source: source/ariba/overlay/modules/onehop/OneHop.cpp @ 3690

// [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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// [License]

#include "OneHop.h"
#include "ariba/overlay/BaseOverlay.h"

#include "ariba/overlay/modules/onehop/messages/OneHopMessage.h"
#include "ariba/overlay/modules/onehop/messages/NodeListingRequest.h"
#include "ariba/overlay/modules/onehop/messages/NodeListingReply.h"

namespace ariba {
namespace overlay {

use_logging_cpp( OneHop );

OneHop::OneHop(BaseOverlay& _baseoverlay, const NodeID& _nodeid, OverlayStructureEvents* _eventsReceiver)
        :       OverlayInterface( _baseoverlay, _nodeid, _eventsReceiver ),
                state           ( OneHopStateInvalid ),
                bootstrapLink   ( LinkID::UNSPECIFIED ),
                pendingLinks    ( 0 ) {

        //
        // insert us as the first node in the overlay
        //
        overlayNodes.insert( make_pair(_nodeid, LinkID::UNSPECIFIED) );
}

OneHop::~OneHop(){
        deleteOverlay();
}

const EndpointDescriptor& OneHop::resolveNode(const NodeID& node){

        OverlayNodeMapping::const_iterator i = overlayNodes.find( node );
        if (i == overlayNodes.end()) return EndpointDescriptor::UNSPECIFIED;

        const EndpointDescriptor& ep = baseoverlay.getEndpointDescriptor( i->second );

        logging_debug( "resolved node " << node.toString() << " to endpoint " << ep.toString() );
        return ep;
}

void OneHop::routeMessage(const NodeID& destnode, Message* msg){

        // in the fullmesh overlay we know every other node
        // so we also have a link to each other node

        logging_debug( "routing message to node " << destnode.toString() );

        OverlayNodeMapping::const_iterator i = overlayNodes.find( destnode );
        if (i == overlayNodes.end()) {
                logging_error( "not able to route message to node " << destnode.toString() );
                return;
        }
        OneHopMessage onehopRoute( OneHopMessage::OneHopMessageTypeRoute );
        onehopRoute.encapsulate(msg);

        baseoverlay.sendMessage( &onehopRoute, i->second );
}

void OneHop::createOverlay() {
        // don't need to bootstrap against ourselfs.
        // the create and join process is completed now.
        logging_info( "creating onehop overlay structure" );
        state = OneHopStateCompleted;
}

void OneHop::deleteOverlay(){

        logging_info( "deleting onehop overlay structure" );
        state = OneHopStateInvalid;
        pendingLinks = 0;
}

OverlayInterface::NodeList OneHop::getKnownNodes() const {

        OverlayInterface::NodeList retlist;

        OverlayNodeMapping::const_iterator i = overlayNodes.begin();
        OverlayNodeMapping::const_iterator iend = overlayNodes.end();

        for( ; i != iend; i++ )
                retlist.push_back( i->first );

        return retlist;
}

void OneHop::joinOverlay(const EndpointDescriptor& bootstrapEp){

        logging_info( "joining onehop overlay structure through end-point " <<
                        (bootstrapEp == EndpointDescriptor::UNSPECIFIED ?
                                        "local" : bootstrapEp.toString()) );

        state = OneHopStateJoinInitiated;
        pendingLinks = 0;

        if( bootstrapEp == EndpointDescriptor::UNSPECIFIED ){

                // we are the initiator and we are to bootstrap against
                // ourselfs. in the onehop overlay this is not an issue
                // and we can just ignore this call.

                state = OneHopStateCompleted;
        } else {
                bootstrapLink = baseoverlay.establishLink( bootstrapEp,
                                        OverlayInterface::OVERLAY_SERVICE_ID );
        }
}

void OneHop::leaveOverlay(){

        logging_info( "leaving onehop overlay structure" );

        // set the state to invalid, this will prevent from
        // handling onLinkDown events, as we are traversing the
        // overlayNodes map and the onLinkDown function is called
        // from the BaseOverlay and OneHop::onLinkDown will also
        // try to access the overlayNodes structure.
        state = OneHopStateInvalid;

        //
        // close all links, this will indicate the other nodes that we left
        //

        OverlayNodeMapping::iterator i = overlayNodes.begin();
        OverlayNodeMapping::iterator iend = overlayNodes.end();

        for( ; i != iend; i++){
                if( i->first != nodeid && i->second != LinkID::UNSPECIFIED )
                        baseoverlay.dropLink( i->second );
        }

        pendingLinks = 0;
}


void OneHop::onLinkDown(const LinkID& lnk, const NodeID& remote){

        // don't handle when we are in state-invalid,
        // see comment in OneHop::leaveOverlay
        if( state == OneHopStateInvalid ) return;

