Changeset - r20332:287acb1cd994
[Not reviewed]
master
0 2 0
fonsinchen - 11 years ago 2013-06-09 12:48:42
fonsinchen@openttd.org
(svn r25345) -Add: implementation of SharesMap and FlowStatMap
2 files changed with 264 insertions and 0 deletions:
0 comments (0 inline, 0 general)
src/station_base.h
Show inline comments
 
@@ -9,25 +9,108 @@
 

	
 
/** @file station_base.h Base classes/functions for stations. */
 

	
 
#ifndef STATION_BASE_H
 
#define STATION_BASE_H
 

	
 
#include "core/random_func.hpp"
 
#include "base_station_base.h"
 
#include "newgrf_airport.h"
 
#include "cargopacket.h"
 
#include "industry_type.h"
 
#include "linkgraph/linkgraph_type.h"
 
#include "newgrf_storage.h"
 
#include <map>
 

	
 
typedef Pool<BaseStation, StationID, 32, 64000> StationPool;
 
extern StationPool _station_pool;
 

	
 
static const byte INITIAL_STATION_RATING = 175;
 

	
 
/**
 
 * 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
 
 * look them up with a random number. A flow share is the difference between a
 
 * key in a map and the previous key. So one key in the map doesn't actually
 
 * mean anything by itself.
 
 */
 
class FlowStat {
 
public:
 
	typedef std::map<uint32, StationID> SharesMap;
 

	
 
	/**
 
	 * Invalid constructor. This can't be called as a FlowStat must not be
 
	 * empty. However, the constructor must be defined and reachable for
 
	 * FlwoStat to be used in a std::map.
 
	 */
 
	inline FlowStat() {NOT_REACHED();}
 

	
 
	/**
 
	 * Create a FlowStat with an initial entry.
 
	 * @param st Station the initial entry refers to.
 
	 * @param flow Amount of flow for the initial entry.
 
	 */
 
	inline FlowStat(StationID st, uint flow)
 
	{
 
		assert(flow > 0);
 
		this->shares[flow] = st;
 
	}
 

	
 
	/**
 
	 * Add some flow to the end of the shares map. Only do that if you know
 
	 * that the station isn't in the map yet. Anything else may lead to
 
	 * inconsistencies.
 
	 * @param st Remote station.
 
	 * @param flow Amount of flow to be added.
 
	 */
 
	inline void AppendShare(StationID st, uint flow)
 
	{
 
		assert(flow > 0);
 
		this->shares[(--this->shares.end())->first + flow] = st;
 
	}
 

	
 
	uint GetShare(StationID st) const;
 

	
 
	void ChangeShare(StationID st, int flow);
 

	
 
	/**
 
	 * Get the actual shares as a const pointer so that they can be iterated
 
	 * over.
 
	 * @return Actual shares.
 
	 */
 
	inline const SharesMap *GetShares() const { return &this->shares; }
 

	
 
	/**
 
	 * Get a station a package can be routed to. This done by drawing a
 
	 * random number between 0 and sum_shares and then looking that up in
 
	 * the map with lower_bound. So each share gets selected with a
 
	 * probability dependent on its flow.
 
	 * @return A station ID from the shares map.
 
	 */
 
	inline StationID GetVia() const
 
	{
 
		assert(!this->shares.empty());
 
		return this->shares.upper_bound(RandomRange((--this->shares.end())->first - 1))->second;
 
	}
 

	
 
	StationID GetVia(StationID excluded, StationID excluded2 = INVALID_STATION) const;
 

	
 
private:
 
	SharesMap shares;  ///< Shares of flow to be sent via specified station (or consumed locally).
 
};
 

	
 
/** Flow descriptions by origin stations. */
 
class FlowStatMap : public std::map<StationID, FlowStat> {
 
public:
 
	void AddFlow(StationID origin, StationID via, uint amount);
 
	void PassOnFlow(StationID origin, StationID via, uint amount);
 
	void DeleteFlows(StationID via);
 
	void FinalizeLocalConsumption(StationID self);
 
};
 

	
 
/**
 
 * Stores station stats for a single cargo.
 
 */
 
struct GoodsEntry {
 
	/** Status of this cargo for the station. */
 
	enum GoodsEntryStatus {
 
		/**
src/station_cmd.cpp
Show inline comments
 
@@ -3976,12 +3976,193 @@ static CommandCost TerraformTile_Station
 
			}
 
		}
 
	}
 
	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 
}
 

	
 
/**
 
 * Get flow for a station.
 
 * @param st Station to get flow for.
 
 * @return Flow for st.
 
 */
 
uint FlowStat::GetShare(StationID st) const
 
{
 
	uint32 prev = 0;
 
	for (SharesMap::const_iterator it = this->shares.begin(); it != this->shares.end(); ++it) {
 
		if (it->second == st) {
 
			return it->first - prev;
 
		} else {
 
			prev = it->first;
 
		}
 
	}
 
	return 0;
 
}
 

	
 
/**
 
 * Get a station a package can be routed to, but exclude the given one.
 
 * @param excluded StationID not to be selected.
 
 * @return A station ID from the shares map.
 
 */
 
StationID FlowStat::GetVia(StationID excluded, StationID excluded2) const
 
{
 
	assert(!this->shares.empty());
 
	uint max = (--this->shares.end())->first - 1;
 
	SharesMap::const_iterator it = this->shares.upper_bound(RandomRange(max));
 
	assert(it != this->shares.end());
 
	if (it->second != excluded && it->second != excluded2) return it->second;
 

	
 
	/* We've hit one of the excluded stations.
 
