source: source/ariba/Node.h@ 2483

// [License]

// The Ariba-Underlay Copyright

//

// Copyright (c) 2008-2009, Institute of Telematics, UniversitÀt Karlsruhe (TH)

//

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// UniversitÀt Karlsruhe (TH)

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// Germany

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// [License]



#ifndef NODE_H_

#define NODE_H_



// forward declarations

namespace ariba {

class Node;

}



#include "Module.h"

#include "Identifiers.h"

#include "SpoVNetProperties.h"

#include "NodeListener.h"

#include "Name.h"

#include "AribaModule.h"

#include "CommunicationListener.h"

#include "DataMessage.h"



namespace ariba {



// forward declaration

namespace interface {

class AribaContext;

class ServiceInterface;

}



/**

 * This class should implement all ariba node functionality.

 *

 * @author Sebastian Mies <mies@tm.uka.de>

 */

class Node: public Module {

public:

        /**

         * Constructs a new node using a given ariba module

         *

         * @param ariba_mod The ariba module

         * @param name The canonical node name of the new node. When NULL a

         *   randomly chosen name is created.

         * @param len The length of the canonical node name or -1, if the name

         *   is a zero-terminated char-string.

         */

        Node(AribaModule& ariba_mod, const Name& node_name = Name::UNSPECIFIED);



        /**

         * Destroys the node. Before destruction some pre-conditions

         * must be met:<br />

         *

         * 1. The node is not part of any SpoVNet <br />

         * 2. All listeners must be unbound from this node <br />

         * 3. The module has been stopped<br />

         */

        ~Node();



        //--- node control ---



        /**

         * This method instructs the node to join a particular spovnet.

         * Callees may bind with a NodeListener to receive events, when

         * a node has been successfully joined.

         *

         * @param vnetId The SpoVNet name

         */

        void join(const Name& name);



        /**

         * This method initiates a new SpoVNet with the given SpoVNetID and

         * parameters.

         *

         * @param name The SpoVNet name

         * @param param The SpoVNet properties

         */

        void initiate(const Name& name, const SpoVNetProperties& parm =

                        SpoVNetProperties::DEFAULT);



        /**

         * This method initiates the leave procedure of this node.

         */

        void leave();



        /**

         * This method is used to bind a node listener to this node.

         *

         * @param listener The node listener

         */

        void bind(NodeListener* listener);



        /**

         * This method is used to unbind a node listener to this node.

         *

         * @param listener The node listener

         */

        void unbind(NodeListener* listener);



        //--- spovnet properties ---



        /**

         * Returns the properties of the spovnet the node has joined.

         *

         * @return The properties of the spovnet the node has joined

         */

        const SpoVNetProperties& getSpoVNetProperties() const;



        /**

         * Returns the spovnet identifier

         *

         * @return The spovnet idenfifier

         */

        const SpoVNetID& getSpoVNetId() const;



        /**

         * Returns true, if the node is part of a spovnet.

         *

         * @return True, if the node is part of a spovnet

         */

        bool isJoined() const;



        //--- addressing ---



        /**

         * Returns the node id of this node if the link id is unspecified or

         * the node id of the remote node.

         *

         * @return The local or the remote node identifier

         */

        const NodeID& getNodeId(const LinkID& lid = LinkID::UNSPECIFIED) const;



        /**

         * Returns the node id to a node name according to the currently joined

         * spovnet (usually derives a node identifier by hashing the name).

         *

         * @return The node identifier to the given name

         */

        NodeID generateNodeId(const Name& name) const;



        /**

         * Returns the name of this node if the link id is unspecified or

         * the node name of the remote node, if known -- otherwise it returns

         * an unspecified name.

         *

         * TODO: RFE -- send request to remote node and inform service.

         *

         * @return A node's name or an unspecified name, if unknown

         */

        const Name getNodeName(const LinkID& lid = LinkID::UNSPECIFIED) const;



        //--- communication ---



        /**

         * Establishes a new link to another node and service with the given

         * link properties. An optional message could be sent with the request.

