C++ array::get_data_memblock方法代码示例

nd::array nd::view(const nd::array& arr, const ndt::type& tp)
{
    // If the types match exactly, simply return 'arr'
    if (arr.get_type() == tp) {
        return arr;
    } else if (arr.get_ndim() == tp.get_ndim()) {
        // Allocate a result array to attempt the view in it
        array result(make_array_memory_block(tp.get_metadata_size()));
        // Copy the fields
        result.get_ndo()->m_data_pointer = arr.get_ndo()->m_data_pointer;
        if (arr.get_ndo()->m_data_reference == NULL) {
            // Embedded data, need reference to the array
            result.get_ndo()->m_data_reference = arr.get_memblock().release();
        } else {
            // Use the same data reference, avoid producing a chain
            result.get_ndo()->m_data_reference = arr.get_data_memblock().release();
        }
        result.get_ndo()->m_type = ndt::type(tp).release();
        result.get_ndo()->m_flags = arr.get_ndo()->m_flags;
        // Now try to copy the metadata as a view
        if (try_view(arr.get_type(), arr.get_ndo_meta(), tp,
                     result.get_ndo_meta(), arr.get_memblock().get())) {
            // If it succeeded, return it
            return result;
        }
        // Otherwise fall through, let it get destructed, and raise an error
    }

    stringstream ss;
    ss << "Unable to view nd::array of type " << arr.get_type();
    ss << "as type " << tp;
    throw type_error(ss.str());
}

static nd::array view_concrete(const nd::array &arr, const ndt::type &tp)
{
  // Allocate a result array to attempt the view in it
  nd::array result(make_array_memory_block(tp.get_arrmeta_size()));
  // Copy the fields
  result.get_ndo()->data.ptr = arr.get_ndo()->data.ptr;
  if (arr.get_ndo()->data.ref == NULL) {
    // Embedded data, need reference to the array
    result.get_ndo()->data.ref = arr.get_memblock().release();
  } else {
    // Use the same data reference, avoid producing a chain
    result.get_ndo()->data.ref = arr.get_data_memblock().release();
  }
  result.get_ndo()->m_type = ndt::type(tp).release();
  result.get_ndo()->m_flags = arr.get_ndo()->m_flags;
  // First handle a special case of viewing outermost "var" as "fixed[#]"
  if (arr.get_type().get_type_id() == var_dim_type_id && tp.get_type_id() == fixed_dim_type_id) {
    const var_dim_type_arrmeta *in_am = reinterpret_cast<const var_dim_type_arrmeta *>(arr.get_arrmeta());
    const var_dim_type_data *in_dat = reinterpret_cast<const var_dim_type_data *>(arr.get_readonly_originptr());
    fixed_dim_type_arrmeta *out_am = reinterpret_cast<fixed_dim_type_arrmeta *>(result.get_arrmeta());
    out_am->dim_size = tp.extended<ndt::fixed_dim_type>()->get_fixed_dim_size();
    out_am->stride = in_am->stride;
    if ((intptr_t)in_dat->size == out_am->dim_size) {
      // Use the more specific data reference from the var arrmeta if possible
      if (in_am->blockref != NULL) {
        memory_block_decref(result.get_ndo()->data.ref);
        memory_block_incref(in_am->blockref);
        result.get_ndo()->data.ref = in_am->blockref;
      }
      result.get_ndo()->data.ptr = in_dat->begin + in_am->offset;
      // Try to copy the rest of the arrmeta as a view
      if (try_view(arr.get_type().extended<ndt::base_dim_type>()->get_element_type(),
                   arr.get_arrmeta() + sizeof(var_dim_type_arrmeta),
                   tp.extended<ndt::base_dim_type>()->get_element_type(),
                   result.get_arrmeta() + sizeof(fixed_dim_type_arrmeta), arr.get_memblock().get())) {
        return result;
      }
    }
  }
  // Otherwise try to copy the arrmeta as a view
  else if (try_view(arr.get_type(), arr.get_arrmeta(), tp, result.get_arrmeta(), arr.get_memblock().get())) {
    // If it succeeded, return it
    return result;
  }

  stringstream ss;
  ss << "Unable to view nd::array of type " << arr.get_type();
  ss << " as type " << tp;
  throw type_error(ss.str());
}

static nd::array view_as_bytes(const nd::array &arr, const ndt::type &tp)
{
  if (arr.get_type().get_flags() & type_flag_destructor) {
    // Can't view arrays of object type
    return nd::array();
  }

