dave/openttd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Linkgraph: Split demand annotations from edge flow annotations

Browse Source 
Use sparse storage format for demand annotations
This commit is contained in:
Jonathan G Rennison
2023-01-05 01:05:40 +00:00
parent 9bc5f69a19
commit 55473bc730
6 changed files with 74 additions and 65 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
src/linkgraph/mcf.cpp
View File

@@ -391,20 +391,20 @@ void MultiCommodityFlow::CleanupPaths(NodeID source_id, PathVector &paths)
/**
* Push flow along a path and update the unsatisfied_demand of the associated
* edge.
* @param edge Edge whose ends the path connects.
* @param anno Distance annotation whose ends the path connects.
* @param path End of the path the flow should be pushed on.
* @param min_step_size Minimum flow size.
* @param accuracy Accuracy of the calculation.
* @param max_saturation If < UINT_MAX only push flow up to the given
* saturation, otherwise the path can be "overloaded".
*/
uint MultiCommodityFlow::PushFlow(AnnoEdge &edge, Path *path, uint min_step_size, uint accuracy,
uint MultiCommodityFlow::PushFlow(DemandAnnotation &anno, Path *path, uint min_step_size, uint accuracy,
uint max_saturation)
{
assert(edge.UnsatisfiedDemand() > 0);
uint flow = std::min(std::max(edge.Demand() / accuracy, min_step_size), edge.UnsatisfiedDemand());
dbg_assert(anno.unsatisfied_demand > 0);
uint flow = std::min(std::max(anno.demand / accuracy, min_step_size), anno.unsatisfied_demand);
flow = path->AddFlow(flow, this->job, max_saturation);
edge.SatisfyDemand(flow);
anno.unsatisfied_demand -= flow;
return flow;
}
@@ -571,10 +571,10 @@ MCF1stPass::MCF1stPass(LinkGraphJob &job) : MultiCommodityFlow(job)
uint64 total_demand = 0;
uint demand_count = 0;
for (NodeID source = 0; source < size; ++source) {
for (NodeID dest = 0; dest < size; ++dest) {
AnnoEdge edge = job[source][dest];
if (edge.UnsatisfiedDemand() > 0) {
total_demand += edge.UnsatisfiedDemand();
const Node &node = job[source];
for (const DemandAnnotation &anno : node.GetDemandAnnotations()) {
if (anno.unsatisfied_demand > 0) {
total_demand += anno.unsatisfied_demand;
demand_count++;
}
}
@@ -593,24 +593,24 @@ MCF1stPass::MCF1stPass(LinkGraphJob &job) : MultiCommodityFlow(job)
this->Dijkstra<DistanceAnnotation, GraphEdgeIterator>(source, paths);
bool source_demand_left = false;
for (NodeID dest = 0; dest < size; ++dest) {
AnnoEdge edge = job[source][dest];
if (edge.UnsatisfiedDemand() > 0) {
for (DemandAnnotation &anno : job[source].GetDemandAnnotations()) {
NodeID dest = anno.dest;
if (anno.unsatisfied_demand > 0) {
Path *path = paths[dest];
assert(path != nullptr);
/* Generally only allow paths that don't exceed the
* available capacity. But if no demand has been assigned
* yet, make an exception and allow any valid path *once*. */
if (path->GetFreeCapacity() > 0 && this->PushFlow(edge, path,
if (path->GetFreeCapacity() > 0 && this->PushFlow(anno, path,
min_step_size, accuracy, this->max_saturation) > 0) {
/* If a path has been found there is a chance we can
* find more. */
more_loops = more_loops || (edge.UnsatisfiedDemand() > 0);
} else if (edge.UnsatisfiedDemand() == edge.Demand() &&
more_loops = more_loops || (anno.unsatisfied_demand > 0);
} else if (anno.unsatisfied_demand == anno.demand &&
path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(edge, path, min_step_size, accuracy, UINT_MAX);
this->PushFlow(anno, path, min_step_size, accuracy, UINT_MAX);
}
if (edge.UnsatisfiedDemand() > 0) source_demand_left = true;
if (anno.unsatisfied_demand > 0) source_demand_left = true;
}
}
if (!source_demand_left) finished_sources[source] = true;
@@ -640,12 +640,12 @@ MCF2ndPass::MCF2ndPass(LinkGraphJob &job) : MultiCommodityFlow(job)
this->Dijkstra<CapacityAnnotation, FlowEdgeIterator>(source, paths);
bool source_demand_left = false;
for (NodeID dest = 0; dest < size; ++dest) {
AnnoEdge edge = this->job[source][dest];
Path *path = paths[dest];
if (edge.UnsatisfiedDemand() > 0 && path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(edge, path, 1, accuracy, UINT_MAX);
if (edge.UnsatisfiedDemand() > 0) {
for (DemandAnnotation &anno : this->job[source].GetDemandAnnotations()) {
if (anno.unsatisfied_demand == 0) continue;
Path *path = paths[anno.dest];
if (path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(anno, path, 1, accuracy, UINT_MAX);
if (anno.unsatisfied_demand > 0) {
demand_left = true;
source_demand_left = true;
}