FlowStatMap: Replace RB-tree with btree-indexed vector

src/cargopacket.cpp

@@ -660,7 +660,7 @@ bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationID
 			if (flow_it == ge->flows.end()) {
 				cargo_next = INVALID_STATION;
 			} else {
-				FlowStat new_shares = flow_it->second;
+				FlowStat new_shares = *flow_it;
 				new_shares.ChangeShare(current_station, INT_MIN);
 				StationIDStack excluded = next_station;
 				while (!excluded.IsEmpty() && !new_shares.GetShares()->empty()) {
@@ -676,20 +676,20 @@ bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationID
 			/* Rewrite an invalid source station to some random other one to
 			 * avoid keeping the cargo in the vehicle forever. */
 			if (cp->source == INVALID_STATION && !ge->flows.empty()) {
-				cp->source = ge->flows.begin()->first;
+				cp->source = ge->flows.FirstStationID();
 			}
 			bool restricted = false;
 			FlowStatMap::const_iterator flow_it(ge->flows.find(cp->source));
 			if (flow_it == ge->flows.end()) {
 				cargo_next = INVALID_STATION;
 			} else {
-				cargo_next = flow_it->second.GetViaWithRestricted(restricted);
+				cargo_next = flow_it->GetViaWithRestricted(restricted);
 			}
 			action = VehicleCargoList::ChooseAction(cp, cargo_next, current_station, accepted, next_station);
 			if (restricted && action == MTA_TRANSFER) {
 				/* If the flow is restricted we can't transfer to it. Choose an
 				 * unrestricted one instead. */
-				cargo_next = flow_it->second.GetVia();
+				cargo_next = flow_it->GetVia();
 				action = VehicleCargoList::ChooseAction(cp, cargo_next, current_station, accepted, next_station);
 			}
 		}

src/linkgraph/flowmapper.cpp

@@ -57,7 +57,7 @@ void FlowMapper::Run(LinkGraphJob &job) const
 			 * LinkGraph::Monthly(). */
 			uint runtime = (job.StartDateTicks() / DAY_TICKS) - job.LastCompression() + 1;
 			for (FlowStatMap::iterator i = flows.begin(); i != flows.end(); ++i) {
-				i->second.ScaleToMonthly(runtime);
+				i->ScaleToMonthly(runtime);
 			}
 		}
 		/* Clear paths. */

src/linkgraph/linkgraphjob.cpp

@@ -146,27 +146,30 @@ void LinkGraphJob::FinaliseJob()
 		 * somewhere. Do delete them and also reroute relevant cargo if
 		 * automatic distribution has been turned off for that cargo. */
 		for (FlowStatMap::iterator it(ge.flows.begin()); it != ge.flows.end();) {
-			FlowStatMap::iterator new_it = flows.find(it->first);
+			FlowStatMap::iterator new_it = flows.find(it->GetOrigin());
 			if (new_it == flows.end()) {
 				if (_settings_game.linkgraph.GetDistributionType(this->Cargo()) != DT_MANUAL) {
-					it->second.Invalidate();
+					it->Invalidate();
 					++it;
 				} else {
-					FlowStat shares(INVALID_STATION, 1);
-					it->second.SwapShares(shares);
-					ge.flows.erase(it++);
+					FlowStat shares(INVALID_STATION, INVALID_STATION, 1);
+					it->SwapShares(shares);
+					it = ge.flows.erase(it);
 					for (FlowStat::SharesMap::const_iterator shares_it(shares.GetShares()->begin());
 							shares_it != shares.GetShares()->end(); ++shares_it) {
 						RerouteCargo(st, this->Cargo(), shares_it->second, st->index);
 					}
 				}
 			} else {
-				it->second.SwapShares(new_it->second);
+				it->SwapShares(*new_it);
 				flows.erase(new_it);
 				++it;
 			}
 		}
-		ge.flows.insert(flows.begin(), flows.end());
+		for (FlowStatMap::iterator it(flows.begin()); it != flows.end(); ++it) {
+			ge.flows.insert(std::move(*it));
+		}
+		ge.flows.SortStorage();
 		InvalidateWindowData(WC_STATION_VIEW, st->index, this->Cargo());
 	}
 }

