Arrow

Files
file	interop.hpp

Classes
struct	cudf::column_metadata
	Detailed metadata information for arrow array. More...

Functions
std::shared_ptr< arrow::Table >	cudf::to_arrow (table_view input, std::vector< column_metadata > const &metadata={}, rmm::cuda_stream_view stream=cudf::get_default_stream(), arrow::MemoryPool *ar_mr=arrow::default_memory_pool())
	Create arrow::Table from cudf table input More...
std::shared_ptr< arrow::Scalar >	cudf::to_arrow (cudf::scalar const &input, column_metadata const &metadata={}, rmm::cuda_stream_view stream=cudf::get_default_stream(), arrow::MemoryPool *ar_mr=arrow::default_memory_pool())
	Create arrow::Scalar from cudf scalar input More...
std::unique_ptr< table >	cudf::from_arrow (arrow::Table const &input, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Create cudf::table from given arrow Table input. More...
std::unique_ptr< cudf::scalar >	cudf::from_arrow (arrow::Scalar const &input, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Create cudf::scalar from given arrow Scalar input. More...

Detailed Description

Function Documentation

from_arrow() [1/2]

std::unique_ptr<cudf::scalar> cudf::from_arrow	(	arrow::Scalar const &	input,
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Create cudf::scalar from given arrow Scalar input.

Parameters

input	arrow::Scalar that needs to be converted to cudf::scalar
stream	CUDA stream used for device memory operations and kernel launches
mr	Device memory resource used to allocate cudf::scalar

Returns

cudf scalar generated from given arrow Scalar

from_arrow() [2/2]

std::unique_ptr<table> cudf::from_arrow	(	arrow::Table const &	input,
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Create cudf::table from given arrow Table input.

Parameters

input	arrow:Table that needs to be converted to cudf::table
stream	CUDA stream used for device memory operations and kernel launches
mr	Device memory resource used to allocate cudf::table

Returns

cudf table generated from given arrow Table

to_arrow() [1/2]

std::shared_ptr<arrow::Scalar> cudf::to_arrow	(	cudf::scalar const &	input,
		column_metadata const &	metadata = {},
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		arrow::MemoryPool *	ar_mr = arrow::default_memory_pool()
	)

Create arrow::Scalar from cudf scalar input

Converts the cudf::scalar to arrow::Scalar.

Parameters

input	scalar that needs to be converted to arrow Scalar
metadata	Contains hierarchy of names of columns and children
stream	CUDA stream used for device memory operations and kernel launches
ar_mr	arrow memory pool to allocate memory for arrow Scalar

Returns

arrow Scalar generated from input

Note

For decimals, since the precision is not stored for them in libcudf, it will be converted to an Arrow decimal128 that has the widest-precision the cudf decimal type supports. For example, numeric::decimal32 will be converted to Arrow decimal128 of the precision 9 which is the maximum precision for 32-bit types. Similarly, numeric::decimal128 will be converted to Arrow decimal128 of the precision 38.

to_arrow() [2/2]

std::shared_ptr<arrow::Table> cudf::to_arrow	(	table_view	input,
		std::vector< column_metadata > const &	metadata = {},
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		arrow::MemoryPool *	ar_mr = arrow::default_memory_pool()
	)

Create arrow::Table from cudf table input

Converts the cudf::table_view to arrow::Table with the provided metadata column_names.

Exceptions

cudf::logic_error

if column_names size doesn't match with number of columns.

Parameters

input	table_view that needs to be converted to arrow Table
metadata	Contains hierarchy of names of columns and children
stream	CUDA stream used for device memory operations and kernel launches
ar_mr	arrow memory pool to allocate memory for arrow Table

Returns

arrow Table generated from input

Note

For decimals, since the precision is not stored for them in libcudf, it will be converted to an Arrow decimal128 that has the widest-precision the cudf decimal type supports. For example, numeric::decimal32 will be converted to Arrow decimal128 of the precision 9 which is the maximum precision for 32-bit types. Similarly, numeric::decimal128 will be converted to Arrow decimal128 of the precision 38.