1 /*
2  * Copyright (c) 2020-2022, NVIDIA CORPORATION.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 #pragma once
18 #include <cuda_runtime.h>
21 #include <cudf/types.hpp>
23 namespace cudf {
25 namespace detail {
33  public:
34  lists_column_device_view() = delete;
35  ~lists_column_device_view() = default;
56  CUDF_HOST_DEVICE lists_column_device_view(column_device_view const& underlying_)
57  : column_device_view(underlying_)
58  {
59 #ifdef __CUDA_ARCH__
60  cudf_assert(underlying_.type().id() == type_id::LIST and
61  "lists_column_device_view only supports lists");
62 #else
63  CUDF_EXPECTS(underlying_.type().id() == type_id::LIST,
64  "lists_column_device_view only supports lists");
65 #endif
66  }
78  [[nodiscard]] __device__ inline column_device_view offsets() const
79  {
81  }
90  [[nodiscard]] __device__ inline size_type offset_at(size_type idx) const
91  {
92  return offsets().size() > 0 ? offsets().element<size_type>(offset() + idx) : 0;
93  }
100  [[nodiscard]] __device__ inline column_device_view child() const
101  {
103  }
110  [[nodiscard]] __device__ inline column_device_view get_sliced_child() const
111  {
112  auto start = offset_at(0);
113  auto end = offset_at(size());
114  return child().slice(start, end - start);
115  }
116 };
118 } // namespace detail
120 } // namespace cudf
An immutable, non-owning view of device data as a column of elements that is trivially copyable and u...
column_device_view child(size_type child_index) const noexcept
Returns the specified child.
T element(size_type element_index) const noexcept
Returns reference to element at the specified index.
CUDF_HOST_DEVICE column_device_view slice(size_type offset, size_type size) const noexcept
Get a new column_device_view which is a slice of this column.
const_iterator< T > end() const
Returns an iterator to the element following the last element of the column.
constexpr type_id id() const noexcept
Returns the type identifier.
Definition: types.hpp:271
CUDF_HOST_DEVICE data_type type() const noexcept
Returns the element type.
CUDF_HOST_DEVICE size_type size() const noexcept
Returns the number of elements in the column.
bool is_null(size_type element_index) const noexcept
Returns whether the specified element is null.
CUDF_HOST_DEVICE size_type offset() const noexcept
Returns the index of the first element relative to the base memory allocation, i.e....
CUDF_HOST_DEVICE bool nullable() const noexcept
Indicates whether the column can contain null elements, i.e., if it has an allocated bitmask.
Given a column_device_view, an instance of this class provides a wrapper on this compound column for ...
column_device_view offsets() const
Fetches the offsets column of the underlying list column.
lists_column_device_view(lists_column_device_view &&)=default
Move constructor.
column_device_view get_sliced_child() const
Fetches the child column of the underlying list column with offset and size applied.
lists_column_device_view & operator=(lists_column_device_view const &)=default
Copy assignment operator.
lists_column_device_view & operator=(lists_column_device_view &&)=default
Move assignment operator.
size_type offset_at(size_type idx) const
Fetches the list offset value at a given row index while taking column offset into account.
lists_column_device_view(lists_column_device_view const &)=default
Copy constructor.
column_device_view child() const
Fetches the child column of the underlying list column.
static constexpr size_type child_column_index
The index of the child column.
static constexpr size_type offsets_column_index
The index of the offsets column.
Column device view class definitions.
#define CUDF_EXPECTS(...)
Macro for checking (pre-)conditions that throws an exception when a condition is violated.
Definition: error.hpp:170
int32_t size_type
Row index type for columns and tables.
Definition: types.hpp:80
List elements.
Class definition for cudf::lists_column_view.
cuDF interfaces
Definition: aggregation.hpp:34
Type declarations for libcudf.