Codechange: [Linkgraph] Store edges in each node and not in a global matrix.

src/core/span_type.hpp

@@ -94,6 +94,8 @@ public:
 
 	constexpr reference operator[](size_type idx) const { return first[idx]; }
 
+	constexpr pointer data() const noexcept { return first; }
+
 private:
 	pointer first;
 	pointer last;

src/linkgraph/linkgraph.cpp

@@ -23,7 +23,7 @@ INSTANTIATE_POOL_METHODS(LinkGraph)
  * @param st ID of the associated station.
  * @param demand Demand for cargo at the station.
  */
-inline void LinkGraph::BaseNode::Init(TileIndex xy, StationID st, uint demand)
+LinkGraph::BaseNode::BaseNode(TileIndex xy, StationID st, uint demand)
 {
 	this->xy = xy;
 	this->supply = 0;
@@ -35,7 +35,7 @@ inline void LinkGraph::BaseNode::Init(TileIndex xy, StationID st, uint demand)
 /**
  * Create an edge.
  */
-inline void LinkGraph::BaseEdge::Init()
+LinkGraph::BaseEdge::BaseEdge()
 {
 	this->capacity = 0;
 	this->usage = 0;
@@ -57,7 +57,7 @@ void LinkGraph::ShiftDates(int interval)
 		BaseNode &source = this->nodes[node1];
 		if (source.last_update != INVALID_DATE) source.last_update += interval;
 		for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
-			BaseEdge &edge = this->edges[node1][node2];
+			BaseEdge &edge = this->nodes[node1].edges[node2];
 			if (edge.last_unrestricted_update != INVALID_DATE) edge.last_unrestricted_update += interval;
 			if (edge.last_restricted_update != INVALID_DATE) edge.last_restricted_update += interval;
 		}
@@ -70,7 +70,7 @@ void LinkGraph::Compress()
 	for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
 		this->nodes[node1].supply /= 2;
 		for (NodeID node2 = 0; node2 < this->Size(); ++node2) {
-			BaseEdge &edge = this->edges[node1][node2];
+			BaseEdge &edge = this->nodes[node1].edges[node2];
 			if (edge.capacity > 0) {
 				uint new_capacity = std::max(1U, edge.capacity / 2);
 				if (edge.capacity < (1 << 16)) {
@@ -101,10 +101,10 @@ void LinkGraph::Merge(LinkGraph *other)
 		st->goods[this->cargo].link_graph = this->index;
 		st->goods[this->cargo].node = new_node;
 		for (NodeID node2 = 0; node2 < node1; ++node2) {
-			BaseEdge &forward = this->edges[new_node][first + node2];
+			BaseEdge &forward = this->nodes[new_node].edges[first + node2];
-			BaseEdge &backward = this->edges[first + node2][new_node];
+			BaseEdge &backward = this->nodes[first + node2].edges[new_node];
-			forward = other->edges[node1][node2];
+			forward = other->nodes[node1].edges[node2];
-			backward = other->edges[node2][node1];
+			backward = other->nodes[node2].edges[node1];
 			forward.capacity = LinkGraph::Scale(forward.capacity, age, other_age);
 			forward.usage = LinkGraph::Scale(forward.usage, age, other_age);
 			forward.travel_time_sum = LinkGraph::Scale(forward.travel_time_sum, age, other_age);
@@ -114,8 +114,8 @@ void LinkGraph::Merge(LinkGraph *other)
 			backward.travel_time_sum = LinkGraph::Scale(backward.travel_time_sum, age, other_age);
 			if (backward.next_edge != INVALID_NODE) backward.next_edge += first;
 		}
-		BaseEdge &new_start = this->edges[new_node][new_node];
+		BaseEdge &new_start = this->nodes[new_node].edges[new_node];
-		new_start = other->edges[node1][node1];
+		new_start = other->nodes[node1].edges[node1];
 		if (new_start.next_edge != INVALID_NODE) new_start.next_edge += first;
 	}
 	delete other;
@@ -132,7 +132,7 @@ void LinkGraph::RemoveNode(NodeID id)
 	NodeID last_node = this->Size() - 1;
 	for (NodeID i = 0; i <= last_node; ++i) {
 		(*this)[i].RemoveEdge(id);
-		BaseEdge *node_edges = this->edges[i];
+		auto node_edges = this->nodes[i].edges;
 		NodeID prev = i;
 		NodeID next = node_edges[i].next_edge;
 		while (next != INVALID_NODE) {
@@ -150,10 +150,9 @@ void LinkGraph::RemoveNode(NodeID id)
 	 * directly from station goods entries so the order and position must remain. */
 	this->nodes[id] = this->nodes.back();
 	this->nodes.pop_back();
-	this->edges.EraseColumn(id);
+	for (auto &n : this->nodes) {
-	/* Not doing EraseRow here, as having the extra invalid row doesn't hurt
+		n.edges.pop_back();
-	 * and removing it would trigger a lot of memmove. The data has already
+	}
-	 * been copied around in the loop above. */
 }
 
