X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;ds=inline;f=org.simantics.interop%2Fsrc%2Forg%2Fsimantics%2Finterop%2Ftest%2FGraphComparator.java;h=0366df96a2a33749eb7074aae083e22d7b5fede2;hb=871c099c9e3bd940029ab2cd9ac4565324b065ce;hp=e52a3bf296f485d11b88f362bf07ada14b566a41;hpb=8f1ee72ae165c01b208423cd2d18a6afc1819a3f;p=simantics%2Finterop.git

diff --git a/org.simantics.interop/src/org/simantics/interop/test/GraphComparator.java b/org.simantics.interop/src/org/simantics/interop/test/GraphComparator.java
index e52a3bf..0366df9 100644
--- a/org.simantics.interop/src/org/simantics/interop/test/GraphComparator.java
+++ b/org.simantics.interop/src/org/simantics/interop/test/GraphComparator.java
@@ -25,10 +25,13 @@ import java.util.Stack;
 
 import org.simantics.db.ReadGraph;
 import org.simantics.db.Resource;
+import org.simantics.db.Session;
 import org.simantics.db.Statement;
+import org.simantics.db.common.request.ReadRequest;
 import org.simantics.db.common.utils.NameUtils;
 import org.simantics.db.exception.DatabaseException;
 import org.simantics.db.exception.DoesNotContainValueException;
+import org.simantics.db.exception.ManyObjectsForFunctionalRelationException;
 import org.simantics.db.exception.ServiceException;
 import org.simantics.db.exception.ValidationException;
 import org.simantics.layer0.Layer0;
@@ -49,9 +52,12 @@ import org.simantics.utils.datastructures.Pair;
  *
  */
 public class GraphComparator {
+	
+	private static final boolean DEBUG = false;
 
 	private Resource r1;
 	private Resource r2;
+	private Set<Resource> strong = new HashSet<Resource>();       // List of relations that identify object, if subject is already identified. 
 	private List<Resource> traversed = new ArrayList<Resource>(); // list of relations that are traversed (and tested)
 	private List<Resource> tested = new ArrayList<Resource>();    // list of relations that are tested, but not traversed
 	private List<Resource> nonTraversed = new ArrayList<Resource>(); // list of relations that are not traversed
@@ -66,7 +72,7 @@ public class GraphComparator {
 
 	private BijectionMap<Statement, Statement> comparableStatements = new BijectionMap<Statement, Statement>();
 	private BijectionMap<Resource, Resource> comparableResources = new BijectionMap<Resource, Resource>();
-	
+	private Set<Resource> processedResources = new HashSet<Resource>();
 	
 	private ResourceComparator comparator;
 	
@@ -150,13 +156,15 @@ public class GraphComparator {
 		comparableResources.addAll(matching);
 	}
 	
-	public void clearRels() {
-		traversed.clear();
-		tested.clear();
-		nonTraversed.clear();
-		nonTested.clear();
+	public void addStrong(Resource r) {
+		strong.add(r);
+	}
+	
+	public void addStrong(Collection<Resource> rels) {
+		strong.addAll(rels);
 	}
 	
+	
 	public void test(ReadGraph g) throws DatabaseException {
 		this.g = g;
 		this.b = Layer0.getInstance(g);
@@ -167,22 +175,110 @@ public class GraphComparator {
 		objectsLeft.push(r1);
 		objectsRight.push(r2);
 		
