Link graph: Store last compression in scaled date ticks

Higher accuracy than using dates at high day legnths

src/date.cpp

@@ -65,6 +65,9 @@ void CheckScaledDateTicksWrap()
 
 	extern void AdjustVehicleScaledTickBase(int64 delta);
 	AdjustVehicleScaledTickBase(-tick_adjust);
+
+	extern void AdjustLinkGraphScaledTickBase(int64 delta);
+	AdjustLinkGraphScaledTickBase(-tick_adjust);
 }
 
 void RebaseScaledDateTicksBase()

src/linkgraph/linkgraph.cpp

@@ -39,7 +39,6 @@ inline void LinkGraph::BaseNode::Init(TileIndex xy, StationID st, uint demand)
  */
 void LinkGraph::ShiftDates(int interval)
 {
-	this->last_compression += interval;
 	for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
 		BaseNode &source = this->nodes[node1];
 		if (source.last_update != INVALID_DATE) source.last_update += interval;
@@ -54,7 +53,7 @@ void LinkGraph::ShiftDates(int interval)
 
 void LinkGraph::Compress()
 {
-	this->last_compression = (_date + this->last_compression) / 2;
+	this->last_compression = (_scaled_date_ticks + this->last_compression) / 2;
 	for (NodeID node1 = 0; node1 < this->Size(); ++node1) {
 		this->nodes[node1].supply /= 2;
 	}
@@ -79,8 +78,8 @@ void LinkGraph::Compress()
  */
 void LinkGraph::Merge(LinkGraph *other)
 {
-	Date age = _date - this->last_compression + 1;
-	Date other_age = _date - other->last_compression + 1;
+	uint32 age = ClampTo<uint32>(CeilDivT<DateTicksScaled>(_scaled_date_ticks - this->last_compression + 1, DAY_TICKS));
+	uint32 other_age = ClampTo<uint32>(CeilDivT<DateTicksScaled>(_scaled_date_ticks - other->last_compression + 1, DAY_TICKS));
 	NodeID first = this->Size();
 	this->nodes.reserve(first + other->Size());
 	for (NodeID node1 = 0; node1 < other->Size(); ++node1) {
@@ -265,3 +264,14 @@ void LinkGraph::Init(uint size)
 	assert(this->Size() == 0);
 	this->nodes.resize(size);
 }
+
+void AdjustLinkGraphScaledTickBase(int64 delta)
+{
+	for (LinkGraph *lg : LinkGraph::Iterate()) lg->last_compression += delta;
+}
+
+void LinkGraphFixupLastCompressionAfterLoad()
+{
+	/* last_compression was previously a Date, change it to a DateTicksScaled */
+	for (LinkGraph *lg : LinkGraph::Iterate()) lg->last_compression = DateToScaledDateTicks((Date)lg->last_compression);
+}

src/linkgraph/linkgraph.h

@@ -289,7 +289,7 @@ public:
 	static const uint STALE_LINK_DEPOT_TIMEOUT = 1024;
 
 	/** Minimum number of days between subsequent compressions of a LG. */
-	static const uint COMPRESSION_INTERVAL = 256;
+	static const uint COMPRESSION_INTERVAL = 256 * DAY_TICKS;
 
 	/**
 	 * Scale a value from a link graph of age orig_age for usage in one of age
@@ -310,7 +310,7 @@ public:
 	 * Real constructor.
 	 * @param cargo Cargo the link graph is about.
 	 */
-	LinkGraph(CargoID cargo) : cargo(cargo), last_compression(_date) {}
+	LinkGraph(CargoID cargo) : cargo(cargo), last_compression(_scaled_date_ticks) {}
 
 	void Init(uint size);
 	void ShiftDates(int interval);
@@ -349,7 +349,7 @@ public:
 	 * Get date of last compression.
 	 * @return Date of last compression.
 	 */
-	inline Date LastCompression() const { return this->last_compression; }
+	inline DateTicksScaled LastCompression() const { return this->last_compression; }
 