src/linkgraph/mcf.cpp

@@ -187,8 +187,8 @@ public:
 		const FlowStatMap &flows = this->job[node].Flows();
 		FlowStatMap::const_iterator it = flows.find(this->job[source].Station());
 		if (it != flows.end()) {
-			this->it = it->second.GetShares()->begin();
-			this->end = it->second.GetShares()->end();
+			this->it = it->GetShares()->begin();
+			this->end = it->GetShares()->end();
 		} else {
 			this->it = FlowStat::empty_sharesmap.begin();
 			this->end = FlowStat::empty_sharesmap.end();

src/saveload/station_sl.cpp

@@ -523,18 +523,18 @@ static void RealSave_STNN(BaseStation *bst)
 			_num_dests = (uint32)st->goods[i].cargo.Packets()->MapSize();
 			_num_flows = 0;
 			for (FlowStatMap::const_iterator it(st->goods[i].flows.begin()); it != st->goods[i].flows.end(); ++it) {
-				_num_flows += (uint32)it->second.GetShares()->size();
+				_num_flows += (uint32)it->GetShares()->size();
 			}
 			SlObjectSaveFiltered(&st->goods[i], _filtered_goods_desc.data());
 			for (FlowStatMap::const_iterator outer_it(st->goods[i].flows.begin()); outer_it != st->goods[i].flows.end(); ++outer_it) {
-				const FlowStat::SharesMap *shares = outer_it->second.GetShares();
+				const FlowStat::SharesMap *shares = outer_it->GetShares();
 				uint32 sum_shares = 0;
 				FlowSaveLoad flow;
-				flow.source = outer_it->first;
+				flow.source = outer_it->GetOrigin();
 				for (FlowStat::SharesMap::const_iterator inner_it(shares->begin()); inner_it != shares->end(); ++inner_it) {
 					flow.via = inner_it->second;
 					flow.share = inner_it->first - sum_shares;
-					flow.restricted = inner_it->first > outer_it->second.GetUnrestricted();
+					flow.restricted = inner_it->first > outer_it->GetUnrestricted();
 					sum_shares = inner_it->first;
 					assert(flow.share > 0);
 
@@ -610,7 +610,7 @@ static void Load_STNN()
 					if (!IsSavegameVersionBefore(SLV_187)) flow.restricted = (buffer->ReadByte() != 0);
 
 					if (fs == nullptr || prev_source != flow.source) {
-						fs = &(st->goods[i].flows.insert(st->goods[i].flows.end(), std::make_pair(flow.source, FlowStat(flow.via, flow.share, flow.restricted)))->second);
+						fs = &(*(st->goods[i].flows.insert(st->goods[i].flows.end(), FlowStat(flow.source, flow.via, flow.share, flow.restricted))));
 					} else {
 						fs->AppendShare(flow.via, flow.share, flow.restricted);
 					}

src/script/api/script_stationlist.cpp

@@ -195,11 +195,11 @@ void ScriptStationList_CargoPlanned::Add(StationID station_id, CargoID cargo, St
 	FlowStatMap::const_iterator iter = collector.GE()->flows.begin();
 	FlowStatMap::const_iterator end = collector.GE()->flows.end();
 	for (; iter != end; ++iter) {
-		const FlowStat::SharesMap *shares = iter->second.GetShares();
+		const FlowStat::SharesMap *shares = iter->GetShares();
 		uint prev = 0;
 		for (FlowStat::SharesMap::const_iterator flow_iter = shares->begin();
 				flow_iter != shares->end(); ++flow_iter) {
-			collector.Update<Tselector>(iter->first, flow_iter->second, flow_iter->first - prev);
+			collector.Update<Tselector>(iter->GetOrigin(), flow_iter->second, flow_iter->first - prev);
 			prev = flow_iter->first;
 		}
 	}
@@ -265,11 +265,11 @@ ScriptStationList_CargoPlannedFromByVia::ScriptStationList_CargoPlannedFromByVia
 
