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authorfonsinchen <fonsinchen@openttd.org>2013-06-09 12:59:51 +0000
committerfonsinchen <fonsinchen@openttd.org>2013-06-09 12:59:51 +0000
commit6a46b5262fa9b5b2de220353eec72d58c7e4484d (patch)
tree1b71a1bda22791f1728654af830e9dcade960204 /src/linkgraph
parentc32eea02dd2de11636f5182a38fc8d577ff1f457 (diff)
downloadopenttd-6a46b5262fa9b5b2de220353eec72d58c7e4484d.tar.xz
(svn r25355) -Add: demand handler for link graph
Diffstat (limited to 'src/linkgraph')
-rw-r--r--src/linkgraph/demands.cpp298
-rw-r--r--src/linkgraph/demands.h43
-rw-r--r--src/linkgraph/linkgraphschedule.cpp2
-rw-r--r--src/linkgraph/linkgraphschedule.h2
4 files changed, 344 insertions, 1 deletions
diff --git a/src/linkgraph/demands.cpp b/src/linkgraph/demands.cpp
new file mode 100644
index 000000000..87426326a
--- /dev/null
+++ b/src/linkgraph/demands.cpp
@@ -0,0 +1,298 @@
+/** @file demands.cpp Definition of demand calculating link graph handler. */
+
+#include "../stdafx.h"
+#include "demands.h"
+#include <list>
+
+typedef std::list<NodeID> NodeList;
+
+/**
+ * Scale various things according to symmetric/asymmetric distribution.
+ */
+class Scaler {
+public:
+ /**
+ * Constructor.
+ */
+ Scaler() : demand_per_node(0) {}
+
+ void SetDemands(LinkGraphJob &job, NodeID from, NodeID to, uint demand_forw);
+
+protected:
+ uint demand_per_node; ///< Mean demand associated with each node.
+};
+
+/**
+ * Scaler for symmetric distribution.
+ */
+class SymmetricScaler : public Scaler {
+public:
+ /**
+ * Constructor.
+ * @param mod_size Size modifier to be used. Determines how much demands
+ * increase with the supply of the remote station.
+ */
+ inline SymmetricScaler(uint mod_size) : mod_size(mod_size), supply_sum(0)
+ {}
+
+ /**
+ * Count a node's supply into the sum of supplies.
+ * @param node Node.
+ */
+ inline void AddNode(const Node &node)
+ {
+ this->supply_sum += node.Supply();
+ }
+
+ /**
+ * Calculate the mean demand per node using the sum of supplies.
+ * @param num_demands Number of accepting nodes.
+ */
+ inline void SetDemandPerNode(uint num_demands)
+ {
+ this->demand_per_node = max(this->supply_sum / num_demands, 1U);
+ }
+
+ /**
+ * Get the effective supply of one node towards another one. In symmetric
+ * distribution the supply of the other node is weighed in.
+ * @param from The supplying node.
+ * @param to The receiving node.
+ * @return Effective supply.
+ */
+ inline uint EffectiveSupply(const Node &from, const Node &to)
+ {
+ return max(from.Supply() * max(1U, to.Supply()) * this->mod_size / 100 / this->demand_per_node, 1U);
+ }
+
+ /**
+ * Check if there is any acceptance left for this node. In symmetric distribution
+ * nodes only accept anything if they also supply something. So if
+ * undelivered_supply == 0 at the node there isn't any demand left either.
+ * @param to Node to be checked.
+ * @return If demand is left.
+ */
+ inline bool HasDemandLeft(const Node &to)
+ {
+ return (to.Supply() == 0 || to.UndeliveredSupply() > 0) && to.Demand() > 0;
+ }
+
+ void SetDemands(LinkGraphJob &job, NodeID from, NodeID to, uint demand_forw);
+
+private:
+ uint mod_size; ///< Size modifier. Determines how much demands increase with the supply of the remote station.
+ uint supply_sum; ///< Sum of all supplies in the component.
+};
+
+/**
+ * A scaler for asymmetric distribution.
+ */
+class AsymmetricScaler : public Scaler {
+public:
+ /**
+ * Constructor.
+ */
+ inline AsymmetricScaler() : demand_sum(0) {}
+
+ /**
+ * Count a node's demand into the sum of demands.
+ * @param node The node to be counted.
+ */
+ inline void AddNode(const Node &node)
+ {
+ this->demand_sum += node.Demand();
+ }
+
+ /**
+ * Calculate the mean demand per node using the sum of demands.
+ * @param num_demands Number of accepting nodes.
+ */
+ inline void SetDemandPerNode(uint num_demands)
+ {
+ this->demand_per_node = max(this->demand_sum / num_demands, (uint)1);
+ }
+
+ /**
+ * Get the effective supply of one node towards another one. In asymmetric
+ * distribution the demand of the other node is weighed in.
