This class provides a concrete implementation for a Point who's data is 32 bit unsigned reference counter. More...

Detailed Description

This class provides a concrete implementation for a Point who's data is 32 bit unsigned reference counter.

A reference counter can be increment or decremented. When incremented, the value is clamped at 2^32 -1 (not allowed to overflow). When decremented, the value is clamped at zero (not allowed to underflow). In addition, change notifications are only generated on the following transitions:

1) Invalid state to the Valid state
2) Valid state to the Invalid state
3) Transition to zero
4) Transition from zero to value greater than zero

The toJSON/fromJSON() format is:

{ name:"<mpname>", type:"<mptypestring>", valid:true|false, seqnum:nnnn, locked:true|false, val:"<act><numvalue>" }
{ name:"<mpname>", type:"<mptypestring>", valid:true|false, seqnum:nnnn, locked:true|false, val:numvalue> }
 
    where <act> can be:
        "+"             -->increment the counter
        "-"             -->decrement the counter
 
    NOTE: The value for the "val" key/value pair is a STRING, NOT a numeric
 
    Examples:
        toJSON():
            { name:"mp_visitors", type:"Cpl::Dm::Mp::RefCounter", valid:true, seqnum:12, locked:false, val:12 }
 
        fromJSON():
            { name:"mp_visitors", val:"+2" }    // Increments the point by 2
            { name:"mp_visitors", val:"-1" }    // Decrements the point by 1
            { name:"mp_visitors", val:0 }       // Resets the counter to zero

NOTE: All methods in this class ARE thread Safe unless explicitly documented otherwise.

#include <RefCounter.h>

Inheritance diagram for Cpl::Dm::Mp::RefCounter:

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Collaboration diagram for Cpl::Dm::Mp::RefCounter:

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Public Types
typedef Cpl::Dm::Subscriber< RefCounter >	Observer
	Type safe subscriber.

Public Types inherited from Cpl::Dm::ModelPoint
enum	LockRequest_T { eNO_REQUEST , eLOCK , eUNLOCK }
	Options related to the Model Point's locked state. More...

enum	Event_T { eATTACH , eDETACH , eDATA_CHANGED , eNOTIFYING , eNOTIFY_COMPLETE }
	Subscriber events. More...

Public Member Functions
	RefCounter (Cpl::Dm::ModelDatabase &myModelBase, const char *symbolicName)
	Constructor. Invalid MP.

	RefCounter (Cpl::Dm::ModelDatabase &myModelBase, const char *symbolicName, uint32_t initialValue)
	Constructor. Valid MP. Requires an initial value.

virtual uint16_t	increment (uint32_t incrementAmount=1, LockRequest_T lockRequest=eNO_REQUEST) noexcept
	Increments the counter. Note: The counter is protected from overflowing.

virtual uint16_t	decrement (uint32_t decrementAmount=1, LockRequest_T lockRequest=eNO_REQUEST) noexcept
	Decrements the counter. Note: The counter is protected from underflowing.

bool	read (uint32_t &dstData, uint16_t *seqNumPtr=0) const noexcept
	Type safe read. See Cpl::Dm::ModelPoint.

virtual uint16_t	reset (uint32_t newValue=0, LockRequest_T lockRequest=eNO_REQUEST) noexcept
	Resets the counter to zero (or to a specific value)

uint16_t	copyFrom (const RefCounter &src, LockRequest_T lockRequest=eNO_REQUEST) noexcept
	Updates the MP with the valid-state/data from 'src'. Note: the src.lock state is NOT copied.

const char *	getTypeAsText () const noexcept
	See Cpl::Dm::ModelPoint.

void	attach (Observer &observer, uint16_t initialSeqNumber=SEQUENCE_NUMBER_UNKNOWN) noexcept
	Type safe register observer.

void	detach (Observer &observer) noexcept
	Type safe un-register observer.

bool	fromJSON_ (JsonVariant &src, LockRequest_T lockRequest, uint16_t &retSequenceNumber, Cpl::Text::String *errorMsg) noexcept
	See Cpl::Dm::Point.

bool	readAndSync (uint32_t &dstData, SubscriberApi &observerToSync)
	See Cpl::Dm::ModelPointCommon.

