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Codechange: [Linkgraph] Split annotation for demand between nodes from the edge annotations.

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This commit is contained in:
Michael Lutz
2023-01-02 01:06:31 +01:00
parent 564de01d66
commit 8f851ead70
4 changed files with 55 additions and 55 deletions
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33
src/linkgraph/mcf.cpp
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@@ -334,19 +334,20 @@ 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 node Node where the path starts.
* @param to Node where the path ends.
* @param path End of the path the flow should be pushed on.
* @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(Edge &edge, Path *path, uint accuracy,
uint MultiCommodityFlow::PushFlow(Node &node, NodeID to, Path *path, uint accuracy,
uint max_saturation)
{
assert(edge.UnsatisfiedDemand() > 0);
uint flow = Clamp(edge.Demand() / accuracy, 1, edge.UnsatisfiedDemand());
assert(node.UnsatisfiedDemandTo(to) > 0);
uint flow = Clamp(node.DemandTo(to) / accuracy, 1, node.UnsatisfiedDemandTo(to));
flow = path->AddFlow(flow, this->job, max_saturation);
edge.SatisfyDemand(flow);
node.SatisfyDemandTo(to, flow);
return flow;
}
@@ -511,25 +512,25 @@ MCF1stPass::MCF1stPass(LinkGraphJob &job) : MultiCommodityFlow(job)
/* First saturate the shortest paths. */
this->Dijkstra<DistanceAnnotation, GraphEdgeIterator>(source, paths);
Node src_node = job[source];
bool source_demand_left = false;
for (NodeID dest = 0; dest < size; ++dest) {
Edge edge = job[source][dest];
if (edge.UnsatisfiedDemand() > 0) {
if (src_node.UnsatisfiedDemandTo(dest) > 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(src_node, dest, path,
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 || (src_node.UnsatisfiedDemandTo(dest) > 0);
} else if (src_node.UnsatisfiedDemandTo(dest) == src_node.DemandTo(dest) &&
path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(edge, path, accuracy, UINT_MAX);
this->PushFlow(src_node, dest, path, accuracy, UINT_MAX);
}
if (edge.UnsatisfiedDemand() > 0) source_demand_left = true;
if (src_node.UnsatisfiedDemandTo(dest) > 0) source_demand_left = true;
}
}
finished_sources[source] = !source_demand_left;
@@ -558,13 +559,13 @@ MCF2ndPass::MCF2ndPass(LinkGraphJob &job) : MultiCommodityFlow(job)
this->Dijkstra<CapacityAnnotation, FlowEdgeIterator>(source, paths);
Node src_node = job[source];
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) {
if (src_node.UnsatisfiedDemandTo(dest) > 0 && path->GetFreeCapacity() > INT_MIN) {
this->PushFlow(src_node, dest, path, accuracy, UINT_MAX);
if (src_node.UnsatisfiedDemandTo(dest) > 0) {
demand_left = true;
source_demand_left = true;
}