+		Set<Statement> unreliableLeft = new HashSet<Statement>();
+		Set<Statement> unreliableRight = new HashSet<Statement>();
+		
+		while (true) {
+			if (objectsLeft.isEmpty())
+				break;
+			
+			
+			// process compares objects that are identified and searches for more resources to process. 
+			process(objectsLeft, objectsRight, unreliableLeft, unreliableRight);
+			// process unreliable handles cases where unidentified statements subject and object have been identified 
+			processUnreliable(unreliableLeft, unreliableRight);
+			// process unreliable handles cases where unidentified resources have path of length one to identified resource
+			processUnreliable(unreliableLeft, unreliableRight,objectsLeft,objectsRight);
+			if (objectsLeft.isEmpty() && unreliableLeft.size() > 0 && unreliableRight.size() > 0) {
+				// comparison is ending, but we have still unprocessed unidentified resources left.
+				// These cases have longer path than one to identified objects.
+				processUnreliableDeep(unreliableLeft, unreliableRight, objectsLeft, objectsRight);
+			}
+			
+		}
+		for (Statement s : unreliableLeft) {
+			if (!comparableStatements.containsLeft(s))
+				addDeletion(s);
+		}
+		for (Statement s : unreliableRight) {
+			if (!comparableStatements.containsRight(s))
+				addAddition(s);
+		}
+		
 		
+ 	}
+	
+	public void test(Session session) throws DatabaseException {
+		
+		comparator.setComparator(this);
+		
+		comparableResources.map(r1, r2);
+		
+		final Stack<Resource> objectsLeft = new Stack<Resource>();
+		final Stack<Resource> objectsRight = new Stack<Resource>();
+		objectsLeft.push(r1);
+		objectsRight.push(r2);
+		
+		final Set<Statement> unreliableLeft = new HashSet<Statement>();
+		final Set<Statement> unreliableRight = new HashSet<Statement>();
+		
+		while (true) {
+			if (objectsLeft.isEmpty())
+				break;
+			session.syncRequest(new ReadRequest() {
+				
+				@Override
+				public void run(ReadGraph graph) throws DatabaseException {
+					g = graph;
+					b = Layer0.getInstance(graph);
+					// process compares objects that are identified and searches for more resources to process. 
+					process(objectsLeft, objectsRight, unreliableLeft, unreliableRight);
+					// process unreliable handles cases where unidentified statements subject and object have been identified 
+					processUnreliable(unreliableLeft, unreliableRight);
+					// process unreliable handles cases where unidentified resources have path of length one to identified resource
+					processUnreliable(unreliableLeft, unreliableRight,objectsLeft,objectsRight);
+					if (objectsLeft.isEmpty() && unreliableLeft.size() > 0 && unreliableRight.size() > 0) {
+						// comparison is ending, but we have still unprocessed unidentified resources left.
+						// These cases have longer path than one to identified objects.
+						processUnreliableDeep(unreliableLeft, unreliableRight, objectsLeft, objectsRight);
+					}
+				}
+			});
+			
+			
+			
+		}
+		for (Statement s : unreliableLeft) {
+			if (!comparableStatements.containsLeft(s))
+				addDeletion(s);
+		}
+		for (Statement s : unreliableRight) {
+			if (!comparableStatements.containsRight(s))
+				addAddition(s);
+		}
+		
+		
+ 	}
+	
+	private void process(Stack<Resource> objectsLeft, Stack<Resource> objectsRight, Set<Statement> unreliableLeft, Set<Statement> unreliableRight) throws DatabaseException {
 		List<Statement> ss1 = new ArrayList<Statement>();
 		List<Statement> ss2 = new ArrayList<Statement>();
 		
-		Set<Statement> unreliableLeft = new HashSet<Statement>();
-		Set<Statement> unreliableRight = new HashSet<Statement>();
-		
 		while (!objectsLeft.isEmpty()) {
 			Resource r1 = objectsLeft.pop();
 			Resource r2 = objectsRight.pop();
-		
-			if (comparableResources.contains(r1, r2)) {
-				//System.out.println("already tested " + NameUtils.getSafeName(g, r1) + " " + NameUtils.getSafeName(g, r2));
+			
+			if (r1.equals(r2))
+				continue;
+			
+			if (processedResources.contains(r1))
 				continue;
+			processedResources.add(r1);
+			
+		
+			if(!comparableResources.contains(r1, r2) && (comparableResources.containsLeft(r1)||comparableResources.containsRight(r2))) {
+				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.");
 			}
-			comparableResources.map(r1, r2);
 			
