// takes a dfs stack and a transaction that is visited twice, and returns the corresponding cycle
// last access in the dfs stack belongs to tx
// the first and last access in the cycle belong to tx
Cycle* AspEventHandler::extract_cycle(DFSStack& stack, Transaction* tx) {
num_cycles_++; // all cycles
// if we have seen another cycle with tx as the revisited transaction, skip reporting this cycle
if(txset_in_cycle.find(tx) != txset_in_cycle.end()) {
return NULL;
}
// record this transaction, so we do not report cycles with the same revisited transaction
txset_in_cycle.insert(tx);
//----------------------------
Cycle* cycle = new Cycle();
num_unique_cycles_++; // unique cycles
DFSStack::iterator itr = stack.begin();
for(; itr < stack.end(); ++itr) {
DFSStackElement current_elt = (*itr);
if(current_elt.tx_ == tx) {
break;
}
}
for(; itr < stack.end(); ++itr) {
DFSStackElement current_elt = (*itr);
Edge edge = *(current_elt.begin_);
cycle->push_back(edge.first);
cycle->push_back(edge.second);
}
assert(cycle->front()->tx() == tx);
assert(cycle->back()->tx() == tx);
return cycle;
}
typename SimplexWithVertices<V>::Cycle
SimplexWithVertices<V>::
boundary() const
{
Cycle bdry;
if (dimension() == 0) return bdry;
for (typename VertexContainer::const_iterator cur = vertices_.begin(); cur != vertices_.end(); ++cur)
{
bdry.push_back(*this);
Self& s = bdry.back();
s.vertices_.erase(*cur);
}
return bdry;
}