FsBuffer Class Reference

#include <FsBuffer.hpp>

Public Member Functions
	FsBuffer ()
const char *	setup (Uint32 *Buffer, Uint32 Size, Uint32 BlockSize=128, Uint32 MinRead=1024, Uint32 MaxRead=1024, Uint32 MaxWrite=1024)
const char *	valid () const
Uint32	getBufferSize () const
Uint32	getUsableSize () const
Uint32 *	getStart () const
bool	getReadPtr (Uint32 **ptr, Uint32 *sz, bool *eof)
void	updateReadPtr (Uint32 sz)
bool	getWritePtr (Uint32 **ptr, Uint32 sz)
void	updateWritePtr (Uint32 sz)
void	eof ()
Uint32	getMaxWrite () const
Uint32	getMinRead () const
Uint32	getFreeSize () const
void	reset ()

Detailed Description

A circular data buffer to be used together with the FS

One writer - Typically your block getWritePtr() updateWritePtr()

One reader - Typically "thread" in your block sending stuff to NDBFS getReadPtr() updateReadPtr()

Definition at line 36 of file FsBuffer.hpp.

Constructor & Destructor Documentation

FsBuffer::FsBuffer ( )

inline

Default constructor

Definition at line 138 of file FsBuffer.hpp.

Member Function Documentation

void FsBuffer::eof ( )

inline

There will be no more writing to this buffer

Definition at line 358 of file FsBuffer.hpp.

Uint32 FsBuffer::getMaxWrite ( ) const

inline

Getters for varibles

Definition at line 108 of file FsBuffer.hpp.

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bool FsBuffer::getReadPtr ( Uint32 **  ptr, Uint32 *  sz, bool *  eof  )

inline

getReadPtr - Get pointer and size of data to send to FS

Parameters

ptr	- Where to fetch data
sz	- How much data in 32-bit words
eof	- Is this the last fetch (only if return false)

Returns

true - If there is data of size >= minread false - If there is can be data be if it is is < minread

• else eof = true

Definition at line 255 of file FsBuffer.hpp.

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bool FsBuffer::getWritePtr ( Uint32 **  ptr, Uint32  sz  )

inline

Note

Must be followed by a updateWritePtr(no of words used)

Definition at line 313 of file FsBuffer.hpp.

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void FsBuffer::reset ( void  )

inline

reset

Definition at line 215 of file FsBuffer.hpp.

const char * FsBuffer::setup ( Uint32 *  Buffer, Uint32  Size, Uint32  BlockSize = 128, Uint32  MinRead = 1024, Uint32  MaxRead = 1024, Uint32  MaxWrite = 1024  )

inline

setup FsBuffer

Parameters

Buffer	- Ptr to continuous memory
Size	- Buffer size in 32-bit words
BlockSize	- Size of block in 32-bit words
MinRead	- Min read size in 32-bit words Get rounded(down) to nearest multiple of block size.
MaxRead	- Max read size in 32-bit words Get rounded(down) to nearest multiple of block size.
MaxWrite	- Maximum write (into buffer) in 32-bit words

Returns

NULL if everything is OK else A string describing problem

Definition at line 166 of file FsBuffer.hpp.

void FsBuffer::updateReadPtr ( Uint32  sz )

inline

Note

: sz must be equal to sz returned by getReadPtr

Definition at line 303 of file FsBuffer.hpp.

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

• storage/ndb/src/kernel/blocks/backup/FsBuffer.hpp