Cpl::Persistent::IndexRecord Class Reference

This concrete class extends the Cpl::Persistent::DataRecord interface to store a latest/oldest 'record index' into a RegionMedia. More...

Detailed Description

This concrete class extends the Cpl::Persistent::DataRecord interface to store a latest/oldest 'record index' into a RegionMedia.

This class is for tracking the head pointer (so to speak) of a collection of IndexedEntryRecords.

From a logical perspective, IndexedEntryRecords are stored in a Ring Buffer and when the buffer is full, the oldest entry/records are overwritten. The head pointer of this logical ring buffer is stored in this class.

Each entry that is stored has an 'index' value associated with it. This 'index' is used to uniquely identify each entry (even across overwritten entries) and it is used to identify the relative age between the entries.

NOTE: The index value for the oldest entry is NOT tracked by the Index Record

NOTE: This class should not be used/directly access by the Application. The methods are public to facilitate use by the Cpl::Persistent namespace ONLY

NOTE: This class can be extended by an application specific child class to add additional information to be stored with the index offsets.

NOTE: This interface/class is NOT THREAD SAFE and should only be 'used' from the Record Server's thread.

#include <IndexRecord.h>

Inheritance diagram for Cpl::Persistent::IndexRecord:

Collaboration diagram for Cpl::Persistent::IndexRecord:

Public Member Functions
	IndexRecord (Cpl::Persistent::Chunk &chunkHandler) noexcept
	Constructor.
virtual bool	getLatestOffset (size_t &offset, uint64_t &indexValue) const noexcept
	This method returns the 'offset-index' (starting from the start of RegionMedia used for the entries) of the most recently written Indexed Entry.
virtual void	setLatestOffset (size_t offset, uint64_t indexValue) noexcept
	This method updates/sets the 'offset-index' (starting from the start of RegionMedia used for the entries) of the most recently written Indexed Entry.
size_t	getPayloadSize () const noexcept
	Helper method: returns the length of the payload.
void	start (Cpl::Dm::MailboxServer &myMbox) noexcept
	See Cpl::Persistent::DataRecord.
void	stop () noexcept
	See Cpl::Persistent::DataRecord.
size_t	getData (void *dst, size_t maxDstLen) noexcept
	Default Payload method: payload is the 2 offset-index values.
bool	putData (const void *src, size_t srcLen) noexcept
	Default Payload method: payload is the 2 offset-index values.
bool	processNoValidData () noexcept
	Default Method: Simply resets both the head/tail pointers to ZERO.
Public Member Functions inherited from Cpl::Persistent::DataRecord
	DataRecord (Cpl::Persistent::Chunk &chunkHandler) noexcept
	Constructor.
	~DataRecord ()
	Destructor.
virtual bool	writeToMedia (size_t index=0) noexcept
	This method is used by the application to write the DataRecord's data to persistent storage.
virtual bool	readFromMedia (size_t index=0) noexcept
	This method is used by the application to read the DataRecord's data from persistent storage.
Public Member Functions inherited from Cpl::Persistent::Record
virtual	~Record ()
	Virtual destructor.
Public Member Functions inherited from Cpl::Persistent::Payload
virtual	~Payload ()
	Virtual destructor.

Protected Attributes
uint64_t	m_latestIndex
	Index of the latest entry.
size_t	m_latest
	Offset for the latest entry.
bool	m_validLatest
	Flag that indicates the state of offsets.
Protected Attributes inherited from Cpl::Persistent::DataRecord
Cpl::Persistent::Chunk &	m_chunkHandler
	Chunk handler for the DataRecord.
bool	m_started
	Remember my started state.

Additional Inherited Members

Constructor & Destructor Documentation

IndexRecord()

Cpl::Persistent::IndexRecord::IndexRecord ( Cpl::Persistent::Chunk &  chunkHandler )

noexcept

Constructor.

Member Function Documentation

getData()

size_t Cpl::Persistent::IndexRecord::getData ( void *  dst, size_t  maxDstLen  )

virtualnoexcept

Default Payload method: payload is the 2 offset-index values.

Implements Cpl::Persistent::Payload.

getLatestOffset()

virtual bool Cpl::Persistent::IndexRecord::getLatestOffset ( size_t &  offset, uint64_t &  indexValue  ) const

virtualnoexcept

This method returns the 'offset-index' (starting from the start of RegionMedia used for the entries) of the most recently written Indexed Entry.

Returns true if there is at least 'entry' persistent stored; else false is returned;

getPayloadSize()

size_t Cpl::Persistent::IndexRecord::getPayloadSize ( ) const

noexcept

Helper method: returns the length of the payload.

processNoValidData()

bool Cpl::Persistent::IndexRecord::processNoValidData ( )

virtualnoexcept

Default Method: Simply resets both the head/tail pointers to ZERO.

Implements Cpl::Persistent::DataRecord.

putData()

bool Cpl::Persistent::IndexRecord::putData ( const void *  src, size_t  srcLen  )

virtualnoexcept

Default Payload method: payload is the 2 offset-index values.

Implements Cpl::Persistent::Payload.

setLatestOffset()

virtual void Cpl::Persistent::IndexRecord::setLatestOffset ( size_t  offset, uint64_t  indexValue  )

virtualnoexcept

This method updates/sets the 'offset-index' (starting from the start of RegionMedia used for the entries) of the most recently written Indexed Entry.

start()

void Cpl::Persistent::IndexRecord::start ( Cpl::Dm::MailboxServer &  myMbox )

virtualnoexcept

See Cpl::Persistent::DataRecord.

Reimplemented from Cpl::Persistent::DataRecord.

stop()

void Cpl::Persistent::IndexRecord::stop ( )

virtualnoexcept

See Cpl::Persistent::DataRecord.

Reimplemented from Cpl::Persistent::DataRecord.

Member Data Documentation

m_latest

size_t Cpl::Persistent::IndexRecord::m_latest

protected

Offset for the latest entry.

m_latestIndex

uint64_t Cpl::Persistent::IndexRecord::m_latestIndex

protected

Index of the latest entry.

m_validLatest

bool Cpl::Persistent::IndexRecord::m_validLatest

protected

Flag that indicates the state of offsets.

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

• Cpl/Persistent/IndexRecord.h