1 files changed, 136 insertions, 0 deletions
diff --git a/framework/src/onos/utils/misc/src/main/java/org/onlab/graph/DefaultMutablePath.java b/framework/src/onos/utils/misc/src/main/java/org/onlab/graph/DefaultMutablePath.java
new file mode 100644
index 00000000..ad7e8402
--- /dev/null
+++ b/framework/src/onos/utils/misc/src/main/java/org/onlab/graph/DefaultMutablePath.java
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onlab.graph;
+
+import com.google.common.collect.ImmutableList;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Simple concrete implementation of a directed graph path.
+ */
+public class DefaultMutablePath<V extends Vertex, E extends Edge<V>> implements MutablePath<V, E> {
+
+    private final List<E> edges = new ArrayList<>();
+    private double cost = 0.0;
+
+    /**
+     * Creates a new empty path.
+     */
+    public DefaultMutablePath() {
+    }
+
+    /**
+     * Creates a new path as a copy of another path.
+     *
+     * @param path path to be copied
+     */
+    public DefaultMutablePath(Path<V, E> path) {
+        checkNotNull(path, "Path cannot be null");
+        this.cost = path.cost();
+        edges.addAll(path.edges());
+    }
+
+    @Override
+    public V src() {
+        return edges.isEmpty() ? null : edges.get(0).src();
+    }
+
+    @Override
+    public V dst() {
+        return edges.isEmpty() ? null : edges.get(edges.size() - 1).dst();
+    }
+
+    @Override
+    public double cost() {
+        return cost;
+    }
+
+    @Override
+    public List<E> edges() {
+        return ImmutableList.copyOf(edges);
+    }
+
+    @Override
+    public void setCost(double cost) {
+        this.cost = cost;
+    }
+
+    @Override
+    public Path<V, E> toImmutable() {
+        return new DefaultPath<>(edges, cost);
+    }
+
+    @Override
+    public void insertEdge(E edge) {
+        checkNotNull(edge, "Edge cannot be null");
+        checkArgument(edges.isEmpty() || src().equals(edge.dst()),
+                      "Edge destination must be the same as the current path source");
+        edges.add(0, edge);
+    }
+
+    @Override
+    public void appendEdge(E edge) {
+        checkNotNull(edge, "Edge cannot be null");
+        checkArgument(edges.isEmpty() || dst().equals(edge.src()),
+                      "Edge source must be the same as the current path destination");
+        edges.add(edge);
+    }
+
+    @Override
+    public void removeEdge(E edge) {
+        checkArgument(edge.src().equals(edge.dst()) ||
+                              edges.indexOf(edge) == 0 ||
+                              edges.lastIndexOf(edge) == edges.size() - 1,
+                      "Edge must be at start or end of path, or it must be a cyclic edge");
+        edges.remove(edge);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("src", src())
+                .add("dst", dst())
+                .add("cost", cost)
+                .add("edges", edges)
+                .toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(edges, cost);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultMutablePath) {
+            final DefaultMutablePath other = (DefaultMutablePath) obj;
+            return Objects.equals(this.cost, other.cost) &&
+                    Objects.equals(this.edges, other.edges);
+        }
+        return false;
+    }
+
+}