/// <inhertidoc />
public void TriggerHighlight(string alg, IMNodeInternal target)
{
if (Equals(_globalHighlightTarget) || Equals(_globalHighlightRoot))
{
TriggerHighlightReset();
return;
}
ClearOld();
_globalTargetKey = target.ID;
_globalHighlightTarget = (IMNode)target;
_globalHighlightRoot = this;
_globalHighlightColour = Colour;
_globalHighlightState = HighlghtState.HighlightingSingle;
_highlightState = HighlghtState.HighlightingSingle;
//If there is a route
if (ForwardingTable.ContainsKey(_globalTargetKey))
{
lock (HighlightLock) {
_highlightedLink = ForwardingTable[_globalTargetKey];
_highlightedLink.Colour = _globalHighlightColour;
IMNode node = ForwardingTable[_globalTargetKey].OtherEnd(this);
node.Highlight(this);
}
}
else
{
_highlightedLink = null;
}
}
internal DVNode(IMNodeInternal node, ForwardDelegate forwardMethod, IAsynchQueue queue, IKeyTableFactory tableFactory, int TTL, IConfigSource config)
: base(node, tableFactory, config)
{
_queue = queue;
_forwardMethod = forwardMethod;
this.TTL = TTL;
distanceVector = new DistanceVector();
neighbourVectors = tableFactory.MakeKeyTable <DistanceVector>();
highlightParameters = new Parameters(new object[] { "HColour", node.Colour });
IConfig dvConfig = config.Configs["DV"];
if (dvConfig == null)
{
dvConfig = config.Configs["DistanceVector"];
}
if (dvConfig == null)
{
dvConfig = config.Configs["Algorithm"];
}
if (dvConfig == null)
{
dvConfig = config.Configs[0];
}
_poison = dvConfig.GetBoolean("PoisonReverse", true);
_everPrint = dvConfig.GetBoolean("EverPrint", false);
_alwaysPrint = dvConfig.GetBoolean("AlwaysPrint", false);
highlightPrintText = dvConfig.GetBoolean("HighlightPrint", false);
}
/// <summary>
/// What to do when a packet relevant to the highlight flooding algorithm is received
///
/// If the node has not already received one of the highlight flooding packets flood highlight packets along all links and send a new
/// highlight all packet back towards the source of the received packet
/// </summary>
/// <param name = "packet"></param>
public void HighlightAll(IMNodeInternal hop)
{
if (HighlightingAll)
{
return;
}
lock (HighlightLock) {
_highlightedLink = ForwardingTable.ContainsKey(_globalTargetKey) ? ForwardingTable[_globalTargetKey] : null;
_highlightState = HighlghtState.HighlightingAll;
if (_highlightedLink != null)
{
_highlightedLink.Colour = _globalHighlightColour;
}
foreach (IMLink l in _links)
{
IMNode neighbour = l.OtherEnd(this);
if (!neighbour.Equals(hop))
{
neighbour.HighlightAll(this);
}
}
}
}
public LinkStateNode(IMNodeInternal node, IKeyTableFactory tableFactory, IAsynchQueue dijkstraQ, IAsynchQueue packetQ, ForwardDelegate forwardMethod, IConfigSource config)
: base(node, tableFactory, dijkstraQ, config)
{
_eventQ = packetQ;
_forwardMethod = forwardMethod;
_processedEvents = new HashSet <int>();
OnRouteChange += (alg, target, oldRoute, newRoute, oldDistance, distance) => {
_changed = true;
if (!Model.IsPaused)
{
return;
}
if (oldRoute != null && newRoute != null)
{
Say("Link State changed route to " + target.Name + " from " + oldRoute.OtherEnd(Node).Name + " to " + newRoute.OtherEnd(Node).Name + ".");
}
else if (oldRoute == null)
{
Say("Link State added route to " + target.Name + " via " + newRoute.OtherEnd(Node).Name + " with distance " + distance + ".");
}
else if (newRoute == null)
{
Say("Link State removed route to " + target.Name + ". " + oldRoute.OtherEnd(Node).Name + " is no longer a valid first hop and no other route was found.");
}
else
{
Say("Link State changed weight of route to " + target.Name + " from " + oldDistance + " to " + distance + ".");
}
};
}
internal DVNode(IMNodeInternal node, ForwardDelegate forwardMethod, IAsynchQueue queue, IKeyTableFactory tableFactory, int TTL, IConfigSource config)
: base(node, tableFactory, config)
{
_queue = queue;
_forwardMethod = forwardMethod;
this.TTL = TTL;
distanceVector = new DistanceVector();
neighbourVectors = tableFactory.MakeKeyTable<DistanceVector>();