 	/**
 	 * Get the cargo ID this component's link graph refers to.
@@ -364,7 +364,7 @@ public:
 	 */
 	inline uint Monthly(uint base) const
 	{
-		return base * 30 / (_date - this->last_compression + 1);
+		return (static_cast<uint64>(base) * 30 * DAY_TICKS * _settings_game.economy.day_length_factor) / std::max<uint64>(_scaled_date_ticks - this->last_compression, DAY_TICKS);
 	}
 
 	NodeID AddNode(const Station *st);
@@ -391,8 +391,11 @@ protected:
 	friend upstream_sl::SlLinkgraphNode;
 	friend upstream_sl::SlLinkgraphEdge;
 
+	friend void AdjustLinkGraphScaledTickBase(int64 delta);
+	friend void LinkGraphFixupLastCompressionAfterLoad();
+
 	CargoID cargo;         ///< Cargo of this component's link graph.
-	Date last_compression; ///< Last time the capacities and supplies were compressed.
+	DateTicksScaled last_compression; ///< Last time the capacities and supplies were compressed.
 	NodeVector nodes;      ///< Nodes in the component.
 	EdgeMatrix edges;      ///< Edges in the component.
 

src/saveload/afterload.cpp

@@ -913,6 +913,12 @@ bool AfterLoadGame()
 		_settings_game.linkgraph.recalc_time     *= SECONDS_PER_DAY;
 	}
 
+	/* Convert link graph last compression from date to scaled ticks. */
+	if (SlXvIsFeatureMissing(XSLFI_LINKGRAPH_DAY_SCALE, 4)) {
+		extern void LinkGraphFixupLastCompressionAfterLoad();
+		LinkGraphFixupLastCompressionAfterLoad();
+	}
+
 	/* Load the sprites */
 	GfxLoadSprites();
 	LoadStringWidthTable();

src/saveload/linkgraph_sl.cpp

@@ -125,7 +125,7 @@ public:
 SaveLoadTable GetLinkGraphDesc()
 {
 	static const SaveLoad link_graph_desc[] = {
-		 SLE_VAR(LinkGraph, last_compression, SLE_INT32),
+		 SLE_VAR(LinkGraph, last_compression, SLE_VAR_I64 | SLE_FILE_I32),
 		SLEG_CONDVAR("num_nodes", _num_nodes, SLE_UINT16, SL_MIN_VERSION, SLV_SAVELOAD_LIST_LENGTH),
 		 SLE_VAR(LinkGraph, cargo,            SLE_UINT8),
 		SLEG_STRUCTLIST("nodes", SlLinkgraphNode),

src/sl/extended_ver_sl.cpp

@@ -107,7 +107,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_EXTRA_LARGE_MAP,                  XSCF_NULL,                0,   1, "extra_large_map",                  nullptr, nullptr, nullptr          },
 	{ XSLFI_REVERSE_AT_WAYPOINT,              XSCF_NULL,                1,   1, "reverse_at_waypoint",              nullptr, nullptr, nullptr          },
 	{ XSLFI_VEH_LIFETIME_PROFIT,              XSCF_NULL,                1,   1, "veh_lifetime_profit",              nullptr, nullptr, nullptr          },
-	{ XSLFI_LINKGRAPH_DAY_SCALE,              XSCF_NULL,                3,   3, "linkgraph_day_scale",              nullptr, nullptr, nullptr          },
+	{ XSLFI_LINKGRAPH_DAY_SCALE,              XSCF_NULL,                4,   4, "linkgraph_day_scale",              nullptr, nullptr, nullptr          },
 	{ XSLFI_TEMPLATE_REPLACEMENT,             XSCF_NULL,                9,   9, "template_replacement",             nullptr, nullptr, "TRPL,TMPL"      },
 	{ XSLFI_MORE_RAIL_TYPES,                  XSCF_NULL,                0,   1, "more_rail_types",                  nullptr, nullptr, nullptr          },
 	{ XSLFI_CARGO_TYPE_ORDERS,                XSCF_NULL,                3,   3, "cargo_type_orders",                nullptr, nullptr, "ORDX,VEOX"      },

