A container of nullable device data as a column of elements. More...

#include <column.hpp>

Classes
struct	contents
	Wrapper for the contents of a column. More...

Public Member Functions
column &	operator= (column const &other)=delete

column &	operator= (column &&other)=delete

	column (column const &other, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Construct a new column object by deep copying the contents of `other`. More...

	column (column &&other) noexcept
	Move the contents from `other` to create a new column. More...

template<typename T , CUDF_ENABLE_IF(cudf::is_numeric< T >() or cudf::is_chrono< T >()) >
	column (rmm::device_uvector< T > &&other, rmm::device_buffer &&null_mask, size_type null_count)
	Construct a new column by taking ownership of the contents of a device_uvector. More...

template<typename B1 , typename B2 = rmm::device_buffer>
	column (data_type dtype, size_type size, B1 &&data, B2 &&null_mask, size_type null_count, std::vector< std::unique_ptr< column >> &&children={})
	Construct a new column from existing device memory. More...

	column (column_view view, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Construct a new column by deep copying the contents of a `column_view`. More...

data_type	type () const noexcept
	Returns the column's logical element type. More...

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

size_type	null_count () const
	Returns the count of null elements. More...

void	set_null_mask (rmm::device_buffer &&new_null_mask, size_type new_null_count)
	Sets the column's null value indicator bitmask to `new_null_mask`. More...

void	set_null_mask (rmm::device_buffer const &new_null_mask, size_type new_null_count, rmm::cuda_stream_view stream=cudf::get_default_stream())
	Sets the column's null value indicator bitmask to `new_null_mask`. More...

void	set_null_count (size_type new_null_count)
	Updates the count of null elements. More...

bool	nullable () const noexcept
	Indicates whether it is possible for the column to contain null values, i.e., it has an allocated null mask. More...

bool	has_nulls () const noexcept
	Indicates whether the column contains null elements. More...

size_type	num_children () const noexcept
	Returns the number of child columns. More...

column &	child (size_type child_index) noexcept
	Returns a reference to the specified child. More...

column const &	child (size_type child_index) const noexcept
	Returns a const reference to the specified child. More...

contents	release () noexcept
	Releases ownership of the column's contents. More...

column_view	view () const
	Creates an immutable, non-owning view of the column's data and children. More...

	operator column_view () const
	Implicit conversion operator to a `column_view`. More...

mutable_column_view	mutable_view ()
	Creates a mutable, non-owning view of the column's data, null mask, and children. More...

	operator mutable_column_view ()
	Implicit conversion operator to a `mutable_column_view`. More...

Detailed Description

A container of nullable device data as a column of elements.

Definition at line 47 of file column.hpp.

Constructor & Destructor Documentation

◆ column() [1/5]

cudf::column::column	(	column const &	other,
		rmm::cuda_stream_view	stream = `cudf::get_default_stream()`,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Construct a new column object by deep copying the contents of other.

Uses the specified stream and device_memory_resource for all allocations and copies.

Parameters

other	The `column` to copy
stream	CUDA stream used for device memory operations.
mr	Device memory resource to use for all device memory allocations

◆ column() [2/5]

cudf::column::column ( column && other )

noexcept

Move the contents from other to create a new column.

After the move, other.size() == 0 and other.type() = {EMPTY}

Parameters

other The column whose contents will be moved into the new column

◆ column() [3/5]

template<typename T , CUDF_ENABLE_IF(cudf::is_numeric< T >() or cudf::is_chrono< T >()) >

cudf::column::column	(	rmm::device_uvector< T > &&	other,
		rmm::device_buffer &&	null_mask,
		size_type	null_count
	)

inline

Construct a new column by taking ownership of the contents of a device_uvector.

Parameters

other	The device_uvector whose contents will be moved into the new column.
null_mask	Column's null value indicator bitmask. May be empty if `null_count` is 0.
null_count	The count of null elements.

Definition at line 86 of file column.hpp.

◆ column() [4/5]

template<typename B1 , typename B2 = rmm::device_buffer>

cudf::column::column	(	data_type	dtype,
		size_type	size,
		B1 &&	data,
		B2 &&	null_mask,
		size_type	null_count,
		std::vector< std::unique_ptr< column >> &&	children = `{}`
	)

inline

Construct a new column from existing device memory.

Note: This constructor is primarily intended for use in column factory functions.

Exceptions

cudf::logic_error if size < 0

Parameters

dtype	The element type
size	The number of elements in the column
data	The column's data
null_mask	Column's null value indicator bitmask. May be empty if `null_count` is 0.
null_count	Optional, the count of null elements.
children	Optional, vector of child columns

Definition at line 117 of file column.hpp.

◆ column() [5/5]

cudf::column::column	(	column_view	view,
		rmm::cuda_stream_view	stream = `cudf::get_default_stream()`,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

explicit

Construct a new column by deep copying the contents of a column_view.

This accounts for the column_view's offset.

Parameters

view	The view to copy
stream	CUDA stream used for device memory operations.
mr	Device memory resource to use for all device memory allocations

Member Function Documentation

◆ child() [1/2]

column const& cudf::column::child ( size_type child_index ) const

inlinenoexcept

Returns a const reference to the specified child.

