std::vector<Xapian::docid> Ranker::rank

std::vector<Xapian::docid>
Ranker::rank(Xapian::MSet & mset, const string & model_key, const Xapian::FeatureList & flist)
{
    LOGCALL(API, std::vector<Xapian::docid>, "Ranker::rank", mset | model_key | flist);
    std::vector<FeatureVector> fvv = flist.create_feature_vectors(mset, letor_query, Xapian::Database(db_path));
    load_model_from_metadata(model_key);
    std::vector<FeatureVector> rankedfvv = rank_fvv(fvv);

    std::vector<Xapian::docid> rankeddid;
    for (size_t i = 0; i < rankedfvv.size(); ++i) {
        rankeddid.push_back(rankedfvv[i].get_did());
    }
    std::vector<Xapian::Internal::MSetItem> items_;
    for (size_t i=0; i < rankeddid.size(); ++i){
        items_.push_back(Xapian::Internal::MSetItem(rankeddid.size()-i,rankeddid[i]));
    }
    mset.swap_items(items_);
    return rankeddid;
}