1 files changed, 80 insertions, 0 deletions
diff --git a/java/cluster/src/main/java/org/apache/qpid/server/cluster/util/Bindings.java b/java/cluster/src/main/java/org/apache/qpid/server/cluster/util/Bindings.java
new file mode 100644
index 0000000000..cca3953f34
--- /dev/null
+++ b/java/cluster/src/main/java/org/apache/qpid/server/cluster/util/Bindings.java
@@ -0,0 +1,80 @@
+/*
+ *
+ * Copyright (c) 2006 The Apache Software Foundation
+ *
+ * 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.apache.qpid.server.cluster.util;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+
+/**
+ * Maps two separate keys to a list of values.
+ *
+ */
+public class Bindings<K1, K2, V>
+{
+    private final MultiValuedMap<K1, Binding<K2>> _a = new MultiValuedMap<K1, Binding<K2>>();
+    private final MultiValuedMap<K2, Binding<K1>> _b = new MultiValuedMap<K2, Binding<K1>>();
+    private final Collection<V> _values = new HashSet<V>();
+
+    public void bind(K1 key1, K2 key2, V value)
+    {
+        _a.add(key1, new Binding<K2>(key2, value));
+        _b.add(key2, new Binding<K1>(key1, value));
+        _values.add(value);
+    }
+
+    public void unbind1(K1 key1)
+    {
+        Collection<Binding<K2>> values = _a.remove(key1);
+        for (Binding<K2> v : values)
+        {
+            _b.remove(v.key);
+            _values.remove(v.value);
+        }
+    }
+
+    public void unbind2(K2 key2)
+    {
+        Collection<Binding<K1>> values = _b.remove(key2);
+        for (Binding<K1> v : values)
+        {
+            _a.remove(v.key);
+            _values.remove(v.value);
+        }
+    }
+
+    public Collection<V> values()
+    {
+        return Collections.unmodifiableCollection(_values);
+    }
+
+    /**
+     * Value needs to hold key to the other map
+     */
+    private class Binding<T>
+    {
+        private final T key;
+        private final V value;
+
+        Binding(T key, V value)
+        {
+            this.key = key;
+            this.value = value;
+        }
+    }
+}