1 files changed, 85 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/memories/NullaryMaskedTupleMemory.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/memories/NullaryMaskedTupleMemory.java
new file mode 100644
index 00000000..7fa9e053
--- /dev/null
+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/memories/NullaryMaskedTupleMemory.java
@@ -0,0 +1,85 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2018, Gabor Bergmann, IncQuery Labs Ltd.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.viatra.runtime.matchers.memories;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Set;
+
+import tools.refinery.viatra.runtime.matchers.tuple.ITuple;
+import tools.refinery.viatra.runtime.matchers.tuple.Tuple;
+import tools.refinery.viatra.runtime.matchers.tuple.TupleMask;
+import tools.refinery.viatra.runtime.matchers.tuple.Tuples;
+import tools.refinery.viatra.runtime.matchers.util.CollectionsFactory.MemoryType;
+
+/**
+ * Specialized for nullary mask; tuples are stored as a simple set/multiset memory.
+ * 
+ * @author Gabor Bergmann
+ * @since 2.0
+ */
+public final class NullaryMaskedTupleMemory<Timestamp extends Comparable<Timestamp>> extends AbstractTrivialMaskedMemory<Timestamp> {
+
+    protected static final Set<Tuple> UNIT_RELATION = 
+            Collections.singleton(Tuples.staticArityFlatTupleOf());
+    protected static final Set<Tuple> EMPTY_RELATION = 
+            Collections.emptySet();
+    /**
+     * @param mask
+     *            The mask used to index the matchings
+     * @param owner the object "owning" this memory
+     * @param bucketType the kind of tuple collection maintained for each indexer bucket
+     * @since 2.0
+     */
+    public NullaryMaskedTupleMemory(TupleMask mask, MemoryType bucketType, Object owner) {
+        super(mask, bucketType, owner);
+        if (0 != mask.getSize()) throw new IllegalArgumentException(mask.toString());
+    }
+
+    @Override
+    public int getKeysetSize() {
+        return tuples.isEmpty() ? 0 : 1;
+    }
+
+    @Override
+    public Iterable<Tuple> getSignatures() {
+        return tuples.isEmpty() ? EMPTY_RELATION : UNIT_RELATION;
+    }
+
+    @Override
+    public Collection<Tuple> get(ITuple signature) {
+        if (0 == signature.getSize())
+            return tuples.distinctValues(); 
+        else return null;
+    }
+
+    @Override
+    public boolean remove(Tuple tuple, Tuple signature) {
+        tuples.removeOne(tuple);
+        return tuples.isEmpty();
+    }
+
+    @Override
+    public boolean remove(Tuple tuple) {
+        return remove(tuple, null);
+    }
+
+    @Override
+    public boolean add(Tuple tuple, Tuple signature) {
+        boolean wasEmpty = tuples.isEmpty();
+        tuples.addOne(tuple);
+        return wasEmpty;
+    }
+
+    @Override
+    public boolean add(Tuple tuple) {
+        return add(tuple, null);
+    }
+
+}