         *

         * @param nid The remote node identifier

         * @param sid The remote service identifier

         * @param req The required link properties

         * @param msg An optional message that is sent with the request

         * @return A new link id

         */

        LinkID establishLink(const NodeID& nid, const ServiceID& sid,

                        const LinkProperties& req = LinkProperties::DEFAULT,

                        const DataMessage& msg = DataMessage::UNSPECIFIED);



        /**

         * This method drops an established link.

         *

         * @param lnk The link identifier of an active link

         */

        void dropLink(const LinkID& lnk);



        // message sending



        /**

         * Sends a one-shot message to a service. If link properties are specified,

         * the node tries to fulfill those requirements. This may cause the node

         * to first establish a temporary link, second sending the message and last

         * dropping the link. This would result in a small amount of extra latency

         * until the message is delivered. If reliable transport was selected,

         * the method returns a sequence number and a communication event is

         * triggered on message delivery or loss.

         *

         * @param msg The message to be sent

         * @param nid The remote node identifier

         * @param sid The remote service identifier

         * @param req The requirements associated with the message

         * @return A sequence number

         */

        seqnum_t sendMessage(const DataMessage& msg, const NodeID& nid, const ServiceID& sid,

                        const LinkProperties& req = LinkProperties::DEFAULT);



        /**

         * Sends a message via an established link. If reliable transport was

         * selected, the method returns a sequence number and a communication event

         * is triggered on message delivery or loss.

         *

         * @param msg The message to be sent

         * @param lnk The link to be used for sending the message

         */

        seqnum_t sendMessage(const DataMessage& msg, const LinkID& lnk);



        /**

         * Sends a message to all known hosts in the overlay structure

         * the nodes that are reached here depend on the overlay structure.

         *

         * @param msg The message to be send

         * @param sid The id of the service that should receive the message

         */

        void sendBroadcastMessage(const DataMessage& msg, const ServiceID& sid);



        // --- communication listeners ---



        /**

         * Binds a listener to a specifed service identifier.

         * Whenever a link is established/dropped or messages are received the

         * events inside the interface are called.

         *

         * @param listener The listener to be registered

         * @param sid The service identifier

         */

        void bind(CommunicationListener* listener, const ServiceID& sid);



        /**

         * Un-binds a listener from this node.

         *

         * @param The listener to be unbound

         */

        void unbind(CommunicationListener* listener, const ServiceID& sid);



        // --- extension proposal: service directory -- TODO

        // main-idea: use this methods to register groups/rendevous points inside

        // the base overlay via a distributed storage service.

        //

        //void put(const KeyID& key, Message* value);

        //void get(const KeyID& key);

        //-------------------------------------------------------------------------

        //

        // --- optimization proposal: allow direct endpoint descriptor exchange ---

        // main-idea: directly allow exchanging endpoint descriptors to establish

        // links. Depending on the overlay structure used in the base overlay, this

        // allows a node to directly establish links between two nodes when an

        // endpoint descriptor is known.

        //

        //const EndpointDescriptor& getEndpointDescriptor( const LinkID& lid );

        //void sendMessage( EndpointDescriptor& epd, Message* msg );

        //LinkID setupLink( const EndpointDescriptor& endpointDesc,

        //              const LinkProperties& req = LinkProperties::UNSPECIFIED,

        //              const Message* msg = NULL );

        //

        //-------------------------------------------------------------------------



        // --- module implementation ---

        //

        // main-idea: use module properties to configure nodeid, spovnetid etc. and

        // select start/stop procedures. This allows simulations to start a

        // node without manually calling join etc.



        /** @see Module.h */

        void initialize();



        /** @see Module.h */

        void start();



        /** @see Module.h */

        void stop();



        /** @see Module.h */

        string getName() const;



        /** @see Module.h */

        void setProperty(string key, string value);



        /** @see Module.h */

        const string getProperty(string key) const;



        /** @see Module.h */

        const vector<string> getProperties() const;



protected:

        // friends

        friend class AribaModule;



        // member variables

        Name name;              //< node name

        AribaModule& ariba_mod; //< ariba module

        SpoVNetID spovnetId;    //< current spovnet id

        NodeID nodeId;          //< current node id



        // delegates

        interface::AribaContext* context;

        static ServiceID anonymousService;

};



} // namespace ariba



#endif /* NODE_H_ */