highlightParameters = new Parameters(new object[] { "HColour", node.Colour });
IConfig dvConfig = config.Configs["DV"];
if (dvConfig == null)
dvConfig = config.Configs["DistanceVector"];
if (dvConfig == null)
dvConfig = config.Configs["Algorithm"];
if (dvConfig == null)
dvConfig = config.Configs[0];
_poison = dvConfig.GetBoolean("PoisonReverse", true);
_everPrint = dvConfig.GetBoolean("EverPrint", false);
_alwaysPrint = dvConfig.GetBoolean("AlwaysPrint", false);
highlightPrintText = dvConfig.GetBoolean("HighlightPrint", false);
}
/// <summary>
/// Initialise a Dijkstra's Packet
/// </summary>
/// <param name = "hop">The node this packet just came from as opposed to its original source</param>
/// <param name = "from">The node the packet was sent from</param>
/// <param name = "to">The node the packet is destined for</param>
/// <param name = "evt">The AddLink along which the packet is currently travelling</param>
/// <param name = "view">The view layer which is used to visualise the packet moving</param>
/// <param name = "visualise">Whether the packet should be visualised</param>
internal LinkStatePacket(IMNodeInternal hop, INode from, INode to, int evt, bool visualise)
: base(from, to, hop, new Parameters(), LinkState.LINK_STATE_NAME, visualise)
{
_event = evt;
Name = "Link IsOn " + Name;
Selected = 1d;
Parameters.Set <bool>("Visualise", visualise);
}
public DVPacket(IMNodeInternal from, INode to, DistanceVector distanceVector, bool visualise = false, int TTL = 51)
: base(from, to, from, new Parameters("Visualise", visualise), DV.DV_NAME, visualise)
{
_distanceVector = distanceVector;
_highlighting = false;
_ttl = TTL - 1;
Name = "Distance Vector " + Name;
Selected = 1d;
}
public MPacket(INode source, INode destination, IMNodeInternal hop, Parameters parameters, string algorithm = null, bool visualise = true)
: base("Packet from " + source.Name + " to " + destination.Name, source.Colour, 0d, parameters)
{
S = source.ID;
D = destination.ID;
Source = source;
Destination = destination;
Hop = hop;
Type = algorithm == null ? PTypes.data : PTypes.Algorithm;
Visualise = Type == PTypes.data || visualise;
Algorithm = algorithm;
}
private void VisualiseAlgorithm(IMNodeInternal target, Parameters parameters)
{
Logger.Debug("Distance vector visualising routing for " + Node.Name + ".");
if (target == null)
{
Node.TriggerHighlightAll(DV.DV_NAME);
}
else
{
Node.TriggerHighlight(DV.DV_NAME, target);
}
}
/// <summary>
/// Initialise the various variables, flags and collections that are used to run the algorithm.
/// </summary>
/// <param name="target">The target being routed to. Null means route to every target.</param>
///
///
private void Init(IMNodeInternal target)
{
_target = _target != null && target == null ? _target : target;
_confirmed.Clear();
_tentative.Clear();
_links.Clear();
_tentative.AddFirst(this);
foreach (DijkstraNode n in this.GetAllNodes <DijkstraNode>())
{
n.SetDistanceFromRoot(ID, float.MaxValue, null, null);
}
_cont = true;
}
protected AbstractAlgorithmNode(IMNodeInternal node, IKeyTableFactory tableFactory, IConfigSource config)
{
AlgCollectionExtension._tableFactory = tableFactory;
Logger = LogManager.GetLogger(GetType());
_node = node;
_table = tableFactory.MakeKeyTable <IMLink>();
_distances = tableFactory.MakeKeyTable <float>();
this.RegisterAlgNode();
Node.OnWeightChange += (link, weight) => WeightChanged(Links[link], IsCurrentAlgorithm && Links[link].Parameters.Get <bool>("Visualise"));
Node.OnLinkAdded += (n, link, parameters) => LinkAdded(link, parameters, IsCurrentAlgorithm && parameters.Get <bool>("Visualise"));
Node.OnLinkRemoved += (n, link, parameters) => LinkRemoved(link, parameters, IsCurrentAlgorithm && parameters.Get <bool>("Visualise"));
}
public MPacket(INode source, INode destination, IMNodeInternal hop, Parameters parameters, string algorithm = null, bool visualise = true)
: base("Packet from " + source.Name + " to " + destination.Name, source.Colour, 0d, parameters)
{
S = source.ID;
D = destination.ID;
Source = source;
Destination = destination;
