This abstract class defines the interface accessing the 'data payload' of an individual Record instance. More...

Detailed Description

This abstract class defines the interface accessing the 'data payload' of an individual Record instance.

#include <Payload.h>

Inheritance diagram for Cpl::Persistent::Payload:

Public Member Functions
virtual size_t	getData (void *dst, size_t maxDstLen) noexcept=0
	This method returns a Record's data payload contents.

virtual bool	putData (const void *src, size_t srcLen) noexcept=0
	This method used to transfer persistently stored data into a Record.

virtual	~Payload ()
	Virtual destructor.

Constructor & Destructor Documentation

◆ ~Payload()

virtual Cpl::Persistent::Payload::~Payload ( )

inlinevirtual

Virtual destructor.

Member Function Documentation

◆ getData()

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

pure virtualnoexcept

This method returns a Record's data payload contents.

The Record is responsible for NOT over-running the 'dst' buffer. The method returns the number of bytes copied to 'dst' on success; else zero is returned when there is failure.

Note: On success, the returned number of bytes MUST be the same on every call of this method, i.e. variable length records at run time is NOT supported.

Note: If the Record returns less data than 'maxDstLen' - the remaining bytes will be zero filled before the record data is written to the media.

Implemented in Cpl::Dm::Persistent::Record, Cpl::Logging::EntryData_T, Cpl::Persistent::IndexedEntryRecord, and Cpl::Persistent::IndexRecord.

◆ putData()

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

pure virtualnoexcept

This method used to transfer persistently stored data into a Record.

The method returns true if successful; else false is returned.

Note: The application is not required to consume all of the incoming data. This is because typically region are 'over-allocated' in order to leave room to grow.