diff --git a/src/mhtree/BuildTree.java b/src/mhtree/BuildTree.java
index f6f7c975baa17c67d5dc4f0029cbb7ad33a2a215..961126ee5513ae9819e36720be28043dccc0bcb6 100644
--- a/src/mhtree/BuildTree.java
+++ b/src/mhtree/BuildTree.java
@@ -65,11 +65,11 @@ class BuildTree {
while (!notProcessedNodeIndices.isEmpty()) {
if (notProcessedNodeIndices.cardinality() < arity) {
- List<Integer> nodeIndices = new ArrayList<>();
+ Set<Integer> nodeIndices = new HashSet<>();
- notProcessedNodeIndices.stream().forEach(nodeIndices::add);
+ int mainNodeIndex = notProcessedNodeIndices.nextSetBit(0);
+ notProcessedNodeIndices.stream().skip(1).forEach(nodeIndices::add);
- int mainNodeIndex = nodeIndices.remove(0);
mergeNodes(mainNodeIndex, nodeIndices);
break;
@@ -78,7 +78,7 @@ class BuildTree {
int furthestNodeIndex = getFurthestIndex(nodeDistances, notProcessedNodeIndices);
notProcessedNodeIndices.clear(furthestNodeIndex);
- List<Integer> nnNodeIndices = new ArrayList<>();
+ Set<Integer> nnNodeIndices = new HashSet<>();
for (int i = 0; i < arity - 1; i++) {
int index = objectDistances.minDistInArrayExceptIdx(nodeDistances[furthestNodeIndex], notProcessedNodeIndices, furthestNodeIndex);
@@ -148,7 +148,7 @@ class BuildTree {
}
}
- private List<LocalAbstractObject> findClosestObjects(int baseObjectIndex, int numberOfObjects, BitSet notProcessedIndices) {
+ private Set<LocalAbstractObject> findClosestObjects(int baseObjectIndex, int numberOfObjects, BitSet notProcessedIndices) {
List<Integer> objectIndices = new ArrayList<>();
objectIndices.add(baseObjectIndex);
@@ -160,7 +160,7 @@ class BuildTree {
int nnIndex = objectDistances.minDistInArray(objectDistances.getDistances(index), notProcessedIndices);
float distanceSum = objectIndices.stream()
- .map(pointIndex -> objectDistances.getDistance(pointIndex, nnIndex))
+ .map(objectIndex -> objectDistances.getDistance(objectIndex, nnIndex))
.reduce(0f, Float::sum);
indexToDistance.put(nnIndex, distanceSum);
@@ -172,7 +172,7 @@ class BuildTree {
objectIndices.add(closestPointIndex);
return objectDistances.getObject(closestPointIndex);
- }).collect(Collectors.toList());
+ }).collect(Collectors.toSet());
}
private void precomputeNodeDistances() {
@@ -193,13 +193,13 @@ class BuildTree {
}
}
- private void mergeNodes(int mainNodeIndex, List<Integer> nodeIndices) {
+ private void mergeNodes(int mainNodeIndex, Set<Integer> nodeIndices) {
if (nodeIndices.size() == 0) return;
- List<Integer> indices = new ArrayList<>(nodeIndices);
+ Set<Integer> indices = new HashSet<>(nodeIndices);
indices.add(mainNodeIndex);
- List<Node> nodes = indices.stream().map(i -> this.nodes[i]).collect(Collectors.toList());
+ Set<Node> nodes = indices.stream().map(i -> this.nodes[i]).collect(Collectors.toSet());
InternalNode parent = Node.createParent(nodes, objectDistances, insertType, distanceMeasure);
nodes.forEach(node -> node.setParent(parent));
@@ -215,7 +215,7 @@ class BuildTree {
updateNodeDistances(mainNodeIndex, nodeIndices);
}
- private void updateNodeDistances(int baseNodeIndex, List<Integer> nodeIndices) {
+ private void updateNodeDistances(int baseNodeIndex, Set<Integer> nodeIndices) {
if (nodeIndices.size() == 0) return;
validNodeIndices.stream().forEach(i -> {
diff --git a/src/mhtree/Histogram.java b/src/mhtree/Histogram.java
index 470c6f681109ba1e129afb7ca38724f03c5da136..3f96f9daff19736b283b0b4a9ecc57b6a20ff521 100644
