Maintain a separate list of pending RoutingStates

[r2c2.git] / source / libr2c2 / trainrouteplanner.cpp

diff --git a/source/libr2c2/trainrouteplanner.cpp b/source/libr2c2/trainrouteplanner.cpp
index c115d924bed8e0603436c0705a0a4bd46deab364..22ac5400ea4fb050437ccdff14de77dbafc483e9 100644 (file)
--- a/source/libr2c2/trainrouteplanner.cpp
+++ b/source/libr2c2/trainrouteplanner.cpp
@@ -21,39 +21,47 @@ TrainRoutePlanner::TrainRoutePlanner(Layout &layout)
                        routed_trains.push_back(info);
        }
 
-       steps.push_back(RoutingStep());
-       RoutingStep &start = steps.back();
+       queue.push_back(RoutingStep());
+       RoutingStep &start = queue.back();
        for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
                start.trains.push_back(TrainRoutingState(*i));
+       start.update_estimate();
 }
 
 void TrainRoutePlanner::plan()
 {
-       RoutingStep *goal = 0;
-       for(list<RoutingStep>::iterator i=steps.begin(); i!=steps.end(); ++i)
+       const RoutingStep *goal = 0;
+       while(!queue.empty())
        {
-               if(i->is_goal())
+               const RoutingStep &step = get_step();
+               if(step.is_goal())
                {
-                       goal = &*i;
+                       goal = &step;
                        break;
                }
 
-               add_steps(*i);
+               add_steps(step);
        }
 
        if(goal)
                create_routes(*goal);
 }
 
-void TrainRoutePlanner::add_steps(RoutingStep &step)
+const TrainRoutePlanner::RoutingStep &TrainRoutePlanner::get_step()
+{
+       steps.splice(steps.end(), queue, queue.begin());
+       return steps.back();
+}
+
+void TrainRoutePlanner::add_steps(const RoutingStep &step)
 {
        list<RoutingStep> new_steps;
        step.create_successors(new_steps);
        new_steps.sort();
-       steps.merge(new_steps);
+       queue.merge(new_steps);
 }
 
-void TrainRoutePlanner::create_routes(RoutingStep &goal)
+void TrainRoutePlanner::create_routes(const RoutingStep &goal)
 {
        for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
        {
@@ -62,9 +70,9 @@ void TrainRoutePlanner::create_routes(RoutingStep &goal)
                i->route->set_temporary(true);
        }
 
-       for(RoutingStep *i=&goal; i; i=i->prev)
+       for(const RoutingStep *i=&goal; i; i=i->prev)
        {
-               for(vector<TrainRoutingState>::iterator j=i->trains.begin(); j!=i->trains.end(); ++j)
+               for(vector<TrainRoutingState>::const_iterator j=i->trains.begin(); j!=i->trains.end(); ++j)
                {
                        if(j->state==WAITING || j->state==BLOCKED)
                                j->info->waits.push_front(&*j);
@@ -75,8 +83,8 @@ void TrainRoutePlanner::create_routes(RoutingStep &goal)
        for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
        {
                i->router->set_route(i->route);
-               TrainRoutingState *current_wait = 0;
-               for(list<TrainRoutingState *>::iterator j=i->waits.begin(); j!=i->waits.end(); ++j)
+               const TrainRoutingState *current_wait = 0;
+               for(list<const TrainRoutingState *>::const_iterator j=i->waits.begin(); j!=i->waits.end(); ++j)
                        if(!current_wait || (*j)->track.track()!=current_wait->track.track())
                        {
                                Block &block = (*j)->track.next()->get_block();
@@ -175,7 +183,7 @@ TrainRoutePlanner::TrainRoutingState::TrainRoutingState(const TrainRoutingState
 
 TrainRoutePlanner::TrainRoutingState::~TrainRoutingState()
 {
-       if(!--occupied_tracks->refcount)
+       if(occupied_tracks && !--occupied_tracks->refcount)
                delete occupied_tracks;
 }
 
@@ -184,7 +192,7 @@ Time::TimeDelta TrainRoutePlanner::TrainRoutingState::get_time_to_next_track() c
        return ((track->get_type().get_path_length(path)-offset)/info->speed)*Time::sec+delay;
 }
 
-bool TrainRoutePlanner::TrainRoutingState::is_occupied(Track &trk) const
+bool TrainRoutePlanner::TrainRoutingState::is_occupying(Track &trk) const
 {
        OccupiedTrack *occ = occupied_tracks;
        for(unsigned n=occ->n_tracks; n>0; --n, occ=occ->next)
@@ -250,13 +258,13 @@ TrainRoutePlanner::RoutingStep::RoutingStep():
        prev(0)
 { }
 
-TrainRoutePlanner::RoutingStep::RoutingStep(RoutingStep *p):
+TrainRoutePlanner::RoutingStep::RoutingStep(const RoutingStep *p):
        time(p->time),
        trains(p->trains),
        prev(p)
 { }
 
-void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_steps)
+void TrainRoutePlanner::RoutingStep::create_successors(list<RoutingStep> &new_steps) const
 {
        RoutingStep next(this);
        if(next.update_states())
@@ -336,17 +344,24 @@ bool TrainRoutePlanner::RoutingStep::update_states()
 
 bool TrainRoutePlanner::RoutingStep::check_deadlocks() const
 {
-       for(unsigned i=0; i<trains.size(); ++i)
+       for(vector<TrainRoutingState>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
        {
-               const TrainRoutingState &train = trains[i];
-               if(train.state!=BLOCKED)
+               if(i->state!=BLOCKED)
                        continue;
 
-               if(train.blocked_by<0)
+               if(i->blocked_by<0)
                        return true;
 
-               if(trains[train.blocked_by].blocked_by==static_cast<int>(i))
-                       return true;
+               int slow = i->blocked_by;
+               int fast = trains[slow].blocked_by;
+               while(fast>=0 && trains[fast].blocked_by>=0)
+               {
+                       if(fast==slow)
+                               return true;
+
+                       slow = trains[slow].blocked_by;
+                       fast = trains[trains[fast].blocked_by].blocked_by;
+               }
        }
 
        return false;
@@ -355,7 +370,7 @@ bool TrainRoutePlanner::RoutingStep::check_deadlocks() const
 int TrainRoutePlanner::RoutingStep::get_occupant(Track &track) const
 {
        for(unsigned i=0; i<trains.size(); ++i)
-               if(trains[i].is_occupied(track))
+               if(trains[i].is_occupying(track))
                        return i;
 
        return -1;