--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tango/tango/net/cluster/model/IChannel.d	Fri Jan 11 17:57:40 2008 +0100
@@ -0,0 +1,206 @@
+/*******************************************************************************
+
+        copyright:      Copyright (c) 2004 Kris Bell. All rights reserved
+
+        license:        BSD style: $(LICENSE)
+        
+        version:        July 2004: Initial release      
+        
+        author:         Kris
+
+*******************************************************************************/
+
+module tango.net.cluster.model.IChannel;
+
+private import  tango.util.log.Logger;
+
+private import  tango.net.cluster.model.IMessage,
+                tango.net.cluster.model.IConsumer;    
+
+/*******************************************************************************
+        
+        A channel represents something akin to a publish/subscribe topic, 
+        or a radio station. These are used to segregate cluster operations
+        into a set of groups, where each group is represented by a channel.
+        Channel names are whatever you want then to be: use of dot notation 
+        has proved useful in the past. See Client.createChannel
+
+*******************************************************************************/
+
+interface IChannel
+{
+        /***********************************************************************
+
+                Return the Logger associated with this cluster
+
+        ***********************************************************************/
+        
+        Logger log ();
+
+        /***********************************************************************
+        
+                Return the name of this channel. This is the name provided
+                when the channel was constructed.
+
+        ***********************************************************************/
+
+        char[] name ();
+
+        /***********************************************************************
+
+                Create a message listener on the given
+                channel. The ChannelListener should be called whenever
+                a corresponding cluster event happens. Note that the
+                notification is expected to be on a seperate thread.
+
+        ***********************************************************************/
+        
+        IConsumer createConsumer (ChannelListener notify);
+
+        /***********************************************************************
+
+                Create a bulletin listener on the given
+                channel. The ChannelListener should be called whenever
+                a corresponding cluster event happens. Note that the
+                notification is expected to be on a seperate thread.
+
+        ***********************************************************************/
+        
+        IConsumer createBulletinConsumer (ChannelListener notify);
+
+        /***********************************************************************
+
+                Place a cache entry into the cluster. If there is already
+                a matching entry, it is replaced.
+
+        ***********************************************************************/
+        
+        bool putCache (char[] key, IMessage message);
+
+        /***********************************************************************
+
+                Return a cluster cache entry, and optionally remove it
+                from the cluster.
+
+        ***********************************************************************/
+        
+        IMessage getCache (char[] key, bool remove, IMessage host=null);
+
+        /***********************************************************************
+
+                Ask the cache host to load an entry, via the provided
+                message. Note that the message itself should contain all 
+                pertinent information to load the entry (such as whatever
+                key values are required). 
+                
+                The host executes the message in a manner akin to RPC, thus
+                the message also needs to be registered with the host server
+
+        ***********************************************************************/
+        
+        bool loadCache (char[] key, IMessage message);
+
+        /***********************************************************************
+
+                Place a new entry into the cluster queue. This may throw
+                a ClusterFullException when there is no space left within
+                the cluster queues.
+
+        ***********************************************************************/
+        
+        IMessage putQueue (IMessage message);
+
+        /***********************************************************************
+                
+                Query the cluster for queued entries on our corresponding 
+                channel. Removes, and returns, the first matching entry 
+                from the cluster.
+
+        ***********************************************************************/
+        
+        IMessage getQueue (IMessage host = null);
+
+        /***********************************************************************
+
+                Scatter a message to all registered listeners. This is
+                akin to multicast.
+
+        ***********************************************************************/
+        
+        void broadcast (IMessage message = null);
+
+        /***********************************************************************
+                
+                Execute the provided message on the cluster, and return the
+                results internally
+
+        ***********************************************************************/
+        
+        bool execute (IMessage message);
+}
+
+
+/*******************************************************************************
+
+        An IEvent is passed as the argument to each ChannelListener callback
+
+*******************************************************************************/
+
+interface IEvent
+{
+        /***********************************************************************
+
+                Return the channel used to initiate the listener
+
+        ***********************************************************************/
+        
+        IChannel channel ();
+
+        /***********************************************************************
+
+                Return one or more messages associated with this event, or
+                null if there is nothing available
+
+        ***********************************************************************/
+        
+        IMessage get (IMessage host = null);
+
+        /***********************************************************************
+
+                Send a message back to the producer. This should support all
+                the various event styles.                 
+
+        ***********************************************************************/
+        
+        void reply (IChannel channel, IMessage message);
+
+        /***********************************************************************
+
+                Return an appropriate reply channel for the given message, 
+                or return null if no reply is expected
+
+        ***********************************************************************/
+        
+        IChannel replyChannel (IMessage message);
+
+        /***********************************************************************
+
+                Return the Logger associated with this cluster
+
+        ***********************************************************************/
+        
+        Logger log ();
+}
+
+/*******************************************************************************
+
+        Declares the contract for listeners within the cluster package.
+        When creating a listener, you provide a callback delegate matching
+        this signature. The delegate is invoked, on a seperate thread, each
+        time a relevant event occurs.
+
+*******************************************************************************/
+
+alias void delegate (IEvent event) ChannelListener;
+
+