(svn r25355) -Add: demand handler for link graph

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 */