private void FinishedReset(DijkstraNode current, DijkstraNode prev)
{
if (hitTarget(current))
{
foreach (var tentative in _tentative)
{
tentative.Reset();
}
_tentative.Clear();
if (_cont && _visualise && prev != null)
{
if (_text)
{
Say("A route to the target was found. The algorithm is finished");
}
current.Reset();
}
}
else
{
if (_cont && _visualise && prev != null)
{
if (_text)
{
Say("There are no more nodes in the tentative list. The algorithm is finished");
}
prev.Reset();
}
}
}
/// <summary>
/// Check a neighbour of the current node to see if it needs to be added to the tentative list
/// or the shortest route to it needs to be updated.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void checkNeighbour(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
float newDistance = dist + link.Weight;
try {
//If the new route from root to neighbour is shorter than the old route or there was no old route
//set the current node as the first step towards the root from neighbour
if (_cont && !_tentative.Contains(neighbour))
{
_tentative.AddFirst(neighbour);
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
}
else if (_cont && newDistance <= neighbour.GetDistanceFromRoot(ID))
{
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
}
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
{
VisualisedNode = null;
}
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
//Incase another thread has modified the distance
if (_cont && newDistance < neighbour.GetDistanceFromRoot(ID))
{
neighbour.SetDistanceFromRoot(ID, newDistance, neighbour, link);
}
}
/// <summary>
/// Once the algorithm has finished use the information it has stored to update the routing table.
/// </summary>
private void UpdateRoutingTable()
{
IKeyTable <IMLink> oldTable = ForwardingTable;
foreach (DijkstraNode target in _confirmed)
{
if (target.ID != ID)
{
//Work backwards along the route, starting at the target, until the first hop is found
DijkstraNode prev = target;
while (prev != null && !Equals(prev.GetPrev(ID)))
{
prev = prev.GetPrev(ID);
}
if (prev != null && Links.ContainsKey(prev.ID))
{
IMLink l = Links[prev.ID];
SetRoute(Algorithm, target.ID, l, target.GetDistanceFromRoot(ID));
oldTable.Remove(target.ID);
}
}
}
//Trigger events for any nodes that can no longer be routed to
foreach (IMNodeInternal n in KnownNodes)
{
if (oldTable.ContainsKey(n.ID))
{
RemoveRoute(Algorithm, n.ID);
}
}
}
//public override event ForwardingTableChangeDelegate OnRouteChange;
public override void Stop()
{
if (_visualise && Equals(VisualisedNode))
{
ResetAlgorithm();
_visualise = false;
_text = false;
VisualisedNode = null;
RunAlgorithm(Name + " visualisation stopped. Re-running algorithm silently.", null, false);
}
}
/// <summary>
/// Check whether the target to be routed to has been found.
/// </summary>
/// <param name="current">The current node.</param>
/// <returns>True if the current node is the target node.</returns>
private bool hitTarget(DijkstraNode current)
{
if (!_cont || _target == null)
{
return(false);
}
if (_cont && _text && _visualise && current.ID == _target.ID)
{
Say("Found the shortest route to target " + _target.Name);
}
return(current.ID == _target.ID);
}
/// <summary>
/// The main loop which is the body of the algorithm.