 			//System.out.println("test " + NameUtils.getSafeName(g, r1) + " " + NameUtils.getSafeName(g, r2));
 			compareProps(r1, r2);
@@ -213,6 +309,52 @@ public class GraphComparator {
 				
 			}
 		}
+	}
+	
+	private void processUnreliable(Set<Statement> unreliableLeft, Set<Statement> unreliableRight) throws DatabaseException {
+		MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> objectRight = new MapList<Resource, Statement>();
+		
+		for (Statement s : unreliableLeft) {
+			subjectLeft.add(s.getSubject(),s);
+			objectLeft.add(s.getObject(),s);
+		}
+		for (Statement s : unreliableRight) {
+			subjectRight.add(s.getSubject(),s);
+			objectRight.add(s.getObject(),s);
+		}
+		
+		for (Resource left : subjectLeft.getKeys()) {
+			if (!comparableResources.containsLeft(left))
+				continue;
+			Resource right = comparableResources.getRight(left);
+			for (Statement leftS : subjectLeft.getValues(left)) {
+				Resource leftO = leftS.getObject();
+				if (!comparableResources.containsLeft(leftO)) 
+					continue;
+				if (!unreliableLeft.contains(leftS))
+					continue;
+				Resource rightO = comparableResources.getRight(leftO);
+				for (Statement rightS : subjectRight.getValues(right)) {
+					if (!rightS.getObject().equals(rightO))
+						continue;
+					if (!unreliableRight.contains(rightS))
+						continue;
+					if (leftS.getPredicate().equals(rightS.getPredicate()) ||
+						comparableResources.contains(leftS.getPredicate(), rightS.getPredicate())) {
+						unreliableLeft.remove(leftS);
+						unreliableRight.remove(rightS);
+						addComparable(leftS, rightS, false);
+					}
+				}
+			}
+			
+		}
+	}
+	
+	private void processUnreliable(Set<Statement> unreliableLeft, Set<Statement> unreliableRight, Stack<Resource> objectsLeft, Stack<Resource> objectsRight) throws DatabaseException {
 		MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
 		MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
 		MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
@@ -228,7 +370,6 @@ public class GraphComparator {
 		}
 		
 		for (Resource ol : objectLeft.getKeys()) {
-
 			// all statements to the left side object
 			List<Statement> left = objectLeft.getValues(ol);
 			// all subjects that have statements to the left side object (ol)
@@ -239,6 +380,58 @@ public class GraphComparator {
 				sLeft.add(s.getSubject());
 				sRight.add(comparableResources.getRight(s.getSubject()));
 			}
+			
+			// check if object left can be reliably identified by available statements
+			// if there are any objects on the left side with similar statements, object left cannot be mapped.
+			boolean hasSimilar = false;
+			MapList<Resource, Statement> comparableOLeft = new MapList<Resource, Statement>();
+			for (Resource sl : sLeft) {
+				for (Statement s : subjectLeft.getValues(sl)) {
+					if (!s.getObject().equals(ol)) {
+						comparableOLeft.add(s.getObject(),s);
+					}
+				}
+			}
+			
+			for (Resource similarOl : comparableOLeft.getKeys()) {
+				List<Statement> similarLeft = comparableOLeft.getValues(similarOl);
+				if (similarLeft.size() == left.size()) {
+					boolean useL[] = new boolean[left.size()];
+					boolean useSL[] = new boolean[left.size()];
+					for (int i = 0; i < left.size(); i++) {
+						useL[i] = false;
+						useSL[i] = false;
+					}
+					for (int i = 0; i < left.size(); i++) {
+						for (int j = 0; j < left.size(); j++) {
+							if (useSL[j])
+								continue;
+							Resource pl = left.get(i).getPredicate();
+							Resource psl = similarLeft.get(j).getPredicate();
+							if (pl.equals(psl)) {
+								useL[i] = true;
+								useSL[j] = true;
+								break;
+							}
+						}
+					}
+					boolean diff = false;
+					for (int i = 0; i < left.size(); i++) {
+						if (!useL[i] || !useSL[i]) {
+							diff = true;
+						}
+					}
+					if (!diff) {
+						hasSimilar = true;
+						break;
+					}
+				}
+			}
+			
+			if (hasSimilar)
+				continue;
+				
+			
 			// all objects that subjects on the right side point to. Object left has its matching resource among these, if it has matching resource
 			MapList<Resource,Statement> possibleOR = new MapList<Resource, Statement>();
 			for (Resource sr : sRight) {
@@ -307,29 +500,171 @@ public class GraphComparator {
 				List<Statement> right = matchingOR.getValues(or);
 				Pair<int[], int[]> indices = matchingStatements.get(or);
 				