Hop = hop;
Type = algorithm == null ? PTypes.data : PTypes.Algorithm;
Visualise = Type == PTypes.data || visualise;
Algorithm = algorithm;
}
public DijkstraNode(IMNodeInternal node, IKeyTableFactory tableFactory, IAsynchQueue queue, IConfigSource config)
: base(node, tableFactory, config)
{
_queue = queue;
_distances = tableFactory.MakeKeyTable <float>();
_wipRoute = tableFactory.MakeKeyTable <IMLink>();
_prev = tableFactory.MakeKeyTable <DijkstraNode>();
_confirmed = new LinkedList <DijkstraNode>();
_tentative = new LinkedList <DijkstraNode>();
_links = new LinkedList <IMLink>();
SetDistanceFromRoot(ID, 0f, null, null);
}
internal void RunAlgorithm(string description, IMNodeInternal to, bool visualise)
{
_visualise = visualise;
ResetAlgorithm();
if (_visualise && IsCurrentAlgorithm)
{
_visualiseThread = new Thread(() => RunAlgorithm(to));
_visualiseThread.Name = description;
_visualiseThread.Start();
}
else
{
_queue.QWork(GetType().Name + " " + description, () => RunAlgorithm(to));
}
}
public Distance(IMNodeInternal target, IMNodeInternal hop, IMLink link, float distance)
{
if (target == null)
throw new Exception("Target node must be set when initialising distance to target");
if (hop == null)
throw new Exception("First hop must be set when initialising distance to target");
if (link == null)
throw new Exception("First hop link must be set when initialising distance to target");
//if (distance <= 0)
// throw new AlgorithmException("Distance must be positive when initialising distance to target");
this.target = target;
this.hop = hop;
this.link = link;
this.distance = distance;
}
internal void update(IMNodeInternal hop, IMLink link, float dist)
{
if (hop == null)
{
throw new Exception("First hop must be set when updating distance to target");
}
if (link == null)
{
throw new Exception("First hop link must be set when updating distance to target");
}
//if (distance <= 0)
// throw new AlgorithmException("Distance must be positive when updating distance to target");
this.hop = hop;
this.link = link;
update(dist);
}
private void UpdateRoutes(IMNodeInternal target, IMNodeInternal hop, IMLink link, float dist)
{
if (target.ID.Equals(ID))
{
return;
}
SetRoute(DV.DV_NAME, target.ID, link, dist);
lock (distanceVector)
if (!distanceVector.ContainsKey(target.ID))
{
distanceVector.Add(target.ID, new Distance(target, hop, link, dist));
}
else
{
distanceVector[target.ID].update(hop, link, dist);
}
}
private void RouteChangeListener(string alg, IMNodeInternal target, IMLink oldRoute, IMLink newRoute, float oldDist, float dist)
{
Logger.Debug(Name + " changing route to " + target.Name + ". " + (oldRoute == null ? "No old route" : "Old route: " + oldRoute.Name) + ". " + (newRoute == null ? "No new route" : "New route: " + newRoute.Name));
if (OnForwardingTableChange != null && (oldRoute == null || newRoute == null || !oldRoute.Equals(newRoute) || oldDist != dist))
{
OnForwardingTableChange(ID, ForwardingTableList);
}
//If not highlighting or not highlighting the route that was changed quit
if ((oldRoute != null && newRoute != null && oldRoute.Equals(newRoute)) ||
!GlobalHighlighting ||
!target.Equals(_globalHighlightTarget) ||
(GlobalHighlightingSingle && !HighlightingSingle && !Equals(_globalHighlightRoot)))
{
return;
}
if (oldRoute != null)
{
oldRoute.Reset();
if (HighlightingSingle)
{
oldRoute.OtherEnd(this).ResetHighlight(this);
}
}
if (newRoute != null)
{
newRoute.Colour = _globalHighlightColour;
if (GlobalHighlightingSingle)
{
_highlightState = HighlghtState.HighlightingSingle;
newRoute.OtherEnd(this).Highlight(this);
}
}
else
{
_highlightState = HighlghtState.NotHighlighting;
}
_highlightedLink = newRoute;
}
/// <summary>
/// What to do when notified that it should highlight
///
/// Will highlight the link and forward the packet on if necessary
/// </summary>
/// <param name = "packet">The packet received</param>
public void Highlight(IMNodeInternal hop)
{
_highlightedLink = ForwardingTable.ContainsKey(_globalTargetKey) ? ForwardingTable[_globalTargetKey] : null;