/// Loops through every neighbour of the current node checking to see if they:
/// A. Have been visited before
/// B. Have been visited before but are now a shorter route
/// </summary>
/// <param name="current">The node currently being checked.</param>
/// <param name="prev">The previous node that was checked.</param>
/// <returns>The last node to be checked.</returns>
private void MainLoop(DijkstraNode current, DijkstraNode prev)
{
while (_cont && current != null && !hitTarget(current))
{
//If necessary display text and wait
if (_cont && _text && _visualise)
{
current.Say("4. Iterating through neighbours excluding neighbours in Confirmed");
Pause();
}
//Get the current distance to the target
float dist = current.GetDistanceFromRoot(ID);
foreach (var n in current.Neighbours)
{
IMLink link = current.Links[n.ID];
if (_visualise)
{
_links.AddFirst(link);
}
var neighbour = this.GetAlgNode <DijkstraNode>(n.ID);
if (_cont && !_confirmed.Contains(neighbour))
{
if (_visualise && _text)
{
VisualiseCheckNeighbourText(neighbour, current, dist, link);
}
else if (_visualise)
{
VisualiseCheckNeighbour(neighbour, current, dist, link);
}
checkNeighbour(neighbour, current, dist, link);
}
if (!_cont)
{
break;
}
}
//Store the old previous node
prev = current;
if (_cont && _text && _visualise)
{
Say("Finished iterating through current's (" + current.Name +
"'s) neighbours, getting next current from tentative list");
Pause();
}
//Get the next node to be checked (the one which has the shortest path to it)
current = getNext(current);
}
FinishedReset(current, prev);
}
/// <summary>
/// Visualise the process of choosing the next node. Will output text about what is going on if necessary.
/// </summary>
/// <param name="next">The next node to be current.</param>
/// <param name="prev">The node that was previously current.</param>
private void VisualiseChooseNext(DijkstraNode next, DijkstraNode prev)
{
if (_cont && !next.Equals(this))
{
if (_cont && _text)
{
Say("8. There are nodes in the tentative list. Finding the node in tentative with the smallest cost");
Pause();
}
Pause(3f);
if (_cont && _text)
{
Say("9. new current = " + next.Name + " with cost " + next.GetDistanceFromRoot(ID));
Pause();
Say("10. Adding link between ct (" + prev.Name + ") and new current (" + next.Name + ") to the shortest path");
Pause();
}
}
prev.Reset();
IMLink confirmedLink = next.GetWIPRoute(ID);
if (_cont && confirmedLink != null)
{
Pause(6f);
confirmedLink.Colour = Color.Red;
}
if (_cont && _text)
{
Say((next.Equals(this) ? "2a" : "11a") + ". Adding " +
(next.Equals(this) ? "root" : "new current") + " (" + next.Name + ") to Confirmed");
Pause();
Say((next.Equals(this) ? "2b" : "11b") + ". Setting current to " +
(next.Equals(this) ? "root" : "new current") + " (" + next.Name + ")");
}
next.Reset();
next.Selected = currentGlow;
next.Colour = Color.White;
if (_cont && _text && !next.Equals(this))
{
Pause();
Say("11c. Going to step 4");
Pause();
}
}
/// <summary>
/// Get the next node to be checked. Next node is the node in the tentative list which is closest to the root.
/// </summary>
/// <param name="prev">The node that was previously checked.</param>
/// <returns>The new current node.</returns>
private DijkstraNode getNext(DijkstraNode prev)
{
if (_cont && _tentative.Count > 0)
{
DijkstraNode next = _tentative.OrderBy(node => node.GetDistanceFromRoot(ID)).First();
if (!_cont)
{
return(null);
}
_tentative.Remove(next);
_confirmed.AddLast(next);
if (_cont && _visualise)
{
VisualiseChooseNext(next, prev);
}
return(next);
}
return(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);
}
internal void SetDistanceFromRoot(UUID root, float value, DijkstraNode prevNode, IMLink link)
{
//if (prevNode != null/* && !Links.ContainsKey(prevNode.ID)*/)
// return;
lock (_distances) {
if (_distances.ContainsKey(root))
{
_distances[root] = value;
_prev[root] = prevNode;
}
else
{
_distances.Add(root, value);
_prev.Add(root, prevNode);
}
}
if (prevNode != null)
{
SetWIPRoute(root, link);
}
}
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>
/// Visualises the process of checking a neighbour node.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void VisualiseCheckNeighbour(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
if (!_visualise)
{
return;
}
if (_cont)
{
Pause(4f);
link.Colour = Color.Blue;
Pause(6);
}
try {
if (_cont && !_tentative.Contains(neighbour))
{
neighbour.Selected = tentativeGlow;
Pause(6);
}
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
{
VisualisedNode = null;
}
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
if (_cont)
{
link.Colour = Color.White;
}
}
/// <summary>
/// Check whether the target to be routed to has been found.
