#include <core/storage/sframe_data/sarray_reader_buffer.hpp>

Public Member Functions
	sarray_reader_buffer (std::shared_ptr< typename sarray< T >::reader_type > reader, size_t row_start, size_t row_end, size_t buffer_size=DEFAULT_SARRAY_READER_BUFFER_SIZE)
	Construct from sarray reader with begin and end row.

void	init (std::shared_ptr< typename sarray< T >::reader_type > &reader, size_t row_start, size_t row_end, size_t internal_buffer_size=DEFAULT_SARRAY_READER_BUFFER_SIZE)

void	init (typename sarray< T >::reader_type *reader_weak, size_t row_start, size_t row_end, size_t internal_buffer_size=DEFAULT_SARRAY_READER_BUFFER_SIZE)

value_type &&	next ()
	Return the next element in the reader. More...

bool	has_next ()
	Return true if the reader has more element. More...

std::vector< value_type > &	get_buffer ()
	Return the buffer.

size_t	size ()
	Return the Number of elements between row_start and row_end.

void	clear ()

Detailed Description

template<typename T>
class turi::sarray_reader_buffer< T >

A buffered reader reading from a range of an sarray<T>.

sarray<flexible_type> mysarray = ...;
// Reader for the first thousand lines
sarray_reader_buffer<flexible_type> reader(mysarray, 0, 1000);
while(reader.has_next()) {
 flexible_type val = reader.next();
 ... do some thing with val ...
}
// Reader for the entire sarray
reader = sarray_reader_buffer<flexible_type>(mysarray, 0, (size_t)(-1));
...

Internally, the reader maintains a vector as buffer, and when reading reaches the end of the buffer, refill the buffer by reading from sarray.

Definition at line 36 of file gl_sarray.hpp.

Member Function Documentation

◆ clear()

template<typename T >

void turi::sarray_reader_buffer< T >::clear ( )

Resets the buffer to the initial starting conditions. Reading from the buffer again will start from row_start.

Definition at line 174 of file sarray_reader_buffer.hpp.

◆ has_next()

template<typename T >

bool turi::sarray_reader_buffer< T >::has_next ( )

Return true if the reader has more element.

Return true if the chunk has remaining element.

Definition at line 160 of file sarray_reader_buffer.hpp.

◆ init() [1/2]

template<typename T>

void turi::sarray_reader_buffer< T >::init	(	std::shared_ptr< typename sarray< T >::reader_type > &	reader,
		size_t	row_start,
		size_t	row_end,
		size_t	internal_buffer_size = `DEFAULT_SARRAY_READER_BUFFER_SIZE`
	)

inline

Construction of a reader_buffer where the reader_buffer owns a reference to the underlying reader.

Definition at line 64 of file sarray_reader_buffer.hpp.

◆ init() [2/2]

template<typename T>

void turi::sarray_reader_buffer< T >::init	(	typename sarray< T >::reader_type *	reader_weak,
		size_t	row_start,
		size_t	row_end,
		size_t	internal_buffer_size = `DEFAULT_SARRAY_READER_BUFFER_SIZE`
	)

inline

Construction of a reader_buffer where the reader_buffer DOES NOT own a reference to the underlying reader.

Note: This is quite unsafe to use since its not even a weak_ptr but a raw pointer. The user has to be careful to ensure that the sarray_reader's lifespan exceeds that of the reader_buffer. This is provided only to support a circular case where the sarray_reader itself uses sarray_reader_buffer for buffering.

Definition at line 87 of file sarray_reader_buffer.hpp.

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

core/data/sframe/gl_sarray.hpp
core/storage/sframe_data/sarray_reader_buffer.hpp

Public Member Functions