if (HighlightingSingle ||
(_highlightedLink != null && _highlightedLink.OtherEnd(this).Equals(hop)))
{
return;
}
lock (HighlightLock) {
_highlightState = HighlghtState.HighlightingSingle;
if (_highlightedLink != null)
{
_highlightedLink.Colour = _globalHighlightColour;
_highlightedLink.OtherEnd(this).Highlight(this);
}
}
}
public void ResetHighlight(IMNodeInternal hop)
{
if (Equals(_globalHighlightTarget) ||
!Highlighting ||
(_highlightedLink != null && _highlightedLink.OtherEnd(this).Equals(hop)))
{
return;
}
lock (HighlightLock) {
_highlightState = HighlghtState.NotHighlighting;
if (_highlightedLink != null)
{
_highlightedLink.Reset();
_highlightedLink.OtherEnd(this).ResetHighlight(this);
_highlightedLink = null;
}
}
}
public override void VisualiseAlgorithm(UUID to, Parameters parameters)
{
if (Equals(VisualisedNode))
{
ResetAlgorithm();
_visualise = false;
VisualisedNode = null;
return;
}
else if (VisualisedNode != null)
{
VisualisedNode.Stop();
}
IMNodeInternal target = KnownNodes.ContainsKey(to) ? KnownNodes[to] : null;
_text = Dijkstra.AlwaysPrint || (Dijkstra.EverPrint && parameters != null && parameters.Get <bool>("Text"));
VisualisedNode = this;
RunAlgorithm("Visualise Dijkstra's Algorithm", target, true);
}
public Distance(IMNodeInternal target, IMNodeInternal hop, IMLink link, float distance)
{
if (target == null)
{
throw new Exception("Target node must be set when initialising distance to target");
}
if (hop == null)
{
throw new Exception("First hop must be set when initialising distance to target");
}
if (link == null)
{
throw new Exception("First hop link must be set when initialising distance to target");
}
//if (distance <= 0)
// throw new AlgorithmException("Distance must be positive when initialising distance to target");
this.target = target;
this.hop = hop;
this.link = link;
this.distance = distance;
}
/// <inhertidoc />
public void RemoveLink(UUID l, Parameters parameters)
{
if (!Neighbours.ContainsKey(l))
{
throw new Exception("The link to be remove is not a known link.");
}
IMNodeInternal neighbour = _neighbours[l];
IMLink link = _links[neighbour.ID];
link.OnWeightChanged -= _weightDelegate;
lock (_links) {
_links.Remove(neighbour.ID);
_links.Remove(l);
} lock (_neighbours)
_neighbours.Remove(link.ID);
if (OnLinkRemoved != null && !parameters.Get <bool>("Clearing"))
{
OnLinkRemoved(ID, link, parameters);
Logger.Debug(Name + " triggered OnLinkRemoved for '" + link.Name + "'.");
}
}
private void RunAlgorithm(IMNodeInternal to)
{
lock (_runLock) {
Init(to);
if (_visualise)
{
Logger.Debug("Dijkstra visualising routing from " + Name);
}
if (_cont && _text && _visualise)
{
Say("Starting Algorithm");
Say("1. Initialising Confirmed and Tentative lists");
}
DijkstraNode current = getNext(this);
DijkstraNode prev = current;
if (_cont && _text && _visualise)
{
Pause();
Say("3. Cost for root (" + Node.Name + ") = 0");
Pause();
}
MainLoop(current, prev);
//If the algorithm didn't finish prematurely
if (_cont)
{
UpdateRoutingTable();
}
algorithmFinished();
}
}
/// <summary>
/// What to do when notified that it should highlight
///
/// Will highlight the link and forward the packet on if necessary
/// </summary>
/// <param name = "packet">The packet received</param>
public void Highlight(IMNodeInternal hop)
{
_highlightedLink = ForwardingTable.ContainsKey(_globalTargetKey) ? ForwardingTable[_globalTargetKey] : null;
if (HighlightingSingle ||
(_highlightedLink != null && _highlightedLink.OtherEnd(this).Equals(hop)))
return;
lock (HighlightLock) {
_highlightState = HighlghtState.HighlightingSingle;
if (_highlightedLink != null) {
_highlightedLink.Colour = _globalHighlightColour;
_highlightedLink.OtherEnd(this).Highlight(this);
}
}
}
public Distance(Distance distance, IMNodeInternal hop, IMLink link, float hopWeight)
: this(distance.Target, hop, link, distance.Dist + hopWeight)
{
}
internal void update(IMNodeInternal hop, IMLink link, float dist)
{
if (hop == null)
