(svn r25362) -Feature: consider cargo waiting at other stations for rating at the origin station

src/cargopacket.cpp

@@ -659,33 +659,53 @@ uint StationCargoList::ShiftCargo(Taction action, StationID next, bool include_i
 /**
  * Truncates where each destination loses roughly the same percentage of its
  * cargo. This is done by randomizing the selection of packets to be removed.
+ * Optionally count the cargo by origin station.
  * @param max_move Maximum amount of cargo to remove.
+ * @param cargo_per_source Container for counting the cargo by origin.
  * @return Amount of cargo actually moved.
  */
-uint StationCargoList::Truncate(uint max_move)
+uint StationCargoList::Truncate(uint max_move, StationCargoAmountMap *cargo_per_source)
 {
 	max_move = min(max_move, this->count);
 	uint prev_count = this->count;
 	uint moved = 0;
+	uint loop = 0;
+	bool do_count = cargo_per_source != NULL;
 	while (max_move > moved) {
 		for (Iterator it(this->packets.begin()); it != this->packets.end();) {
+			CargoPacket *cp = *it;
 			if (prev_count > max_move && RandomRange(prev_count) < prev_count - max_move) {
+				if (do_count && loop == 0) {
+					(*cargo_per_source)[cp->source] += cp->count;
+				}
 				++it;
 				continue;
 			}
-			CargoPacket *cp = *it;
 			uint diff = max_move - moved;
 			if (cp->count > diff) {
-				this->RemoveFromCache(cp, diff);
+				if (diff > 0) {
-				cp->Reduce(diff);
+					this->RemoveFromCache(cp, diff);
-				return moved + diff;
+					cp->Reduce(diff);
+					moved += diff;
+				}
+				if (loop > 0) {
+					if (do_count) (*cargo_per_source)[cp->source] -= diff;
+					return moved;
+				} else {
+					if (do_count) (*cargo_per_source)[cp->source] += cp->count;
+					++it;
+				}
 			} else {
 				it = this->packets.erase(it);
+				if (do_count && loop > 0) {
+					(*cargo_per_source)[cp->source] -= cp->count;
+				}
 				moved += cp->count;
 				this->RemoveFromCache(cp, cp->count);
 				delete cp;
 			}
 		}
+		loop++;
 	}
 	return moved;
 }

src/cargopacket.h

@@ -443,6 +443,7 @@ public:
 };
 
 typedef MultiMap<StationID, CargoPacket *> StationCargoPacketMap;
+typedef std::map<StationID, uint> StationCargoAmountMap;
 
 /**
  * CargoList that is used for stations.
@@ -532,7 +533,7 @@ public:
 
 	uint Reserve(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next);
 	uint Load(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next);
-	uint Truncate(uint max_move = UINT_MAX);
+	uint Truncate(uint max_move = UINT_MAX, StationCargoAmountMap *cargo_per_source = NULL);
 	uint Reroute(uint max_move, StationCargoList *dest, StationID avoid, StationID avoid2, const GoodsEntry *ge);
 
 	/**

src/saveload/station_sl.cpp

@@ -282,6 +282,7 @@ const SaveLoad *GetGoodsDesc()
 		 SLE_CONDVAR(GoodsEntry, link_graph,           SLE_UINT16,                183, SL_MAX_VERSION),
 		 SLE_CONDVAR(GoodsEntry, node,                 SLE_UINT16,                183, SL_MAX_VERSION),
 		SLEG_CONDVAR(            _num_flows,           SLE_UINT32,                183, SL_MAX_VERSION),
+		 SLE_CONDVAR(GoodsEntry, max_waiting_cargo,    SLE_UINT32,                183, SL_MAX_VERSION),
 		SLE_END()
 	};
 

src/station_base.h

@@ -160,7 +160,8 @@ struct GoodsEntry {
 		last_speed(0),
 		last_age(255),
 		link_graph(INVALID_LINK_GRAPH),
-		node(INVALID_NODE)
+		node(INVALID_NODE),
+		max_waiting_cargo(0)
 	{}
 
 	byte acceptance_pickup; ///< Status of this cargo, see #GoodsEntryStatus.
@@ -197,6 +198,7 @@ struct GoodsEntry {
 	LinkGraphID link_graph; ///< Link graph this station belongs to.
 	NodeID node;            ///< ID of node in link graph referring to this goods entry.
 	FlowStatMap flows;      ///< Planned flows through this station.
+	uint max_waiting_cargo; ///< Max cargo from this station waiting at any station.
 