Public Member Functions inherited from Cpl::Dm::ModelPointCommon_
const char *	getName () const noexcept
	See Cpl::Dm::ModelPoint.

size_t	getSize () const noexcept
	See Cpl::Dm::ModelPoint. This method IS thread safe.

uint16_t	getSequenceNumber () const noexcept
	See Cpl::Dm::ModelPoint.

uint16_t	touch () noexcept
	See Cpl::Dm::ModelPoint.

uint16_t	setInvalid (LockRequest_T lockRequest=eNO_REQUEST) noexcept
	See Cpl::Dm::ModelPoint.

bool	isNotValid (uint16_t *seqNumPtr=0) const noexcept
	See Cpl::Dm::ModelPoint.

bool	isLocked () const noexcept
	See Cpl::Dm::ModelPoint.

uint16_t	setLockState (LockRequest_T lockRequest) noexcept
	See Cpl::Dm::ModelPoint.

size_t	getExternalSize (bool includeLockedState=false) const noexcept
	See Cpl::Dm::ModelPoint.

size_t	exportData (void dstDataStream, size_t maxDstLength, uint16_t retSequenceNumber=0, bool includeLockedState=false) const noexcept
	See Cpl::Dm::ModelPoint. Note: The implementation does NOT account for Endianess, i.e. assumes the 'platform' is the same for export/import.

size_t	importData (const void srcDataStream, size_t srcLength, uint16_t retSequenceNumber=0, bool includeLockedState=false) noexcept
	See Cpl::Dm::ModelPoint. Note: The implementation does NOT account for Endianess, i.e. assumes the 'platform' is the same for export/import.

void	genericAttach (SubscriberApi &observer, uint16_t initialSeqNumber=SEQUENCE_NUMBER_UNKNOWN) noexcept
	See Cpl::Dm::ModelPoint.

void	genericDetach (SubscriberApi &observer) noexcept
	See Cpl::Dm::ModelPoint.

bool	toJSON (char *dst, size_t dstSize, bool &truncated, bool verbose=true, bool pretty=false) noexcept
	See Cpl::Dm::ModelPoint.

bool	isNotValidAndSync (SubscriberApi &observerToSync)
	This method is used to test the validate state of the MP and synchronize the observer with the current MP contents.

void	processSubscriptionEvent_ (SubscriberApi &subscriber, Event_T event) noexcept
	See Cpl::Dm::ModelPoint.

Public Member Functions inherited from Cpl::Dm::ModelPoint
uint16_t	removeLock () noexcept
	Short hand for unconditionally removing the lock from the MP.

uint16_t	applyLock () noexcept
	Short hand for putting the MP into the locked state.

virtual bool	exportMetadata_ (void *dstDataStream, size_t &bytesAdded) const noexcept
	This method has PACKAGE Scope, i.e.

virtual bool	importMetadata_ (const void *srcDataStream, size_t &bytesConsumed) noexcept
	This method has PACKAGE Scope, i.e.

virtual	~ModelPoint ()
	Virtual destructor to make the compiler happy.

Public Member Functions inherited from Cpl::Container::Item
bool	insert_ (void *newContainerPtr)
	Helper method to trap when inserting an item in multiple containers.

bool	isInContainer_ (const void *containerPtr) const noexcept
	Returns 'true' if the instance is in the specified container.

Protected Member Functions
void	setJSONVal (JsonDocument &doc) noexcept
	See Cpl::Dm::Point.

void	updateAndCheckForChangeNotification (uint32_t newValue)
	Helper method for only generating change notification on certain transitions.

Protected Member Functions inherited from Cpl::Dm::ModelPointCommon_
	ModelPointCommon_ (ModelDatabase &myModelBase, const char symbolicName, void myDataPtr, size_t dataSizeInBytes, bool isValid=false)
	Constructor.

bool	readAndSync (void *dstData, size_t dstSize, SubscriberApi &observerToSync)
	This method is used to read the MP contents and synchronize the observer with the current MP contents.

bool	readData (void dstData, size_t dstSize, uint16_t seqNumPtr=0) const noexcept
	See Cpl::Dm::ModelPoint.

uint16_t	writeData (const void *srcData, size_t srcSize, LockRequest_T lockRequest=eNO_REQUEST) noexcept
	See Cpl::Dm::ModelPoint.

