1 files changed, 114 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/MatchingFrame.java b/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/MatchingFrame.java
new file mode 100644
index 00000000..bdbc663c
--- /dev/null
+++ b/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/MatchingFrame.java
@@ -0,0 +1,114 @@
+/*******************************************************************************
+ * Copyright (c) 2004-2008 Akos Horvath, Gergely Varro Zoltan Ujhelyi and Daniel Varro
+ * 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.localsearch;
+
+import tools.refinery.viatra.runtime.matchers.tuple.IModifiableTuple;
+import tools.refinery.viatra.runtime.matchers.tuple.VolatileTuple;
+import tools.refinery.viatra.runtime.matchers.util.Preconditions;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+/**
+ * A MatchingFrame is a Volatile Tuple implementation used by the local search engine internally.
+ */
+public class MatchingFrame extends VolatileTuple implements IModifiableTuple {
+
+    /**
+     * The array that physically holds the values.
+     */
+    private Object[] frame;
+
+    /**
+     * @since 1.7
+     */
+    public MatchingFrame(int frameSize) {
+        this.frame = new Object[frameSize];
+    }
+
+    /**
+     * Creates a copy of another matching frame; the two frames can be updated separately
+     * @param other
+     * @since 1.7
+     */
+    public MatchingFrame(MatchingFrame other) {
+        this.frame = Arrays.copyOf(other.frame, other.frame.length);
+    }
+
+
+
+    /**
+     * Returns the value stored inside the matching frame.
+     *
+     * @param position
+     * @return the element stored in the selected position in the frame, or null if it is not yet set
+     * @throws IndexOutOfBoundsException
+     *             if position is negative
+     * @throws IllegalArgumentException
+     *             if the position is larger then the length of the frame
+     */
+    public Object getValue(int position) {
+        Preconditions.checkElementIndex(position, frame.length);
+        return frame[position];
+    }
+
+    /**
+     * Sets the value of the variable at the given position. For internal use in LS matching only.
+     *
+     * @param position the position of the variable within the frame
+     * @param value the value to be set for the variable
+     */
+    public void setValue(int position, Object value) {
+        Preconditions.checkElementIndex(position, frame.length);
+        frame[position] = value;
+    }
+
+    public boolean testAndSetValue(Integer position, Object value) {
+        Preconditions.checkElementIndex(position, frame.length);
+        if (frame[position] == null) {
+            frame[position] = value;
+            return true;
+        } else {
+            return frame[position].equals(value);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return Arrays.stream(frame).map(this::stringRepresentation).collect(Collectors.joining(", ", "[", "]"));
+    }
+
+    private String stringRepresentation(Object obj) {
+        if (obj == null) {
+            return "_";
+        }
+        return obj.toString();
+    }
+
+    @Override
+    public int getSize() {
+        return frame.length;
+    }
+
+    @Override
+    public Object get(int index) {
+        return getValue(index);
+    }
+
+    @Override
+    public Object[] getElements() {
+        return Arrays.copyOf(frame, frame.length);
+    }
+
+    @Override
+    public void set(int index, Object value) {
+        frame[index] = value;
+    }
+}