strus::DataRecordFile Class Reference

Basic portable file type for collections of equal sized records with random access. More...

#include <dataRecordFile.hpp>

Public Types
enum	Mode { NoAccess =0x0, SharedRead =0x1, ExclusiveAppendWrite =0x4 }
	Implemented modes to access a data record file. More...

Public Member Functions
	DataRecordFile ()
	Constructor. More...
	~DataRecordFile ()
	Destructor. More...
bool	open (const std::string &filename, const Mode &mode_, unsigned int recordsize_, unsigned int headersize_=0, const void *headerstruct=0)
	Open a file. More...
const void *	read (std::size_t fpos)
	Read one record of the file. More...
const void *	read ()
	Read the record at the current file position of the file. More...
const void *	header ()
	Get a pointer to the header of of the file. More...
bool	append (const void *recbuf)
	Append a record at the end of the file. More...
bool	close ()
	Close the file. More...
int	error () const
	Get the error of the last operation to this file. More...
std::size_t	recordsize () const
	Get the size of one record of this file. More...
std::size_t	size ()
	Get the number of records stored in the file. More...

Detailed Description

Basic portable file type for collections of equal sized records with random access.

Remarks

Access of the same file with the same DataRecordFile class is not thread safe

Member Enumeration Documentation

enum strus::DataRecordFile::Mode

Implemented modes to access a data record file.

Enumerator
NoAccess
SharedRead
ExclusiveAppendWrite

Constructor & Destructor Documentation

strus::DataRecordFile::DataRecordFile

(

)

Constructor.

strus::DataRecordFile::~DataRecordFile

(

)

Destructor.

Member Function Documentation

bool strus::DataRecordFile::append

(

const void *

recbuf

)

Append a record at the end of the file.

Parameters

[in]

recbuf

buffer containing the record to write

Returns

true, if success, false on failure (see error() for the system error code ~ errno)

bool strus::DataRecordFile::close

(

)

Close the file.

Returns

true, if success, false on failure (see error() for the system error code ~ errno)

int strus::DataRecordFile::error

(

)

const

Get the error of the last operation to this file.

Returns

the error code (system errno)

const void* strus::DataRecordFile::header

(

)

Get a pointer to the header of of the file.

Returns

pointer to the header, a structure of a size specified as last argument of DataRecordFile::open(..)

bool strus::DataRecordFile::open	(	const std::string &	filename,
		const Mode &	mode_,
		unsigned int	recordsize_,
		unsigned int	headersize_ = 0,
		const void *	headerstruct = 0
	)

Open a file.

Parameters

[in]	filename	name of the file o open
[in]	mode_	file mode describing the access to the file
[in]	recordsize_	size of one record in bytes
[in]	headersize_	size of the file header in bytes (0 for no header is default)
[in]	headerstruct	header structure in case of open for write

Returns

true, if success, false on failure (see error() for the system error code ~ errno)

const void* strus::DataRecordFile::read

(

std::size_t

fpos

)

Read one record of the file.

Parameters

[in]

fpos

index of the record to read (file position is the index multiplied with the record size)

Returns

pointer to buffer read if success, (0) NULL on failure (see error() for the system error code ~ errno)

const void* strus::DataRecordFile::read

(

)

Read the record at the current file position of the file.

Returns

pointer to buffer read if success, (0) NULL on failure (see error() for the system error code ~ errno)

std::size_t strus::DataRecordFile::recordsize ( ) const

inline

Get the size of one record of this file.

std::size_t strus::DataRecordFile::size

(

)

Get the number of records stored in the file.

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

• /home/patrick/Projects/github/strusBase/include/strus/base/dataRecordFile.hpp