(svn r25898) -Codechange: Add second timestamp for 'restricted links' to all edges.

5 files changed, 104 insertions, 31 deletions

diff --git a/src/linkgraph/linkgraph.cpp b/src/linkgraph/linkgraph.cpp
index 87a95ad18..6bd29c92d 100644
--- a/src/linkgraph/linkgraph.cpp
+++ b/src/linkgraph/linkgraph.cpp
@@ -39,7 +39,8 @@ inline void LinkGraph::BaseEdge::Init(uint distance)
 	this->distance = distance;
 	this->capacity = 0;
 	this->usage = 0;
-	this->last_update = INVALID_DATE;
+	this->last_unrestricted_update = INVALID_DATE;
+	this->last_restricted_update = INVALID_DATE;
 	this->next_edge = INVALID_NODE;
 }
 
@@ -56,7 +57,8 @@ void LinkGraph::ShiftDates(int interval)
 		if (source.last_update != INVALID_DATE) source.last_update += interval;
 		for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
 			BaseEdge &edge = this->edges[node1][node2];
-			if (edge.last_update != INVALID_DATE) edge.last_update += interval;
+			if (edge.last_unrestricted_update != INVALID_DATE) edge.last_unrestricted_update += interval;
+			if (edge.last_restricted_update != INVALID_DATE) edge.last_restricted_update += interval;
 		}
 	}
 }
@@ -178,9 +180,11 @@ NodeID LinkGraph::AddNode(const Station *st)
 }
 
 /**
- * Fill an edge with values from a link.
+ * Fill an edge with values from a link. If usage < capacity set the usage,
+ * otherwise set the restricted or unrestricted update timestamp.
  * @param to Destination node of the link.
  * @param capacity Capacity of the link.
+ * @param usage Usage to be added or REFRESH_UNRESTRICTED or REFRESH_RESTRICTED.
  */
 void LinkGraph::Node::AddEdge(NodeID to, uint capacity, uint usage)
 {
@@ -188,17 +192,32 @@ void LinkGraph::Node::AddEdge(NodeID to, uint capacity, uint usage)
 	BaseEdge &edge = this->edges[to];
 	BaseEdge &first = this->edges[this->index];
 	edge.capacity = capacity;
-	edge.usage = usage == UINT_MAX ? 0 : usage;
 	edge.next_edge = first.next_edge;
 	first.next_edge = to;
-	edge.last_update = _date;
+	switch (usage) {
+		case REFRESH_UNRESTRICTED:
+			edge.last_unrestricted_update = _date;
+			break;
+		case REFRESH_RESTRICTED:
+			edge.last_restricted_update = _date;
+			break;
+		default:
+			edge.usage = usage;
+			break;
+	}
 }
 
+/**
+ * Creates an edge if none exists yet or updates an existing edge.
+ * @param to Target node.
+ * @param capacity Capacity of the link.
+ * @param usage Usage to be added or REFRESH_UNRESTRICTED or REFRESH_RESTRICTED.
+ */
 void LinkGraph::Node::UpdateEdge(NodeID to, uint capacity, uint usage)
 {
 	assert(capacity > 0);
-	assert(usage <= capacity || usage == UINT_MAX);
-	if (this->edges[to].last_update == INVALID_DATE) {
+	assert(usage <= capacity || usage == REFRESH_RESTRICTED || usage == REFRESH_UNRESTRICTED);
+	if (this->edges[to].capacity == 0) {
 		this->AddEdge(to, capacity, usage);
 	} else {
 		(*this)[to].Update(capacity, usage);
@@ -214,7 +233,8 @@ void LinkGraph::Node::RemoveEdge(NodeID to)
 	if (this->index == to) return;
 	BaseEdge &edge = this->edges[to];
 	edge.capacity = 0;
-	edge.last_update = INVALID_DATE;
+	edge.last_unrestricted_update = INVALID_DATE;
+	edge.last_restricted_update = INVALID_DATE;
 	edge.usage = 0;
 
 	NodeID prev = this->index;
@@ -233,24 +253,34 @@ void LinkGraph::Node::RemoveEdge(NodeID to)
 }
 
