vrs::RecordReader Class Reference

Abstract VRS internal helper class to read & (if necessary) uncompress records. More...

#include <RecordReaders.h>

Inheritance diagram for vrs::RecordReader:

Public Member Functions
RecordReader *	init (FileHandler &file, uint32_t diskSize, uint32_t expandedSize)
virtual int	read (DataReference &destination, uint32_t &outReadSize)=0
template<typename T , std::enable_if_t< std::is_trivially_copyable< T >::value, int > = 0>
int	read (std::vector< T > &buffer)
int	read (void *destination, size_t size)
virtual void	finish ()
	Discard any unread data.
uint32_t	getUnreadDiskBytes () const
uint32_t	getUnreadBytes () const
int64_t	getFileOffset () const
int	getFileError () const
virtual CompressionType	getCompressionType () const =0
const void *	getRef () const

Protected Attributes
FileHandler *	file_
uint32_t	remainingDiskBytes_
uint32_t	remainingUncompressedSize_
int	fileError_ {}

Detailed Description

Abstract VRS internal helper class to read & (if necessary) uncompress records.

Member Function Documentation

finish()

virtual void vrs::RecordReader::finish ( )

inlinevirtual

Discard any unread data.

Reimplemented in vrs::CompressedRecordReader.

getCompressionType()

virtual CompressionType vrs::RecordReader::getCompressionType ( ) const

pure virtual

Tell if/how the record was compressed.

Returns

The compression type.

Implemented in vrs::UncompressedRecordReader, and vrs::CompressedRecordReader.

getFileError()

int vrs::RecordReader::getFileError ( ) const

inline

Get the first error returned by the file handler while reading the current record, if any. Errors such as decompression failures or reads past the end of the record aren't file errors.

Returns

0 if no file error happened since init().

getUnreadBytes()

uint32_t vrs::RecordReader::getUnreadBytes ( ) const

inline

Tell how many bytes of record data haven't been read/consumed yet.

Returns

Number of unread bytes (uncompressed).

getUnreadDiskBytes()

uint32_t vrs::RecordReader::getUnreadDiskBytes ( ) const

inline

Tell how many disk bytes of record data haven't been read/consumed yet.

Returns

Number of unread disk bytes.

init()

RecordReader * vrs::RecordReader::init	(	FileHandler &	file,
		uint32_t	diskSize,
		uint32_t	expandedSize
	)

Initialize the RecordReader to read a record from a file.

Parameters

file	File to read from, ready to read the record at the current file position.
diskSize	Size of the record on disk.
expandedSize	Size of the record uncompressed.

Returns

Pointer to the reader.

read() [1/3]

virtual int vrs::RecordReader::read ( DataReference &  destination, uint32_t &  outReadSize  )

pure virtual

Read data to a DataReference.

Parameters

destination	DataReference to read data to.
outReadSize	Reference to set to the number of bytes read.

Returns

0 on success, or a non-zero error code.

Implemented in vrs::UncompressedRecordReader, and vrs::CompressedRecordReader.

read() [2/3]

template<typename T , std::enable_if_t< std::is_trivially_copyable< T >::value, int > = 0>

int vrs::RecordReader::read ( std::vector< T > &  buffer )

inline

Fill-up a buffer. Might reduce the buffer's size, if not enough data was available.

Parameters

buffer

Reference to a buffer of bytes to fill-up.

Returns

0 on success, or a non-zero error code.

read() [3/3]

int vrs::RecordReader::read ( void *  destination, size_t  size  )

inline

Read a number of bytes to the destination buffer. If the record is compressed, the data is uncompressed.

Parameters

destination	Pointer to the buffer where to write the read data.
size	Number of bytes to read.

Returns

0 on success, or a non-zero error code.

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

• vrs/RecordReaders.h
• vrs/RecordReaders.cpp