template <class U> IteratorSeq<U> * IteratorSeq<T>::flatMap(vector<U> (*f)(T&)) {
VectorIteratorSeq<U> *ret = new VectorIteratorSeq<U>();
for(size_t i = 0; i < size(); i++) {
T t = this->at(i);
vector<U> u = f(t);
ret->push_back(u);
}
return ret;
}
vector< IteratorSeq<T>* > ParallelArrayRDD<T>::slice(IteratorSeq<T> *seq)
{
vector< IteratorSeq<T>* > slices;
if (numSlices < 1)
{
// logError("ParallelArray: slice number should be positive integer!");
return slices;
}
long seqSize = seq->size();
long num_group = seqSize / numSlices;
if (seq->getType() == 0)
{
T step = seq->at(1) - seq->at(0);
for (int i = 0; i < numSlices - 1; i++)
{
T start = seq->at(0) + i * num_group * step;
T end = start + (num_group - 1) * step;
IteratorSeq<T> *it = new RangeIteratorSeq<T>(start, end , step);
slices.push_back(it);
}
T last_start = seq->at(0) + (numSlices - 1) * num_group * step;
T end = seq->at(seqSize-1);
IteratorSeq<T> *last = new RangeIteratorSeq<T>(last_start, end, step);
slices.push_back(last);
}
else
{
// type == 1
for (int i = 0; i < numSlices - 1; i++)
{
vector<T> group;
VectorIteratorSeq<T> *it = new VectorIteratorSeq<T>(group);
for (long j = 0; j < num_group; j++)
{
it->push_back(seq->at(i * num_group + j));
}
slices.push_back(it);
}
vector<T> last;
VectorIteratorSeq<T> *it = new VectorIteratorSeq<T>(last);
for (size_t i = (numSlices - 1) * num_group; i < seq->size(); i++)
{
it->push_back(seq->at(i));
}
slices.push_back(it);
}
return slices;
}