Method acknowledge

bolt/exec/OutputBuffer.cpp:215–250

}

std::vector<std::shared_ptr<SerializedPage>> DestinationBuffer::acknowledge(
    int64_t sequence,
    bool fromGetData) {
  const int64_t numDeleted = sequence - sequence_;
  if (numDeleted == 0 && fromGetData) {
    // If called from getData, it is expected that there will be
    // nothing to delete because a previous acknowledgement has been
    // received before the getData. This is not guaranteed though
    // because the messages may arrive out of order. Note that getData
    // implicitly acknowledges all messages with a lower sequence
    // number than the one in getData.
    return {};
  }
  if (numDeleted <= 0) {
    // Acknowledges come out of order, e.g. ack of 10 and 9 have
    // swapped places in flight.
    VLOG(1) << this << " Out of order ack: " << sequence << " over "
            << sequence_;
    return {};
  }

  BOLT_CHECK_LE(
      numDeleted, data_.size(), "Ack received for a not yet produced item");
  std::vector<std::shared_ptr<SerializedPage>> freed;
  for (auto i = 0; i < numDeleted; ++i) {
    if (data_[i] == nullptr) {
      BOLT_CHECK_EQ(i, data_.size() - 1, "null marker found in the middle");
      break;
    }
    stats_.recordAcknowledge(*data_[i]);
    freed.push_back(std::move(data_[i]));
  }
  data_.erase(data_.begin(), data_.begin() + numDeleted);
  sequence_ += numDeleted;
  return freed;
}

std::vector<std::shared_ptr<SerializedPage>>
DestinationBuffer::deleteResults() {