RED-7141: Performance improvments

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/model/Character.java

@@ -77,9 +77,9 @@ public class Character {
     public double angle(Character character) {
 
         if (getX() > character.getX()) {
-            return FastAtan2.atan2(getY() - character.getY(), getX() - character.getX());
+            return FastAtan2.fastAtan2(getY() - character.getY(), getX() - character.getX());
         } else {
-            return FastAtan2.atan2(character.getY() - getY(), character.getX() - getX());
+            return FastAtan2.fastAtan2(character.getY() - getY(), character.getX() - getX());
         }
     }
 

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/model/Neighbor.java

@@ -6,8 +6,7 @@ public class Neighbor {
 
     @Getter
     private final double distance;
-    @Getter
-    private final double angle;
+    private Double angle;
     private final Character originCharacter;
     @Getter
     private final Character character;
@@ -16,7 +15,6 @@ public class Neighbor {
     public Neighbor(Character neighbor, Character origin) {
 
         this.distance = neighbor.distance(origin);
-        this.angle = neighbor.angle(origin);
         this.character = neighbor;
         this.originCharacter = origin;
     }
@@ -33,4 +31,13 @@ public class Neighbor {
         return character.verticalDistance(originCharacter);
     }
 
+
+    public double getAngle() {
+
+        if (angle != null) {
+            return angle;
+        }
+        return this.character.angle(this.originCharacter);
+    }
+
 }

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/service/NearestNeighbourService.java

@@ -31,8 +31,9 @@ public class NearestNeighbourService {
 
         for (int i = 0; i < characters.size(); i++) {
 
-            List<Neighbor> candidates = new ArrayList<>();
-
+            Neighbor[] candidates = new Neighbor[maxNeighborCount + 1];
+            int neighborInsertionIndex = 0;
+            int neighborCount = 0;
             int start = i;
             int end = i + 1;
 
@@ -45,42 +46,83 @@ public class NearestNeighbourService {
 
                 while (start > 0 && characters.get(i).getX() - characters.get(start - 1).getX() < searchDistance) {
                     start--;
-                    candidates.add(new Neighbor(characters.get(start), characters.get(i)));
-                    clearMostDistant(candidates, maxNeighborCount);
+                    candidates[neighborInsertionIndex] = new Neighbor(characters.get(start), characters.get(i));
+                    neighborCount++;
+                    if (neighborCount > maxNeighborCount) {
+                        neighborInsertionIndex = clearMostDistant(candidates);
+                        neighborCount--;
+                    } else {
+                        neighborInsertionIndex++;
+                    }
                     newCandidatesFound = true;
                 }
 
                 while (end < characters.size() && characters.get(end).getX() - characters.get(i).getX() < searchDistance) {
-                    candidates.add(new Neighbor(characters.get(end), characters.get(i)));
-                    clearMostDistant(candidates, maxNeighborCount);
+                    candidates[neighborInsertionIndex] = new Neighbor(characters.get(end), characters.get(i));
+                    neighborCount++;
+                    if (neighborCount > maxNeighborCount) {
+                        neighborInsertionIndex = clearMostDistant(candidates);
+                        neighborCount--;
+                    } else {
+                        neighborInsertionIndex++;
+                    }
                     end++;
                     newCandidatesFound = true;
                 }
 
-                if (newCandidatesFound && candidates.size() >= maxNeighborCount) {
-                    distance = candidates.stream().mapToDouble(Neighbor::getDistance).max().orElse(Double.POSITIVE_INFINITY);
+                if (newCandidatesFound && neighborCount >= maxNeighborCount) {
+                    distance = maxDistance(candidates);
                 }
             }
-            clearMostDistant(candidates, maxNeighborCount);
-            characters.get(i).setNeighbors(new ArrayList<>(candidates));
+            if (neighborCount < maxNeighborCount) {
+                clearMostDistant(candidates);
+            }
+
+            List<Neighbor> candidatesList = new ArrayList<>(maxNeighborCount);
+            for (Neighbor candidate : candidates) {
+                if (candidate != null) {
+                    candidatesList.add(candidate);
+                }
+            }
+            candidatesList.sort(Comparator.comparingDouble(Neighbor::getDistance));
+            assert candidatesList.size() == maxNeighborCount;
+            characters.get(i).setNeighbors(candidatesList);
         }
     }
 
 
-    private void clearMostDistant(List<Neighbor> candidates, int maxNeighborCount) {
+    private double maxDistance(Neighbor[] candidates) {
 
-        if (candidates.size() > maxNeighborCount) {
-            double maxDistance = 0;
-            int maxIndex = 0;
-            for (int i = 0; i < candidates.size(); i++) {
-                Neighbor candidate = candidates.get(i);
-                if (candidate.getDistance() > maxDistance) {
-                    maxDistance = candidate.getDistance();
-                    maxIndex = i;
-                }
+        double maxDistance = 0;
+        for (Neighbor candidate : candidates) {
+            if (candidate == null) {
+                continue;
+            }
+            if (candidate.getDistance() > maxDistance) {
+                maxDistance = candidate.getDistance();
             }
-            candidates.remove(maxIndex);
         }
+        return maxDistance;
+    }
+
+
+    private int clearMostDistant(Neighbor[] candidates) {
+
+        double maxDistance = 0;
+        int maxIndex = 0;
+        for (int i = 0; i < candidates.length; i++) {
+            Neighbor candidate = candidates[i];
+            if (candidate == null) {
+                continue;
+            }
+            if (candidate.getDistance() > maxDistance) {
+                maxDistance = candidate.getDistance();
+                maxIndex = i;
+            }
+        }
+        candidates[maxIndex] = null;
+        return maxIndex;
     }
 
 }
+

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/utils/FastAtan2.java

@@ -37,7 +37,7 @@ public class FastAtan2 {
     }
 
     @SuppressWarnings("ParameterAssignment")
-    static public double atan2(double y, double x) {
+    static public double fastAtan2(double y, double x) {
 
         if (y < 0) {
             if (x < 0) {

layoutparser-service/layoutparser-service-server/src/test/java/com/knecon/fforesight/service/layoutparser/server/graph/ViewerDocumentTest.java

@@ -33,8 +33,8 @@ public class ViewerDocumentTest extends BuildDocumentTest {
         ViewerDocumentService viewerDocumentService = new ViewerDocumentService(null);
         LayoutGridService layoutGridService = new LayoutGridService(viewerDocumentService);
 
-        Document document = buildGraph(fileName, LayoutParsingType.REDACT_MANAGER);
         long start = System.currentTimeMillis();
+        Document document = buildGraph(fileName, LayoutParsingType.REDACT_MANAGER);
         layoutGridService.addLayoutGrid(documentFile, document, new File(tmpFileName), true);
         System.out.printf("Total time: %.2fs%n", ((float) (System.currentTimeMillis() - start)) / 1000);
     }