throw new Exception("First hop must be set when updating distance to target");
if (link == null)
throw new Exception("First hop link must be set when updating distance to target");
//if (distance <= 0)
// throw new AlgorithmException("Distance must be positive when updating distance to target");
this.hop = hop;
this.link = link;
update(dist);
}
public IAlgorithmNode MakeNode(IMNodeInternal node, ForwardDelegate forwardMethod)
{
return(new LinkStateNode(node, _tableFactory, _dijkstraQ, _eventQ, forwardMethod, _config));
}
public Distance(Distance distance, IMNodeInternal hop, IMLink link, float hopWeight)
: this(distance.Target, hop, link, distance.Dist + hopWeight)
{
}
public IAlgorithmNode MakeNode(IMNodeInternal node, ForwardDelegate forwardMethod)
{
return new DVNode(node, forwardMethod, _queue, _tableFactory, TTL, _config);
}
public DijkstraNode(IMNodeInternal node, IKeyTableFactory tableFactory, IAsynchQueue queue, IConfigSource config)
: base(node, tableFactory, config)
{
_queue = queue;
_distances = tableFactory.MakeKeyTable<float>();
_wipRoute = tableFactory.MakeKeyTable<IMLink>();
_prev = tableFactory.MakeKeyTable<DijkstraNode>();
_confirmed = new LinkedList<DijkstraNode>();
_tentative = new LinkedList<DijkstraNode>();
_links = new LinkedList<IMLink>();
SetDistanceFromRoot(ID, 0f, null, null);
}
internal void RunAlgorithm(string description, IMNodeInternal to, bool visualise)
{
_visualise = visualise;
ResetAlgorithm();
if (_visualise && IsCurrentAlgorithm) {
_visualiseThread = new Thread(() => RunAlgorithm(to));
_visualiseThread.Name = description;
_visualiseThread.Start();
} else {
_queue.QWork(GetType().Name + " " + description, () => RunAlgorithm(to));
}
}
/// <summary>
/// Initialise the various variables, flags and collections that are used to run the algorithm.
/// </summary>
/// <param name="target">The target being routed to. Null means route to every target.</param>
///
///
private void Init(IMNodeInternal target)
{
_target = _target != null && target == null ? _target : target;
_confirmed.Clear();
_tentative.Clear();
_links.Clear();
_tentative.AddFirst(this);
foreach (DijkstraNode n in this.GetAllNodes<DijkstraNode>())
n.SetDistanceFromRoot(ID, float.MaxValue, null, null);
_cont = true;
}
private void UpdateRoutes(IMNodeInternal target, IMNodeInternal hop, IMLink link, float dist)
{
if (target.ID.Equals(ID))
return;
SetRoute(DV.DV_NAME, target.ID, link, dist);
lock (distanceVector)
if (!distanceVector.ContainsKey(target.ID))
distanceVector.Add(target.ID, new Distance(target, hop, link, dist));
else
distanceVector[target.ID].update(hop, link, dist);
}
/// <summary>
/// Finds the shortest route to a target.
///
/// To start with can be in one of two states:
/// A: No route known
/// B: There is a route known
///
/// Can finish in one of four states
/// 1. There was no route originally and one has been found
/// 2. There is a new, shorter route along a different link
/// 3. The target can no longer be reached but used to be reachable
/// 4. The original route is still shortest but is now a different length
/// 5. The original route is no longer available but a new route was found
/// 6. The original route is still shortest and has not changed
/// 7. The target was not reachable before and is still not reachable
///
/// 1 = Update distance vector, broadcast update, trigger routing table changed event
/// 2 = Update distance vector, broadcast update, trigger routing table changed event
/// 3 = Update distance vector, broadcast update, trigger routing table changed event
/// 4 = Update distance vector, broadcast update, trigger routing table changed event
/// 5 = Update distance vector, broadcast update, trigger routing table changed event
/// 6 = No events triggered
/// 7 = No events triggered
/// </summary>
/// <param name="targetNode"></param>
/// <returns></returns>
private bool findShortestPath(IMNodeInternal targetNode, List<string> changes)
{
UUID target = targetNode.ID;
//oldDist == null indicates initial state A, otherwise initial state B.