+ * @param from The supplying node.
+ * @param to The receiving node.
+ */
+ inline uint EffectiveSupply(const Node &from, const Node &to)
+ {
+ return max(from.Supply() * to.Demand() / this->demand_per_node, (uint)1);
+ }
+
+ /**
+ * Check if there is any acceptance left for this node. In asymmetric distribution
+ * nodes always accept as long as their demand > 0.
+ * @param to The node to be checked.
+ * @param to_anno Unused.
+ */
+ inline bool HasDemandLeft(const Node &to) { return to.Demand() > 0; }
+
+private:
+ uint demand_sum; ///< Sum of all demands in the component.
+};
+
+/**
+ * Set the demands between two nodes using the given base demand. In symmetric mode
+ * this sets demands in both directions.
+ * @param job The link graph job.
+ * @param from_id The supplying node.
+ * @þaram to_id The receiving node.
+ * @param demand_forw Demand calculated for the "forward" direction.
+ */
+void SymmetricScaler::SetDemands(LinkGraphJob &job, NodeID from_id, NodeID to_id, uint demand_forw)
+{
+ if (job[from_id].Demand() > 0) {
+ uint demand_back = demand_forw * this->mod_size / 100;
+ uint undelivered = job[to_id].UndeliveredSupply();
+ if (demand_back > undelivered) {
+ demand_back = undelivered;
+ demand_forw = max(1U, demand_back * 100 / this->mod_size);
+ }
+ this->Scaler::SetDemands(job, to_id, from_id, demand_back);
+ }
+
+ this->Scaler::SetDemands(job, from_id, to_id, demand_forw);
+}
+
+/**
+ * Set the demands between two nodes using the given base demand. In asymmetric mode
+ * this only sets demand in the "forward" direction.
+ * @param job The link graph job.
+ * @param from_id The supplying node.
+ * @þaram to_id The receiving node.
+ * @param demand_forw Demand calculated for the "forward" direction.
+ */
+inline void Scaler::SetDemands(LinkGraphJob &job, NodeID from_id, NodeID to_id, uint demand_forw)
+{
+ job[from_id].DeliverSupply(to_id, demand_forw);
+}
+
+/**
+ * Do the actual demand calculation, called from constructor.
+ * @param job Job to calculate the demands for.
+ * @tparam Tscaler Scaler to be used for scaling demands.
+ */
+template<class Tscaler>
+void DemandCalculator::CalcDemand(LinkGraphJob &job, Tscaler scaler)
+{
+ NodeList supplies;
+ NodeList demands;
+ uint num_supplies = 0;
+ uint num_demands = 0;
+
+ for (NodeID node = 0; node < job.Size(); node++) {
+ scaler.AddNode(job[node]);
+ if (job[node].Supply() > 0) {
+ supplies.push_back(node);
+ num_supplies++;
+ }
+ if (job[node].Demand() > 0) {
+ demands.push_back(node);
+ num_demands++;
+ }
+ }
+
+ if (num_supplies == 0 || num_demands == 0) return;
+
+ /* Mean acceptance attributed to each node. If the distribution is
+ * symmetric this is relative to remote supply, otherwise it is
+ * relative to remote demand. */
+ scaler.SetDemandPerNode(num_demands);
+ uint chance = 0;
+
+ while (!supplies.empty() && !demands.empty()) {
+ NodeID from_id = supplies.front();
+ supplies.pop_front();
+
+ for (uint i = 0; i < num_demands; ++i) {
+ assert(!demands.empty());
+ NodeID to_id = demands.front();
+ demands.pop_front();
+ if (from_id == to_id) {
+ /* Only one node with supply and demand left */
+ if (demands.empty() && supplies.empty()) return;
+
+ demands.push_back(to_id);
+ continue;
+ }
+
+ int32 supply = scaler.EffectiveSupply(job[from_id], job[to_id]);
+ assert(supply > 0);
+
+ /* Scale the distance by mod_dist around max_distance */
+ int32 distance = this->max_distance - (this->max_distance -
+ (int32)job[from_id][to_id].Distance()) * this->mod_dist / 100;
+
+ /* Scale the accuracy by distance around accuracy / 2 */
+ int32 divisor = this->accuracy * (this->mod_dist - 50) / 100 +
+ this->accuracy * distance / this->max_distance + 1;
+
+ assert(divisor > 0);
+
+ uint demand_forw = 0;
+ if (divisor <= supply) {
+ /* At first only distribute demand if
+ * effective supply / accuracy divisor >= 1
+ * Others are too small or too far away to be considered. */
+ demand_forw = supply / divisor;
+ } else if (++chance > this->accuracy * num_demands * num_supplies) {
+ /* After some trying, if there is still supply left, distribute
+ * demand also to other nodes. */
+ demand_forw = 1;
+ }
+
+ demand_forw = min(demand_forw, job[from_id].UndeliveredSupply());
+
+ scaler.SetDemands(job, from_id, to_id, demand_forw);
+
+ if (scaler.HasDemandLeft(job[to_id])) {
+ demands.push_back(to_id);
+ } else {
+ num_demands--;
+ }
+
+ if (job[from_id].UndeliveredSupply() == 0) break;
+ }
+
+ if (job[from_id].UndeliveredSupply() != 0) {
+ supplies.push_back(from_id);
+ } else {
+ num_supplies--;
+ }
+ }
+}
+
+/**
+ * Create the DemandCalculator and immediately do the calculation.
