--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlib/session/Subscriber.h	Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,84 @@
+/*
+ *    Copyright 2007 Intel Corporation
+ * 
+ *    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.
+ */
+
+#ifndef _SUBSCRIBER_H_
+#define _SUBSCRIBER_H_
+
+#include <vector>
+
+#include <oasys/debug/DebugUtils.h>
+#include <oasys/debug/Formatter.h>
+
+#include "naming/EndpointID.h"
+
+namespace dtn {
+
+class Registration;
+
+/**
+ * A subscriber for a session is either a local registration or a next
+ * hop destination.
+ */
+class Subscriber : public oasys::Formatter {
+public:
+    /// Constructor for a NULL subscriber (used for 
+    Subscriber()
+        : reg_(NULL), nexthop_(EndpointID::NULL_EID()) {}
+    
+    /// Constructor for a local subscriber
+    Subscriber(Registration* reg)
+        : reg_(reg), nexthop_(EndpointID::NULL_EID()) {}
+
+    /// Constructor for a remote subscriber
+    Subscriber(const EndpointID& nexthop)
+        : reg_(NULL), nexthop_(nexthop) {}
+
+    /// Destructor
+    virtual ~Subscriber();
+
+    /// Virtual from Formatter
+    int format(char* buf, size_t sz) const;
+
+    /// Comparison operator
+    bool operator==(const Subscriber& other) const;
+
+    /// @{ Accessors
+    bool              is_null()  const;
+    bool              is_local() const { return reg_ != NULL; }
+    Registration*  reg()         const { ASSERT(is_local()); return reg_; }
+    const EndpointID& nexthop()  const { ASSERT(!is_local()); return nexthop_; }
+    /// @}
+
+protected:
+    Registration* reg_;
+    EndpointID    nexthop_;
+};
+
+//----------------------------------------------------------------------
+inline bool
+Subscriber::is_null() const
+{
+    return (reg_ == NULL && nexthop_ == EndpointID::NULL_EID());
+}
+
+/**
+ * Type for a vector of subscriber objects.
+ */
+typedef std::vector<Subscriber> SubscriberList;
+
+} // namespace dtn
+
+#endif /* _SUBSCRIBER_H_ */