 	FlowStatMap::const_iterator iter = collector.GE()->flows.find(from);
 	if (iter == collector.GE()->flows.end()) return;
-	const FlowStat::SharesMap *shares = iter->second.GetShares();
+	const FlowStat::SharesMap *shares = iter->GetShares();
 	uint prev = 0;
 	for (FlowStat::SharesMap::const_iterator flow_iter = shares->begin();
 			flow_iter != shares->end(); ++flow_iter) {
-		collector.Update<CS_FROM_BY_VIA>(iter->first, flow_iter->second, flow_iter->first - prev);
+		collector.Update<CS_FROM_BY_VIA>(iter->GetOrigin(), flow_iter->second, flow_iter->first - prev);
 		prev = flow_iter->first;
 	}
 }

src/station_base.h

@@ -24,12 +24,16 @@
 #include "bitmap_type.h"
 #include <map>
 #include <vector>
+#include <iterator>
+#include <functional>
 
 typedef Pool<BaseStation, StationID, 32, 64000> StationPool;
 extern StationPool _station_pool;
 
 static const byte INITIAL_STATION_RATING = 175;
 
+class FlowStatMap;
+
 /**
  * Flow statistics telling how much flow should be sent along a link. This is
  * done by creating "flow shares" and using std::map's upper_bound() method to
@@ -38,6 +42,7 @@ static const byte INITIAL_STATION_RATING = 175;
  * mean anything by itself.
  */
 class FlowStat {
+	friend FlowStatMap;
 public:
 	typedef btree::btree_map<uint32, StationID> SharesMap;
 
@@ -52,15 +57,17 @@ public:
 
 	/**
 	 * Create a FlowStat with an initial entry.
-	 * @param st Station the initial entry refers to.
+	 * @param origin Origin station for this flow.
+	 * @param via Station the initial entry refers to.
 	 * @param flow Amount of flow for the initial entry.
 	 * @param restricted If the flow to be added is restricted.
 	 */
-	inline FlowStat(StationID st, uint flow, bool restricted = false)
+	inline FlowStat(StationID origin, StationID via, uint flow, bool restricted = false)
 	{
 		assert(flow > 0);
-		this->shares[flow] = st;
+		this->shares[flow] = via;
 		this->unrestricted = restricted ? 0 : flow;
+		this->origin = origin;
 	}
 
 	/**
@@ -148,14 +155,66 @@ public:
 
 	void Invalidate();
 
+	inline StationID GetOrigin() const
+	{
+		return this->origin;
+	}
+
 private:
 	SharesMap shares;  ///< Shares of flow to be sent via specified station (or consumed locally).
 	uint unrestricted; ///< Limit for unrestricted shares.
+	StationID origin;
+};
+static_assert(std::is_nothrow_move_constructible<FlowStat>::value, "FlowStat must be nothrow move constructible");
+
+template<typename cv_value, typename cv_container, typename cv_index_iter>
+class FlowStatMapIterator
+{
+	friend FlowStatMap;
+	friend FlowStatMapIterator<FlowStat, FlowStatMap, btree::btree_map<StationID, uint16>::iterator>;
+	friend FlowStatMapIterator<const FlowStat, const FlowStatMap, btree::btree_map<StationID, uint16>::const_iterator>;
+public:
+	typedef FlowStat value_type;
+	typedef cv_value& reference;
+	typedef cv_value* pointer;
+	typedef ptrdiff_t difference_type;
+	typedef std::forward_iterator_tag iterator_category;
+
+	FlowStatMapIterator(cv_container *fsm, cv_index_iter current) :
+		fsm(fsm), current(current) {}
+
+	FlowStatMapIterator(const FlowStatMapIterator<FlowStat, FlowStatMap, btree::btree_map<StationID, uint16>::iterator> &other) :
+		fsm(other.fsm), current(other.current) {}
+
+	reference operator*() const { return this->fsm->flows_storage[this->current->second]; }
+	pointer operator->() const { return &(this->fsm->flows_storage[this->current->second]); }
+
+	FlowStatMapIterator& operator++()
+	{
+		++this->current;
+		return *this;
+	}
+
+	bool operator==(const FlowStatMapIterator& rhs) const { return this->current == rhs.current; }
+	bool operator!=(const FlowStatMapIterator& rhs) const { return !(operator==(rhs)); }
+
+private:
+	cv_container *fsm;
+	cv_index_iter current;
 };
 