-				comparableResources.map(ol, or);
+				objectsLeft.add(ol);
+				objectsRight.add(or);
+				addComparable(ol, or, false);
 				for (int l = 0; l < left.size(); l++) {
 					int r = indices.first[l];
-					comparableStatements.map(left.get(l), right.get(r));
+					Statement sl = left.get(l);
+					Statement sr = right.get(r);
+					addComparable(sl, sr, true);
+					unreliableLeft.remove(sl);
+					unreliableRight.remove(sr);
 				}
 				
 			}
 
 		}
 		
+		
+	}
+	
+	private void processUnreliableDeep(Set<Statement> unreliableLeft, Set<Statement> unreliableRight, Stack<Resource> objectsLeft, Stack<Resource> objectsRight) throws DatabaseException {
+		MapList<Resource,Statement> subjectLeft = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> subjectRight = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> objectLeft = new MapList<Resource, Statement>();
+		MapList<Resource,Statement> objectRight = new MapList<Resource, Statement>();
+		
 		for (Statement s : unreliableLeft) {
-			if (!comparableStatements.containsLeft(s))
-				addDeletion(s);
+			subjectLeft.add(s.getSubject(),s);
+			objectLeft.add(s.getObject(),s);
 		}
 		for (Statement s : unreliableRight) {
-			if (!comparableStatements.containsRight(s))
-				addAddition(s);
+			subjectRight.add(s.getSubject(),s);
+			objectRight.add(s.getObject(),s);
+		}
+		for (Resource ol : objectLeft.getKeys()) {
+			Set<Path> pathsLeft = new HashSet<Path>();
+			for (Resource rel : traversed) {
+				pathsLeft.addAll(Path.create(g.getStatements(ol, rel)));
+			}
+			while (true) {
+				expand(pathsLeft);
+				if (pathsLeft.size() == 0)
+					break;
+				Collection<Path> endPaths = new ArrayList<Path>(1);
+				for (Path p : pathsLeft) {
+					if (comparableResources.containsLeft(p.getEnd())) {
+						endPaths.add(p);
+					}
+				}
+				if (endPaths.size() > 0) {
+					pathsLeft.clear();
+					pathsLeft.addAll(endPaths);
+					break;
+				}	
+			}
+			if (pathsLeft.size() > 0) {
+				Resource sl = objectLeft.getValues(ol).get(0).getSubject();
+				Resource sr = comparableResources.getRight(sl);
+				Collection<Resource> possibleOR = new ArrayList<Resource>();
+				for (Statement s : subjectRight.getValues(sr)) {
+					possibleOR.add(s.getObject());
+				}
+				Map<Resource,Set<Path>> matchingPaths = new HashMap<Resource, Set<Path>>();
+				for (Resource or : possibleOR) {
+					Set<Path> possiblePathsRight = new HashSet<Path>();
+					for (Path leftPath : pathsLeft) {
+						possiblePathsRight.addAll(findComparableRight(leftPath, or));
+					}
+					if (hasMatchingPaths(pathsLeft, possiblePathsRight)) {
+						matchingPaths.put(or, possiblePathsRight);
+					}
+				}
+				if (matchingPaths.size() > 0) {
+					if (matchingPaths.size() == 1) {
+						Resource or = matchingPaths.keySet().iterator().next();
+						
+						objectsLeft.add(ol);
+						objectsRight.add(or);
+						addComparable(ol, or, false);
+						Collection<Statement> statementsLeft = objectLeft.getValues(ol);
+						Collection<Statement> statementsRight = objectRight.getValues(or);
+						unreliableLeft.removeAll(statementsLeft);
+						unreliableRight.removeAll(statementsRight);
+						BijectionMap<Path,Path> map = getMatchingPaths(pathsLeft, matchingPaths.get(or));
+						for (Path left : map.getLeftSet()) {
+							Path right = map.getRight(left);
+							for (int i = 0; i < left.getLength(); i++) {
+								addComparable(left.getStatements().get(i),right.getStatements().get(i),false);
+							}
+						}
+					} 
+				}
+			}
+			
 		}
 		