Distance oldDist;
lock (distanceVector)
oldDist = distanceVector.ContainsKey(target) ? distanceVector[target].copy() : null;
IKeyTable<DistanceVector> tmpNeighbours = neighbourVectors.Copy();
IMLink link = null;
float dist = float.MaxValue;
if (oldDist != null && oldDist.Link.OtherEnd(ID).Equals(target) && Links.ContainsKey(target)) {
//If there was an old route and target is a neighbour and the link was the link between them use the weight of that link as the starting weight
link = Links[target];
dist = link.Weight;
} else if (oldDist != null && tmpNeighbours.ContainsKey(oldDist.Hop.ID) && tmpNeighbours[oldDist.Hop.ID].ContainsKey(target) && tmpNeighbours[oldDist.Hop.ID][target].Dist > 0f) {
//If there was an old route and it involved routing via a neighbour and that neighbour can still route then take the starting weight as the distance to the neighbour + the distance from the neighbour to the target
link = Links[oldDist.Hop.ID];
dist = tmpNeighbours[oldDist.Hop.ID][target].Dist + link.Weight;
}
//Check every neighbour to see if the weight of the link to that neighbour + the distance the neighbour can achieve to the target is shorter .
foreach (var neighbour in Neighbours) {
var neighbourLink = Links[neighbour.ID];
var neighbourVector = tmpNeighbours.ContainsKey(neighbour.ID) && tmpNeighbours[neighbour.ID].ContainsKey(target) ? tmpNeighbours[neighbour.ID][target] : null;
var neighbourDist = neighbourVector != null ? neighbourLink.Weight + neighbourVector.Dist : float.MaxValue;
//Neighbour vector distance of 0 or less indicates poison reverse or a link to itself
//Also checks to see if the link at the other end is the neighbour and whether the weight of the link is less than the current distance
if ((neighbourVector != null && neighbourVector.Dist > 0 && neighbourDist < dist) ||
neighbour.Equals(targetNode) && neighbourLink.Weight < dist) {
link = neighbourLink;
dist = neighbour.Equals(targetNode) ? link.Weight : neighbourDist;
}
}
if (link == null && oldDist == null)
//Case 5 + 6
return false;
if (link != null && oldDist == null) {
//1. There was no route originally and one has been found
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector added route to " + targetNode.Name + " via " + link.OtherEnd(Node).Name + " with distance " + Math.Round(dist, 2) + ".");
} else if (link == null && oldDist != null) {
//3. The target can no longer be reached but used to be reachable
lock (distanceVector) {
distanceVector.Remove(target);
RemoveRoute(DV.DV_NAME, target);
changes.Add("Distance Vector removed route to " + targetNode.Name + ". " + oldDist.Hop.Name + " is no longer a valid first hop and no other route was found.");
}
} else if (oldDist != null && !link.Equals(oldDist.Link)) {
//2. There is a new, shorter route along a different link
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector changed route to " + targetNode.Name + " from " + oldDist.Hop.Name + " to " + link.OtherEnd(Node).Name + " with distance " + Math.Round(dist, 2) + ".");
} else if (oldDist != null && link.Equals(oldDist.Link) && dist != oldDist.Dist) {
//4. The original route is still shortest but is now a different length
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector changed weight of route to " + targetNode.Name + " from " + Math.Round(oldDist.Dist, 2) + " to " + Math.Round(dist, 2) + ".");
} else
return false;
return true;
}
public IAlgorithmNode MakeNode(IMNodeInternal node, ForwardDelegate forwardMethod)
{
return(new DVNode(node, forwardMethod, _queue, _tableFactory, TTL, _config));
}
private void VisualiseAlgorithm(IMNodeInternal target, Parameters parameters)
{
Logger.Debug("Distance vector visualising routing for " + Node.Name + ".");
if (target == null)
Node.TriggerHighlightAll(DV.DV_NAME);
else
Node.TriggerHighlight(DV.DV_NAME, target);
}
/// <summary>
/// Finds the shortest route to a target.