 /**
- * Create a new edge or update an existing one. If usage is UINT_MAX refresh
- * the edge to have at least the given capacity, otherwise add the capacity.
+ * Create a new edge or update an existing one. If usage is REFRESH_UNRESTRICTED
+ * or REFRESH_RESTRICTED refresh the edge to have at least the given capacity
+ * and also update the respective update timestamp, otherwise add the capacity.
  * @param from Start node of the edge.
  * @param to End node of the edge.
  * @param capacity Capacity to be added/updated.
- * @param usage Usage to be added or UINT_MAX.
+ * @param usage Usage to be added or REFRESH_UNRESTRICTED or REFRESH_RESTRICTED.
  */
 void LinkGraph::Edge::Update(uint capacity, uint usage)
 {
 	assert(this->edge.capacity > 0);
-	if (usage == UINT_MAX) {
+	if (usage > capacity) {
 		this->edge.capacity = max(this->edge.capacity, capacity);
+		switch (usage) {
+			case REFRESH_UNRESTRICTED:
+				this->edge.last_unrestricted_update = _date;
+				break;
+			case REFRESH_RESTRICTED:
+				this->edge.last_restricted_update = _date;
+				break;
+			default:
+				NOT_REACHED();
+				break;
+		}
 	} else {
-		assert(capacity >= usage);
 		this->edge.capacity += capacity;
 		this->edge.usage += usage;
 	}
-	this->edge.last_update = _date;
 }
 
 /**
diff --git a/src/linkgraph/linkgraph.h b/src/linkgraph/linkgraph.h
index 07a6bed95..cad557e19 100644
--- a/src/linkgraph/linkgraph.h
+++ b/src/linkgraph/linkgraph.h
@@ -41,6 +41,22 @@ class LinkGraph : public LinkGraphPool::PoolItem<&_link_graph_pool> {
 public:
 
 	/**
+	 * Special modes for updating links. 'Restricted' means that vehicles with
+	 * 'no loading' orders are serving the link. If a link is only served by
+	 * such vehicles it's 'fully restricted'. This means the link can be used
+	 * by cargo arriving in such vehicles, but not by cargo generated or
+	 * transferring at the source station of the link. In order to find out
+	 * about this condition we keep two update timestamps in each link, one for
+	 * the restricted and one for the unrestricted part of it. If either one
+	 * times out while the other is still valid the link becomes fully
+	 * restricted or fully unrestricted, respectively.
+	 */
+	enum UpdateMode {
+		REFRESH_RESTRICTED = UINT_MAX - 1, ///< Refresh restricted link.
+		REFRESH_UNRESTRICTED = UINT_MAX    ///< Refresh unrestricted link.
+	};
+
+	/**
 	 * Node of the link graph. contains all relevant information from the associated
 	 * station. It's copied so that the link graph job can work on its own data set
 	 * in a separate thread.
@@ -60,11 +76,12 @@ public:
 	 * the column as next_edge.
 	 */
 	struct BaseEdge {
-		uint distance;    ///< Length of the link.
-		uint capacity;    ///< Capacity of the link.
-		uint usage;       ///< Usage of the link.
-		Date last_update; ///< When the link was last updated.
-		NodeID next_edge; ///< Destination of next valid edge starting at the same source node.
+		uint distance;                 ///< Length of the link.
+		uint capacity;                 ///< Capacity of the link.
+		uint usage;                    ///< Usage of the link.
+		Date last_unrestricted_update; ///< When the unrestricted part of the link was last updated.
+		Date last_restricted_update;   ///< When the restricted part of the link was last updated.
+		NodeID next_edge;              ///< Destination of next valid edge starting at the same source node.
 		void Init(uint distance = 0);
 	};
 
@@ -104,10 +121,22 @@ public:
 		uint Distance() const { return this->edge.distance; }
 
 		/**
-		 * Get edge's last update.
+		 * Get the date of the last update to the edge's unrestricted capacity.
+		 * @return Last update.
+		 */
+		Date LastUnrestrictedUpdate() const { return this->edge.last_unrestricted_update; }
+
+		/**
+		 * Get the date of the last update to the edge's restricted capacity.
+		 * @return Last update.
+		 */
+		Date LastRestrictedUpdate() const { return this->edge.last_restricted_update; }
+
+		/**
+		 * Get the date of the last update to any part of the edge's capacity.
 		 * @return Last update.
 		 */
-		Date LastUpdate() const { return this->edge.last_update; }
+		Date LastUpdate() const { return max(this->edge.last_unrestricted_update, this->edge.last_restricted_update); }
 	};
 