	 * Draw another share, from outside its range. */
 

	
 
	uint end = it->first;
 
	uint begin = (it == this->shares.begin() ? 0 : (--it)->first);
 
	uint interval = end - begin;
 
	if (interval > max) return INVALID_STATION; // Only one station in the map.
 
	uint new_max = max - interval;
 
	uint rand = RandomRange(new_max);
 
	SharesMap::const_iterator it2 = (rand < begin) ? this->shares.upper_bound(rand) :
 
			this->shares.upper_bound(rand + interval);
 
	assert(it2 != this->shares.end());
 
	if (it2->second != excluded && it2->second != excluded2) return it2->second;
 

	
 
	/* We've hit the second excluded station.
 
	 * Same as before, only a bit more complicated. */
 

	
 
	uint end2 = it2->first;
 
	uint begin2 = (it2 == this->shares.begin() ? 0 : (--it2)->first);
 
	uint interval2 = end2 - begin2;
 
	if (interval2 > new_max) return INVALID_STATION; // Only the two excluded stations in the map.
 
	new_max -= interval2;
 
	if (begin > begin2) {
 
		Swap(begin, begin2);
 
		Swap(end, end2);
 
		Swap(interval, interval2);
 
	}
 
	rand = RandomRange(new_max);
 
	SharesMap::const_iterator it3 = this->shares.end();
 
	if (rand < begin) {
 
		it3 = this->shares.upper_bound(rand);
 
	} else if (rand < begin2 - interval) {
 
		it3 = this->shares.upper_bound(rand + interval);
 
	} else {
 
		it3 = this->shares.upper_bound(rand + interval + interval2);
 
	}
 
	assert(it3 != this->shares.end());
 
	return it3->second;
 

	
 
}
 

	
 
/**
 
 * Change share for specified station. By specifing INT_MIN as parameter you
 
 * can erase a share.
 
 * @param st Next Hop to be removed.
 
 * @param flow Share to be added or removed.
 
 */
 
void FlowStat::ChangeShare(StationID st, int flow)
 
{
 
	/* We assert only before changing as afterwards the shares can actually
 
	 * be empty. In that case the whole flow stat must be deleted then. */
 
	assert(!this->shares.empty());
 

	
 
	int32 added_shares = 0;
 
	uint32 last_share = 0;
 
	SharesMap new_shares;
 
	for (SharesMap::iterator it(this->shares.begin()); it != this->shares.end(); ++it) {
 
		if (it->second == st) {
 
			uint share = it->first - last_share;
 
			int change = flow - added_shares;
 
			uint new_share = (change < 0 && (uint)(-change) > share) ? 0 : share + change;
 
			added_shares -= share;
 
			added_shares += new_share;
 
			if (new_share > 0) {
 
				new_shares[it->first + added_shares] = it->second;
 
			}
 
		} else {
 
			new_shares[it->first + added_shares] = it->second;
 
		}
 
		last_share = it->first;
 
	}
 
	if (flow > added_shares) {
 
		new_shares[last_share + flow - added_shares] = st;
 
	}
 
	this->shares.swap(new_shares);
 
}
 

	
 
/**
 
 * Add some flow from "origin", going via "via".
 
 * @param origin Origin of the flow.
 
 * @param via Next hop.
 
 * @param flow Amount of flow to be added.
 
 */
 
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)));
 
	} else {
 
		origin_it->second.ChangeShare(via, flow);
 
		assert(!origin_it->second.GetShares()->empty());
 
	}
 
}
 

	
 
/**
 
 * Pass on some flow, remembering it as invalid, for later subtraction from
 
 * locally consumed flow. This is necessary because we can't have negative
 
 * flows and we don't want to sort the flows before adding them up.
 
 * @param origin Origin of the flow.
 
 * @param via Next hop.
 
 * @param flow Amount of flow to be passed.
 
 */
 
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);
 
		fs.AppendShare(INVALID_STATION, flow);
 
		this->insert(std::make_pair(origin, fs));
 
	} else {
 
		prev_it->second.ChangeShare(via, flow);
 
		prev_it->second.ChangeShare(INVALID_STATION, flow);
 
		assert(!prev_it->second.GetShares()->empty());
 
	}
 
}
 

	
 
/**
 
 * Subtract invalid flows from locally consumed flow.
 
 * @param self ID of own station.
 
 */
 
void FlowStatMap::FinalizeLocalConsumption(StationID self)
 
{
 
	for (FlowStatMap::iterator i = this->begin(); i != this->end(); ++i) {
 
		FlowStat &fs = i->second;
 
		uint local = fs.GetShare(INVALID_STATION);
 
		fs.ChangeShare(self, -local);
 
		fs.ChangeShare(INVALID_STATION, -local);
 

	
 
		/* If the local share is used up there must be a share for some
 
		 * remote station. */
 
		assert(!fs.GetShares()->empty());
 
	}
 
}
 

	
 
/**
 
 * Delete all flows at a station for specific cargo and destination.
 
 * @param via Remote station of flows to be deleted.
 
 */
 
void FlowStatMap::DeleteFlows(StationID via)
 
{
 
	for (FlowStatMap::iterator f_it = this->begin(); f_it != this->end();) {
 
		FlowStat &s_flows = f_it->second;
 
		s_flows.ChangeShare(via, INT_MIN);
 
		if (s_flows.GetShares()->empty()) {
 
			this->erase(f_it++);
 
		} else {
 
			++f_it;
 
		}
 
	}
 
}
 

	
 
extern const TileTypeProcs _tile_type_station_procs = {
 
	DrawTile_Station,           // draw_tile_proc
 
	GetSlopePixelZ_Station,     // get_slope_z_proc
 
	ClearTile_Station,          // clear_tile_proc
 
	NULL,                       // add_accepted_cargo_proc
0 comments (0 inline, 0 general)