linkgraphjob.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * 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.
00006  * 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.
00007  * 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/>.
00008  */
00009 
00012 #include "../stdafx.h"
00013 #include "../core/pool_func.hpp"
00014 #include "../window_func.h"
00015 #include "linkgraphjob.h"
00016 
00017 /* Initialize the link-graph-job-pool */
00018 LinkGraphJobPool _link_graph_job_pool("LinkGraphJob");
00019 INSTANTIATE_POOL_METHODS(LinkGraphJob)
00020 
00021 
00027 LinkGraphJob::LinkGraphJob(const LinkGraph &orig) :
00028     /* Copying the link graph here also copies its index member.
00029      * This is on purpose. */
00030     link_graph(orig),
00031     settings(_settings_game.linkgraph),
00032     thread(NULL),
00033     join_date(_date + _settings_game.linkgraph.recalc_time)
00034 {
00035 }
00036 
00040 LinkGraphJob::~LinkGraphJob()
00041 {
00042   assert(this->thread == NULL);
00043 
00044   /* Link graph has been merged into another one. */
00045   if (!LinkGraph::IsValidID(this->link_graph.index)) return;
00046 
00047   uint size = this->Size();
00048   for (NodeID node_id = 0; node_id < size; ++node_id) {
00049     StationID station = (*this)[node_id].Station();
00050     if (Station::IsValidID(station)) continue;
00051 
00052     /* Station got removed during the link graph run. We have to remove all
00053      * flows pointing to it now. This is costly but it should be rare. */
00054     for (NodeID from_id = 0; from_id < size; ++from_id) {
00055       if ((*this)[from_id][node_id].Capacity() > 0) {
00056         FlowStatMap &flows = this->nodes[from_id].flows;
00057         for (FlowStatMap::iterator it(flows.begin()); it != flows.end();) {
00058           it->second.ChangeShare(station, INT_MIN);
00059           if (it->second.GetShares()->empty()) {
00060             flows.erase(it++);
00061           } else {
00062             ++it;
00063           }
00064         }
00065       }
00066     }
00067   }
00068 
00069   for (NodeID node_id = 0; node_id < size; ++node_id) {
00070 
00071     /* The station can have been deleted. */
00072     Station *st = Station::GetIfValid((*this)[node_id].Station());
00073     if (st == NULL) continue;
00074 
00075     /* Link graph merging and station deletion may change around IDs. Make
00076      * sure that everything is still consistent or ignore it otherwise. */
00077     GoodsEntry &ge = st->goods[this->Cargo()];
00078     if (ge.link_graph != this->link_graph.index || ge.node != node_id) continue;
00079 
00080     /* Remove flows for links that have been deleted in the mean time. */
00081     FlowStatMap &flows = this->nodes[node_id].flows;
00082     flows.Cleanup(node_id, this->link_graph.index);
00083 
00084     ge.flows.swap(flows);
00085     InvalidateWindowData(WC_STATION_VIEW, st->index, this->Cargo());
00086   }
00087 }
00088 
00094 void LinkGraphJob::Init()
00095 {
00096   uint size = this->Size();
00097   this->nodes.Resize(size);
00098   this->edges.Resize(size, size);
00099   for (uint i = 0; i < size; ++i) {
00100     this->nodes[i].Init(this->link_graph[i].Supply());
00101     EdgeAnnotation *node_edges = this->edges[i];
00102     for (uint j = 0; j < size; ++j) {
00103       node_edges[j].Init();
00104     }
00105   }
00106 }
00107 
00111 void LinkGraphJob::EdgeAnnotation::Init()
00112 {
00113   this->demand = 0;
00114   this->flow = 0;
00115   this->unsatisfied_demand = 0;
00116 }
00117 
00123 void LinkGraphJob::NodeAnnotation::Init(uint supply)
00124 {
00125   this->undelivered_supply = supply;
00126   new (&this->flows) FlowStatMap;
00127   new (&this->paths) PathList;
00128 }
00129 
00138 void Path::Fork(Path *base, uint cap, int free_cap, uint dist)
00139 {
00140   this->capacity = min(base->capacity, cap);
00141   this->free_capacity = min(base->free_capacity, free_cap);
00142   this->distance = base->distance + dist;
00143   assert(this->distance > 0);
00144   if (this->parent != base) {
00145     this->Detach();
00146     this->parent = base;
00147     this->parent->num_children++;
00148   }
00149   this->origin = base->origin;
00150 }
00151 
00160 uint Path::AddFlow(uint new_flow, LinkGraphJob &job, uint max_saturation)
00161 {
00162   if (this->parent != NULL) {
00163     LinkGraphJob::Edge edge = job[this->parent->node][this->node];
00164     if (max_saturation != UINT_MAX) {
00165       uint usable_cap = edge.Capacity() * max_saturation / 100;
00166       if (usable_cap > edge.Flow()) {
00167         new_flow = min(new_flow, usable_cap - edge.Flow());
00168       } else {
00169         return 0;
00170       }
00171     }
00172     new_flow = this->parent->AddFlow(new_flow, job, max_saturation);
00173     if (this->flow == 0 && new_flow > 0) {
00174       job[this->parent->node].Paths().push_back(this);
00175     }
00176     edge.AddFlow(new_flow);
00177   }
00178   this->flow += new_flow;
00179   return new_flow;
00180 }
00181 
00187 Path::Path(NodeID n, bool source) :
00188   distance(source ? 0 : UINT_MAX),
00189   capacity(0),
00190   free_capacity(source ? INT_MAX : INT_MIN),
00191   flow(0), node(n), origin(source ? n : INVALID_NODE),
00192   num_children(0), parent(NULL)
00193 {}
00194