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(svn r25885) -Codechange: Keep paths sorted so that the ones with flow == 0 are in the back and don't have to be iterated over so often.

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fonsinchen
2013-10-19 17:15:19 +00:00
parent f16b78eb81
commit 6580fd4b8f
4 changed files with 28 additions and 7 deletions
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26
src/linkgraph/mcf.cpp
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@@ -351,7 +351,17 @@ void MCF1stPass::EliminateCycle(PathVector &path, Path *cycle_begin, uint flow)
do {
NodeID prev = cycle_begin->GetNode();
cycle_begin->ReduceFlow(flow);
cycle_begin = path[cycle_begin->GetNode()];
if (cycle_begin->GetFlow() == 0) {
PathList &node_paths = this->job[cycle_begin->GetParent()->GetNode()].Paths();
for (PathList::iterator i = node_paths.begin(); i != node_paths.end(); ++i) {
if (*i == cycle_begin) {
node_paths.erase(i);
node_paths.push_back(cycle_begin);
break;
}
}
}
cycle_begin = path[prev];
Edge edge = this->job[prev][cycle_begin->GetNode()];
edge.RemoveFlow(flow);
} while (cycle_begin != cycle_end);
@@ -379,18 +389,28 @@ bool MCF1stPass::EliminateCycles(PathVector &path, NodeID origin_id, NodeID next
* in one path each. */
PathList &paths = this->job[next_id].Paths();
PathViaMap next_hops;
for (PathList::iterator i = paths.begin(); i != paths.end(); ++i) {
for (PathList::iterator i = paths.begin(); i != paths.end();) {
Path *new_child = *i;
uint new_flow = new_child->GetFlow();
if (new_flow == 0) break;
if (new_child->GetOrigin() == origin_id) {
PathViaMap::iterator via_it = next_hops.find(new_child->GetNode());
if (via_it == next_hops.end()) {
next_hops[new_child->GetNode()] = new_child;
++i;
} else {
Path *child = via_it->second;
uint new_flow = new_child->GetFlow();
child->AddFlow(new_flow);
new_child->ReduceFlow(new_flow);
/* We might hit end() with with the ++ here and skip the
* newly push_back'ed path. That's good as the flow of that
* path is 0 anyway. */
paths.erase(i++);
paths.push_back(new_child);
}
} else {
++i;
}
}
bool found = false;