Method GetNextBatch

be/src/exec/row-batch-cache.h:43–53

Returns the next batch from the cache. Expands the cache if necessary. If a new batch is created, its memory is tracked against 'mem_tracker'.

  /// Returns the next batch from the cache. Expands the cache if necessary.
  /// If a new batch is created, its memory is tracked against 'mem_tracker'.
  RowBatch* GetNextBatch(MemTracker* mem_tracker) {
    if (next_row_batch_idx_ >= row_batches_.size()) {
      // Expand the cache with a new row batch.
      row_batches_.push_back(
          std::make_unique<RowBatch>(row_desc_, batch_size_, mem_tracker));
    } else {
      // Reset batch from the cache before returning it.
      row_batches_[next_row_batch_idx_]->Reset();
    }
    return row_batches_[next_row_batch_idx_++].get();
  }

  /// Resets the cache such that subsequent calls to GetNextBatch() return batches from
  /// the beginning of the cache. All batches previously returned by GetNextBatch()