Maintain map of vehicle order destinations refcounts, by type

src/economy.cpp

@@ -314,6 +314,8 @@ void ChangeOwnershipOfCompanyItems(Owner old_owner, Owner new_owner)
 		assert(old_owner != _local_company);
 	}
 
+	ClearOrderDestinationRefcountMap();
+
 	Town *t;
 
 	assert(old_owner != new_owner);
@@ -589,6 +591,8 @@ void ChangeOwnershipOfCompanyItems(Owner old_owner, Owner new_owner)
 	/* Change owner of deferred cargo payments */
 	ChangeOwnershipOfCargoPacketDeferredPayments(old_owner, new_owner);
 
+	IntialiseOrderDestinationRefcountMap();
+
 	cur_company.Restore();
 
 	MarkWholeScreenDirty();

src/misc.cpp

@@ -102,6 +102,7 @@ void InitializeGame(uint size_x, uint size_y, bool reset_date, bool reset_settin
 	FreeSignalDependencies();
 
 	ClearZoningCaches();
+	IntialiseOrderDestinationRefcountMap();
 
 	ResetPersistentNewGRFData();
 

src/openttd.cpp

@@ -362,6 +362,7 @@ static void ShutdownGame()
 	FreeSignalDependencies();
 
 	ClearZoningCaches();
+	ClearOrderDestinationRefcountMap();
 
 	/* No NewGRFs were loaded when it was still bootstrapping. */
 	if (_game_mode != GM_BOOTSTRAP) ResetNewGRFData();

src/order_base.h

@@ -24,11 +24,32 @@
 
 #include <memory>
 #include <vector>
+#include "3rdparty/cpp-btree/btree_map.h"
 
 typedef Pool<Order, OrderID, 256, 0xFF0000> OrderPool;
 typedef Pool<OrderList, OrderListID, 128, 64000> OrderListPool;
 extern OrderPool _order_pool;
 extern OrderListPool _orderlist_pool;
+extern btree::btree_map<uint32, uint32> _order_destination_refcount_map;
+extern bool _order_destination_refcount_map_valid;
+
+inline uint32 OrderDestinationRefcountMapKey(DestinationID dest, CompanyID cid, OrderType order_type, VehicleType veh_type)
+{
+	static_assert(sizeof(dest) == 2);
+	static_assert(OT_END <= 16);
+	return (((uint32) dest) << 16) | (((uint32) cid) << 8) | (((uint32) order_type) << 4) | ((uint32) veh_type);
+}
+
+template <typename F> void IterateOrderRefcountMapForDestinationID(DestinationID dest, F handler)
+{
+	for (auto lb = _order_destination_refcount_map.lower_bound(OrderDestinationRefcountMapKey(dest, (CompanyID) 0, (OrderType) 0, (VehicleType) 0)); lb != _order_destination_refcount_map.end(); ++lb) {
+		if (GB(lb->first, 16, 16) != dest) return;
+		if (lb->second && !handler((CompanyID) GB(lb->first, 8, 8), (OrderType) GB(lb->first, 4, 4), (VehicleType) GB(lb->first, 0, 4), lb->second)) return;
+	}
+}
+
+void IntialiseOrderDestinationRefcountMap();
+void ClearOrderDestinationRefcountMap();
 
 struct OrderExtraInfo {
 	uint8 cargo_type_flags[NUM_CARGO] = {}; ///< Load/unload types for each cargo type.

src/order_cmd.cpp

@@ -55,6 +55,47 @@ INSTANTIATE_POOL_METHODS(Order)
 OrderListPool _orderlist_pool("OrderList");
 INSTANTIATE_POOL_METHODS(OrderList)
 
