An immutable, non-owning view of device data as a column of elements that is trivially copyable and usable in CUDA device code. More...

Inheritance diagram for cudf::detail::column_device_view_base:

Classes
struct	has_element_accessor_impl

struct	has_element_accessor_impl< C, T, void_t< decltype(cuda::std::declval< C >().template element< T >(cuda::std::declval< size_type >()))> >

Public Member Functions
	column_device_view_base (column_device_view_base const &)=default
	Copy constructor.

	column_device_view_base (column_device_view_base &&)=default
	Move constructor.

column_device_view_base &	operator= (column_device_view_base const &)=default
	Copy assignment operator. More...

column_device_view_base &	operator= (column_device_view_base &&)=default
	Move assignment operator. More...

template<typename T = void, CUDF_ENABLE_IF(std::is_same_v< T, void > or is_rep_layout_compatible< T >()) >
CUDF_HOST_DEVICE T const *	head () const noexcept
	Returns pointer to the base device memory allocation casted to the specified type. More...

template<typename T , CUDF_ENABLE_IF(is_rep_layout_compatible< T >()) >
CUDF_HOST_DEVICE T const *	data () const noexcept
	Returns the underlying data casted to the specified type, plus the offset. More...

CUDF_HOST_DEVICE size_type	size () const noexcept
	Returns the number of elements in the column. More...

CUDF_HOST_DEVICE data_type	type () const noexcept
	Returns the element type. More...

CUDF_HOST_DEVICE bool	nullable () const noexcept
	Indicates whether the column can contain null elements, i.e., if it has an allocated bitmask. More...

CUDF_HOST_DEVICE bitmask_type const *	null_mask () const noexcept
	Returns raw pointer to the underlying bitmask allocation. More...

CUDF_HOST_DEVICE size_type	offset () const noexcept
	Returns the index of the first element relative to the base memory allocation, i.e., what is returned from `head<T>()`. More...

bool	is_valid (size_type element_index) const noexcept
	Returns whether the specified element holds a valid value (i.e., not null). More...

bool	is_valid_nocheck (size_type element_index) const noexcept
	Returns whether the specified element holds a valid value (i.e., not null) More...

bool	is_null (size_type element_index) const noexcept
	Returns whether the specified element is null. More...

bool	is_null_nocheck (size_type element_index) const noexcept
	Returns whether the specified element is null. More...

bitmask_type	get_mask_word (size_type word_index) const noexcept
	Returns the specified bitmask word from the `null_mask()`. More...

Protected Member Functions
CUDF_HOST_DEVICE	column_device_view_base (data_type type, size_type size, void const data, bitmask_type const null_mask, size_type offset)
	Constructs a column with the specified type, size, data, nullmask and offset. More...

Protected Attributes
data_type	_type {type_id::EMPTY}
	Element type.

cudf::size_type	_size {}
	Number of elements.

void const *	_data {}
	Pointer to device memory containing elements.

bitmask_type const *	_null_mask {}

size_type	_offset {}

Detailed Description

An immutable, non-owning view of device data as a column of elements that is trivially copyable and usable in CUDA device code.

column_device_view_base and derived classes do not support has_nulls() or null_count(). The primary reason for this is that creation of column_device_views from column_views that have UNKNOWN null counts would require an on-the-spot, and not-obvious computation of null count, which could lead to undesirable performance issues. This information is also generally not needed in device code, and on the host-side is easily accessible from the associated column_view.

Definition at line 102 of file column_device_view.cuh.

Constructor & Destructor Documentation

◆ column_device_view_base()

CUDF_HOST_DEVICE cudf::detail::column_device_view_base::column_device_view_base	(	data_type	type,
		size_type	size,
		void const *	data,
		bitmask_type const *	null_mask,
		size_type	offset
	)

inlineprotected

Constructs a column with the specified type, size, data, nullmask and offset.

Parameters

type	The type of the column
size	The number of elements in the column
data	Pointer to device memory containing elements
null_mask	Pointer to device memory containing bitmask representing valid elements
offset	Index position of the first element

Definition at line 314 of file column_device_view.cuh.

Member Function Documentation

◆ data()

template<typename T , CUDF_ENABLE_IF(is_rep_layout_compatible< T >()) >

CUDF_HOST_DEVICE T const* cudf::detail::column_device_view_base::data ( ) const

inlinenoexcept

Returns the underlying data casted to the specified type, plus the offset.

Note: If offset() == 0, then head<T>() == data<T>()

For columns with children, the pointer returned is undefined and should not be used.

This function does not participate in overload resolution if is_rep_layout_compatible<T> is false.

Template Parameters

T	The type to cast to

Returns: Typed pointer to underlying data, including the offset

Definition at line 160 of file column_device_view.cuh.

◆ get_mask_word()

bitmask_type cudf::detail::column_device_view_base::get_mask_word ( size_type word_index ) const

inlinenoexcept

Returns the specified bitmask word from the null_mask().

Note: It is undefined behavior to call this function if nullable() == false.

Parameters

word_index The index of the word to get

Returns: bitmask word for the given word_index

Definition at line 291 of file column_device_view.cuh.

◆ head()

template<typename T = void, CUDF_ENABLE_IF(std::is_same_v< T, void > or is_rep_layout_compatible< T >()) >

CUDF_HOST_DEVICE T const* cudf::detail::column_device_view_base::head ( ) const

inlinenoexcept

Returns pointer to the base device memory allocation casted to the specified type.

