Function PairwiseExec

cpp/src/arrow/compute/kernels/vector_pairwise.cc:92–110

}

Status PairwiseExec(KernelContext* ctx, const ExecSpan& batch, ExecResult* out) {
  const auto& state = checked_cast<const PairwiseState&>(*ctx->state());
  auto input = batch[0].array;

  // The scalar diff kernel will only write into the non-null output area.
  // We must therefore pre-initialize the output, otherwise the left or right
  // margin would be left uninitialized.
  ARROW_ASSIGN_OR_RAISE(auto builder,
                        MakeBuilder(out->type()->GetSharedPtr(), ctx->memory_pool()));
  // Append nulls rather than empty values, so as to allocate a null bitmap.
  RETURN_NOT_OK(builder->AppendNulls(out->length()));
  std::shared_ptr<ArrayData> out_data;
  RETURN_NOT_OK(builder->FinishInternal(&out_data));
  out_data->null_count = kUnknownNullCount;
  out->value = std::move(out_data);

  return PairwiseExecImpl(ctx, batch[0].array, state.scalar_exec, state.periods,
                          out->array_data_mutable());
}

const FunctionDoc pairwise_diff_doc(
    "Compute first order difference of an array",