1 files changed, 106 insertions, 0 deletions
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/virtualhost/plugins/ConfiguredQueueBindingListener.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/virtualhost/plugins/ConfiguredQueueBindingListener.java
new file mode 100644
index 0000000000..12206013eb
--- /dev/null
+++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/virtualhost/plugins/ConfiguredQueueBindingListener.java
@@ -0,0 +1,106 @@
+/*
+ *
+ * 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.qpid.server.virtualhost.plugins;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+import org.apache.log4j.Logger;
+import org.apache.qpid.server.binding.Binding;
+import org.apache.qpid.server.configuration.plugins.SlowConsumerDetectionQueueConfiguration;
+import org.apache.qpid.server.exchange.AbstractExchange;
+import org.apache.qpid.server.exchange.Exchange;
+import org.apache.qpid.server.exchange.Exchange.BindingListener;
+import org.apache.qpid.server.queue.AMQQueue;
+
+/**
+ * This is a listener that caches queues that are configured for slow consumer disconnection.
+ * 
+ * There should be one listener per virtual host, which can be added to all exchanges on
+ * that host.
+ * 
+ * TODO In future, it will be possible to configure the policy at runtime, so only the queue
+ * itself is cached, and the configuration looked up by the housekeeping thread. This means
+ * that there may be occasions where the copy of the cache contents retrieved by the thread
+ * does not contain queues that are configured, or that configured queues are not present.
+ * 
+ * @see BindingListener
+ */
+public class ConfiguredQueueBindingListener implements BindingListener
+{
+    private static final Logger _log = Logger.getLogger(ConfiguredQueueBindingListener.class);
+    
+    private String _vhostName;
+    private Set<AMQQueue> _cache = Collections.synchronizedSet(new HashSet<AMQQueue>());
+    
+    public ConfiguredQueueBindingListener(String vhostName)
+    {
+        _vhostName = vhostName;
+    }
+
+    /**
+     * @see BindingListener#bindingAdded(Exchange, Binding)
+     */
+    public void bindingAdded(Exchange exchange, Binding binding)
+    {
+        processBinding(binding);
+    }
+
+    /**
+     * @see BindingListener#bindingRemoved(Exchange, Binding)
+     */
+    public void bindingRemoved(Exchange exchange, Binding binding)
+    {
+        processBinding(binding);
+    }
+    
+    private void processBinding(Binding binding)
+    {
+        AMQQueue queue = binding.getQueue();
+        
+        SlowConsumerDetectionQueueConfiguration config =
+            queue.getConfiguration().getConfiguration(SlowConsumerDetectionQueueConfiguration.class.getName());
+        if (config != null)
+        {
+            _cache.add(queue);
+        }
+        else
+        {
+            _cache.remove(queue);
+        }
+    }
+    
+    /**
+     * Lookup and return the cache of configured {@link AMQQueue}s.
+     * 
+	 * Note that when accessing the cached queues, the {@link Iterator} is not thread safe
+	 * (see the {@link Collections#synchronizedSet(Set)} documentation) so a copy of the
+	 * cache is returned.
+     * 
+     * @return a copy of the cached {@link java.util.Set} of queues
+     */
+    public Set<AMQQueue> getQueueCache()
+    {
+        return new HashSet<AMQQueue>(_cache);
+    }
+}