+	}
+	
+	private boolean hasMatchingPaths(Set<Path> leftPaths, Set<Path> rightPaths) {
+		if (leftPaths.size() != rightPaths.size())
+			return false;
+		BijectionMap<Path,Path> map = getMatchingPaths(leftPaths, rightPaths);
+		return map.size() == leftPaths.size();
+			
+	}
+	
+	private BijectionMap<Path,Path> getMatchingPaths(Set<Path> leftPaths, Set<Path> rightPaths) {
+		BijectionMap<Path,Path> map = new BijectionMap<Path, Path>();
+		for (Path leftPath : leftPaths) {
+			for (Path rightPath : rightPaths) {
+				if (map.containsRight(rightPath))
+					continue;
+				if (leftPath.getLength() != rightPath.getLength())
+					continue;
+				if (comparableResources.contains(leftPath.getEnd(), rightPath.getEnd())) {
+					map.map(leftPath, rightPath);
+					break;
+				}
+			}
+		}
+		return map;
+	}
+	
+	private void expand(Set<Path> paths) throws ManyObjectsForFunctionalRelationException, ServiceException {
+		Set<Path> stepPathsLeft = new HashSet<Path>();
+		if (paths.size() == 0)
+			return;
+		int length = paths.iterator().next().getLength() + 1;
+		for (Path p : paths) {
+			for (Resource rel : traversed) {
+				stepPathsLeft.addAll(Path.expand(p,g.getStatements(p.getEnd(), rel)));
+			}
+		}
+		paths.clear();
+		for (Path p : stepPathsLeft) {
+			if (p.getLength() == length)
+				paths.add(p);
+		}
+	}
+	
+	private Collection<Path> findComparableRight(Path leftPath, Resource beginRight) throws ManyObjectsForFunctionalRelationException, ServiceException {
+		Set<Path> rightPaths = new HashSet<Path>();
+		rightPaths.addAll(Path.create(g.getStatements(beginRight, getRight(leftPath.getStatements().get(0).getPredicate()))));
+		for (int i = 1; i < leftPath.getLength(); i++) {
+			if (rightPaths.size() == 0)
+				return rightPaths;
+			Set<Path> stepPaths = new HashSet<Path>();
+			for (Path p : rightPaths) {
+				stepPaths.addAll(Path.expand(p, g.getStatements(p.getEnd(), getRight(leftPath.getStatements().get(i).getPredicate()))));
+			}
+			rightPaths.clear();
+			for (Path p : stepPaths)
+				if (p.getLength() == i+1) 
+					rightPaths.add(p);
+		}
+		return rightPaths;
 		