 	/**
@@ -285,6 +314,8 @@ public:
 		 */
 		Edge(BaseEdge &edge) : EdgeWrapper<BaseEdge>(edge) {}
 		void Update(uint capacity, uint usage);
+		void Restrict() { this->edge.last_unrestricted_update = INVALID_DATE; }
+		void Release() { this->edge.last_restricted_update = INVALID_DATE; }
 	};
 
 	/**
diff --git a/src/saveload/linkgraph_sl.cpp b/src/saveload/linkgraph_sl.cpp
index f7d2893ce..f0dcb1dd4 100644
--- a/src/saveload/linkgraph_sl.cpp
+++ b/src/saveload/linkgraph_sl.cpp
@@ -118,12 +118,13 @@ static const SaveLoad _node_desc[] = {
  * SaveLoad desc for a link graph edge.
  */
 static const SaveLoad _edge_desc[] = {
-	SLE_VAR(Edge, distance,    SLE_UINT32),
-	SLE_VAR(Edge, capacity,    SLE_UINT32),
-	SLE_VAR(Edge, usage,       SLE_UINT32),
-	SLE_VAR(Edge, last_update, SLE_INT32),
-	SLE_VAR(Edge, next_edge,   SLE_UINT16),
-	SLE_END()
+	    SLE_VAR(Edge, distance,                 SLE_UINT32),
+	    SLE_VAR(Edge, capacity,                 SLE_UINT32),
+	    SLE_VAR(Edge, usage,                    SLE_UINT32),
+	    SLE_VAR(Edge, last_unrestricted_update, SLE_INT32),
+	SLE_CONDVAR(Edge, last_restricted_update,   SLE_INT32, 187, SL_MAX_VERSION),
+	    SLE_VAR(Edge, next_edge,                SLE_UINT16),
+	    SLE_END()
 };
 
 /**
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index acc036636..f8bf61968 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -3417,13 +3417,18 @@ void DeleteStaleLinks(Station *from)
 			Edge edge = it->second;
 			Station *to = Station::Get((*lg)[it->first].Station());
 			assert(to->goods[c].node == it->first);
-			++it; // Do that before removing the node. Anything else may crash.
+			++it; // Do that before removing the edge. Anything else may crash.
 			assert(_date >= edge.LastUpdate());
-			if ((uint)(_date - edge.LastUpdate()) > LinkGraph::MIN_TIMEOUT_DISTANCE +
-					(DistanceManhattan(from->xy, to->xy) >> 2)) {
+			uint timeout = LinkGraph::MIN_TIMEOUT_DISTANCE + (DistanceManhattan(from->xy, to->xy) >> 2);
+			if ((uint)(_date - edge.LastUpdate()) > timeout) {
 				node.RemoveEdge(to->goods[c].node);
 				ge.flows.DeleteFlows(to->index);
 				RerouteCargo(from, c, to->index, from->index);
+			} else if (edge.LastUnrestrictedUpdate() != INVALID_DATE && (uint)(_date - edge.LastUnrestrictedUpdate()) > timeout) {
+				edge.Restrict();
+				RerouteCargo(from, c, to->index, from->index);
+			} else if (edge.LastRestrictedUpdate() != INVALID_DATE && (uint)(_date - edge.LastRestrictedUpdate()) > timeout) {
+				edge.Release();
 			}
 		}
 		assert(_date >= lg->LastCompression());
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 3d9da8447..0abe6689d 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -50,6 +50,7 @@
 #include "tunnel_map.h"
 #include "depot_map.h"
 #include "gamelog.h"
+#include "linkgraph/linkgraph.h"
 
 #include "table/strings.h"
 
@@ -2267,7 +2268,12 @@ uint Vehicle::RefreshNextHopsStats(CapacitiesMap &capacities,
 					if (st != NULL && next_station != INVALID_STATION && next_station != st->index) {
 						for (CapacitiesMap::const_iterator i = capacities.begin(); i != capacities.end(); ++i) {
 							/* Refresh the link and give it a minimum capacity. */
-							if (i->second > 0) IncreaseStats(st, i->first, next_station, i->second, UINT_MAX);
+							if (i->second > 0) {
+								/* A link is at least partly restricted if a
+								 * vehicle can't load at its source. */
+								IncreaseStats(st, i->first, next_station, i->second,
+										(cur->GetLoadType() & OLFB_NO_LOAD) == 0 ? LinkGraph::REFRESH_UNRESTRICTED : LinkGraph::REFRESH_RESTRICTED);
+							}
 						}
 					}
 				}