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Linkgraph: MCF: Skip source node Dijkstra when all demand satisfied

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This commit is contained in:
Jonathan G Rennison
2019-10-06 17:02:38 +01:00
parent 04cf7d5500
commit 3e8b091913
1 changed files with 18 additions and 1 deletions
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19
src/linkgraph/mcf.cpp
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@@ -523,13 +523,18 @@ MCF1stPass::MCF1stPass(LinkGraphJob &job) : MultiCommodityFlow(job)
uint size = job.Size();
uint accuracy = job.Settings().accuracy;
bool more_loops;
std::vector<bool> finished_sources;
finished_sources.resize(size);
do {
more_loops = false;
for (NodeID source = 0; source < size; ++source) {
if (finished_sources[source]) continue;
/* First saturate the shortest paths. */
this->Dijkstra<DistanceAnnotation, GraphEdgeIterator>(source, paths);
bool source_demand_left = false;
for (NodeID dest = 0; dest < size; ++dest) {
Edge edge = job[source][dest];
if (edge.UnsatisfiedDemand() > 0) {
@@ -547,8 +552,10 @@ MCF1stPass::MCF1stPass(LinkGraphJob &job) : MultiCommodityFlow(job)
path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(edge, path, accuracy, UINT_MAX);
}
if (edge.UnsatisfiedDemand() > 0) source_demand_left = true;
}
}
if (!source_demand_left) finished_sources[source] = true;
this->CleanupPaths(source, paths);
}
} while ((more_loops || this->EliminateCycles()) && !job.IsJobAborted());
@@ -566,18 +573,28 @@ MCF2ndPass::MCF2ndPass(LinkGraphJob &job) : MultiCommodityFlow(job)
uint size = job.Size();
uint accuracy = job.Settings().accuracy;
bool demand_left = true;
std::vector<bool> finished_sources;
finished_sources.resize(size);
while (demand_left && !job.IsJobAborted()) {
demand_left = false;
for (NodeID source = 0; source < size; ++source) {
if (finished_sources[source]) continue;
this->Dijkstra<CapacityAnnotation, FlowEdgeIterator>(source, paths);
bool source_demand_left = false;
for (NodeID dest = 0; dest < size; ++dest) {
Edge edge = this->job[source][dest];
Path *path = paths[dest];
if (edge.UnsatisfiedDemand() > 0 && path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(edge, path, accuracy, UINT_MAX);
if (edge.UnsatisfiedDemand() > 0) demand_left = true;
if (edge.UnsatisfiedDemand() > 0) {
demand_left = true;
source_demand_left = true;
}
}
}
if (!source_demand_left) finished_sources[source] = true;
this->CleanupPaths(source, paths);
}
}