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diff --git a/qpid/cpp/src/qpid/broker/Messages.h b/qpid/cpp/src/qpid/broker/Messages.h
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+++ b/qpid/cpp/src/qpid/broker/Messages.h
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+#ifndef QPID_BROKER_MESSAGES_H
+#define QPID_BROKER_MESSAGES_H
+
+/*
+ *
+ * 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.
+ *
+ */
+#include <boost/function.hpp>
+
+namespace qpid {
+namespace framing {
+class SequenceNumber;
+}
+namespace broker {
+struct QueuedMessage;
+
+/**
+ * This interface abstracts out the access to the messages held for
+ * delivery by a Queue instance.
+ */
+class Messages
+{
+  public:
+    typedef boost::function1<void, QueuedMessage&> Functor;
+    typedef boost::function1<bool, QueuedMessage&> Predicate;
+
+    virtual ~Messages() {}
+    /**
+     * @return the number of messages available for delivery.
+     */
+    virtual size_t size() = 0;
+    /**
+     * @return true if there are no messages for delivery, false otherwise
+     */
+    virtual bool empty() = 0;
+
+    /**
+     * Re-inserts a message back into its original position - used
+     * when requeing released messages.
+     */
+    virtual void reinsert(const QueuedMessage&) = 0;
+    /**
+     * Remove the message at the specified position, returning true if
+     * found, false otherwise. The removed message is passed back via
+     * the second parameter.
+     */
+    virtual bool remove(const framing::SequenceNumber&, QueuedMessage&) = 0;
+    /**
+     * Find the message at the specified position, returning true if
+     * found, false otherwise. The matched message is passed back via
+     * the second parameter.
+     */
+    virtual bool find(const framing::SequenceNumber&, QueuedMessage&) = 0;
+    /**
+     * Return the next message to be given to a browsing subscrption
+     * that has reached the specified poisition. The next messages is
+     * passed back via the second parameter.
+     *
+     * @return true if there is another message, false otherwise.
+     */
+    virtual bool next(const framing::SequenceNumber&, QueuedMessage&) = 0;
+
+    /**
+     * Note: Caller is responsible for ensuring that there is a front
+     * (e.g. empty() returns false)
+     *
+     * @return the next message to be delivered
+     */
+    virtual QueuedMessage& front() = 0;
+    /**
+     * Removes the front message
+     */
+    virtual void pop() = 0;
+    /**
+     * @return true if there is a mesage to be delivered - in which
+     * case that message will be returned via the parameter and
+     * removed - otherwise false.
+     */
+    virtual bool pop(QueuedMessage&) = 0;
+    /**
+     * Pushes a message to the back of the 'queue'. For some types of
+     * queue this may cause another message to be removed; if that is
+     * the case the method will return true and the removed message
+     * will be passed out via the second parameter.
+     */
+    virtual bool push(const QueuedMessage& added, QueuedMessage& removed) = 0;
+
+    /**
+     * Apply the functor to each message held
+     */
+    virtual void foreach(Functor) = 0;
+    /**
+     * Remove every message held that for which the specified
+     * predicate returns true
+     */
+    virtual void removeIf(Predicate) = 0;
+  private:
+};
+}} // namespace qpid::broker
+
+#endif  /*!QPID_BROKER_MESSAGES_H*/