+ * @param job Job to calculate the demands for.
+ */
+DemandCalculator::DemandCalculator(LinkGraphJob &job) :
+ max_distance(MapSizeX() + MapSizeY() - 2)
+{
+ const LinkGraphSettings &settings = job.Settings();
+ CargoID cargo = job.Cargo();
+
+ this->accuracy = settings.accuracy;
+ this->mod_dist = settings.demand_distance;
+ if (this->mod_dist > 100) {
+ /* Increase effect of mod_dist > 100 */
+ int over100 = this->mod_dist - 100;
+ this->mod_dist = 100 + over100 * over100;
+ }
+
+ switch (settings.GetDistributionType(cargo)) {
+ case DT_SYMMETRIC:
+ this->CalcDemand<SymmetricScaler>(job, SymmetricScaler(settings.demand_size));
+ break;
+ case DT_ASYMMETRIC:
+ this->CalcDemand<AsymmetricScaler>(job, AsymmetricScaler());
+ break;
+ default:
+ /* Nothing to do. */
+ break;
+ }
+}
diff --git a/src/linkgraph/demands.h b/src/linkgraph/demands.h
new file mode 100644
index 000000000..c3d9dc7cd
--- /dev/null
+++ b/src/linkgraph/demands.h
@@ -0,0 +1,43 @@
+/** @file demands.h Declaration of demand calculating link graph handler. */
+
+#ifndef DEMANDS_H
+#define DEMANDS_H
+
+#include "linkgraphjob_base.h"
+
+/**
+ * Calculate the demands. This class has a state, but is recreated for each
+ * call to of DemandHandler::Run.
+ */
+class DemandCalculator {
+public:
+ DemandCalculator(LinkGraphJob &job);
+
+private:
+ int32 max_distance; ///< Maximum distance possible on the map.
+ int32 mod_dist; ///< Distance modifier, determines how much demands decrease with distance.
+ int32 accuracy; ///< Accuracy of the calculation.
+
+ template<class Tscaler>
+ void CalcDemand(LinkGraphJob &job, Tscaler scaler);
+};
+
+/**
+ * Stateless, thread safe demand hander. Doesn't do anything but call DemandCalculator.
+ */
+class DemandHandler : public ComponentHandler {
+public:
+
+ /**
+ * Call the demand calculator on the given component.
+ * @param graph Component to calculate the demands for.
+ */
+ virtual void Run(LinkGraphJob &job) const { DemandCalculator c(job); }
+
+ /**
+ * Virtual destructor has to be defined because of virtual Run().
+ */
+ virtual ~DemandHandler() {}
+};
+
+#endif /* DEMANDS_H */
diff --git a/src/linkgraph/linkgraphschedule.cpp b/src/linkgraph/linkgraphschedule.cpp
index 31a837ad1..b3e512506 100644
--- a/src/linkgraph/linkgraphschedule.cpp
+++ b/src/linkgraph/linkgraphschedule.cpp
@@ -12,6 +12,7 @@
#include "../stdafx.h"
#include "linkgraphschedule.h"
#include "init.h"
+#include "demands.h"
/**
* Spawn a thread if possible and run the link graph job in the thread. If
@@ -128,6 +129,7 @@ void LinkGraphSchedule::SpawnAll()
LinkGraphSchedule::LinkGraphSchedule()
{
this->handlers[0] = new InitHandler;
+ this->handlers[1] = new DemandHandler;
}
/**
diff --git a/src/linkgraph/linkgraphschedule.h b/src/linkgraph/linkgraphschedule.h
index 3b71f2954..32e0dc6f4 100644
--- a/src/linkgraph/linkgraphschedule.h
+++ b/src/linkgraph/linkgraphschedule.h
@@ -44,7 +44,7 @@ private:
friend const SaveLoad *GetLinkGraphScheduleDesc();
protected:
- ComponentHandler *handlers[1]; ///< Handlers to be run for each job.
+ ComponentHandler *handlers[2]; ///< Handlers to be run for each job.
GraphList schedule; ///< Queue for new jobs.
JobList running; ///< Currently running jobs.