- 	}
+	}
 	
+	private Resource getRight(Resource r) {
+		if (comparableResources.containsLeft(r))
+			return comparableResources.getRight(r);
+		return r;
+	}
 	
+
 	
 	public BijectionMap<Statement, Statement> getComparableStatements() {
 		return comparableStatements;
@@ -339,7 +674,24 @@ public class GraphComparator {
 		return new GraphChanges(r1,r2,changes1,changes2,modifications,comparableResources);
 	}
 	
-	private List<Statement> filterAsserted(Resource r, Collection<Statement> in) throws ServiceException {
+	private void addComparable(Statement left, Statement right, boolean process) throws DatabaseException {
+		addComparable(left.getObject(), right.getObject(), process);
+		comparableStatements.map(left, right);
+		comparableResources.map(left.getObject(), right.getObject());
+	}
+	
+	private void addComparable(Resource left, Resource right, boolean process) throws DatabaseException {
+		if(!comparableResources.contains(r1, r2)) {
+			if (comparableResources.containsLeft(r1)||comparableResources.containsRight(r2)) {
+				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.");
+			} else {
+				comparableResources.map(left, right);		
+			}
+		}
+		
+	}
+	
+	public List<Statement> filterAsserted(Resource r, Collection<Statement> in) throws ServiceException {
 		List<Statement> out = new ArrayList<Statement>();
 		for (Statement s : in) {
 			if (!s.isAsserted(r))
@@ -348,7 +700,7 @@ public class GraphComparator {
 		}
 		return out;
 	}
-	
+
 	private String printStatement(ReadGraph graph, Statement s) throws ValidationException, ServiceException {
 		return NameUtils.getSafeName(graph, s.getSubject()) + " " + NameUtils.getSafeName(graph, s.getPredicate()) + " " + NameUtils.getSafeName(graph, s.getObject());
 	}
@@ -479,7 +831,6 @@ public class GraphComparator {
 				}
 			}
 			js++;
-			
 		}
 	}
 	
@@ -495,7 +846,7 @@ public class GraphComparator {
 					break;
 				} else {
 					while (i2 < ss2.size()) {
-						System.out.println("Compare Statements diff2 " + printStatement(g,ss2.get(i2)));
+						if (DEBUG) System.out.println("Compare Statements diff2 " + printStatement(g,ss2.get(i2)));
 						
 						addAddition(ss2.get(i2));
 						i2++;
@@ -504,7 +855,7 @@ public class GraphComparator {
 				}
 			} else if (i2 >= ss2.size()) {
 				while (i1 < ss1.size()) {
-					System.out.println("Compare Statements diff1 " + printStatement(g,ss1.get(i1)));
+					if (DEBUG) System.out.println("Compare Statements diff1 " + printStatement(g,ss1.get(i1)));
 					addDeletion(ss1.get(i1));
 					i1++;
 				}
@@ -519,19 +870,18 @@ public class GraphComparator {
 				i2+=same2;
 			} else if (c < 0) {
 				for (int i = 0; i < same1; i++) {
-					System.out.println("Compare Statements diff1 " + printStatement(g,ss1.get(i+i1)));
+					if (DEBUG) System.out.println("Compare Statements diff1 " + printStatement(g,ss1.get(i+i1)));
 					addDeletion(ss1.get(i+i1));
 				}
 				i1 += same1;
 			} else {
 				for (int i = 0; i < same2; i++) {
-					System.out.println("Compare Statements diff2 " + printStatement(g,ss2.get(i+i2)));
+					if (DEBUG) System.out.println("Compare Statements diff2 " + printStatement(g,ss2.get(i+i2)));
 					addAddition(ss2.get(i+i2));
 				}
 				
