.size()) {
1106                                         if (DEBUG) System.out.println("Compare Prop diff1 " + printStatement(g,ss1.get(i1)));
1107                                         addDeletion(ss1.get(i1));
1108                                         i1++;
1109                                 }
1110                                 break;
1111                         }
1112                         Statement s1 = ss1.get(i1);
1113                         Statement s2 = ss2.get(i2);
1114                         if (s1.isAsserted(r1) && s2.isAsserted(r2)) {
1115                                 i1++;
1116                                 i2++;
1117                                 continue;
1118                         }
1119                         int c = scomp.compare(s1, s2);
1120                         switch (c) {
1121                                 case 0:{
1122                                         boolean b1 = g.hasValue(s1.getObject());
1123                                         boolean b2 = g.hasValue(s2.getObject());
1124                                         if (b1 == b2) {
1125                                                 if (b1) {
1126                                                         Object v1 = g.getValue(s1.getObject());
1127                                                         Object v2 = g.getValue(s2.getObject());
1128                                                         boolean eq = compareValue(v1, v2);
1129                                                         if (!eq) {
1130                                                                 addModification(s1, s2);
1131                                                                 addComparable(s1, s2, false);
1132                                                         }
1133                                                 } else {
1134                                                         if (!s1.getObject().equals(s1.getSubject()) && !s2.getObject().equals(s2.getSubject()))
1135                                                                 compareProps(s1.getObject(), s2.getObject());
1136                                                 }
1137                                         } else {
1138                                                 addModification(s1, s2);
1139                                                 addComparable(s1, s2, false);
1140                                         }
1141                                         i1++;
1142                                         i2++;
1143                                         break;
1144                                 }
1145                                 case -1:{
1146                                         if (DEBUG) System.out.println("Compare Prop diff1s " + printStatement(g,s1));
1147                                         addDeletion(s1);
1148                                         i1++;
1149                                         break;
1150                                 }
1151
1152                                 case 1:{
1153                                         if (DEBUG) System.out.println("Compare Prop diff2s " + printStatement(g,s2));
1154                                         addAddition(s2);
1155                                         i2++;
1156                                         break;
1157                                 }
1158                         }
1159
1160                 }
1161
1162                 ss1.clear();
1163                 ss2.clear();
1164
1165         }
1166
1167         public static boolean compareValue(Object v1, Object v2) {
1168                 if (v1 instanceof Object[] && v2 instanceof Object[])
1169                         return Arrays.deepEquals((Object[])v1, (Object[])v2);
1170                 else if (v1 instanceof int[] && v2 instanceof int[])
1171                         return Arrays.equals((int[])v1, (int[])v2);
1172                 else if (v1 instanceof float[] && v2 instanceof float[])
1173                         return Arrays.equals((float[])v1, (float[])v2);
1174                 else if (v1 instanceof double[] && v2 instanceof double[])
1175                         return Arrays.equals((double[])v1, (double[])v2);
1176                 else if (v1 instanceof long[] && v2 instanceof long[])
1177                         return  Arrays.equals((long[])v1, (long[])v2);
1178                 else if (v1 instanceof byte[] && v2 instanceof byte[])
1179                         return Arrays.equals((byte[])v1, (byte[])v2);
1180                 else if (v1 instanceof boolean[] && v2 instanceof boolean[])
1181                         return Arrays.equals((boolean[])v1, (boolean[])v2);
1182                 else
1183                         return v1.equals(v2);
1184         }
1185
1186
1187         public class PredicateComparator implements Comparator<Statement> {
1188                 @Override
1189                 public int compare(Statement o1, Statement o2) {
1190                         if (comparableResources.contains(o1.getPredicate(), o2.getPredicate()))
1191                                 return 0;
1192                         if (o1.getPredicate().getResourceId() < o2.getPredicate().getResourceId())
1193                                 return -1;
1194                         if (o1.getPredicate().getResourceId() > o2.getPredicate().getResourceId())
1195                                 return 1;
1196                         return 0;
1197                 }
1198         }
1199
1200         public class SubjectComparator implements Comparator<Statement> {
1201                 @Override
1202                 public int compare(Statement o1, Statement o2) {
1203                         if (comparableResources.contains(o1.getSubject(), o2.getSubject()))
1204                                 return 0;
1205                         if (o1.getSubject().getResourceId() < o2.getSubject().getResourceId())
1206                                 return -1;
1207                         if (o1.getSubject().getResourceId() > o2.getSubject().getResourceId())
1208                                 return 1;
1209                         return 0;
1210                 }
1211         }
1212
1213         public class ObjectComparator implements Comparator<Statement> {
1214                 @Override
1215                 public int compare(Statement o1, Statement o2) {
1216                         if (comparableResources.contains(o1.getObject(), o2.getObject()))
1217                                 return 0;
1218                         if (o1.getObject().getResourceId() < o2.getObject().getResourceId())
1219                                 return -1;
1220                         if (o1.getObject().getResourceId() > o2.getObject().getResourceId())
1221                                 return 1;
1222                         return 0;
1223                 }
1224         }
1225
1226         public static class FullStatementComparator implements Comparator<Statement> {
1227                 @Override
1228                 public int compare(Statement o1, Statement o2) {
1229                         if (o1.getSubject().getResourceId() < o2.getSubject().getResourceId())
1230                                 return -1;
1231                         if (o1.getSubject().getResourceId() > o2.getSubject().getResourceId())
1232                                 return 1;
1233                         if (o1.getPredicate().getResourceId() < o2.getPredicate().getResourceId())
1234                                 return -1;
1235                         if (o1.getPredicate().getResourceId() > o2.getPredicate().getResourceId())
1236                                 return 1;
1237                         if (o1.getObject().getResourceId() < o2.getObject().getResourceId())
1238                                 return -1;
1239                         if (o1.getObject().getResourceId() > o2.getObject().getResourceId())
1240                                 return 1;
1241                         return 0;
1242                 }
1243         }
1244
1245         public class ResComparator implements Comparator<Resource> {
1246                 @Override
1247                 public int compare(Resource o1, Resource o2) {
1248                         if (comparableResources.contains(o1, o2))
1249                                 return 0;
1250                         if (o1.getResourceId() < o2.getResourceId())
1251                                 return -1;
1252                         if (o1.getResourceId() > o2.getResourceId())
1253                                 return 1;
1254                         return 0;
1255                 }
1256         }
1257
1258 }