/// </summary>
/// <param name="current">The current node.</param>
/// <returns>True if the current node is the target node.</returns>
private bool hitTarget(DijkstraNode current)
{
if (!_cont || _target == null)
return false;
if (_cont && _text && _visualise && current.ID == _target.ID)
Say("Found the shortest route to target " + _target.Name);
return current.ID == _target.ID;
}
/// <summary>
/// Get the next node to be checked. Next node is the node in the tentative list which is closest to the root.
/// </summary>
/// <param name="prev">The node that was previously checked.</param>
/// <returns>The new current node.</returns>
private DijkstraNode getNext(DijkstraNode prev)
{
if (_cont && _tentative.Count > 0) {
DijkstraNode next = _tentative.OrderBy(node => node.GetDistanceFromRoot(ID)).First();
if (!_cont)
return null;
_tentative.Remove(next);
_confirmed.AddLast(next);
if (_cont && _visualise)
VisualiseChooseNext(next, prev);
return next;
}
return null;
}
private void FinishedReset(DijkstraNode current, DijkstraNode prev)
{
if (hitTarget(current)) {
foreach (var tentative in _tentative)
tentative.Reset();
_tentative.Clear();
if (_cont && _visualise && prev != null) {
if (_text)
Say("A route to the target was found. The algorithm is finished");
current.Reset();
}
} else {
if (_cont && _visualise && prev != null) {
if (_text)
Say("There are no more nodes in the tentative list. The algorithm is finished");
prev.Reset();
}
}
}
/// <summary>
/// Check a neighbour of the current node to see if it needs to be added to the tentative list
/// or the shortest route to it needs to be updated.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void checkNeighbour(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
float newDistance = dist + link.Weight;
try {
//If the new route from root to neighbour is shorter than the old route or there was no old route
//set the current node as the first step towards the root from neighbour
if (_cont && !_tentative.Contains(neighbour)) {
_tentative.AddFirst(neighbour);
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
} else if (_cont && newDistance <= neighbour.GetDistanceFromRoot(ID))
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
VisualisedNode = null;
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
//Incase another thread has modified the distance
if (_cont && newDistance < neighbour.GetDistanceFromRoot(ID))
neighbour.SetDistanceFromRoot(ID, newDistance, neighbour, link);
}
internal void SetDistanceFromRoot(UUID root, float value, DijkstraNode prevNode, IMLink link)
{
//if (prevNode != null/* && !Links.ContainsKey(prevNode.ID)*/)
// return;
lock (_distances) {
if (_distances.ContainsKey(root)) {
_distances[root] = value;
_prev[root] = prevNode;
} else {
_distances.Add(root, value);
_prev.Add(root, prevNode);
}
}
if (prevNode != null)
SetWIPRoute(root, link);
}
/// <summary>
/// Visualises the process of checking a neighbour node and prints out text explaining what is happening.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void VisualiseCheckNeighbourText(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
if (!_visualise && !_text)
return;
float newDistance = dist + link.Weight;
if (_cont) {
//if (_cont && _text)
// current.Say("Examining neighbour " + neighbour.Name);
Pause(4f);
link.Colour = Color.Blue;
if (_cont && _text) {
Pause();
current.Say("5. Test cost to " + neighbour.Name + " = " + dist + " + " + link.Weight + " = " +