src/sl/linkgraph_sl.cpp

@@ -31,7 +31,8 @@ static uint16 _num_nodes;
 SaveLoadTable GetLinkGraphDesc()
 {
 	static const SaveLoad link_graph_desc[] = {
-		 SLE_VAR(LinkGraph, last_compression, SLE_INT32),
+	SLE_CONDVAR_X(LinkGraph, last_compression, SLE_VAR_I64 | SLE_FILE_I32, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_LINKGRAPH_DAY_SCALE, 0, 3)),
+	SLE_CONDVAR_X(LinkGraph, last_compression,                  SLE_INT64,  SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_LINKGRAPH_DAY_SCALE, 4)),
 		SLEG_VAR(_num_nodes,                  SLE_UINT16),
 		 SLE_VAR(LinkGraph, cargo,            SLE_UINT8),
 	};
@@ -225,7 +226,7 @@ static void DoSave_LGRJ(LinkGraphJob *lgj)
 {
 	SlObjectSaveFiltered(lgj, _filtered_job_desc);
 	_num_nodes = lgj->Size();
-	SlObjectSaveFiltered(const_cast<LinkGraph *>(&lgj->Graph()), GetLinkGraphDesc()); // GetLinkGraphDesc has no conditionals
+	SlObject(const_cast<LinkGraph *>(&lgj->Graph()), GetLinkGraphDesc());
 	Save_LinkGraph(const_cast<LinkGraph &>(lgj->Graph()));
 }
 
@@ -236,7 +237,7 @@ static void DoSave_LGRJ(LinkGraphJob *lgj)
 static void DoSave_LGRP(LinkGraph *lg)
 {
 	_num_nodes = lg->Size();
-	SlObjectSaveFiltered(lg, GetLinkGraphDesc()); // GetLinkGraphDesc has no conditionals
+	SlObject(lg, GetLinkGraphDesc());
 	Save_LinkGraph(*lg);
 }
 
@@ -253,7 +254,7 @@ static void Load_LGRP()
 			NOT_REACHED();
 		}
 		LinkGraph *lg = new (index) LinkGraph();
-		SlObjectLoadFiltered(lg, GetLinkGraphDesc()); // GetLinkGraphDesc has no conditionals
+		SlObject(lg, GetLinkGraphDesc());
 		lg->Init(_num_nodes);
 		Load_LinkGraph(*lg);
 	}
@@ -278,7 +279,7 @@ static void Load_LGRJ()
 			GetLinkGraphJobDayLengthScaleAfterLoad(lgj);
 		}
 		LinkGraph &lg = const_cast<LinkGraph &>(lgj->Graph());
-		SlObjectLoadFiltered(&lg, GetLinkGraphDesc()); // GetLinkGraphDesc has no conditionals
+		SlObject(&lg, GetLinkGraphDesc());
 		lg.Init(_num_nodes);
 		Load_LinkGraph(lg);
 	}

src/station_cmd.cpp

@@ -4531,8 +4531,8 @@ void DeleteStaleLinks(Station *from)
 
 			return result;
 		});
-		assert(_date >= lg->LastCompression());
-		if ((uint)(_date - lg->LastCompression()) > std::max<uint>(LinkGraph::COMPRESSION_INTERVAL / _settings_game.economy.day_length_factor, 1)) {
+		assert(_scaled_date_ticks >= lg->LastCompression());
+		if ((_scaled_date_ticks - lg->LastCompression()) > LinkGraph::COMPRESSION_INTERVAL) {
 			lg->Compress();
 		}
 	}