avoid expensive string concatenation in frequently-called place

Change-Id: I86cde10a4c15ae7e2286bd8ea1d236cac89959ce

java/com.sap.sailing.windestimation.test/src/com/sap/sailing/windestimation/aggregator/msthmm/DijkstraTest.java

@@ -10,6 +10,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -20,9 +21,9 @@ import com.sap.sailing.windestimation.aggregator.graph.ElementAdjacencyQualityMe
 import com.sap.sailing.windestimation.aggregator.graph.ElementWithQuality;
 import com.sap.sailing.windestimation.aggregator.graph.GroupOutOfWhichToPickTheBestElement;
 import com.sap.sailing.windestimation.aggregator.graph.InnerGraphSuccessorSupplier;
+import com.sap.sse.common.Named;
 import com.sap.sse.common.Util;
 import com.sap.sse.common.Util.Pair;
-import com.sap.sse.common.impl.NamedImpl;
 
 public class DijkstraTest {
     private Node startNode;
@@ -30,13 +31,23 @@ public class DijkstraTest {
     private Map<Node, Set<Node>> successors;
     private Map<Pair<Node, Node>, Double> edgeQuality;
     
-    private static class Node extends NamedImpl implements ElementWithQuality {
-        private static final long serialVersionUID = 6000367519447493367L;
+    private static class Node implements ElementWithQuality, Named {
+        private static final long serialVersionUID = 4495016215564212071L;
         private final double quality;
+        private final Supplier<String> nameSupplier;
         
         public Node(String name, double quality) {
-            super(name);
+            this(()->name, quality);
+        }
+        
+        public Node(Supplier<String> nameSupplier, double quality) {
             this.quality = quality;
+            this.nameSupplier = nameSupplier;
+        }
+        
+        @Override
+        public String getName() {
+            return nameSupplier.get();
         }
 
         @Override

java/com.sap.sailing.windestimation/src/com/sap/sailing/windestimation/aggregator/graph/InnerGraphSuccessorSupplier.java

@@ -6,6 +6,7 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 import com.sap.sse.common.Util;
 
@@ -31,7 +32,7 @@ implements Function<T, Iterable<T>> {
     private final Map<T, Set<T>> successors;
     private final T artificialRoot;
     private final Map<G, T> artificialLeaves;
-    private final Function<String, T> artificialInnerNodeConstructor;
+    private final Function<Supplier<String>, T> artificialInnerNodeConstructor;
     
     /**
      * Constructs the inner graph's edge structure from the {@code overarchingTree}.
@@ -54,10 +55,10 @@ implements Function<T, Iterable<T>> {
      *            quality} of the element created is expected to be set to the same value for all invocations, e.g.,
      *            {@code 1.0}.
      */
-    public InnerGraphSuccessorSupplier(Tree<G> overarchingTree, Function<String, T> artificialInnerNodeConstructor) {
+    public InnerGraphSuccessorSupplier(Tree<G> overarchingTree, Function<Supplier<String>, T> artificialInnerNodeConstructor) {
         successors = new HashMap<>();
         this.artificialInnerNodeConstructor = artificialInnerNodeConstructor;
-        artificialRoot = artificialInnerNodeConstructor.apply("End Node at Root");
+        artificialRoot = artificialInnerNodeConstructor.apply(()->"End Node at Root");
         artificialLeaves = new HashMap<>();
         if (overarchingTree.getRoot() != null) {
             // add the edges to the artificial root node
@@ -72,7 +73,7 @@ implements Function<T, Iterable<T>> {
         final Iterable<T> innerChildElements;
         if (Util.isEmpty(node.getChildren())) {
             // leaf node; add an artificial leaf:
-            final T artificialLeaf = artificialInnerNodeConstructor.apply("Start Node for "+node);
+            final T artificialLeaf = artificialInnerNodeConstructor.apply(()->"Start Node for "+node);
             artificialLeaves.put(node, artificialLeaf);
             innerChildElements = Collections.singleton(artificialLeaf);
         } else {

java/com.sap.sailing.windestimation/src/com/sap/sailing/windestimation/aggregator/msthmm/MstBestPathsCalculatorImpl.java

@@ -8,6 +8,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
+import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
 import com.sap.sailing.windestimation.aggregator.graph.DijkstraShortestPathFinderImpl;
@@ -129,10 +130,10 @@ public class MstBestPathsCalculatorImpl implements MstBestPathsCalculator {
             final InnerGraphSuccessorSupplier<GraphNode<MstGraphLevel>, MstGraphLevel> innerGraphSuccessorSupplier =
                     new InnerGraphSuccessorSupplier<GraphNode<MstGraphLevel>, MstGraphLevel>(graphComponents,
                             // supplier for artificial nodes; always full confidence and full possible wind course range
-                            (final String name)->new GraphNode<MstGraphLevel>(/* maneuverType */ null, /* tackAfter */ null, new WindCourseRange(0, 360), /* confidence */ 1.0, /* indexInLevel */ 0, /* graphLevel */ null) {
+                            (final Supplier<String> nameSupplier)->new GraphNode<MstGraphLevel>(/* maneuverType */ null, /* tackAfter */ null, new WindCourseRange(0, 360), /* confidence */ 1.0, /* indexInLevel */ 0, /* graphLevel */ null) {
                                 @Override
                                 public String toString() {
-                                    return name;
+                                    return nameSupplier.get();
                                 }
                             });
             final DijsktraShortestPathFinder<GraphNode<MstGraphLevel>> dijsktraShortestPathFinder = new DijkstraShortestPathFinderImpl<GraphNode<MstGraphLevel>>(