source: source/ariba/CommunicationListener.h

// [License]
// The Ariba-Underlay Copyright
//
// Copyright (c) 2008-2009, Institute of Telematics, UniversitÀt Karlsruhe (TH)
//
// Institute of Telematics
// UniversitÀt Karlsruhe (TH)
// Zirkel 2, 76128 Karlsruhe
// Germany
//
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// 1. Redistributions of source code must retain the above copyright
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// [License]

#ifndef COMMUNICATIONLISTENER_H_
#define COMMUNICATIONLISTENER_H_

#include "Message.h"
#include "Identifiers.h"
#include "LinkProperties.h"
#include "DataMessage.h"
#include "ariba/overlay/SequenceNumber.h"

namespace ariba {

typedef ariba::overlay::SequenceNumber SequenceNumber;

// forward decl
namespace overlay {
        class BaseOverlay;
        class OverlayMsg;
}

/** \addtogroup public
 * @{
 * Listener for communication events on links.
 */
class CommunicationListener {

        friend class ariba::overlay::BaseOverlay;
        friend class Node;

public:
        static CommunicationListener DEFAULT; //< default implementation

protected:

        /**
         * Construct a communication listener
         */
        CommunicationListener();

        /**
         * Destruct a communication listener
         */
        virtual ~CommunicationListener();

        // --- link events ---

        /**
         * Event called when a link goes up
         * @param lnk The id of the link
         * @param remote The remote node where the link ends
         */
        virtual void onLinkUp(const LinkID& lnk, const NodeID& remote);

        /**
         * Event called when a link goes down
         * @param lnk The id of the link
         * @param remote The remote node where the link ends
         */
        virtual void onLinkDown(const LinkID& lnk, const NodeID& remote);

        /**
         * Event called when a link has changed,
         * e.g. through mobility
         * @param lnk The id of the link
         * @param remote The remote node where the link ends
         */
        virtual void onLinkChanged(const LinkID& lnk, const NodeID& remote);

        /**
         * Event called when a link has failed
         * @param lnk The id of the link
         * @param remote The remote node where the link ends
         */
        virtual void onLinkFail(const LinkID& lnk, const NodeID& remote);

        /**
         * Request from remote node to open up a link
         * @param remote The remote node that requests the new link
         */
        virtual bool onLinkRequest(const NodeID& remote);

        // --- general receive method ---

        /**
         * @DEPRECATED
         * 
         * Called when a message is incoming
         * @param msg The data message that is received
         * @param remote The remote node that sent the message
         * @param lnk The link id of the link where the message is received
         */
        virtual void onMessage(const DataMessage& msg, const NodeID& remote,
                        const LinkID& lnk = LinkID::UNSPECIFIED);


    /**
     * NOTE: This interface is still unstable and may change in future releases.
     *   ---> Especially the parameter «overlay_msg» may be replaced or removed.
     *   
     * Called when a message is incoming
     * @param msg A shared buffer with the (serialized) payload
     * @param remote The remote node that sent the message
     * @param lnk The link id of the link where the message is received
     * @param overlay_msg A pointer to the ariba internal Overlay Message
     */
    virtual void onMessage(reboost::shared_buffer_t message,
            const NodeID& remote,
            const LinkID& lnk,
            const SequenceNumber& seqnum,
            const ariba::overlay::OverlayMsg* overlay_msg);

        // --- dht functionality ---

        /**
         * Called when a key has been resolved in the DHT
         * @param key The key that was requested
         * @param value the data items the key was resolved to
         */
        virtual void onKeyValue( const Data& key, const vector<Data>& value );

    // --- ping pong (routed) ---
    /**
     * Called when a ping message was received.
     * 
     * @param remote Node which sent the ping message
     * @return bool Allows to send a pong message (default: true)
     */
    virtual bool onPing(const NodeID& remote);

    /**
     * Called when a ping message is lost.
     * 
     * NOTE: A ping message could also get lost without notice.
     * 
     * @param remote Node to which the ping message was sent
     */
    virtual void onPingLost(const NodeID& remote);
    
    /**
     * Called when a pong message was received.
     * 
     * @param remote Node which sent the pong message
     */
    virtual void onPong(const NodeID& remote);
};

} // namespace ariba

/** @} */

#endif /* COMMUNICATIONLISTENER_H_ */