+btree::btree_map<uint32, uint32> _order_destination_refcount_map;
+bool _order_destination_refcount_map_valid = false;
+
+void IntialiseOrderDestinationRefcountMap()
+{
+	ClearOrderDestinationRefcountMap();
+	const Vehicle *v;
+	FOR_ALL_VEHICLES(v) {
+		const Order *order;
+		FOR_VEHICLE_ORDERS(v, order) {
+			if (order->IsType(OT_GOTO_STATION) || order->IsType(OT_GOTO_WAYPOINT) || order->IsType(OT_IMPLICIT)) {
+				_order_destination_refcount_map[OrderDestinationRefcountMapKey(order->GetDestination(), v->owner, order->GetType(), v->type)]++;
+			}
+		}
+	}
+	_order_destination_refcount_map_valid = true;
+}
+
+void ClearOrderDestinationRefcountMap()
+{
+	_order_destination_refcount_map.clear();
+	_order_destination_refcount_map_valid = false;
+}
+
+static void UpdateOrderDestinationRefcount(const Order *order, VehicleType type, Owner owner, int delta)
+{
+	if (order->IsType(OT_GOTO_STATION) || order->IsType(OT_GOTO_WAYPOINT) || order->IsType(OT_IMPLICIT)) {
+		_order_destination_refcount_map[OrderDestinationRefcountMapKey(order->GetDestination(), owner, order->GetType(), type)] += delta;
+	}
+}
+
+inline void RegisterOrderDestination(const Order *order, VehicleType type, Owner owner)
+{
+	if (_order_destination_refcount_map_valid) UpdateOrderDestinationRefcount(order, type, owner, 1);
+}
+
+inline void UnregisterOrderDestination(const Order *order, VehicleType type, Owner owner)
+{
+	if (_order_destination_refcount_map_valid) UpdateOrderDestinationRefcount(order, type, owner, -1);
+}
+
 /** Clean everything up. */
 Order::~Order()
 {
@@ -397,6 +438,9 @@ void OrderList::Initialize(Order *chain, Vehicle *v)
 	this->total_duration = 0;
 	this->order_index.clear();
 
+	VehicleType type = v->type;
+	Owner owner = v->owner;
+
 	for (Order *o = this->first; o != nullptr; o = o->next) {
 		if (!o->IsType(OT_IMPLICIT)) ++this->num_manual_orders;
 		if (!o->IsType(OT_CONDITIONAL)) {
@@ -404,6 +448,7 @@ void OrderList::Initialize(Order *chain, Vehicle *v)
 			this->total_duration += o->GetWaitTime() + o->GetTravelTime();
 		}
 		this->order_index.push_back(o);
+		RegisterOrderDestination(o, type, owner);
 	}
 
 	for (Vehicle *u = this->first_shared->PreviousShared(); u != nullptr; u = u->PreviousShared()) {
@@ -422,7 +467,10 @@ void OrderList::Initialize(Order *chain, Vehicle *v)
 void OrderList::FreeChain(bool keep_orderlist)
 {
 	Order *next;
+	VehicleType type = this->GetFirstSharedVehicle()->type;
+	Owner owner = this->GetFirstSharedVehicle()->owner;
 	for (Order *o = this->first; o != nullptr; o = next) {
+		UnregisterOrderDestination(o, type, owner);
 		next = o->next;
 		delete o;
 	}
@@ -629,6 +677,7 @@ void OrderList::InsertOrderAt(Order *new_order, int index)
 		this->timetable_duration += new_order->GetTimetabledWait() + new_order->GetTimetabledTravel();
 		this->total_duration += new_order->GetWaitTime() + new_order->GetTravelTime();
 	}
+	RegisterOrderDestination(new_order, this->GetFirstSharedVehicle()->type, this->GetFirstSharedVehicle()->owner);
 	this->ReindexOrderList();
 
 	/* We can visit oil rigs and buoys that are not our own. They will be shown in
@@ -664,6 +713,7 @@ void OrderList::DeleteOrderAt(int index)
 		this->timetable_duration -= (to_remove->GetTimetabledWait() + to_remove->GetTimetabledTravel());
 		this->total_duration -= (to_remove->GetWaitTime() + to_remove->GetTravelTime());
 	}
+	UnregisterOrderDestination(to_remove, this->GetFirstSharedVehicle()->type, this->GetFirstSharedVehicle()->owner);
 	delete to_remove;
 	this->ReindexOrderList();
 }