 /** Flow descriptions by origin stations. */
-class FlowStatMap : public std::map<StationID, FlowStat> {
+class FlowStatMap {
+	std::vector<FlowStat> flows_storage;
+	btree::btree_map<StationID, uint16> flows_index;
+
 public:
+	using iterator = FlowStatMapIterator<FlowStat, FlowStatMap, btree::btree_map<StationID, uint16>::iterator>;
+	using const_iterator = FlowStatMapIterator<const FlowStat, const FlowStatMap, btree::btree_map<StationID, uint16>::const_iterator>;
+
+	friend iterator;
+	friend const_iterator;
+
 	uint GetFlow() const;
 	uint GetFlowVia(StationID via) const;
 	uint GetFlowFrom(StationID from) const;
@@ -167,6 +226,78 @@ public:
 	void RestrictFlows(StationID via);
 	void ReleaseFlows(StationID via);
 	void FinalizeLocalConsumption(StationID self);
+
+private:
+	btree::btree_map<StationID, uint16>::iterator erase_priv(btree::btree_map<StationID, uint16>::iterator iter)
+	{
+		uint16 index = iter->second;
+		iter = this->flows_index.erase(iter);
+		if (index != this->flows_storage.size() - 1) {
+			this->flows_storage[index] = std::move(this->flows_storage.back());
+			this->flows_index[this->flows_storage[index].GetOrigin()] = index;
+		}
+		this->flows_storage.pop_back();
+		return iter;
+	}
+
+public:
+	iterator begin() { return iterator(this, this->flows_index.begin()); }
+	const_iterator begin() const { return const_iterator(this, this->flows_index.begin()); }
+	iterator end() { return iterator(this, this->flows_index.end()); }
+	const_iterator end() const { return const_iterator(this, this->flows_index.end()); }
+
+	iterator find(StationID from)
+	{
+		return iterator(this, this->flows_index.find(from));
+	}
+	const_iterator find(StationID from) const
+	{
+		return const_iterator(this, this->flows_index.find(from));
+	}
+
+	bool empty() const
+	{
+		return this->flows_index.empty();
+	}
+
+	void erase(StationID st)
+	{
+		auto iter = this->flows_index.find(st);
+		if (iter != this->flows_index.end()) {
+			this->erase_priv(iter);
+		}
+	}
+
+	iterator erase(iterator iter)
+	{
+		return iterator(this, this->erase_priv(iter.current));
+	}
+
+	std::pair<iterator, bool> insert(FlowStat flow_stat)
+	{
+		StationID st = flow_stat.GetOrigin();
+		auto res = this->flows_index.insert(std::pair<StationID, uint16>(st, this->flows_storage.size()));
+		if (res.second) {
+			this->flows_storage.push_back(std::move(flow_stat));
+		}
+		return std::make_pair(iterator(this, res.first), res.second);
+	}
+
+	iterator insert(iterator hint, FlowStat flow_stat)
+	{
+		auto res = this->flows_index.insert(hint.current, std::pair<StationID, uint16>(flow_stat.GetOrigin(), this->flows_storage.size()));
+		if (res->second == this->flows_storage.size()) {
+			this->flows_storage.push_back(std::move(flow_stat));
+		}
+		return iterator(this, res);
+	}
+
+	StationID FirstStationID() const
+	{
+		return this->flows_index.begin()->first;
+	}
+
+	void SortStorage();
 };
 
 /**
@@ -291,7 +422,7 @@ struct GoodsEntry {
 	inline StationID GetVia(StationID source) const
 	{
 		FlowStatMap::const_iterator flow_it(this->flows.find(source));
-		return flow_it != this->flows.end() ? flow_it->second.GetVia() : INVALID_STATION;
+		return flow_it != this->flows.end() ? flow_it->GetVia() : INVALID_STATION;
 	}
 