 /**
@@ -169,23 +168,15 @@ NodeID LinkGraph::AddNode(const Station *st)
 	const GoodsEntry &good = st->goods[this->cargo];
 
 	NodeID new_node = this->Size();
-	this->nodes.emplace_back();
+	this->nodes.emplace_back(st->xy, st->index, HasBit(good.status, GoodsEntry::GES_ACCEPTANCE));
-	/* Avoid reducing the height of the matrix as that is expensive and we
-	 * most likely will increase it again later which is again expensive. */
-	this->edges.Resize(new_node + 1U, std::max(new_node + 1U, this->edges.Height()));
 
-	this->nodes[new_node].Init(st->xy, st->index,
+	for (auto &n : this->nodes) {
-			HasBit(good.status, GoodsEntry::GES_ACCEPTANCE));
+		n.edges.resize(this->Size());
-
+	}
-	BaseEdge *new_edges = this->edges[new_node];
 
 	/* Reset the first edge starting at the new node */
-	new_edges[new_node].next_edge = INVALID_NODE;
+	this->nodes[new_node].edges[new_node].next_edge = INVALID_NODE;
 
-	for (NodeID i = 0; i <= new_node; ++i) {
-		new_edges[i].Init();
-		this->edges[i][new_node].Init();
-	}
 	return new_node;
 }
 
@@ -200,8 +191,8 @@ NodeID LinkGraph::AddNode(const Station *st)
 void LinkGraph::Node::AddEdge(NodeID to, uint capacity, uint usage, uint32 travel_time, EdgeUpdateMode mode)
 {
 	assert(this->index != to);
-	BaseEdge &edge = this->edges[to];
+	BaseEdge &edge = this->node.edges[to];
-	BaseEdge &first = this->edges[this->index];
+	BaseEdge &first = this->node.edges[this->index];
 	edge.capacity = capacity;
 	edge.usage = usage;
 	edge.travel_time_sum = static_cast<uint64>(travel_time) * capacity;
@@ -222,7 +213,7 @@ void LinkGraph::Node::UpdateEdge(NodeID to, uint capacity, uint usage, uint32 tr
 {
 	assert(capacity > 0);
 	assert(usage <= capacity);
-	if (this->edges[to].capacity == 0) {
+	if (this->node.edges[to].capacity == 0) {
 		this->AddEdge(to, capacity, usage, travel_time, mode);
 	} else {
 		(*this)[to].Update(capacity, usage, travel_time, mode);
@@ -236,7 +227,7 @@ void LinkGraph::Node::UpdateEdge(NodeID to, uint capacity, uint usage, uint32 tr
 void LinkGraph::Node::RemoveEdge(NodeID to)
 {
 	if (this->index == to) return;
-	BaseEdge &edge = this->edges[to];
+	BaseEdge &edge = this->node.edges[to];
 	edge.capacity = 0;
 	edge.last_unrestricted_update = INVALID_DATE;
 	edge.last_restricted_update = INVALID_DATE;
@@ -244,16 +235,16 @@ void LinkGraph::Node::RemoveEdge(NodeID to)
 	edge.travel_time_sum = 0;
 
