Function MakeSparseTensor

cpp/src/arrow/ipc/metadata_internal.cc:1245–1279

}

Status MakeSparseTensor(FBB& fbb, const SparseTensor& sparse_tensor, int64_t body_length,
                        const std::vector<BufferMetadata>& buffers,
                        SparseTensorOffset* offset) {
  flatbuf::Type fb_type_type;
  Offset fb_type;
  RETURN_NOT_OK(
      TensorTypeToFlatbuffer(fbb, *sparse_tensor.type(), &fb_type_type, &fb_type));

  using TensorDimOffset = flatbuffers::Offset<flatbuf::TensorDim>;
  std::vector<TensorDimOffset> dims;
  for (int i = 0; i < sparse_tensor.ndim(); ++i) {
    FBString name = fbb.CreateString(sparse_tensor.dim_name(i));
    dims.push_back(flatbuf::CreateTensorDim(fbb, sparse_tensor.shape()[i], name));
  }

  auto fb_shape = fbb.CreateVector(dims);

  flatbuf::SparseTensorIndex fb_sparse_index_type;
  Offset fb_sparse_index;
  size_t num_index_buffers = 0;
  RETURN_NOT_OK(MakeSparseTensorIndex(fbb, *sparse_tensor.sparse_index(), buffers,
                                      &fb_sparse_index_type, &fb_sparse_index,
                                      &num_index_buffers));

  const BufferMetadata& data_metadata = buffers[num_index_buffers];
  flatbuf::Buffer data(data_metadata.offset, data_metadata.length);

  const int64_t non_zero_length = sparse_tensor.non_zero_length();

  *offset =
      flatbuf::CreateSparseTensor(fbb, fb_type_type, fb_type, fb_shape, non_zero_length,
                                  fb_sparse_index_type, fb_sparse_index, &data);

  return Status::OK();
}

}  // namespace