 	/**
 	 * Reports whether a vehicle has ever tried to load the cargo at this station.

src/station_cmd.cpp

@@ -3241,6 +3241,19 @@ static void UpdateStationRating(Station *st)
 			int rating = 0;
 			uint waiting = ge->cargo.TotalCount();
 
+			/* num_dests is at least 1 if there is any cargo as
+			 * INVALID_STATION is also a destination.
+			 */
+			uint num_dests = (uint)ge->cargo.Packets()->MapSize();
+
+			/* Average amount of cargo per next hop, but prefer solitary stations
+			 * with only one or two next hops. They are allowed to have more
+			 * cargo waiting per next hop.
+			 * With manual cargo distribution waiting_avg = waiting / 2 as then
+			 * INVALID_STATION is the only destination.
+			 */
+			uint waiting_avg = waiting / (num_dests + 1);
+
 			if (HasBit(cs->callback_mask, CBM_CARGO_STATION_RATING_CALC)) {
 				/* Perform custom station rating. If it succeeds the speed, days in transit and
 				 * waiting cargo ratings must not be executed. */
@@ -3248,7 +3261,7 @@ static void UpdateStationRating(Station *st)
 				/* NewGRFs expect last speed to be 0xFF when no vehicle has arrived yet. */
 				uint last_speed = ge->HasVehicleEverTriedLoading() ? ge->last_speed : 0xFF;
 
-				uint32 var18 = min(ge->time_since_pickup, 0xFF) | (min(waiting, 0xFFFF) << 8) | (min(last_speed, 0xFF) << 24);
+				uint32 var18 = min(ge->time_since_pickup, 0xFF) | (min(ge->max_waiting_cargo, 0xFFFF) << 8) | (min(last_speed, 0xFF) << 24);
 				/* Convert to the 'old' vehicle types */
 				uint32 var10 = (st->last_vehicle_type == VEH_INVALID) ? 0x0 : (st->last_vehicle_type + 0x10);
 				uint16 callback = GetCargoCallback(CBID_CARGO_STATION_RATING_CALC, var10, var18, cs);
@@ -3273,11 +3286,11 @@ static void UpdateStationRating(Station *st)
 				(rating += 45, waittime > 3) ||
 				(rating += 35, true);
 
-				(rating -= 90, waiting > 1500) ||
+				(rating -= 90, ge->max_waiting_cargo > 1500) ||
-				(rating += 55, waiting > 1000) ||
+				(rating += 55, ge->max_waiting_cargo > 1000) ||
-				(rating += 35, waiting > 600) ||
+				(rating += 35, ge->max_waiting_cargo > 600) ||
-				(rating += 10, waiting > 300) ||
+				(rating += 10, ge->max_waiting_cargo > 300) ||
-				(rating += 20, waiting > 100) ||
+				(rating += 20, ge->max_waiting_cargo > 100) ||
 				(rating += 10, true);
 			}
 
@@ -3295,12 +3308,12 @@ static void UpdateStationRating(Station *st)
 				/* only modify rating in steps of -2, -1, 0, 1 or 2 */
 				ge->rating = rating = or_ + Clamp(Clamp(rating, 0, 255) - or_, -2, 2);
 
-				/* if rating is <= 64 and more than 200 items waiting,
+				/* if rating is <= 64 and more than 100 items waiting on average per destination,
 				 * remove some random amount of goods from the station */
-				if (rating <= 64 && waiting >= 200) {
+				if (rating <= 64 && waiting_avg >= 100) {
 					int dec = Random() & 0x1F;
-					if (waiting < 400) dec &= 7;
+					if (waiting_avg < 200) dec &= 7;
-					waiting -= dec + 1;
+					waiting -= (dec + 1) * num_dests;
 					waiting_changed = true;
 				}
 
@@ -3309,7 +3322,7 @@ static void UpdateStationRating(Station *st)
 					uint32 r = Random();
 					if (rating <= (int)GB(r, 0, 7)) {
 						/* Need to have int, otherwise it will just overflow etc. */
-						waiting = max((int)waiting - (int)GB(r, 8, 2) - 1, 0);
+						waiting = max((int)waiting - (int)((GB(r, 8, 2) - 1) * num_dests), 0);
 						waiting_changed = true;
 					}
 				}
@@ -3332,7 +3345,25 @@ static void UpdateStationRating(Station *st)
 				/* We can't truncate cargo that's already reserved for loading.
 				 * Thus StoredCount() here. */
 				if (waiting_changed && waiting < ge->cargo.AvailableCount()) {
-					ge->cargo.Truncate(ge->cargo.AvailableCount() - waiting);
+					/* Feed back the exact own waiting cargo at this station for the
+					 * next rating calculation. */
+					ge->max_waiting_cargo = 0;
+
+					/* If truncating also punish the source stations' ratings to
+					 * decrease the flow of incoming cargo. */
+
+					StationCargoAmountMap waiting_per_source;
+					ge->cargo.Truncate(ge->cargo.AvailableCount() - waiting, &waiting_per_source);
+					for (StationCargoAmountMap::iterator i(waiting_per_source.begin()); i != waiting_per_source.end(); ++i) {
+						Station *source_station = Station::GetIfValid(i->first);
+						if (source_station == NULL) continue;
+
+						GoodsEntry &source_ge = source_station->goods[cs->Index()];
+						source_ge.max_waiting_cargo = max(source_ge.max_waiting_cargo, i->second);
+					}
+				} else {
+					/* If the average number per next hop is low, be more forgiving. */
+					ge->max_waiting_cargo = waiting_avg;
 				}
 			}
 		}