OpenTTD
linkgraph.h
Go to the documentation of this file.
1 /* $Id: linkgraph.h 26646 2014-06-14 13:35:39Z fonsinchen $ */
2 
3 /*
4  * This file is part of OpenTTD.
5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
8  */
9 
12 #ifndef LINKGRAPH_H
13 #define LINKGRAPH_H
14 
15 #include "../core/pool_type.hpp"
16 #include "../core/smallmap_type.hpp"
17 #include "../core/smallmatrix_type.hpp"
18 #include "../station_base.h"
19 #include "../cargotype.h"
20 #include "../date_func.h"
21 #include "linkgraph_type.h"
22 
23 struct SaveLoad;
24 class LinkGraph;
25 
33 
40 class LinkGraph : public LinkGraphPool::PoolItem<&_link_graph_pool> {
41 public:
42 
48  struct BaseNode {
49  uint supply;
50  uint demand;
51  StationID station;
54  void Init(TileIndex xy = INVALID_TILE, StationID st = INVALID_STATION, uint demand = 0);
55  };
56 
63  struct BaseEdge {
64  uint capacity;
65  uint usage;
68  NodeID next_edge;
69  void Init();
70  };
71 
76  template<typename Tedge>
77  class EdgeWrapper {
78  protected:
79  Tedge &edge;
80 
81  public:
82 
87  EdgeWrapper (Tedge &edge) : edge(edge) {}
88 
93  uint Capacity() const { return this->edge.capacity; }
94 
99  uint Usage() const { return this->edge.usage; }
100 
105  Date LastUnrestrictedUpdate() const { return this->edge.last_unrestricted_update; }
106 
111  Date LastRestrictedUpdate() const { return this->edge.last_restricted_update; }
112 
117  Date LastUpdate() const { return max(this->edge.last_unrestricted_update, this->edge.last_restricted_update); }
118  };
119 
125  template<typename Tnode, typename Tedge>
126  class NodeWrapper {
127  protected:
128  Tnode &node;
129  Tedge *edges;
130  NodeID index;
131 
132  public:
133 
140  NodeWrapper(Tnode &node, Tedge *edges, NodeID index) : node(node),
141  edges(edges), index(index) {}
142 
147  uint Supply() const { return this->node.supply; }
148 
153  uint Demand() const { return this->node.demand; }
154 
159  StationID Station() const { return this->node.station; }
160 
165  Date LastUpdate() const { return this->node.last_update; }
166 
171  TileIndex XY() const { return this->node.xy; }
172  };
173 
181  template <class Tedge, class Tedge_wrapper, class Titer>
183  protected:
184  Tedge *base;
185  NodeID current;
186 
193  class FakePointer : public SmallPair<NodeID, Tedge_wrapper> {
194  public:
195 
200  FakePointer(const SmallPair<NodeID, Tedge_wrapper> &pair) : SmallPair<NodeID, Tedge_wrapper>(pair) {}
201 
207  };
208 
209  public:
215  BaseEdgeIterator (Tedge *base, NodeID current) :
216  base(base),
217  current(current == INVALID_NODE ? current : base[current].next_edge)
218  {}
219 
224  Titer &operator++()
225  {
226  this->current = this->base[this->current].next_edge;
227  return static_cast<Titer &>(*this);
228  }
229 
234  Titer operator++(int)
235  {
236  Titer ret(static_cast<Titer &>(*this));
237  this->current = this->base[this->current].next_edge;
238  return ret;
239  }
240 
248  template<class Tother>
249  bool operator==(const Tother &other)
250  {
251  return this->base == other.base && this->current == other.current;
252  }
253 
261  template<class Tother>
262  bool operator!=(const Tother &other)
263  {
264  return this->base != other.base || this->current != other.current;
265  }
266 
272  {
273  return SmallPair<NodeID, Tedge_wrapper>(this->current, Tedge_wrapper(this->base[this->current]));
274  }
275 
280  FakePointer operator->() const {
281  return FakePointer(this->operator*());
282  }
283  };
284 
289 
293  class Edge : public EdgeWrapper<BaseEdge> {
294  public:
300  void Update(uint capacity, uint usage, EdgeUpdateMode mode);
301  void Restrict() { this->edge.last_unrestricted_update = INVALID_DATE; }
302  void Release() { this->edge.last_restricted_update = INVALID_DATE; }