--- a/src/mhtree/Histogram.java
+++ b/src/mhtree/Histogram.java
@@ -5,6 +5,7 @@ import messif.objects.LocalAbstractObject;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
+import java.util.Set;
public class Histogram {
private final HashMap<Integer, HashMap<Long, Integer>> levelToHullsCoveredToObjectCount = new HashMap<>();
@@ -16,7 +17,7 @@ public class Histogram {
Histogram histogram = new Histogram();
for (int level = 1; level <= x.getHeight() + 1; level++) {
- List<Node> levelNodes = x.getNodesOnLevel(level);
+ Set<Node> levelNodes = x.getNodesOnLevel(level);
for (LocalAbstractObject object : x.getObjects()) {
long coveredObjectCount = levelNodes.stream()
diff --git a/src/mhtree/InternalNode.java b/src/mhtree/InternalNode.java
index 4b961df514c9ad55bbc11669590eed719ca46b0a..3a383a1c7dd04bd6d6ea8661b300e530ec879852 100644
--- a/src/mhtree/InternalNode.java
+++ b/src/mhtree/InternalNode.java
@@ -15,18 +15,18 @@ public class InternalNode extends Node implements Serializable {
*/
private static final long serialVersionUID = 2L;
- private final List<Node> children;
+ private final Set<Node> children;
InternalNode(PrecomputedDistances distances, InsertType insertType, DistanceMeasure distanceMeasure) {
super(distances, insertType, distanceMeasure);
- children = new ArrayList<>();
+ children = new HashSet<>();
}
- public void addChildren(List<Node> children) {
+ public void addChildren(Set<Node> children) {
this.children.addAll(children);
}
- public List<Node> getChildren() {
+ public Set<Node> getChildren() {
return children;
}
@@ -41,11 +41,11 @@ public class InternalNode extends Node implements Serializable {
addNewObject(object);
}
- public List<LocalAbstractObject> getObjects() {
+ public Set<LocalAbstractObject> getObjects() {
return children.stream()
.map(Node::getObjects)
.flatMap(Collection::stream)
- .collect(Collectors.toList());
+ .collect(Collectors.toSet());
}
public boolean contains(LocalAbstractObject object) {
@@ -66,12 +66,12 @@ public class InternalNode extends Node implements Serializable {
.getMax() + 1;
}
- public List<Node> getNodesOnLevel(int level) {
- if (getLevel() == level) return Collections.singletonList(this);
+ public Set<Node> getNodesOnLevel(int level) {
+ if (getLevel() == level) return Collections.singleton(this);
return children.stream()
.map(child -> child.getNodesOnLevel(level))
.flatMap(Collection::stream)
- .collect(Collectors.toList());
+ .collect(Collectors.toSet());
}
}
diff --git a/src/mhtree/LeafNode.java b/src/mhtree/LeafNode.java
index d720c984167e4a7b53c034f9174afd19409a86a5..d4c92824a2423dca306c1cb400a8bc4299a5160c 100644
--- a/src/mhtree/LeafNode.java
+++ b/src/mhtree/LeafNode.java
@@ -7,9 +7,7 @@ import messif.objects.LocalAbstractObject;
import messif.objects.util.AbstractObjectIterator;
import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
public class LeafNode extends Node implements Serializable {
@@ -32,8 +30,8 @@ public class LeafNode extends Node implements Serializable {
addNewObject(object);
}
- public List<LocalAbstractObject> getObjects() {
- List<LocalAbstractObject> objects = new ArrayList<>();
+ public Set<LocalAbstractObject> getObjects() {
+ Set<LocalAbstractObject> objects = new HashSet<>();
for (AbstractObjectIterator<LocalAbstractObject> it = bucket.getAllObjects(); it.hasNext(); )
objects.add(it.next());