///
/// To start with can be in one of two states:
/// A: No route known
/// B: There is a route known
///
/// Can finish in one of four states
/// 1. There was no route originally and one has been found
/// 2. There is a new, shorter route along a different link
/// 3. The target can no longer be reached but used to be reachable
/// 4. The original route is still shortest but is now a different length
/// 5. The original route is no longer available but a new route was found
/// 6. The original route is still shortest and has not changed
/// 7. The target was not reachable before and is still not reachable
///
/// 1 = Update distance vector, broadcast update, trigger routing table changed event
/// 2 = Update distance vector, broadcast update, trigger routing table changed event
/// 3 = Update distance vector, broadcast update, trigger routing table changed event
/// 4 = Update distance vector, broadcast update, trigger routing table changed event
/// 5 = Update distance vector, broadcast update, trigger routing table changed event
/// 6 = No events triggered
/// 7 = No events triggered
/// </summary>
/// <param name="targetNode"></param>
/// <returns></returns>
private bool findShortestPath(IMNodeInternal targetNode, List <string> changes)
{
UUID target = targetNode.ID;
//oldDist == null indicates initial state A, otherwise initial state B.
Distance oldDist;
lock (distanceVector)
oldDist = distanceVector.ContainsKey(target) ? distanceVector[target].copy() : null;
IKeyTable <DistanceVector> tmpNeighbours = neighbourVectors.Copy();
IMLink link = null;
float dist = float.MaxValue;
if (oldDist != null && oldDist.Link.OtherEnd(ID).Equals(target) && Links.ContainsKey(target))
{
//If there was an old route and target is a neighbour and the link was the link between them use the weight of that link as the starting weight
link = Links[target];
dist = link.Weight;
}
else if (oldDist != null && tmpNeighbours.ContainsKey(oldDist.Hop.ID) && tmpNeighbours[oldDist.Hop.ID].ContainsKey(target) && tmpNeighbours[oldDist.Hop.ID][target].Dist > 0f)
{
//If there was an old route and it involved routing via a neighbour and that neighbour can still route then take the starting weight as the distance to the neighbour + the distance from the neighbour to the target
link = Links[oldDist.Hop.ID];
dist = tmpNeighbours[oldDist.Hop.ID][target].Dist + link.Weight;
}
//Check every neighbour to see if the weight of the link to that neighbour + the distance the neighbour can achieve to the target is shorter .
foreach (var neighbour in Neighbours)
{
var neighbourLink = Links[neighbour.ID];
var neighbourVector = tmpNeighbours.ContainsKey(neighbour.ID) && tmpNeighbours[neighbour.ID].ContainsKey(target) ? tmpNeighbours[neighbour.ID][target] : null;
var neighbourDist = neighbourVector != null ? neighbourLink.Weight + neighbourVector.Dist : float.MaxValue;
//Neighbour vector distance of 0 or less indicates poison reverse or a link to itself
//Also checks to see if the link at the other end is the neighbour and whether the weight of the link is less than the current distance
if ((neighbourVector != null && neighbourVector.Dist > 0 && neighbourDist < dist) ||
neighbour.Equals(targetNode) && neighbourLink.Weight < dist)
{
link = neighbourLink;
dist = neighbour.Equals(targetNode) ? link.Weight : neighbourDist;
}
}
if (link == null && oldDist == null)
{
//Case 5 + 6
return(false);
}
if (link != null && oldDist == null)
{
//1. There was no route originally and one has been found
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector added route to " + targetNode.Name + " via " + link.OtherEnd(Node).Name + " with distance " + Math.Round(dist, 2) + ".");
}
else if (link == null && oldDist != null)
{
//3. The target can no longer be reached but used to be reachable
lock (distanceVector) {
distanceVector.Remove(target);
RemoveRoute(DV.DV_NAME, target);
changes.Add("Distance Vector removed route to " + targetNode.Name + ". " + oldDist.Hop.Name + " is no longer a valid first hop and no other route was found.");
}
}
else if (oldDist != null && !link.Equals(oldDist.Link))
{
//2. There is a new, shorter route along a different link
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector changed route to " + targetNode.Name + " from " + oldDist.Hop.Name + " to " + link.OtherEnd(Node).Name + " with distance " + Math.Round(dist, 2) + ".");
}