303  };
304 
309  class ConstEdgeIterator : public BaseEdgeIterator<const BaseEdge, ConstEdge, ConstEdgeIterator> {
310  public:
317  BaseEdgeIterator<const BaseEdge, ConstEdge, ConstEdgeIterator>(edges, current) {}
318  };
319 
324  class EdgeIterator : public BaseEdgeIterator<BaseEdge, Edge, EdgeIterator> {
325  public:
332  BaseEdgeIterator<BaseEdge, Edge, EdgeIterator>(edges, current) {}
333  };
334 
339  class ConstNode : public NodeWrapper<const BaseNode, const BaseEdge> {
340  public:
346  ConstNode(const LinkGraph *lg, NodeID node) :
347  NodeWrapper<const BaseNode, const BaseEdge>(lg->nodes[node], lg->edges[node], node)
348  {}
349 
356  ConstEdge operator[](NodeID to) const { return ConstEdge(this->edges[to]); }
357 
362  ConstEdgeIterator Begin() const { return ConstEdgeIterator(this->edges, this->index); }
363 
368  ConstEdgeIterator End() const { return ConstEdgeIterator(this->edges, INVALID_NODE); }
369  };
370 
374  class Node : public NodeWrapper<BaseNode, BaseEdge> {
375  public:
381  Node(LinkGraph *lg, NodeID node) :
382  NodeWrapper<BaseNode, BaseEdge>(lg->nodes[node], lg->edges[node], node)
383  {}
384 
391  Edge operator[](NodeID to) { return Edge(this->edges[to]); }
392 
397  EdgeIterator Begin() { return EdgeIterator(this->edges, this->index); }
398 
403  EdgeIterator End() { return EdgeIterator(this->edges, INVALID_NODE); }
404 
409  void UpdateSupply(uint supply)
410  {
411  this->node.supply += supply;
412  this->node.last_update = _date;
413  }
414 
420  {
421  this->node.xy = xy;
422  }
423 
428  void SetDemand(uint demand)
429  {
430  this->node.demand = demand;
431  }
432 
433  void AddEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode);
434  void UpdateEdge(NodeID to, uint capacity, uint usage, EdgeUpdateMode mode);
435  void RemoveEdge(NodeID to);
436  };
437 
438  typedef SmallVector<BaseNode, 16> NodeVector;
439  typedef SmallMatrix<BaseEdge> EdgeMatrix;
440 
442  static const uint MIN_TIMEOUT_DISTANCE = 32;
443 
445  static const uint COMPRESSION_INTERVAL = 256;
446 
455  inline static uint Scale(uint val, uint target_age, uint orig_age)
456  {
457  return val > 0 ? max(1U, val * target_age / orig_age) : 0;
458  }
459 
467 
468  void Init(uint size);
469  void ShiftDates(int interval);
470  void Compress();
471  void Merge(LinkGraph *other);
472 
473  /* Splitting link graphs is intentionally not implemented.
474  * The overhead in determining connectedness would probably outweigh the
475  * benefit of having to deal with smaller graphs. In real world examples
476  * networks generally grow. Only rarely a network is permanently split.
477  * Reacting to temporary splits here would obviously create performance
478  * problems and detecting the temporary or permanent nature of splits isn't
479  * trivial. */
480 
486  inline Node operator[](NodeID num) { return Node(this, num); }
487 
493  inline ConstNode operator[](NodeID num) const { return ConstNode(this, num); }
494 
499  inline uint Size() const { return this->nodes.Length(); }
500 
505  inline Date LastCompression() const { return this->last_compression; }
506 
511  inline CargoID Cargo() const { return this->cargo; }
512 
518  inline uint Monthly(uint base) const
519  {
520  return base * 30 / (_date - this->last_compression + 1);
521  }
522 
523  NodeID AddNode(const Station *st);
524  void RemoveNode(NodeID id);
525 
526 protected:
527  friend class LinkGraph::ConstNode;
528  friend class LinkGraph::Node;
529  friend const SaveLoad *GetLinkGraphDesc();
530  friend const SaveLoad *GetLinkGraphJobDesc();
531  friend void SaveLoad_LinkGraph(LinkGraph &lg);
532 
537 };
538 
539 #define FOR_ALL_LINK_GRAPHS(var) FOR_ALL_ITEMS_FROM(LinkGraph, link_graph_index, var, 0)
540 
541 #endif /* LINKGRAPH_H */