 	NodeID prev = this->index;
-	NodeID next = this->edges[this->index].next_edge;
+	NodeID next = this->node.edges[this->index].next_edge;
 	while (next != INVALID_NODE) {
 		if (next == to) {
 			/* Will be removed, skip it. */
-			this->edges[prev].next_edge = edge.next_edge;
+			this->node.edges[prev].next_edge = edge.next_edge;
 			edge.next_edge = INVALID_NODE;
 			break;
 		} else {
 			prev = next;
-			next = this->edges[next].next_edge;
+			next = this->node.edges[next].next_edge;
 		}
 	}
 }
@@ -305,12 +296,9 @@ void LinkGraph::Edge::Update(uint capacity, uint usage, uint32 travel_time, Edge
 void LinkGraph::Init(uint size)
 {
 	assert(this->Size() == 0);
-	this->edges.Resize(size, size);
 	this->nodes.resize(size);
 
-	for (uint i = 0; i < size; ++i) {
+	for (auto &n : this->nodes) {
-		this->nodes[i].Init();
+		n.edges.resize(size);
-		BaseEdge *column = this->edges[i];
-		for (uint j = 0; j < size; ++j) column[j].Init();
 	}
 }

src/linkgraph/linkgraph.h

@@ -12,7 +12,6 @@
 
 #include "../core/pool_type.hpp"
 #include "../core/smallmap_type.hpp"
-#include "../core/smallmatrix_type.hpp"
 #include "../station_base.h"
 #include "../cargotype.h"
 #include "../date_func.h"
@@ -38,21 +37,6 @@ extern LinkGraphPool _link_graph_pool;
  */
 class LinkGraph : public LinkGraphPool::PoolItem<&_link_graph_pool> {
 public:
-
-	/**
-	 * 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.
-	 */
-	struct BaseNode {
-		uint supply;             ///< Supply at the station.
-		uint demand;             ///< Acceptance at the station.
-		StationID station;       ///< Station ID.
-		TileIndex xy;            ///< Location of the station referred to by the node.
-		Date last_update;        ///< When the supply was last updated.
-		void Init(TileIndex xy = INVALID_TILE, StationID st = INVALID_STATION, uint demand = 0);
-	};
-
 	/**
 	 * An edge in the link graph. Corresponds to a link between two stations or at
 	 * least the distance between them. Edges from one node to itself contain the
@@ -66,7 +50,25 @@ public:
 		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();
+
+		BaseEdge();
+	};
+
+	/**
+	 * 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.
+	 */
+	struct BaseNode {
+		uint supply;             ///< Supply at the station.
+		uint demand;             ///< Acceptance at the station.
+		StationID station;       ///< Station ID.
+		TileIndex xy;            ///< Location of the station referred to by the node.
+		Date last_update;        ///< When the supply was last updated.
+
+		std::vector<BaseEdge> edges;
+
+		BaseNode(TileIndex xy = INVALID_TILE, StationID st = INVALID_STATION, uint demand = 0);
 	};
 
 	/**
@@ -125,26 +127,22 @@ public:
 
 	/**
 	 * Wrapper for a node (const or not) allowing retrieval, but no modification.
-	 * @tparam Tedge Actual node class, may be "const BaseNode" or just "BaseNode".
+	 * @tparam Tnode Actual node class, may be "const BaseNode" or just "BaseNode".
-	 * @tparam Tedge Actual edge class, may be "const BaseEdge" or just "BaseEdge".
 	 */
-	template<typename Tnode, typename Tedge>
+	template<typename Tnode>
 	class NodeWrapper {
 	protected:
-		Tnode &node;  ///< Node being wrapped.
+		Tnode &node;       ///< Node being wrapped.
-		Tedge *edges; ///< Outgoing edges for wrapped node.
+		NodeID index;      ///< ID of wrapped node.
-		NodeID index; ///< ID of wrapped node.
 
 	public:
 
 		/**
 		 * Wrap a node.
 		 * @param node Node to be wrapped.
-		 * @param edges Outgoing edges for node to be wrapped.
 		 * @param index ID of node to be wrapped.
 		 */
-		NodeWrapper(Tnode &node, Tedge *edges, NodeID index) : node(node),
+		NodeWrapper(Tnode &node, NodeID index) : node(node), index(index) {}
-			edges(edges), index(index) {}
 
 		/**
 		 * Get supply of wrapped node.
@@ -187,8 +185,8 @@ public:
 	template <class Tedge, class Tedge_wrapper, class Titer>
 	class BaseEdgeIterator {
 	protected:
-		Tedge *base;    ///< Array of edges being iterated.
+		span<Tedge> base; ///< Array of edges being iterated.
-		NodeID current; ///< Current offset in edges array.
+		NodeID current;   ///< Current offset in edges array.
 