  // Get the essential components of the array to analyze
  memory_block_ptr data_ref = arr.get_data_memblock();
  char *data_ptr = arr.get_ndo()->data.ptr;
  ndt::type data_tp = arr.get_type();
  const char *data_meta = arr.get_arrmeta();
  intptr_t data_dim_size = -1, data_stride = 0;
  // Repeatedly refine the data
  while (data_tp.get_type_id() != uninitialized_type_id) {
    refine_bytes_view(data_ref, data_ptr, data_tp, data_meta, data_dim_size, data_stride);
  }
  // Check that it worked, and that the resulting data pointer is aligned
  if (data_dim_size < 0 ||
      !offset_is_aligned(reinterpret_cast<size_t>(data_ptr), tp.extended<ndt::bytes_type>()->get_target_alignment())) {
    // This signals we could not view the data as a
    // contiguous chunk of bytes
    return nd::array();
  }

  char *result_data_ptr = NULL;
  nd::array result(make_array_memory_block(tp.extended()->get_arrmeta_size(), tp.get_data_size(),
                                           tp.get_data_alignment(), &result_data_ptr));
  // Set the bytes extents
  ((char **)result_data_ptr)[0] = data_ptr;
  ((char **)result_data_ptr)[1] = data_ptr + data_dim_size;
  // Set the array arrmeta
  array_preamble *ndo = result.get_ndo();
  ndo->m_type = ndt::type(tp).release();
  ndo->data.ptr = result_data_ptr;
  ndo->data.ref = NULL;
  ndo->m_flags = arr.get_flags();
  // Set the bytes arrmeta
  bytes_type_arrmeta *ndo_meta = reinterpret_cast<bytes_type_arrmeta *>(result.get_arrmeta());
  ndo_meta->blockref = data_ref.release();
  return result;
}

nd::array dynd::struct_concat(nd::array lhs, nd::array rhs)
{
  nd::array res;
  if (lhs.is_null()) {
    res = rhs;
    return res;
  }
  if (rhs.is_null()) {
    res = lhs;
    return res;
  }
  const ndt::type &lhs_tp = lhs.get_type(), &rhs_tp = rhs.get_type();
  if (lhs_tp.get_kind() != struct_kind) {
    stringstream ss;
    ss << "Cannot concatenate array with type " << lhs_tp << " as a struct";
    throw invalid_argument(ss.str());
  }
  if (rhs_tp.get_kind() != struct_kind) {
    stringstream ss;
    ss << "Cannot concatenate array with type " << rhs_tp << " as a struct";
    throw invalid_argument(ss.str());
  }

  // Make an empty shell struct by concatenating the fields together
  intptr_t lhs_n = lhs_tp.extended<ndt::base_struct_type>()->get_field_count();
  intptr_t rhs_n = rhs_tp.extended<ndt::base_struct_type>()->get_field_count();
  intptr_t res_n = lhs_n + rhs_n;
  nd::array res_field_names = nd::empty(res_n, ndt::string_type::make());
  nd::array res_field_types = nd::empty(res_n, ndt::make_type());
  res_field_names(irange(0, lhs_n)).vals() = lhs_tp.extended<ndt::base_struct_type>()->get_field_names();
  res_field_names(irange(lhs_n, res_n)).vals() = rhs_tp.extended<ndt::base_struct_type>()->get_field_names();
  res_field_types(irange(0, lhs_n)).vals() = lhs_tp.extended<ndt::base_struct_type>()->get_field_types();
  res_field_types(irange(lhs_n, res_n)).vals() = rhs_tp.extended<ndt::base_struct_type>()->get_field_types();
  ndt::type res_tp = ndt::struct_type::make(res_field_names, res_field_types);
  const ndt::type *res_field_tps = res_tp.extended<ndt::base_struct_type>()->get_field_types_raw();
  res = nd::empty_shell(res_tp);

