Method Init

cpp/src/arrow/compute/row/row_internal.cc:174–223

RowTableImpl::RowTableImpl() : pool_(nullptr), rows_capacity_(0), bytes_capacity_(0) {}

Status RowTableImpl::Init(MemoryPool* pool, const RowTableMetadata& metadata) {
  pool_ = pool;
  metadata_ = metadata;

  DCHECK(!null_masks_ && !offsets_ && !rows_);

  constexpr int64_t kInitialRowsCapacity = 8;
  constexpr int64_t kInitialBytesCapacity = 1024;

  // Null masks
  ARROW_ASSIGN_OR_RAISE(
      auto null_masks,
      AllocateResizableBuffer(size_null_masks(kInitialRowsCapacity), pool_));
  null_masks_ = std::move(null_masks);
  memset(null_masks_->mutable_data(), 0, size_null_masks(kInitialRowsCapacity));

  // Offsets and rows
  if (!metadata.is_fixed_length) {
    ARROW_ASSIGN_OR_RAISE(
        auto offsets, AllocateResizableBuffer(size_offsets(kInitialRowsCapacity), pool_));
    offsets_ = std::move(offsets);
    memset(offsets_->mutable_data(), 0, size_offsets(kInitialRowsCapacity));
    reinterpret_cast<offset_type*>(offsets_->mutable_data())[0] = 0;

    ARROW_ASSIGN_OR_RAISE(
        auto rows,
        AllocateResizableBuffer(size_rows_varying_length(kInitialBytesCapacity), pool_));
    rows_ = std::move(rows);
    memset(rows_->mutable_data(), 0, size_rows_varying_length(kInitialBytesCapacity));
    bytes_capacity_ =
        size_rows_varying_length(kInitialBytesCapacity) - kPaddingForVectors;
  } else {
    ARROW_ASSIGN_OR_RAISE(
        auto rows,
        AllocateResizableBuffer(size_rows_fixed_length(kInitialRowsCapacity), pool_));
    rows_ = std::move(rows);
    memset(rows_->mutable_data(), 0, size_rows_fixed_length(kInitialRowsCapacity));
    bytes_capacity_ = size_rows_fixed_length(kInitialRowsCapacity) - kPaddingForVectors;
  }

  UpdateBufferPointers();

  rows_capacity_ = kInitialRowsCapacity;

  num_rows_ = 0;
  num_rows_for_has_any_nulls_ = 0;
  has_any_nulls_ = false;

  return Status::OK();
}

void RowTableImpl::Clean() {
  num_rows_ = 0;