 		/**
 		 * A "fake" pointer to enable operator-> on temporaries. As the objects
@@ -218,7 +216,7 @@ public:
 		 * @param base Array of edges to be iterated.
 		 * @param current ID of current node (to locate the first edge).
 		 */
-		BaseEdgeIterator (Tedge *base, NodeID current) :
+		BaseEdgeIterator (span<Tedge> base, NodeID current) :
 			base(base),
 			current(current == INVALID_NODE ? current : base[current].next_edge)
 		{}
@@ -254,7 +252,7 @@ public:
 		template<class Tother>
 		bool operator==(const Tother &other)
 		{
-			return this->base == other.base && this->current == other.current;
+			return this->base.data() == other.base.data() && this->current == other.current;
 		}
 
 		/**
@@ -267,7 +265,7 @@ public:
 		template<class Tother>
 		bool operator!=(const Tother &other)
 		{
-			return this->base != other.base || this->current != other.current;
+			return this->base.data() != other.base.data() || this->current != other.current;
 		}
 
 		/**
@@ -319,7 +317,7 @@ public:
 		 * @param edges Array of edges to be iterated over.
 		 * @param current ID of current edge's end node.
 		 */
-		ConstEdgeIterator(const BaseEdge *edges, NodeID current) :
+		ConstEdgeIterator(span<const BaseEdge> edges, NodeID current) :
 			BaseEdgeIterator<const BaseEdge, ConstEdge, ConstEdgeIterator>(edges, current) {}
 	};
 
@@ -334,7 +332,7 @@ public:
 		 * @param edges Array of edges to be iterated over.
 		 * @param current ID of current edge's end node.
 		 */
-		EdgeIterator(BaseEdge *edges, NodeID current) :
+		EdgeIterator(span<BaseEdge> edges, NodeID current) :
 			BaseEdgeIterator<BaseEdge, Edge, EdgeIterator>(edges, current) {}
 	};
 
@@ -342,16 +340,14 @@ public:
 	 * Constant node class. Only retrieval operations are allowed on both the
 	 * node itself and its edges.
 	 */
-	class ConstNode : public NodeWrapper<const BaseNode, const BaseEdge> {
+	class ConstNode : public NodeWrapper<const BaseNode> {
 	public:
 		/**
 		 * Constructor.
 		 * @param lg LinkGraph to get the node from.
 		 * @param node ID of the node.
 		 */
-		ConstNode(const LinkGraph *lg, NodeID node) :
+		ConstNode(const LinkGraph *lg, NodeID node) : NodeWrapper<const BaseNode>(lg->nodes[node], node) {}
-			NodeWrapper<const BaseNode, const BaseEdge>(lg->nodes[node], lg->edges[node], node)
-		{}
 
 		/**
 		 * Get a ConstEdge. This is not a reference as the wrapper objects are
@@ -359,34 +355,32 @@ public:
 		 * @param to ID of end node of edge.
 		 * @return Constant edge wrapper.
 		 */
-		ConstEdge operator[](NodeID to) const { return ConstEdge(this->edges[to]); }
+		ConstEdge operator[](NodeID to) const { return ConstEdge(this->node.edges[to]); }
 
 		/**
 		 * Get an iterator pointing to the start of the edges array.
 		 * @return Constant edge iterator.
 		 */
-		ConstEdgeIterator Begin() const { return ConstEdgeIterator(this->edges, this->index); }
+		ConstEdgeIterator Begin() const { return ConstEdgeIterator(this->node.edges, this->index); }
 
 		/**
 		 * Get an iterator pointing beyond the end of the edges array.
 		 * @return Constant edge iterator.
 		 */
-		ConstEdgeIterator End() const { return ConstEdgeIterator(this->edges, INVALID_NODE); }
+		ConstEdgeIterator End() const { return ConstEdgeIterator(this->node.edges, INVALID_NODE); }
 	};
 
