1 files changed, 236 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/core/src/main/java/org/apache/tuscany/sca/core/invocation/impl/PhaseSorter.java b/sca-java-2.x/tags/2.0.1-RC1/modules/core/src/main/java/org/apache/tuscany/sca/core/invocation/impl/PhaseSorter.java
new file mode 100644
index 0000000000..175f3463ad
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/core/src/main/java/org/apache/tuscany/sca/core/invocation/impl/PhaseSorter.java
@@ -0,0 +1,236 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.tuscany.sca.core.invocation.impl;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Directed, weighted graph
+ * 
+ * @param <V> The type of vertex object
+ * @param <E> The type of edge object
+ *
+ * @version $Rev$ $Date$
+ */
+public class PhaseSorter<V> implements Cloneable {
+    private final Map<V, Vertex> vertices = new HashMap<V, Vertex>();
+
+    /**
+     * Vertex of a graph
+     */
+    public final class Vertex {
+        private V value;
+
+        // TODO: Do we want to support multiple edges for a vertex pair? If so,
+        // we should use a List instead of Map
+        private Map<Vertex, Edge> outEdges = new HashMap<Vertex, Edge>();
+        private Map<Vertex, Edge> inEdges = new HashMap<Vertex, Edge>();
+
+        private Vertex(V value) {
+            this.value = value;
+        }
+
+        @Override
+        public String toString() {
+            return "(" + value + ")";
+        }
+
+        public V getValue() {
+            return value;
+        }
+
+        public Map<Vertex, Edge> getOutEdges() {
+            return outEdges;
+        }
+
+        public Map<Vertex, Edge> getInEdges() {
+            return inEdges;
+        }
+
+    }
+
+    /**
+     * An Edge connects two vertices in one direction
+     */
+    public final class Edge {
+        private Vertex sourceVertex;
+
+        private Vertex targetVertex;
+
+        public Edge(Vertex source, Vertex target) {
+            this.sourceVertex = source;
+            this.targetVertex = target;
+        }
+
+        @Override
+        public String toString() {
+            return sourceVertex + "->" + targetVertex;
+        }
+
+        public Vertex getTargetVertex() {
+            return targetVertex;
+        }
+
+        public void setTargetVertex(Vertex vertex) {
+            this.targetVertex = vertex;
+        }
+
+        public Vertex getSourceVertex() {
+            return sourceVertex;
+        }
+
+        public void setSourceVertex(Vertex sourceVertex) {
+            this.sourceVertex = sourceVertex;
+        }
+    }
+
+    public void addEdge(V source, V target) {
+        Vertex s = getVertex(source);
+        if (s == null) {
+            s = new Vertex(source);
+            vertices.put(source, s);
+        }
+        Vertex t = getVertex(target);
+        if (t == null) {
+            t = new Vertex(target);
+            vertices.put(target, t);
+        }
+        Edge edge = new Edge(s, t);
+        s.outEdges.put(t, edge);
+        t.inEdges.put(s, edge);
+    }
+
+    public void addVertext(V source) {
+        Vertex s = getVertex(source);
+        if (s == null) {
+            s = new Vertex(source);
+            vertices.put(source, s);
+        }
+    }
+
+    public Vertex getVertex(V source) {
+        Vertex s = vertices.get(source);
+        return s;
+    }
+
+    public boolean removeEdge(V source, V target) {
+        Vertex s = getVertex(source);
+        if (s == null) {
+            return false;
+        }
+
+        Vertex t = getVertex(target);
+        if (t == null) {
+            return false;
+        }
+
+        return s.outEdges.remove(t) != null && t.inEdges.remove(s) != null;
+
+    }
+
+    public void removeEdge(Edge edge) {
+        edge.sourceVertex.outEdges.remove(edge.targetVertex);
+        edge.targetVertex.inEdges.remove(edge.sourceVertex);
+    }
+
+    public void removeVertex(Vertex vertex) {
+        vertices.remove(vertex.getValue());
+        for (Edge e : new ArrayList<Edge>(vertex.outEdges.values())) {
+            removeEdge(e);
+        }
+        for (Edge e : new ArrayList<Edge>(vertex.inEdges.values())) {
+            removeEdge(e);
+        }
+    }
+
+    public Edge getEdge(Vertex source, Vertex target) {
+        return source.outEdges.get(target);
+    }
+
+    public Edge getEdge(V source, V target) {
+        Vertex sv = getVertex(source);
+        if (sv == null) {
+            return null;
+        }
+        Vertex tv = getVertex(target);
+        if (tv == null) {
+            return null;
+        }
+        return getEdge(getVertex(source), getVertex(target));
+    }
+
+    @Override
+    public String toString() {
+        StringBuffer sb = new StringBuffer();
+        for (Vertex v : vertices.values()) {
+            sb.append(v.outEdges.values()).append("\n");
+        }
+        return sb.toString();
+    }
+
+    public Map<V, Vertex> getVertices() {
+        return vertices;
+    }
+
+    public void addGraph(PhaseSorter<V> otherGraph) {
+        for (Vertex v : otherGraph.vertices.values()) {
+            for (Edge e : v.outEdges.values()) {
+                addEdge(e.sourceVertex.value, e.targetVertex.value);
+            }
+        }
+    }
+
+    private Vertex getFirst() {
+        for (Vertex v : vertices.values()) {
+            if (v.inEdges.isEmpty()) {
+                return v;
+            }
+        }
+        if (!vertices.isEmpty()) {
+            throw new IllegalArgumentException("Circular ordering has been detected: " + toString());
+        } else {
+            return null;
+        }
+    }
+
+    public List<V> topologicalSort(boolean readOnly) {
+        PhaseSorter<V> graph = (!readOnly) ? this : (PhaseSorter<V>)clone();
+        List<V> list = new ArrayList<V>();
+        while (true) {
+            Vertex v = graph.getFirst();
+            if (v == null) {
+                break;
+            }
+            list.add(v.getValue());
+            graph.removeVertex(v);
+        }
+
+        return list;
+    }
+
+    @Override
+    public Object clone() {
+        PhaseSorter<V> copy = new PhaseSorter<V>();
+        copy.addGraph(this);
+        return copy;
+    }
+}