        // node went down, remove from overlay mapping
        logging_debug( "node " << remote.toString() << " left overlay structure" );

        OverlayNodeMapping::iterator i = overlayNodes.begin();
        OverlayNodeMapping::iterator iend = overlayNodes.end();

        for( ; i != iend; i++ ){
                if( i->second == lnk ){
                        overlayNodes.erase( i );
                        break;
                }
        }
}

void OneHop::onLinkUp(const LinkID& lnk, const NodeID& remote){

        //
        // as soon as a link goes up, we always request the node listing.
        // and try to get connections to as much nodes as possible in a greedy way.
        //

        if( lnk != bootstrapLink ){
                if( pendingLinks > 0 )  pendingLinks--;
                if( pendingLinks == 0 ) state = OneHopStateCompleted;
        }

        logging_debug( "link is up, sending out node listing request" );

        NodeListingRequest requestmsg;
        OneHopMessage onemsg( OneHopMessage::OneHopMessageTypeListingRequest );
        onemsg.encapsulate( &requestmsg );

        state = OneHopStateJoinListingRequested;
        baseoverlay.sendMessage( &onemsg, lnk );
}

void OneHop::onMessage(const DataMessage& msg, const NodeID& remote, const LinkID& lnk){

        OneHopMessage* onemsg = msg.getMessage()->convert<OneHopMessage>();
        if( onemsg == NULL ) return;

        //
        // handle node listing request
        //

        if( onemsg->isType( OneHopMessage::OneHopMessageTypeListingRequest ) ){

                NodeListingRequest* request = onemsg->decapsulate<NodeListingRequest>();

                logging_info( "onehop received node listing request from node " << remote.toString() );

                //
                // first, insert the nodes and the link into our mapping
                //

                overlayNodes.insert( make_pair(remote, lnk) );

                //
                // send back a message with all nodes
                // and their current EndpointDescriptor
                //

                OneHopMessage onehopReply( OneHopMessage::OneHopMessageTypeListingReply );
                NodeListingReply listingReply;

                OverlayNodeMapping::iterator i = overlayNodes.begin();
                OverlayNodeMapping::iterator iend = overlayNodes.end();

                logging_debug( "sending out node listing reply with the following items" );

                for( ; i != iend; i++ ){

                        const NodeID node = i->first;
                        const LinkID link = i->second;
                        const EndpointDescriptor& endpoint = baseoverlay.getEndpointDescriptor( link );

                        logging_debug( "node: " + node.toString() + ", endp: " + endpoint.toString());
                        listingReply.add( node, const_cast<EndpointDescriptor*>(new EndpointDescriptor(endpoint)) );
                }

                onehopReply.encapsulate( &listingReply );
                baseoverlay.sendMessage( &onehopReply, lnk );

                //
                // now that we know the node, we can tell the baseoverlay
                // that the node has joined our overlay structure
                //

                eventsReceiver->onNodeJoin( remote );

        } // if( request != NULL )

        //
        // handle node listing reply
        //

        if( onemsg->isType( OneHopMessage::OneHopMessageTypeListingReply) ){

                NodeListingReply* reply = onemsg->decapsulate<NodeListingReply>();

                logging_debug( "received node listing reply from node " << remote.toString()
                                        << " with all overlay nodes. connecting to all of them" );

                //
                // get out all the EndpointDescriptors from the
                // overlay nodes and connect to all nodes where
                // we don't have a link yet
                //

                const NodeListingReply::NodeEndpointList& endpoints = reply->getList();
                logging_debug( "received " << endpoints.size() << " nodes in listing" );
                pendingLinks = 0;

                NodeListingReply::NodeEndpointList::const_iterator i = endpoints.begin();
                NodeListingReply::NodeEndpointList::const_iterator iend = endpoints.end();

                for( ; i != iend; i++ ){

                        //
                        // don't connect to nodes that we already have
                        // a link to and don't connect to ourself
                        //

                        const NodeID& node = (*i).first;
                        if( overlayNodes.find(node) != overlayNodes.end() ) continue;
                        if( node == nodeid ) continue;

                        logging_debug( "building up link to node in overlay " << node.toString() );
                        const LinkID link = baseoverlay.establishLink( *((*i).second),
                                                        OverlayInterface::OVERLAY_SERVICE_ID );

                        overlayNodes.insert( make_pair(node, link) );
                        pendingLinks++;

                } // for( ; i != iend; i++ )

        } // if( reply != NULL )

        if( onemsg->isType( OneHopMessage::OneHopMessageTypeRoute) ){
                logging_debug( "Route message arrived at destination node -> delegate to BaseOverlay" );
                baseoverlay.incomingRouteMessage( onemsg );
        }


}

}} // namespace ariba, overlay