 	/**
 	 * Updatable node class. The node itself as well as its edges can be modified.
 	 */
-	class Node : public NodeWrapper<BaseNode, BaseEdge> {
+	class Node : public NodeWrapper<BaseNode> {
 	public:
 		/**
 		 * Constructor.
 		 * @param lg LinkGraph to get the node from.
 		 * @param node ID of the node.
 		 */
-		Node(LinkGraph *lg, NodeID node) :
+		Node(LinkGraph *lg, NodeID node) : NodeWrapper<BaseNode>(lg->nodes[node], node) {}
-			NodeWrapper<BaseNode, BaseEdge>(lg->nodes[node], lg->edges[node], node)
-		{}
 
 		/**
 		 * Get an Edge. This is not a reference as the wrapper objects are not
@@ -394,19 +388,19 @@ public:
 		 * @param to ID of end node of edge.
 		 * @return Edge wrapper.
 		 */
-		Edge operator[](NodeID to) { return Edge(this->edges[to]); }
+		Edge operator[](NodeID to) { return Edge(this->node.edges[to]); }
 
 		/**
 		 * Get an iterator pointing to the start of the edges array.
 		 * @return Edge iterator.
 		 */
-		EdgeIterator Begin() { return EdgeIterator(this->edges, this->index); }
+		EdgeIterator Begin() { return EdgeIterator(this->node.edges, this->index); }
 
 		/**
 		 * Get an iterator pointing beyond the end of the edges array.
 		 * @return Constant edge iterator.
 		 */
-		EdgeIterator End() { return EdgeIterator(this->edges, INVALID_NODE); }
+		EdgeIterator End() { return EdgeIterator(this->node.edges, INVALID_NODE); }
 
 		/**
 		 * Update the node's supply and set last_update to the current date.
@@ -442,7 +436,6 @@ public:
 	};
 
 	typedef std::vector<BaseNode> NodeVector;
-	typedef SmallMatrix<BaseEdge> EdgeMatrix;
 
 	/** Minimum effective distance for timeout calculation. */
 	static const uint MIN_TIMEOUT_DISTANCE = 32;
@@ -539,11 +532,11 @@ protected:
 	friend SaveLoadTable GetLinkGraphJobDesc();
 	friend class SlLinkgraphNode;
 	friend class SlLinkgraphEdge;
+	friend class LinkGraphJob;
 
 	CargoID cargo;         ///< Cargo of this component's link graph.
 	Date last_compression; ///< Last time the capacities and supplies were compressed.
 	NodeVector nodes;      ///< Nodes in the component.
-	EdgeMatrix edges;      ///< Edges in the component.
 };
 
 #endif /* LINKGRAPH_H */

src/linkgraph/linkgraphjob.cpp

@@ -180,39 +180,12 @@ LinkGraphJob::~LinkGraphJob()
 void LinkGraphJob::Init()
 {
 	uint size = this->Size();
-	this->nodes.resize(size);
+	this->nodes.reserve(size);
-	this->edges.Resize(size, size);
 	for (uint i = 0; i < size; ++i) {
-		this->nodes[i].Init(this->link_graph[i].Supply());
+		this->nodes.emplace_back(this->link_graph.nodes[i]);
-		EdgeAnnotation *node_edges = this->edges[i];
-		for (uint j = 0; j < size; ++j) {
-			node_edges[j].Init();
-		}
 	}
 }
 
-/**
- * Initialize a linkgraph job edge.
- */
-void LinkGraphJob::EdgeAnnotation::Init()
-{
-	this->demand = 0;
-	this->flow = 0;
-	this->unsatisfied_demand = 0;
-}
-
-/**
- * Initialize a Linkgraph job node. The underlying memory is expected to be
- * freshly allocated, without any constructors having been called.
- * @param supply Initial undelivered supply.
- */
-void LinkGraphJob::NodeAnnotation::Init(uint supply)
-{
-	this->undelivered_supply = supply;
-	new (&this->flows) FlowStatMap;
-	new (&this->paths) PathList;
-}
-
 /**
  * Add this path as a new child to the given base path, thus making this path
  * a "fork" of the base path.