  // Initialize the default data offsets for the struct arrmeta
  ndt::struct_type::fill_default_data_offsets(res_n, res_tp.extended<ndt::base_struct_type>()->get_field_types_raw(),
                                              reinterpret_cast<uintptr_t *>(res.get_arrmeta()));
  // Get information about the arrmeta layout of the input and res
  const uintptr_t *lhs_arrmeta_offsets = lhs_tp.extended<ndt::base_struct_type>()->get_arrmeta_offsets_raw();
  const uintptr_t *rhs_arrmeta_offsets = rhs_tp.extended<ndt::base_struct_type>()->get_arrmeta_offsets_raw();
  const uintptr_t *res_arrmeta_offsets = res_tp.extended<ndt::base_struct_type>()->get_arrmeta_offsets_raw();
  const char *lhs_arrmeta = lhs.get_arrmeta();
  const char *rhs_arrmeta = rhs.get_arrmeta();
  char *res_arrmeta = res.get_arrmeta();
  // Copy the arrmeta from the input arrays
  for (intptr_t i = 0; i < lhs_n; ++i) {
    const ndt::type &tp = res_field_tps[i];
    if (!tp.is_builtin()) {
      tp.extended()->arrmeta_copy_construct(res_arrmeta + res_arrmeta_offsets[i], lhs_arrmeta + lhs_arrmeta_offsets[i],
                                            lhs.get_data_memblock().get());
    }
  }
  for (intptr_t i = 0; i < rhs_n; ++i) {
    const ndt::type &tp = res_field_tps[i + lhs_n];
    if (!tp.is_builtin()) {
      tp.extended()->arrmeta_copy_construct(res_arrmeta + res_arrmeta_offsets[i + lhs_n],
                                            rhs_arrmeta + rhs_arrmeta_offsets[i], rhs.get_data_memblock().get());
    }
  }

  // Get information about the data layout of the input and res
  const uintptr_t *lhs_data_offsets = lhs_tp.extended<ndt::base_struct_type>()->get_data_offsets(lhs.get_arrmeta());
  const uintptr_t *rhs_data_offsets = rhs_tp.extended<ndt::base_struct_type>()->get_data_offsets(rhs.get_arrmeta());
  const uintptr_t *res_data_offsets = res_tp.extended<ndt::base_struct_type>()->get_data_offsets(res.get_arrmeta());
  const char *lhs_data = lhs.get_readonly_originptr();
  const char *rhs_data = rhs.get_readonly_originptr();
  char *res_data = res.get_readwrite_originptr();
  // Copy the data from the input arrays
  for (intptr_t i = 0; i < lhs_n; ++i) {
    const ndt::type &tp = res_field_tps[i];
    typed_data_copy(tp, res_arrmeta + res_arrmeta_offsets[i], res_data + res_data_offsets[i],
                    lhs_arrmeta + lhs_arrmeta_offsets[i], lhs_data + lhs_data_offsets[i]);
  }

  for (intptr_t i = 0; i < rhs_n; ++i) {
    const ndt::type &tp = res_field_tps[i + lhs_n];
    typed_data_copy(tp, res_arrmeta + res_arrmeta_offsets[i + lhs_n], res_data + res_data_offsets[i + lhs_n],
                    rhs_arrmeta + rhs_arrmeta_offsets[i], rhs_data + rhs_data_offsets[i]);
  }

  return res;
}