 				i2 += same2;
 			}
-			
 		}
 	}
 	
@@ -553,6 +903,8 @@ public class GraphComparator {
 	}
 
 	private int compareObject(Resource o1, Resource o2) throws DatabaseException {
+		if (o1.equals(o2))
+			return -1;
 		if (comparableResources.contains(o1, o2))
 			return (-1);
 		if (comparableResources.containsLeft(o1))
@@ -581,6 +933,14 @@ public class GraphComparator {
 			for (int i2 = off2; i2 < off2 + len2; i2++) {
 				Statement s2 = ss2.get(i2);
 				int d = compareObject(s1.getObject(), s2.getObject());
+				if (d == 0) {
+					for (Resource t : strong) {
+						 if (s1.getPredicate().equals(t) || g.isSubrelationOf(s1.getPredicate(), t)) {
+							 d = 1;
+							 break;
+						 }
+					}
+				}
 				diff.add(d);
 			}
 			differences.add(diff);
@@ -618,13 +978,10 @@ public class GraphComparator {
 							Statement s2  = ss2.get(i2+off2);
 							
 							if (objectsLeft != null) {
-								
-									objectsLeft.add(s1.getObject());
-									objectsRight.add(s2.getObject());
-								
+								objectsLeft.add(s1.getObject());
+								objectsRight.add(s2.getObject());
 							} 
-							comparableStatements.map(s1, s2);
-							//comparableResources.map(s1.getObject(), s2.getObject());
+							addComparable(s1, s2, true);
 							break;
 						}
 					}
@@ -669,13 +1026,13 @@ public class GraphComparator {
 		}
 		for (int i1 = off1; i1 < off1 + len1; i1++) {
 			if (!used1[i1-off1]) {
-				System.out.println("Compare Object diff1 " + printStatement(g,ss1.get(i1)));
+				if (DEBUG) System.out.println("Compare Object diff1 " + printStatement(g,ss1.get(i1)));
 				addDeletion(ss1.get(i1));
 			}
 		}
 		for (int i2 = off2; i2 < off2 + len2; i2++) {
 			if (!used2[i2-off2]) {
-				System.out.println("Compare Object diff2 " + printStatement(g,ss2.get(i2)));
+				if (DEBUG) System.out.println("Compare Object diff2 " + printStatement(g,ss2.get(i2)));
 				addAddition(ss2.get(i2));
 			}
 		}
@@ -691,14 +1048,13 @@ public class GraphComparator {
 	 * @throws DoesNotContainValueException
 	 * @throws ValidationException 
 	 */
-	private void compareProps(Resource r1, Resource r2) throws ServiceException, DoesNotContainValueException, ValidationException {
+	private void compareProps(Resource r1, Resource r2) throws DatabaseException {
+		if (DEBUG) System.out.println("compareProps " + r1 + " " + NameUtils.getSafeName(g, r1) + " " + r2 + " " + NameUtils.getSafeName(g, r2));
 		ArrayList<Statement> ss1 = new ArrayList<Statement>();
 		ArrayList<Statement> ss2 = new ArrayList<Statement>();
 		ss1.addAll(g.getStatements(r1, b.HasProperty));
 		ss2.addAll(g.getStatements(r2, b.HasProperty));
 		sortStatement(ss1, ss2);
-//		Collections.sort(ss1, scomp);
-//		Collections.sort(ss2, scomp);
 		