else if (oldDist != null && link.Equals(oldDist.Link) && dist != oldDist.Dist)
{
//4. The original route is still shortest but is now a different length
UpdateRoutes(targetNode, link.OtherEnd(Node), link, dist);
changes.Add("Distance Vector changed weight of route to " + targetNode.Name + " from " + Math.Round(oldDist.Dist, 2) + " to " + Math.Round(dist, 2) + ".");
}
else
{
return(false);
}
return(true);
}
/// <summary>
/// What to do when a packet relevant to the highlight flooding algorithm is received
///
/// If the node has not already received one of the highlight flooding packets flood highlight packets along all links and send a new
/// highlight all packet back towards the source of the received packet
/// </summary>
/// <param name = "packet"></param>
public void HighlightAll(IMNodeInternal hop)
{
if (HighlightingAll) return;
lock (HighlightLock) {
_highlightedLink = ForwardingTable.ContainsKey(_globalTargetKey) ? ForwardingTable[_globalTargetKey] : null;
_highlightState = HighlghtState.HighlightingAll;
if (_highlightedLink != null)
_highlightedLink.Colour = _globalHighlightColour;
foreach (IMLink l in _links) {
IMNode neighbour = l.OtherEnd(this);
if (!neighbour.Equals(hop))
neighbour.HighlightAll(this);
}
}
}
private void RunAlgorithm(IMNodeInternal to)
{
lock (_runLock) {
Init(to);
if (_visualise)
Logger.Debug("Dijkstra visualising routing from " + Name);
if (_cont && _text && _visualise) {
Say("Starting Algorithm");
Say("1. Initialising Confirmed and Tentative lists");
}
DijkstraNode current = getNext(this);
DijkstraNode prev = current;
if (_cont && _text && _visualise) {
Pause();
Say("3. Cost for root (" + Node.Name + ") = 0");
Pause();
}
MainLoop(current, prev);
//If the algorithm didn't finish prematurely
if (_cont)
UpdateRoutingTable();
algorithmFinished();
}
}
public void ResetHighlight(IMNodeInternal hop)
{
if (Equals(_globalHighlightTarget) ||
!Highlighting ||
(_highlightedLink != null && _highlightedLink.OtherEnd(this).Equals(hop)))
return;
lock (HighlightLock) {
_highlightState = HighlghtState.NotHighlighting;
if (_highlightedLink != null) {
_highlightedLink.Reset();
_highlightedLink.OtherEnd(this).ResetHighlight(this);
_highlightedLink = null;
}
}
}
/// <inhertidoc />
public void TriggerHighlight(string alg, IMNodeInternal target)
{
if (Equals(_globalHighlightTarget) || Equals(_globalHighlightRoot)) {
TriggerHighlightReset();
return;
}
ClearOld();
_globalTargetKey = target.ID;
_globalHighlightTarget = (IMNode)target;
_globalHighlightRoot = this;
_globalHighlightColour = Colour;
_globalHighlightState = HighlghtState.HighlightingSingle;
_highlightState = HighlghtState.HighlightingSingle;
//If there is a route
if (ForwardingTable.ContainsKey(_globalTargetKey)) {
lock (HighlightLock) {
_highlightedLink = ForwardingTable[_globalTargetKey];
_highlightedLink.Colour = _globalHighlightColour;
IMNode node = ForwardingTable[_globalTargetKey].OtherEnd(this);
node.Highlight(this);
}
} else
_highlightedLink = null;
}
private void RouteChangeListener(string alg, IMNodeInternal target, IMLink oldRoute, IMLink newRoute, float oldDist, float dist)
{
Logger.Debug(Name + " changing route to " + target.Name + ". " + (oldRoute == null ? "No old route" : "Old route: " + oldRoute.Name) + ". " + (newRoute == null ? "No new route" : "New route: " + newRoute.Name));
if (OnForwardingTableChange != null && (oldRoute == null || newRoute == null || !oldRoute.Equals(newRoute) || oldDist != dist))
OnForwardingTableChange(ID, ForwardingTableList);
//If not highlighting or not highlighting the route that was changed quit
if ((oldRoute != null && newRoute != null && oldRoute.Equals(newRoute)) ||
!GlobalHighlighting ||
!target.Equals(_globalHighlightTarget) ||
(GlobalHighlightingSingle && !HighlightingSingle && !Equals(_globalHighlightRoot)))
return;
if (oldRoute != null) {
oldRoute.Reset();
if (HighlightingSingle)
oldRoute.OtherEnd(this).ResetHighlight(this);
}
if (newRoute != null) {
newRoute.Colour = _globalHighlightColour;
if (GlobalHighlightingSingle) {
_highlightState = HighlghtState.HighlightingSingle;
newRoute.OtherEnd(this).Highlight(this);
}
} else
_highlightState = HighlghtState.NotHighlighting;
_highlightedLink = newRoute;
}
public IAlgorithmNode MakeNode(IMNodeInternal node, ForwardDelegate forwardMethod)
{
return new LinkStateNode(node, _tableFactory, _dijkstraQ, _eventQ, forwardMethod, _config);
}