 	/**
@@ -305,7 +436,7 @@ struct GoodsEntry {
 	inline StationID GetVia(StationID source, StationID excluded, StationID excluded2 = INVALID_STATION) const
 	{
 		FlowStatMap::const_iterator flow_it(this->flows.find(source));
-		return flow_it != this->flows.end() ? flow_it->second.GetVia(excluded, excluded2) : INVALID_STATION;
+		return flow_it != this->flows.end() ? flow_it->GetVia(excluded, excluded2) : INVALID_STATION;
 	}
 };
 

src/station_cmd.cpp

@@ -4866,10 +4866,10 @@ void FlowStatMap::AddFlow(StationID origin, StationID via, uint flow)
 {
 	FlowStatMap::iterator origin_it = this->find(origin);
 	if (origin_it == this->end()) {
-		this->insert(std::make_pair(origin, FlowStat(via, flow)));
+		this->insert(FlowStat(origin, via, flow));
 	} else {
-		origin_it->second.ChangeShare(via, flow);
-		assert(!origin_it->second.GetShares()->empty());
+		origin_it->ChangeShare(via, flow);
+		assert(!origin_it->GetShares()->empty());
 	}
 }
 
@@ -4885,13 +4885,13 @@ void FlowStatMap::PassOnFlow(StationID origin, StationID via, uint flow)
 {
 	FlowStatMap::iterator prev_it = this->find(origin);
 	if (prev_it == this->end()) {
-		FlowStat fs(via, flow);
+		FlowStat fs(origin, via, flow);
 		fs.AppendShare(INVALID_STATION, flow);
-		this->insert(std::make_pair(origin, fs));
+		this->insert(std::move(fs));
 	} else {
-		prev_it->second.ChangeShare(via, flow);
-		prev_it->second.ChangeShare(INVALID_STATION, flow);
-		assert(!prev_it->second.GetShares()->empty());
+		prev_it->ChangeShare(via, flow);
+		prev_it->ChangeShare(INVALID_STATION, flow);
+		assert(!prev_it->GetShares()->empty());
 	}
 }
 
@@ -4902,7 +4902,7 @@ void FlowStatMap::PassOnFlow(StationID origin, StationID via, uint flow)
 void FlowStatMap::FinalizeLocalConsumption(StationID self)
 {
 	for (FlowStatMap::iterator i = this->begin(); i != this->end(); ++i) {
-		FlowStat &fs = i->second;
+		FlowStat &fs = *i;
 		uint local = fs.GetShare(INVALID_STATION);
 		if (local > INT_MAX) { // make sure it fits in an int
 			fs.ChangeShare(self, -INT_MAX);
@@ -4928,11 +4928,11 @@ StationIDStack FlowStatMap::DeleteFlows(StationID via)
 {
 	StationIDStack ret;
 	for (FlowStatMap::iterator f_it = this->begin(); f_it != this->end();) {
-		FlowStat &s_flows = f_it->second;
+		FlowStat &s_flows = *f_it;
 		s_flows.ChangeShare(via, INT_MIN);
 		if (s_flows.GetShares()->empty()) {
-			ret.Push(f_it->first);
-			this->erase(f_it++);
+			ret.Push(f_it->GetOrigin());
+			f_it = this->erase(f_it);
 		} else {
 			++f_it;
 		}
@@ -4947,7 +4947,7 @@ StationIDStack FlowStatMap::DeleteFlows(StationID via)
 void FlowStatMap::RestrictFlows(StationID via)
 {
 	for (FlowStatMap::iterator it = this->begin(); it != this->end(); ++it) {
-		it->second.RestrictShare(via);
+		it->RestrictShare(via);
 	}
 }
 
@@ -4958,7 +4958,7 @@ void FlowStatMap::RestrictFlows(StationID via)
 void FlowStatMap::ReleaseFlows(StationID via)
 {
 	for (FlowStatMap::iterator it = this->begin(); it != this->end(); ++it) {
-		it->second.ReleaseShare(via);
+		it->ReleaseShare(via);
 	}
 }
 
