refactor(store): neighborhood optimization

* Use LinekdHashMap in delta-based stores to improve iteration performance
* Avoid allocating ObjectCodeImpl

3 files changed, 17 insertions, 6 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/map/internal/delta/VersionedMapDeltaImpl.java b/subprojects/store/src/main/java/tools/refinery/store/map/internal/delta/VersionedMapDeltaImpl.java
index d530ae87..8be42712 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/map/internal/delta/VersionedMapDeltaImpl.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/map/internal/delta/VersionedMapDeltaImpl.java
@@ -23,7 +23,7 @@ public class VersionedMapDeltaImpl<K, V> implements VersionedMap<K, V> {
                 this.store = store;
                 this.defaultValue = defaultValue;
 
-                current = new HashMap<>();
+                current = new LinkedHashMap<>();
                 if (summarizeChanges) {
                         this.uncommittedStore = new UncommittedDeltaMapStore<>(this);
                 } else {
diff --git a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
index 785fda7a..1442c915 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/NeighbourhoodCalculator.java
@@ -18,21 +18,25 @@ import java.util.List;
 import java.util.Objects;
 
 public class NeighbourhoodCalculator extends AbstractNeighbourhoodCalculator implements StateCodeCalculator {
+        private ObjectCodeImpl previousObjectCode = new ObjectCodeImpl();
+        private ObjectCodeImpl nextObjectCode = new ObjectCodeImpl();
+
         public NeighbourhoodCalculator(List<? extends Interpretation<?>> interpretations, IntSet individuals) {
                 super(interpretations, individuals);
         }
 
         public StateCoderResult calculateCodes() {
-                ObjectCodeImpl previousObjectCode = new ObjectCodeImpl();
+                previousObjectCode.clear();
+                nextObjectCode.clear();
                 initializeWithIndividuals(previousObjectCode);
 
                 int rounds = 0;
                 do {
-                        final ObjectCodeImpl nextObjectCode = rounds == 0 ? new ObjectCodeImpl() :
-                                        new ObjectCodeImpl(previousObjectCode.getSize());
-
                         constructNextObjectCodes(previousObjectCode, nextObjectCode);
+                        var tempObjectCode = previousObjectCode;
                         previousObjectCode = nextObjectCode;
+                        nextObjectCode = tempObjectCode;
+                        nextObjectCode.clear();
                         rounds++;
                 } while (rounds <= 7 && rounds <= previousObjectCode.getEffectiveSize());
 
@@ -43,7 +47,7 @@ public class NeighbourhoodCalculator extends AbstractNeighbourhoodCalculator imp
         private long calculateLastSum(ObjectCode codes) {
                 long result = 0;
                 for (var nullImpactValue : nullImpactValues) {
-                        result = result * 31 + Objects.hashCode(((Interpretation<?>) nullImpactValue).get(Tuple0.INSTANCE));
+                        result = result * PRIME + Objects.hashCode(((Interpretation<?>) nullImpactValue).get(Tuple0.INSTANCE));
                 }
 
                 for (int i = 0; i < codes.getSize(); i++) {
diff --git a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/ObjectCodeImpl.java b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/ObjectCodeImpl.java
index 0cd7ff58..422e1d73 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/ObjectCodeImpl.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/statecoding/neighbourhood/ObjectCodeImpl.java
@@ -32,6 +32,13 @@ public class ObjectCodeImpl implements ObjectCode {
                 effectiveSize = copy.effectiveSize;
         }
 
+        public void clear() {
+                effectiveSize = 0;
+                for (int i = 0; i < size; i++) {
+                        vector[i] = 0;
+                }
+        }
+
         public void ensureSize(int object) {
                 if (object >= size) {
                         size = object + 1;