Method Emplace

cpp/src/arrow/dataset/scanner.cc:672–683

  std::vector<RecordBatchVector> batches{};

  void Emplace(const EnumeratedRecordBatch& batch) {
    std::lock_guard<std::mutex> lock(mutex);
    auto fragment_index = batch.fragment.index;
    auto batch_index = batch.record_batch.index;
    if (static_cast<int>(batches.size()) <= fragment_index) {
      batches.resize(fragment_index + 1);
    }
    if (static_cast<int>(batches[fragment_index].size()) <= batch_index) {
      batches[fragment_index].resize(batch_index + 1);
    }
    batches[fragment_index][batch_index] = batch.record_batch.value;
  }

  RecordBatchVector Finish() {
    RecordBatchVector all_batches;