Note: If offset() == 0, then head<T>() == data<T>(); It should be rare to need to access the head<T>() allocation of a column, and instead, accessing the elements should be done via data<T>().

This function will only participate in overload resolution if is_rep_layout_compatible<T>() or std::is_same_v<T,void> are true.

Template Parameters

The	type to cast to

Returns: Typed pointer to underlying data

Definition at line 139 of file column_device_view.cuh.

◆ is_null()

bool cudf::detail::column_device_view_base::is_null ( size_type element_index ) const

inlinenoexcept

Returns whether the specified element is null.

Checks first for the existence of the null bitmask. If nullable() == false, this function always returns false.

Note: If nullable() == true can be guaranteed, then it is more performant to use is_null_nocheck().

Parameters

element_index The index of the element to query

Returns: true The element is null; false The element is valid

Definition at line 261 of file column_device_view.cuh.

◆ is_null_nocheck()

bool cudf::detail::column_device_view_base::is_null_nocheck ( size_type element_index ) const

inlinenoexcept

Returns whether the specified element is null.

This function does not verify the existence of the bitmask before attempting to read it. Therefore, it is undefined behavior to call this function if nullable() == false.

Parameters

element_index The index of the element to query

Returns: true The element is null; false The element is valid

Definition at line 277 of file column_device_view.cuh.

◆ is_valid()

bool cudf::detail::column_device_view_base::is_valid ( size_type element_index ) const

inlinenoexcept

Returns whether the specified element holds a valid value (i.e., not null).

Checks first for the existence of the null bitmask. If nullable() == false, this function always returns true.

Note: If nullable() == true can be guaranteed, then it is more performant to use is_valid_nocheck().

Parameters

element_index The index of the element to query

Returns: true The element is valid; false The element is null

Definition at line 226 of file column_device_view.cuh.

◆ is_valid_nocheck()

bool cudf::detail::column_device_view_base::is_valid_nocheck ( size_type element_index ) const

inlinenoexcept

Returns whether the specified element holds a valid value (i.e., not null)

This function does not verify the existence of the bitmask before attempting to read it. Therefore, it is undefined behavior to call this function if nullable() == false.

Parameters

element_index The index of the element to query

Returns: true The element is valid; false The element is null

Definition at line 243 of file column_device_view.cuh.

◆ null_mask()

CUDF_HOST_DEVICE bitmask_type const* cudf::detail::column_device_view_base::null_mask ( ) const

inlinenoexcept

Returns raw pointer to the underlying bitmask allocation.

Note: This function does not account for the offset().; If null_count() == 0, this may return nullptr.

Returns: Raw pointer to the underlying bitmask allocation

Definition at line 199 of file column_device_view.cuh.

◆ nullable()

CUDF_HOST_DEVICE bool cudf::detail::column_device_view_base::nullable ( ) const

inlinenoexcept

Indicates whether the column can contain null elements, i.e., if it has an allocated bitmask.

Note: If null_count() > 0, this function must always return true.

Returns: true The bitmask is allocated; false The bitmask is not allocated

Definition at line 188 of file column_device_view.cuh.

◆ offset()

CUDF_HOST_DEVICE size_type cudf::detail::column_device_view_base::offset ( ) const

inlinenoexcept

Returns the index of the first element relative to the base memory allocation, i.e., what is returned from head<T>().

Returns: The index of the first element relative to the head<T>()

Definition at line 210 of file column_device_view.cuh.

◆ operator=() [1/2]

column_device_view_base& cudf::detail::column_device_view_base::operator= ( column_device_view_base && )

default

Move assignment operator.

Returns: Reference to this object (after transferring ownership)

◆ operator=() [2/2]

column_device_view_base& cudf::detail::column_device_view_base::operator= ( column_device_view_base const & )

default

Copy assignment operator.

Returns: Reference to this object

◆ size()

CUDF_HOST_DEVICE size_type cudf::detail::column_device_view_base::size ( ) const

inlinenoexcept

Returns the number of elements in the column.

Returns: The number of elements in the column

Definition at line 170 of file column_device_view.cuh.

◆ type()

CUDF_HOST_DEVICE data_type cudf::detail::column_device_view_base::type ( ) const

inlinenoexcept

Returns the element type.

Returns: The element type

Definition at line 177 of file column_device_view.cuh.

Member Data Documentation

◆ _null_mask

bitmask_type const* cudf::detail::column_device_view_base::_null_mask {}

protected

Pointer to device memory containing bitmask representing null elements.

Definition at line 300 of file column_device_view.cuh.

◆ _offset

size_type cudf::detail::column_device_view_base::_offset {}

protected

Index position of the first element. Enables zero-copy slicing

Definition at line 302 of file column_device_view.cuh.

The documentation for this class was generated from the following file:

column_device_view.cuh

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ column_device_view_base()

Member Function Documentation

◆ data()

◆ get_mask_word()

◆ head()

◆ is_null()

◆ is_null_nocheck()

◆ is_valid()

◆ is_valid_nocheck()

◆ null_mask()

◆ nullable()

◆ offset()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ size()

◆ type()

Member Data Documentation

◆ _null_mask

◆ _offset