src/linkgraph/linkgraphjob.h

@@ -36,7 +36,6 @@ private:
 		uint demand;             ///< Transport demand between the nodes.
 		uint unsatisfied_demand; ///< Demand over this edge that hasn't been satisfied yet.
 		uint flow;               ///< Planned flow over this edge.
-		void Init();
 	};
 
 	/**
@@ -46,11 +45,16 @@ private:
 		uint undelivered_supply; ///< Amount of supply that hasn't been distributed yet.
 		PathList paths;          ///< Paths through this node, sorted so that those with flow == 0 are in the back.
 		FlowStatMap flows;       ///< Planned flows to other nodes.
-		void Init(uint supply);
+
+		std::vector<EdgeAnnotation> edges;
+
+		NodeAnnotation(const LinkGraph::BaseNode &node) : undelivered_supply(node.supply), paths(), flows()
+		{
+			this->edges.resize(node.edges.size());
+		}
 	};
 
 	typedef std::vector<NodeAnnotation> NodeAnnotationVector;
-	typedef SmallMatrix<EdgeAnnotation> EdgeAnnotationMatrix;
 
 	friend SaveLoadTable GetLinkGraphJobDesc();
 	friend class LinkGraphSchedule;
@@ -61,7 +65,6 @@ protected:
 	std::thread thread;               ///< Thread the job is running in or a default-constructed thread if it's running in the main thread.
 	Date join_date;                   ///< Date when the job is to be joined.
 	NodeAnnotationVector nodes;       ///< Extra node data necessary for link graph calculation.
-	EdgeAnnotationMatrix edges;       ///< Extra edge data necessary for link graph calculation.
 	std::atomic<bool> job_completed;  ///< Is the job still running. This is accessed by multiple threads and reads may be stale.
 	std::atomic<bool> job_aborted;    ///< Has the job been aborted. This is accessed by multiple threads and reads may be stale.
 
@@ -146,7 +149,7 @@ public:
 	 * Iterator for job edges.
 	 */
 	class EdgeIterator : public LinkGraph::BaseEdgeIterator<const LinkGraph::BaseEdge, Edge, EdgeIterator> {
-		EdgeAnnotation *base_anno; ///< Array of annotations to be (indirectly) iterated.
+		span<EdgeAnnotation> base_anno; ///< Array of annotations to be (indirectly) iterated.
 	public:
 		/**
 		 * Constructor.
@@ -154,10 +157,14 @@ public:
 		 * @param base_anno Array of annotations to be iterated.
 		 * @param current Start offset of iteration.
 		 */
-		EdgeIterator(const LinkGraph::BaseEdge *base, EdgeAnnotation *base_anno, NodeID current) :
+		EdgeIterator(span<const LinkGraph::BaseEdge> base, span<EdgeAnnotation> base_anno, NodeID current) :
 				LinkGraph::BaseEdgeIterator<const LinkGraph::BaseEdge, Edge, EdgeIterator>(base, current),
 				base_anno(base_anno) {}
 
+		EdgeIterator() :
+				LinkGraph::BaseEdgeIterator<const LinkGraph::BaseEdge, Edge, EdgeIterator>(span<const LinkGraph::BaseEdge>(), INVALID_NODE),
+				base_anno() {}
+
 		/**
 		 * Dereference.
 		 * @return Pair of the edge currently pointed to and the ID of its
@@ -184,8 +191,8 @@ public:
 	 */
 	class Node : public LinkGraph::ConstNode {
 	private:
-		NodeAnnotation &node_anno;  ///< Annotation being wrapped.
+		NodeAnnotation       &node_anno; ///< Annotation being wrapped.
-		EdgeAnnotation *edge_annos; ///< Edge annotations belonging to this node.
+		span<EdgeAnnotation> edge_annos; ///< Edge annotations belonging to this node.
 	public:
 
 		/**
@@ -195,7 +202,7 @@ public:
 		 */
 		Node (LinkGraphJob *lgj, NodeID node) :
 			LinkGraph::ConstNode(&lgj->link_graph, node),
-			node_anno(lgj->nodes[node]), edge_annos(lgj->edges[node])
+			node_anno(lgj->nodes[node]), edge_annos(lgj->nodes[node].edges)
 		{}
 