virtual uint16_t	copyDataAndStateFrom (const ModelPointCommon_ &src, LockRequest_T lockRequest) noexcept
	Updates the MP with the valid-state/data from 'src'. Note: the src.lock state is NOT copied.

void	attachSubscriber (SubscriberApi &observer, uint16_t initialSeqNumber=SEQUENCE_NUMBER_UNKNOWN) noexcept
	See Cpl::Dm::ModelPoint.

void	detachSubscriber (SubscriberApi &observer) noexcept
	See Cpl::Dm::ModelPoint.

void	copyDataTo_ (void *dstData, size_t dstSize) const noexcept
	See Cpl::Dm::ModelPoint.

void	copyDataFrom_ (const void *srcData, size_t srcSize) noexcept
	See Cpl::Dm::ModelPoint.

bool	isDataEqual_ (const void *otherData) const noexcept
	See Cpl::Dm::ModelPoint. Note: This implementation does NOT work if the any of the data content are floats/double data types.

const void *	getImportExportDataPointer_ () const noexcept
	See Cpl::Dm::ModelPoint.

size_t	getInternalDataSize_ () const noexcept
	See Cpl::Dm::ModelPoint.

virtual void	processDataUpdated () noexcept
	Internal helper method that completes the data update process as well as ensuring any change notifications get generated.

virtual void	processChangeNotifications () noexcept
	Internal helper method that handles generating change notifications when the Model Point's data/state has changed.

virtual void	advanceSequenceNumber () noexcept
	Internal helper method that advances/updates the Model Point's sequence number.

virtual bool	testAndUpdateLock (LockRequest_T lockRequest) noexcept
	Internal helper method that manages testing and updating the locked state.

virtual void	transitionToNotifyPending (SubscriberApi &subscriber) noexcept
	Helper FSM method.

virtual void	transitionToSubscribed (SubscriberApi &subscriber) noexcept
	Helper FSM method.

virtual JsonDocument &	beginJSON (bool isValid, bool locked, uint16_t seqnum, bool verbose=true) noexcept
	Helper method when converting MP to a JSON string.

virtual void	endJSON (char *dst, size_t dstSize, bool &truncated, bool verbose=true, bool pretty=false) noexcept
	Helper method when converting MP to a JSON string.

virtual void	hookSetInvalid () noexcept
	Helper method that a child a class can override to change behavior when an MP is set to the invalid state.

Protected Member Functions inherited from Cpl::Container::Item
	Item ()
	Constructor.

	Item (const char *)
	Constructor used ONLY with the child class MapItem: -->special constructor to allow a Map to be statically allocated.

Protected Attributes
uint32_t	m_data
	My data.

Protected Attributes inherited from Cpl::Dm::ModelPointCommon_
Cpl::Container::DList< SubscriberApi >	m_subscribers
	List of Active Subscribers.

const char *	m_name
	The model point's symbolic name.

ModelDatabase &	m_modelDatabase
	Reference to the containing Model Base.

void *	m_dataPtr
	Reference to my Data.

size_t	m_dataSize
	Size of my data.

uint16_t	m_seqNum
	Sequence number used for tracking changes in the Point data.

bool	m_locked
	Locked state.

bool	m_valid
	valid/invalid state

Additional Inherited Members
Static Public Member Functions inherited from Cpl::Container::Item
static void	remove_ (Item *itemPtr) noexcept
	Helper method to do the proper 'clean-up' for the multiple-containers-error-trap when removing an item from a container.

Public Attributes inherited from Cpl::Container::Item
void *	m_nextPtr_
	The link field.

void *	m_inListPtr_
	Debug field.

Static Public Attributes inherited from Cpl::Dm::ModelPoint
static const uint16_t	SEQUENCE_NUMBER_UNKNOWN
	Magic value to use when registering for a change notification and application does not 'know' the current sequence number value of the Model Point.

Member Typedef Documentation

◆ Observer

typedef Cpl::Dm::Subscriber<RefCounter> Cpl::Dm::Mp::RefCounter::Observer

Type safe subscriber.

Constructor & Destructor Documentation

◆ RefCounter() [1/2]

Cpl::Dm::Mp::RefCounter::RefCounter	(	Cpl::Dm::ModelDatabase &	myModelBase,
		const char *	symbolicName
	)

Constructor. Invalid MP.

