1 files changed, 109 insertions, 0 deletions
diff --git a/java/broker/src/main/java/org/apache/qpid/server/queue/ExchangeBindings.java b/java/broker/src/main/java/org/apache/qpid/server/queue/ExchangeBindings.java
new file mode 100644
index 0000000000..424330bd11
--- /dev/null
+++ b/java/broker/src/main/java/org/apache/qpid/server/queue/ExchangeBindings.java
@@ -0,0 +1,109 @@
+/*
+ *
+ * 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.queue;
+
+import org.apache.qpid.server.exchange.Exchange;
+import org.apache.qpid.AMQException;
+
+import java.util.List;
+import java.util.HashSet;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * When a queue is deleted, it should be deregistered from any
+ * exchange it has been bound to. This class assists in this task,
+ * by keeping track of all bindings for a given queue.
+ */
+class ExchangeBindings
+{
+    static class ExchangeBinding
+    {
+        private final Exchange exchange;
+        private final String routingKey;
+
+        ExchangeBinding(String routingKey, Exchange exchange)
+        {
+            this.routingKey = routingKey;
+            this.exchange = exchange;
+        }
+
+        void unbind(AMQQueue queue) throws AMQException
+        {
+            exchange.deregisterQueue(routingKey, queue);
+        }
+
+        public Exchange getExchange()
+        {
+            return exchange;
+        }
+
+        public String getRoutingKey()
+        {
+            return routingKey;
+        }
+
+        public int hashCode()
+        {
+            return exchange.hashCode() + routingKey.hashCode();
+        }
+
+        public boolean equals(Object o)
+        {
+            if (!(o instanceof ExchangeBinding)) return false;
+            ExchangeBinding eb = (ExchangeBinding) o;
+            return exchange.equals(eb.exchange) && routingKey.equals(eb.routingKey);
+        }
+    }
+
+    private final List<ExchangeBinding> _bindings = new CopyOnWriteArrayList<ExchangeBinding>();
+    private final AMQQueue _queue;
+
+    ExchangeBindings(AMQQueue queue)
+    {
+        _queue = queue;
+    }
+
+    /**
+     * Adds the specified binding to those being tracked.
+     * @param routingKey the routing key with which the queue whose bindings
+     * are being tracked by the instance has been bound to the exchange
+     * @param exchange the exchange bound to
+     */
+    void addBinding(String routingKey, Exchange exchange)
+    {
+        _bindings.add(new ExchangeBinding(routingKey, exchange));
+    }
+
+    /**
+     * Deregisters this queue from any exchange it has been bound to
+     */
+    void deregister() throws AMQException
+    {
+        //remove duplicates at this point
+        HashSet<ExchangeBinding> copy = new HashSet<ExchangeBinding>(_bindings);
+        for (ExchangeBinding b : copy)
+        {
+            b.unbind(_queue);
+        }
+    }
+
+    List<ExchangeBinding> getExchangeBindings()
+    {
+        return _bindings;
+    }
+}