 		/**
@@ -204,21 +211,21 @@ public:
 		 * @param to Remote end of the edge.
 		 * @return Edge between this node and "to".
 		 */
-		Edge operator[](NodeID to) const { return Edge(this->edges[to], this->edge_annos[to]); }
+		Edge operator[](NodeID to) const { return Edge(this->node.edges[to], this->edge_annos[to]); }
 
 		/**
 		 * Iterator for the "begin" of the edge array. Only edges with capacity
 		 * are iterated. The others are skipped.
 		 * @return Iterator pointing to the first edge.
 		 */
-		EdgeIterator Begin() const { return EdgeIterator(this->edges, this->edge_annos, index); }
+		EdgeIterator Begin() const { return EdgeIterator(this->node.edges, this->edge_annos, index); }
 
 		/**
 		 * Iterator for the "end" of the edge array. Only edges with capacity
 		 * are iterated. The others are skipped.
 		 * @return Iterator pointing beyond the last edge.
 		 */
-		EdgeIterator End() const { return EdgeIterator(this->edges, this->edge_annos, INVALID_NODE); }
+		EdgeIterator End() const { return EdgeIterator(this->node.edges, this->edge_annos, INVALID_NODE); }
 
 		/**
 		 * Get amount of supply that hasn't been delivered, yet.

src/linkgraph/mcf.cpp

@@ -103,9 +103,7 @@ public:
 	 * Construct a GraphEdgeIterator.
 	 * @param job Job to iterate on.
 	 */
-	GraphEdgeIterator(LinkGraphJob &job) : job(job),
+	GraphEdgeIterator(LinkGraphJob &job) : job(job), i(), end() {}
-		i(nullptr, nullptr, INVALID_NODE), end(nullptr, nullptr, INVALID_NODE)
-	{}
 
 	/**
 	 * Setup the node to start iterating at.

src/saveload/linkgraph_sl.cpp

@@ -43,24 +43,25 @@ public:
 	void Save(Node *bn) const override
 	{
 		uint16 size = 0;
-		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->edges[_linkgraph_from][to].next_edge) {
+		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->nodes[_linkgraph_from].edges[to].next_edge) {
 			size++;
 		}
 
 		SlSetStructListLength(size);
-		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->edges[_linkgraph_from][to].next_edge) {
+		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->nodes[_linkgraph_from].edges[to].next_edge) {
-			SlObject(&_linkgraph->edges[_linkgraph_from][to], this->GetDescription());
+			SlObject(&_linkgraph->nodes[_linkgraph_from].edges[to], this->GetDescription());
 		}
 	}
 
 	void Load(Node *bn) const override
 	{
 		uint16 max_size = _linkgraph->Size();
+		_linkgraph->nodes[_linkgraph_from].edges.resize(max_size);
 
 		if (IsSavegameVersionBefore(SLV_191)) {
 			/* We used to save the full matrix ... */
 			for (NodeID to = 0; to < max_size; ++to) {
-				SlObject(&_linkgraph->edges[_linkgraph_from][to], this->GetLoadDescription());
+				SlObject(&_linkgraph->nodes[_linkgraph_from].edges[to], this->GetLoadDescription());
 			}
 			return;
 		}
@@ -68,12 +69,12 @@ public:
 		size_t used_size = IsSavegameVersionBefore(SLV_SAVELOAD_LIST_LENGTH) ? max_size : SlGetStructListLength(UINT16_MAX);
 
 		/* ... but as that wasted a lot of space we save a sparse matrix now. */
-		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->edges[_linkgraph_from][to].next_edge) {
+		for (NodeID to = _linkgraph_from; to != INVALID_NODE; to = _linkgraph->nodes[_linkgraph_from].edges[to].next_edge) {
 			if (used_size == 0) SlErrorCorrupt("Link graph structure overflow");
 			used_size--;
 
 			if (to >= max_size) SlErrorCorrupt("Link graph structure overflow");
-			SlObject(&_linkgraph->edges[_linkgraph_from][to], this->GetLoadDescription());
+			SlObject(&_linkgraph->nodes[_linkgraph_from].edges[to], this->GetLoadDescription());
 		}
 
 		if (!IsSavegameVersionBefore(SLV_SAVELOAD_LIST_LENGTH) && used_size > 0) SlErrorCorrupt("Corrupted link graph");