Method ScheduleConvertTasks

r/src/array_to_vector.cpp:66–97

converter is passed as self to outlive the scope of Converter::Convert()

  // converter is passed as self to outlive the scope of Converter::Convert()
  SEXP ScheduleConvertTasks(RTasks& tasks, std::shared_ptr<Converter> self) {
    // try altrep first
    SEXP alt = altrep::MakeAltrepVector(chunked_array_);
    if (!Rf_isNull(alt)) {
      return alt;
    }

    // otherwise use the Converter api:

    // allocating the R vector upfront
    SEXP out = PROTECT(Allocate(chunked_array_->length()));

    // for each array, fill the relevant slice of `out`, potentially in parallel
    R_xlen_t k = 0, i = 0;
    for (const auto& array : chunked_array_->chunks()) {
      auto n_chunk = array->length();

      tasks.Append(Parallel(), [=] {
        if (array->null_count() == n_chunk) {
          return self->Ingest_all_nulls(out, k, n_chunk);
        } else {
          return self->Ingest_some_nulls(out, array, k, n_chunk, i);
        }
      });

      k += n_chunk;
      i++;
    }

    UNPROTECT(1);
    return out;
  }

  // Converter factory
  static std::shared_ptr<Converter> Make(