 		int i1 = 0; 
 		int i2 = 0;
@@ -709,7 +1065,7 @@ public class GraphComparator {
 					break;
 				else {
 					while (i2 < ss2.size()) {
-						System.out.println("Compare Prop diff2 " + printStatement(g,ss2.get(i2)));
+						if (DEBUG) System.out.println("Compare Prop diff2 " + printStatement(g,ss2.get(i2)));
 						addAddition(ss2.get(i2));
 						i2++;
 					}
@@ -717,7 +1073,7 @@ public class GraphComparator {
 				}
 			} else if (i2 >= ss2.size()) {
 				while (i1 < ss1.size()) {
-					System.out.println("Compare Prop diff1 " + printStatement(g,ss1.get(i1)));
+					if (DEBUG) System.out.println("Compare Prop diff1 " + printStatement(g,ss1.get(i1)));
 					addDeletion(ss1.get(i1));
 					i1++;
 				}
@@ -725,49 +1081,52 @@ public class GraphComparator {
 			}
 			Statement s1 = ss1.get(i1);
 			Statement s2 = ss2.get(i2);
+			if (s1.isAsserted(r1) && s2.isAsserted(r2)) {
+				i1++;
+				i2++;
+				continue;
+			}
 			int c = scomp.compare(s1, s2);
 			switch (c) {
-			case 0:{
-				boolean b1 = g.hasValue(s1.getObject());
-				boolean b2 = g.hasValue(s2.getObject());
-				if (b1 == b2) {
-					if (b1) {
-						Object v1 = g.getValue(s1.getObject());
-						Object v2 = g.getValue(s2.getObject());
-						boolean eq = compareValue(v1, v2);
-						if (!eq) {
-							addModification(s1, s2);
-							comparableStatements.map(s1, s2);
-							comparableResources.map(s1.getObject(),s2.getObject());
+				case 0:{
+					boolean b1 = g.hasValue(s1.getObject());
+					boolean b2 = g.hasValue(s2.getObject());
+					if (b1 == b2) {
+						if (b1) {
+							Object v1 = g.getValue(s1.getObject());
+							Object v2 = g.getValue(s2.getObject());
+							boolean eq = compareValue(v1, v2);
+							if (!eq) {
+								addModification(s1, s2);
+								addComparable(s1, s2, false);
+							}
+						} else {
+							if (!s1.getObject().equals(s1.getSubject()) && !s2.getObject().equals(s2.getSubject()))
+								compareProps(s1.getObject(), s2.getObject());
 						}
 					} else {
-						compareProps(s1.getObject(), s2.getObject());
+						addModification(s1, s2);
+						addComparable(s1, s2, false);
 					}
-				} else {
-					addModification(s1, s2);
-					comparableStatements.map(s1, s2);
-					comparableResources.map(s1.getObject(),s2.getObject());
+					i1++;
+					i2++;
+					break;
+				}
+				case -1:{
+					if (DEBUG) System.out.println("Compare Prop diff1s " + printStatement(g,s1));
+					addDeletion(s1);
+					i1++;
+					break;
+				}
+					
+				case 1:{
+					if (DEBUG) System.out.println("Compare Prop diff2s " + printStatement(g,s2));
+					addAddition(s2);
+					i2++;
+					break;
 				}
-				i1++;
-				i2++;
-				break;
-			}
-			case -1:{
-				System.out.println("Compare Prop diff1s " + printStatement(g,s1));
-				addDeletion(s1);
-				i1++;
-				break;
-			}
-				
-			case 1:{
-				System.out.println("Compare Prop diff2s " + printStatement(g,s2));
-				addAddition(s2);
-				i2++;
-				break;
-			}
 			}
-			
-			
+
 		}
 		
 		ss1.clear();
@@ -775,7 +1134,6 @@ public class GraphComparator {
 		
 	}
 	
-	
 	public static boolean compareValue(Object v1, Object v2) {
 		if (v1 instanceof Object[] && v2 instanceof Object[])
 			return Arrays.deepEquals((Object[])v1, (Object[])v2);
@@ -796,7 +1154,6 @@ public class GraphComparator {
 	}
 
 	
-	
 	public class PredicateComparator implements Comparator<Statement> {
 		@Override
 		public int compare(Statement o1, Statement o2) {
@@ -855,8 +1212,6 @@ public class GraphComparator {
 		}
 	}
 	
-
-	
 	public class ResComparator implements Comparator<Resource> {
 		@Override
 		public int compare(Resource o1, Resource o2) {
@@ -869,6 +1224,5 @@ public class GraphComparator {
 			return 0;
 		}
 	}
-	
-	
+
 }