@@ -4970,7 +4970,7 @@ uint FlowStatMap::GetFlow() const
 {
 	uint ret = 0;
 	for (FlowStatMap::const_iterator i = this->begin(); i != this->end(); ++i) {
-		ret += (--(i->second.GetShares()->end()))->first;
+		ret += (--(i->GetShares()->end()))->first;
 	}
 	return ret;
 }
@@ -4984,7 +4984,7 @@ uint FlowStatMap::GetFlowVia(StationID via) const
 {
 	uint ret = 0;
 	for (FlowStatMap::const_iterator i = this->begin(); i != this->end(); ++i) {
-		ret += i->second.GetShare(via);
+		ret += i->GetShare(via);
 	}
 	return ret;
 }
@@ -4998,7 +4998,7 @@ uint FlowStatMap::GetFlowFrom(StationID from) const
 {
 	FlowStatMap::const_iterator i = this->find(from);
 	if (i == this->end()) return 0;
-	return (--(i->second.GetShares()->end()))->first;
+	return (--(i->GetShares()->end()))->first;
 }
 
 /**
@@ -5011,7 +5011,20 @@ uint FlowStatMap::GetFlowFromVia(StationID from, StationID via) const
 {
 	FlowStatMap::const_iterator i = this->find(from);
 	if (i == this->end()) return 0;
-	return i->second.GetShare(via);
+	return i->GetShare(via);
+}
+
+void FlowStatMap::SortStorage()
+{
+	assert(this->flows_storage.size() == this->flows_index.size());
+	std::sort(this->flows_storage.begin(), this->flows_storage.end(), [](const FlowStat &a, const FlowStat &b) -> bool {
+		return a.origin < b.origin;
+	});
+	uint16 index = 0;
+	for (auto &it : this->flows_index) {
+		it.second = index;
+		index++;
+	}
 }
 
 extern const TileTypeProcs _tile_type_station_procs = {

src/station_gui.cpp

@@ -1513,9 +1513,9 @@ struct StationViewWindow : public Window {
 
 		const FlowStatMap &flows = st->goods[i].flows;
 		for (FlowStatMap::const_iterator it = flows.begin(); it != flows.end(); ++it) {
-			StationID from = it->first;
+			StationID from = it->GetOrigin();
 			CargoDataEntry *source_entry = cargo_entry->InsertOrRetrieve(from);
-			const FlowStat::SharesMap *shares = it->second.GetShares();
+			const FlowStat::SharesMap *shares = it->GetShares();
 			uint32 prev_count = 0;
 			for (FlowStat::SharesMap::const_iterator flow_it = shares->begin(); flow_it != shares->end(); ++flow_it) {
 				StationID via = flow_it->second;
@@ -1546,7 +1546,7 @@ struct StationViewWindow : public Window {
 			const FlowStatMap &flowmap = Station::Get(next)->goods[cargo].flows;
 			FlowStatMap::const_iterator map_it = flowmap.find(source);
 			if (map_it != flowmap.end()) {
-				const FlowStat::SharesMap *shares = map_it->second.GetShares();
+				const FlowStat::SharesMap *shares = map_it->GetShares();
 				uint32 prev_count = 0;
 				for (FlowStat::SharesMap::const_iterator i = shares->begin(); i != shares->end(); ++i) {
 					tmp.InsertOrRetrieve(i->second)->Update(i->first - prev_count);
@@ -1596,9 +1596,9 @@ struct StationViewWindow : public Window {
 	{
 		const CargoDataEntry *source_dest = this->cached_destinations.Retrieve(i);
 		for (FlowStatMap::const_iterator it = flows.begin(); it != flows.end(); ++it) {
-			StationID from = it->first;
+			StationID from = it->GetOrigin();
 			const CargoDataEntry *source_entry = source_dest->Retrieve(from);
-			const FlowStat::SharesMap *shares = it->second.GetShares();
+			const FlowStat::SharesMap *shares = it->GetShares();
 			for (FlowStat::SharesMap::const_iterator flow_it = shares->begin(); flow_it != shares->end(); ++flow_it) {
 				const CargoDataEntry *via_entry = source_entry->Retrieve(flow_it->second);
 				for (CargoDataSet::iterator dest_it = via_entry->Begin(); dest_it != via_entry->End(); ++dest_it) {