dmlc::SeekStream Class Reference

interface of i/o stream that support seek More...

#include <io.h>

Inheritance diagram for dmlc::SeekStream:

Public Member Functions
virtual void	Seek (size_t pos)=0
	seek to certain position of the file
virtual size_t	Tell (void)=0
	tell the position of the stream
Public Member Functions inherited from dmlc::Stream
virtual size_t	Read (void *ptr, size_t size)=0
	reads data from a stream
virtual void	Write (const void *ptr, size_t size)=0
	writes data to a stream
virtual	~Stream (void)
	virtual destructor
template<typename T >
void	Write (const T &data)
	writes a data to stream.
template<typename T >
bool	Read (T *out_data)
	loads a data from stream.
template<typename T >
void	WriteArray (const T *data, size_t num_elems)
	Endian aware write array of data.
template<typename T >
bool	ReadArray (T *data, size_t num_elems)
	Endian aware read array of data.

Static Public Member Functions
static SeekStream *	CreateForRead (const char *uri, bool allow_null=false)
	generic factory function create an SeekStream for read only, the stream will close the underlying files upon deletion error will be reported and the system will exit when create failed
Static Public Member Functions inherited from dmlc::Stream
static Stream *	Create (const char *uri, const char *const flag, bool allow_null=false)
	generic factory function create an stream, the stream will close the underlying files upon deletion

Detailed Description

interface of i/o stream that support seek

Member Function Documentation

CreateForRead()

SeekStream * dmlc::SeekStream::CreateForRead ( const char *  uri, bool  allow_null = false  )

static

generic factory function create an SeekStream for read only, the stream will close the underlying files upon deletion error will be reported and the system will exit when create failed

Parameters

uri	the uri of the input currently we support hdfs://, s3://, and file:// by default file:// will be used
allow_null	whether NULL can be returned, or directly report error

Returns

the created stream, can be NULL when allow_null == true and file do not exist

Seek()

virtual void dmlc::SeekStream::Seek ( size_t  pos )

pure virtual

seek to certain position of the file

Implemented in dmlc::MemoryFixedSizeStream, dmlc::MemoryStringStream, dmlc::io::HDFSStream, dmlc::io::FileStream, dmlc::io::s3::CURLReadStreamBase, and rabit::utils::MemoryBufferStream.

Tell()

virtual size_t dmlc::SeekStream::Tell ( void  )

pure virtual

tell the position of the stream

Implemented in rabit::utils::MemoryFixSizeBuffer, rabit::utils::MemoryBufferStream, dmlc::MemoryFixedSizeStream, dmlc::MemoryStringStream, dmlc::io::HDFSStream, dmlc::io::FileStream, and dmlc::io::s3::CURLReadStreamBase.

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

• External/xgboost/dmlc-core/include/dmlc/io.h
• External/xgboost/dmlc-core/src/io.cc