newDistance);
Pause();
}
Pause(4f);
}
try {
if (_cont && !_tentative.Contains(neighbour)) {
if (_cont && _text)
current.Say(neighbour.Name + " is not in tentative list");
_tentative.AddFirst(neighbour);
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
if (_cont) {
Pause(4f);
neighbour.Selected = tentativeGlow;
if (_cont && _text) {
current.Say("6a. Adding " + neighbour.Name + " to the tentative list");
Pause();
current.Say("6b. " + neighbour.Name + ".cost = test cost (" + newDistance + ")");
}
}
}
//If the new route from root to neighbour is shorter than the old route or there was no old route
//set the current node as the first step towards the root from neighbour
else if (_cont && newDistance <= neighbour.GetDistanceFromRoot(ID)) {
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
if (_cont && _text) {
current.Say(neighbour.Name + ".cost (" + neighbour.GetDistanceFromRoot(ID) + ") > test cost (" +
newDistance + ")");
Pause();
current.Say("7. " + neighbour.Name + ".cost = test cost (" + newDistance + ")");
Pause();
}
}
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
VisualisedNode = null;
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
if (_cont && newDistance < neighbour.GetDistanceFromRoot(ID))
neighbour.SetDistanceFromRoot(ID, newDistance, neighbour, link);
if (_cont) {
Pause(4f);
link.Colour = Color.White;
Pause(6f);
}
}
/// <summary>
/// Visualises the process of checking a neighbour node and prints out text explaining what is happening.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void VisualiseCheckNeighbourText(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
if (!_visualise && !_text)
{
return;
}
float newDistance = dist + link.Weight;
if (_cont)
{
//if (_cont && _text)
// current.Say("Examining neighbour " + neighbour.Name);
Pause(4f);
link.Colour = Color.Blue;
if (_cont && _text)
{
Pause();
current.Say("5. Test cost to " + neighbour.Name + " = " + dist + " + " + link.Weight + " = " +
newDistance);
Pause();
}
Pause(4f);
}
try {
if (_cont && !_tentative.Contains(neighbour))
{
if (_cont && _text)
{
current.Say(neighbour.Name + " is not in tentative list");
}
_tentative.AddFirst(neighbour);
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
if (_cont)
{
Pause(4f);
neighbour.Selected = tentativeGlow;
if (_cont && _text)
{
current.Say("6a. Adding " + neighbour.Name + " to the tentative list");
Pause();
current.Say("6b. " + neighbour.Name + ".cost = test cost (" + newDistance + ")");
}
}
}
//If the new route from root to neighbour is shorter than the old route or there was no old route
//set the current node as the first step towards the root from neighbour
else if (_cont && newDistance <= neighbour.GetDistanceFromRoot(ID))
{
neighbour.SetDistanceFromRoot(ID, newDistance, current, link);
if (_cont && _text)
{
current.Say(neighbour.Name + ".cost (" + neighbour.GetDistanceFromRoot(ID) + ") > test cost (" +
newDistance + ")");
Pause();
current.Say("7. " + neighbour.Name + ".cost = test cost (" + newDistance + ")");
Pause();
}
}
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
{
VisualisedNode = null;
}
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
if (_cont && newDistance < neighbour.GetDistanceFromRoot(ID))
{
neighbour.SetDistanceFromRoot(ID, newDistance, neighbour, link);
}
if (_cont)
{
Pause(4f);
link.Colour = Color.White;
Pause(6f);
}
}
/// <summary>
/// The main loop which is the body of the algorithm.