@@ -57,7 +55,7 @@ public class LeafNode extends Node implements Serializable {
return 0;
}
- public List<Node> getNodesOnLevel(int level) {
- return Collections.singletonList(this);
+ public Set<Node> getNodesOnLevel(int level) {
+ return Collections.singleton(this);
}
}
diff --git a/src/mhtree/Node.java b/src/mhtree/Node.java
index 05344b492c0ae200655578ffc4955c4c8fa89edc..731b6887c778a1ade08e752590a627681be9335c 100644
--- a/src/mhtree/Node.java
+++ b/src/mhtree/Node.java
@@ -16,8 +16,8 @@ public abstract class Node implements Serializable {
* Serialization ID
*/
private static final long serialVersionUID = 420L;
- protected final InsertType insertType;
private final DistanceMeasure distanceMeasure;
+ protected final InsertType insertType;
protected HullOptimizedRepresentationV3 hull;
protected Node parent;
@@ -28,7 +28,7 @@ public abstract class Node implements Serializable {
this.distanceMeasure = distanceMeasure;
}
- public static InternalNode createParent(List<Node> nodes, PrecomputedDistances distances, InsertType insertType, DistanceMeasure distanceMeasure) {
+ public static InternalNode createParent(Set<Node> nodes, PrecomputedDistances distances, InsertType insertType, DistanceMeasure distanceMeasure) {
List<LocalAbstractObject> objects = nodes.stream()
.map(Node::getObjects)
.flatMap(Collection::stream)
@@ -77,7 +77,7 @@ public abstract class Node implements Serializable {
public abstract void addObject(LocalAbstractObject object) throws BucketStorageException;
- public abstract List<LocalAbstractObject> getObjects();
+ public abstract Set<LocalAbstractObject> getObjects();
public abstract boolean contains(LocalAbstractObject object);
@@ -85,7 +85,7 @@ public abstract class Node implements Serializable {
public abstract int getHeight();
- public abstract List<Node> getNodesOnLevel(int level);
+ public abstract Set<Node> getNodesOnLevel(int level);
protected void rebuildHull(LocalAbstractObject object) {
List<LocalAbstractObject> objects = new ArrayList<>(getObjects());
@@ -106,6 +106,12 @@ public abstract class Node implements Serializable {
rebuildHull(object);
}
+ private static <T extends Collection<LocalAbstractObject>> double sumOfDistanceToObject(LocalAbstractObject object, T objects) {
+ return objects.stream()
+ .mapToDouble(object::getDistance)
+ .sum();
+ }
+
private double getDistanceToNearestHullObject(LocalAbstractObject object) {
return hull.getHull().stream()
.mapToDouble(object::getDistance)
@@ -121,17 +127,14 @@ public abstract class Node implements Serializable {
}
private double getSumOfDistancesToHullObjects(LocalAbstractObject object) {
- return hull.getHull().stream()
- .mapToDouble(object::getDistance)
- .sum();
+ return sumOfDistanceToObject(object, hull.getHull());
}
private double getDistanceToMedoid(LocalAbstractObject object) {
- List<LocalAbstractObject> objects = getObjects();
- Function<LocalAbstractObject, Double> sumOfDistanceToObject = obj -> objects.stream().mapToDouble(obj::getDistance).sum();
+ Set<LocalAbstractObject> objects = getObjects();
Map<LocalAbstractObject, Double> objectToObjectDistance = objects.stream()
- .collect(Collectors.toMap(Function.identity(), sumOfDistanceToObject));
+ .collect(Collectors.toMap(Function.identity(), o -> sumOfDistanceToObject(o, objects)));
LocalAbstractObject medoid = Collections.min(objectToObjectDistance.entrySet(), Map.Entry.comparingByValue()).getKey();