◆ RefCounter() [2/2]

Cpl::Dm::Mp::RefCounter::RefCounter	(	Cpl::Dm::ModelDatabase &	myModelBase,
		const char *	symbolicName,
		uint32_t	initialValue
	)

Constructor. Valid MP. Requires an initial value.

Member Function Documentation

◆ attach()

void Cpl::Dm::Mp::RefCounter::attach	(	Observer &	observer,
		uint16_t	initialSeqNumber = `SEQUENCE_NUMBER_UNKNOWN`
	)

noexcept

Type safe register observer.

◆ copyFrom()

uint16_t Cpl::Dm::Mp::RefCounter::copyFrom	(	const RefCounter &	src,
		LockRequest_T	lockRequest = `eNO_REQUEST`
	)

inlinenoexcept

Updates the MP with the valid-state/data from 'src'. Note: the src.lock state is NOT copied.

◆ decrement()

virtual uint16_t Cpl::Dm::Mp::RefCounter::decrement	(	uint32_t	decrementAmount = `1`,
		LockRequest_T	lockRequest = `eNO_REQUEST`
	)

virtualnoexcept

Decrements the counter. Note: The counter is protected from underflowing.

◆ detach()

void Cpl::Dm::Mp::RefCounter::detach ( Observer & observer )

noexcept

Type safe un-register observer.

◆ fromJSON_()

bool Cpl::Dm::Mp::RefCounter::fromJSON_	(	JsonVariant &	src,
		LockRequest_T	lockRequest,
		uint16_t &	retSequenceNumber,
		Cpl::Text::String *	errorMsg
	)

virtualnoexcept

See Cpl::Dm::Point.

Implements Cpl::Dm::ModelPoint.

◆ getTypeAsText()

const char * Cpl::Dm::Mp::RefCounter::getTypeAsText ( ) const

virtualnoexcept

See Cpl::Dm::ModelPoint.

Implements Cpl::Dm::ModelPoint.

◆ increment()

virtual uint16_t Cpl::Dm::Mp::RefCounter::increment	(	uint32_t	incrementAmount = `1`,
		LockRequest_T	lockRequest = `eNO_REQUEST`
	)

virtualnoexcept

Increments the counter. Note: The counter is protected from overflowing.

◆ read()

bool Cpl::Dm::Mp::RefCounter::read	(	uint32_t &	dstData,
		uint16_t *	seqNumPtr = `0`
	)		const

inlinenoexcept

Type safe read. See Cpl::Dm::ModelPoint.

◆ readAndSync()

bool Cpl::Dm::Mp::RefCounter::readAndSync	(	uint32_t &	dstData,
		SubscriberApi &	observerToSync
	)

inline

See Cpl::Dm::ModelPointCommon.

◆ reset()

virtual uint16_t Cpl::Dm::Mp::RefCounter::reset	(	uint32_t	newValue = `0`,
		LockRequest_T	lockRequest = `eNO_REQUEST`
	)

virtualnoexcept

Resets the counter to zero (or to a specific value)

◆ setJSONVal()

void Cpl::Dm::Mp::RefCounter::setJSONVal ( JsonDocument & doc )

protectedvirtualnoexcept

See Cpl::Dm::Point.

Implements Cpl::Dm::ModelPoint.

◆ updateAndCheckForChangeNotification()

void Cpl::Dm::Mp::RefCounter::updateAndCheckForChangeNotification ( uint32_t newValue )

protected

Helper method for only generating change notification on certain transitions.

Member Data Documentation

◆ m_data

uint32_t Cpl::Dm::Mp::RefCounter::m_data

protected

My data.

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

Cpl/Dm/Mp/RefCounter.h

Detailed Description

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Member Typedef Documentation

◆ Observer

Constructor & Destructor Documentation

◆ RefCounter() [1/2]

◆ RefCounter() [2/2]

Member Function Documentation

◆ attach()

◆ copyFrom()

◆ decrement()

◆ detach()

◆ fromJSON_()

◆ getTypeAsText()

◆ increment()

◆ read()

◆ readAndSync()

◆ reset()

◆ setJSONVal()

◆ updateAndCheckForChangeNotification()

Member Data Documentation

◆ m_data