/// Loops through every neighbour of the current node checking to see if they:
/// A. Have been visited before
/// B. Have been visited before but are now a shorter route
/// </summary>
/// <param name="current">The node currently being checked.</param>
/// <param name="prev">The previous node that was checked.</param>
/// <returns>The last node to be checked.</returns>
private void MainLoop(DijkstraNode current, DijkstraNode prev)
{
while (_cont && current != null && !hitTarget(current)) {
//If necessary display text and wait
if (_cont && _text && _visualise) {
current.Say("4. Iterating through neighbours excluding neighbours in Confirmed");
Pause();
}
//Get the current distance to the target
float dist = current.GetDistanceFromRoot(ID);
foreach (var n in current.Neighbours) {
IMLink link = current.Links[n.ID];
if (_visualise)
_links.AddFirst(link);
var neighbour = this.GetAlgNode<DijkstraNode>(n.ID);
if (_cont && !_confirmed.Contains(neighbour)) {
if (_visualise && _text)
VisualiseCheckNeighbourText(neighbour, current, dist, link);
else if (_visualise)
VisualiseCheckNeighbour(neighbour, current, dist, link);
checkNeighbour(neighbour, current, dist, link);
}
if (!_cont)
break;
}
//Store the old previous node
prev = current;
if (_cont && _text && _visualise) {
Say("Finished iterating through current's (" + current.Name +
"'s) neighbours, getting next current from tentative list");
Pause();
}
//Get the next node to be checked (the one which has the shortest path to it)
current = getNext(current);
}
FinishedReset(current, prev);
}
/// <summary>
/// Visualises the process of checking a neighbour node.
/// </summary>
/// <param name="neighbour">The neighbour to check.</param>
/// <param name="current">The current node.</param>
/// <param name="dist">The distance from the root to the current node.</param>
/// <param name="link">The link between current and neighbour.</param>
private void VisualiseCheckNeighbour(DijkstraNode neighbour, DijkstraNode current, float dist, IMLink link)
{
if (!_visualise)
return;
if (_cont) {
Pause(4f);
link.Colour = Color.Blue;
Pause(6);
}
try {
if (_cont && !_tentative.Contains(neighbour)) {
neighbour.Selected = tentativeGlow;
Pause(6);
}
} catch (KeyNotFoundException e) {
//If the AddLink being checked is no Keyer in the list of links the algorithm needs to stop
_cont = false;
if (_visualise)
VisualisedNode = null;
Logger.Debug("Trying to work with a neighbour (" + neighbour.Name + ") which is not actually connected to " +
current.Name + " (root = " + Name + ")");
}
if (_cont)
link.Colour = Color.White;
}
//public override event ForwardingTableChangeDelegate OnRouteChange;
public override void Stop()
{
if (_visualise && Equals(VisualisedNode)) {
ResetAlgorithm();
_visualise = false;
_text = false;
VisualisedNode = null;
RunAlgorithm(Name + " visualisation stopped. Re-running algorithm silently.", null, false);
}
}
/// <summary>
/// Visualise the process of choosing the next node. Will output text about what is going on if necessary.
/// </summary>
/// <param name="next">The next node to be current.</param>
/// <param name="prev">The node that was previously current.</param>
private void VisualiseChooseNext(DijkstraNode next, DijkstraNode prev)
{
if (_cont && !next.Equals(this)) {
if (_cont && _text) {
Say("8. There are nodes in the tentative list. Finding the node in tentative with the smallest cost");
Pause();
}
Pause(3f);
if (_cont && _text) {
Say("9. new current = " + next.Name + " with cost " + next.GetDistanceFromRoot(ID));
Pause();
Say("10. Adding link between ct (" + prev.Name + ") and new current (" + next.Name + ") to the shortest path");
Pause();
}
}
prev.Reset();
IMLink confirmedLink = next.GetWIPRoute(ID);
if (_cont && confirmedLink != null) {
Pause(6f);
confirmedLink.Colour = Color.Red;
}
if (_cont && _text) {
Say((next.Equals(this) ? "2a" : "11a") + ". Adding " +
(next.Equals(this) ? "root" : "new current") + " (" + next.Name + ") to Confirmed");
Pause();
Say((next.Equals(this) ? "2b" : "11b") + ". Setting current to " +
(next.Equals(this) ? "root" : "new current") + " (" + next.Name + ")");
}
next.Reset();
next.Selected = currentGlow;
next.Colour = Color.White;
if (_cont && _text && !next.Equals(this)) {
Pause();
Say("11c. Going to step 4");
Pause();
}
}
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);
}