Parameters

child_index Index of the desired child

Returns: Const reference to the desired child

Definition at line 249 of file column.hpp.

◆ child() [2/2]

column& cudf::column::child ( size_type child_index )

inlinenoexcept

Returns a reference to the specified child.

Parameters

child_index Index of the desired child

Returns: Reference to the desired child

Definition at line 241 of file column.hpp.

◆ has_nulls()

bool cudf::column::has_nulls ( ) const

inlinenoexcept

Indicates whether the column contains null elements.

Returns: true One or more elements are null; false Zero elements are null

Definition at line 226 of file column.hpp.

◆ mutable_view()

mutable_column_view cudf::column::mutable_view ( )

Creates a mutable, non-owning view of the column's data, null mask, and children.

Returns: The mutable, non-owning view

◆ null_count()

size_type cudf::column::null_count ( ) const

inline

Returns the count of null elements.

Returns: The number of null elements

Definition at line 166 of file column.hpp.

◆ nullable()

bool cudf::column::nullable ( ) const

inlinenoexcept

Indicates whether it is possible for the column to contain null values, i.e., it has an allocated null mask.

This may return false iff null_count() == 0.

May return true even if null_count() == 0. This function simply indicates whether the column has an allocated null mask.

Returns: true The column can hold null values; false The column cannot hold null values

Definition at line 218 of file column.hpp.

◆ num_children()

size_type cudf::column::num_children ( ) const

inlinenoexcept

Returns the number of child columns.

Returns: The number of child columns

Definition at line 233 of file column.hpp.

◆ operator column_view()

cudf::column::operator column_view ( ) const

inline

Implicit conversion operator to a column_view.

This allows passing a column object directly into a function that requires a column_view. The conversion is automatic.

Returns: Immutable, non-owning column_view

Definition at line 298 of file column.hpp.

◆ operator mutable_column_view()

cudf::column::operator mutable_column_view ( )

inline

Implicit conversion operator to a mutable_column_view.

This allows passing a column object into a function that accepts a mutable_column_view. The conversion is automatic.

The caller is expected to update the null count appropriately if the null mask is modified.

Returns: Mutable, non-owning mutable_column_view

Definition at line 319 of file column.hpp.

◆ release()

contents cudf::column::release ( )

noexcept

Releases ownership of the column's contents.

It is the caller's responsibility to query the size(), null_count(), type() before invoking release().

After calling release() on a column it will be empty, i.e.:

type() == data_type{EMPTY}
size() == 0
null_count() == 0
num_children() == 0

Returns: A contents struct containing the data, null mask, and children of the column.

◆ set_null_count()

void cudf::column::set_null_count ( size_type new_null_count )

Updates the count of null elements.

Exceptions

cudf::logic_error if new_null_count > 0 and nullable() == false

Parameters

new_null_count The new null count.

◆ set_null_mask() [1/2]

void cudf::column::set_null_mask	(	rmm::device_buffer &&	new_null_mask,
		size_type	new_null_count
	)

Sets the column's null value indicator bitmask to new_null_mask.

Exceptions

cudf::logic_error if new_null_count is larger than 0 and the size of new_null_mask does not match the size of this column.

Parameters

new_null_mask	New null value indicator bitmask (rvalue overload & moved) to set the column's null value indicator mask. May be empty if `new_null_count` is 0.
new_null_count	The count of null elements.

◆ set_null_mask() [2/2]

void cudf::column::set_null_mask	(	rmm::device_buffer const &	new_null_mask,
		size_type	new_null_count,
		rmm::cuda_stream_view	stream = `cudf::get_default_stream()`
	)

Sets the column's null value indicator bitmask to new_null_mask.

Exceptions

cudf::logic_error if new_null_count is larger than 0 and the size of new_null_mask does not match the size of this column.

Parameters

new_null_mask	New null value indicator bitmask (lvalue overload & copied) to set the column's null value indicator mask. May be empty if `new_null_count` is 0.
new_null_count	The count of null elements
stream	The stream on which to perform the allocation and copy. Uses the default CUDF stream if none is specified.

◆ size()

size_type cudf::column::size ( ) const

inlinenoexcept

Returns the number of elements.

Returns: The number of elements

Definition at line 159 of file column.hpp.

◆ type()

data_type cudf::column::type ( ) const

inlinenoexcept

Returns the column's logical element type.

Returns: The column's logical element type

Definition at line 152 of file column.hpp.

◆ view()

column_view cudf::column::view ( ) const

Creates an immutable, non-owning view of the column's data and children.

Returns: The immutable, non-owning view

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

column.hpp

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ column() [1/5]

◆ column() [2/5]

◆ column() [3/5]

◆ column() [4/5]

◆ column() [5/5]

Member Function Documentation

◆ child() [1/2]

◆ child() [2/2]

◆ has_nulls()

◆ mutable_view()

◆ null_count()

◆ nullable()

◆ num_children()

◆ operator column_view()

◆ operator mutable_column_view()

◆ release()

◆ set_null_count()

◆ set_null_mask() [1/2]

◆ set_null_mask() [2/2]

◆ size()

◆ type()

◆ view()