Coap::Observer Class Reference

A remote CoAP observer. More...

#include <Observers.h>

Public Member Functions
	Observer ()
	Default constructor that creates an inactive observer.
	Observer (IPAddress ip, uint16_t port, const uint8_t *token, uint8_t tokenLength)
	Constructor that creates an active observer with the given parameters.
bool	isActive () const
	Check if the observer is currently active.
bool	isStale () const
	Check if the observer is stale.
void	activate ()
	Set the observer as active.
void	deactivate ()
	Set the observer as deactivated.
IPAddress	getIp () const
	Get the IP address of the observer.
uint16_t	getPort () const
	Get the port of the observer.
const uint8_t *	getToken () const
	Get the token pointer used by the observer.
uint8_t	getTokenLength () const
	Get the token length used by the observer.
uint32_t	getNextSequentialNumber ()
	The sequential number for notifications, as per specifications.

Detailed Description

A remote CoAP observer.

It tracks a remote observer registered to a specific resource for notifications.

Constructor & Destructor Documentation

Observer() [1/2]

Coap::Observer::Observer ( )

inline

Default constructor that creates an inactive observer.

Observer() [2/2]

Coap::Observer::Observer ( IPAddress ip, uint16_t port, const uint8_t * token, uint8_t tokenLength )

inline

Constructor that creates an active observer with the given parameters.

Parameters

ip	The IP address of the observer.
port	The port of the observer.
token	The token used by the observer.
tokenLength	The length of the token in bytes.

Member Function Documentation

activate()

void Coap::Observer::activate

(

)

Set the observer as active.

Setting an observer as active also updates its internal last seen value. Inactive observers are ignored by the registry and their slot can be reused to store new observers.

deactivate()

void Coap::Observer::deactivate

(

)

Set the observer as deactivated.

Inactive observers are ignored by the registry and their slot can be reused to store new observers.

getIp()

IPAddress Coap::Observer::getIp ( ) const

inline

Get the IP address of the observer.

Returns

The IP address.

getNextSequentialNumber()

uint32_t Coap::Observer::getNextSequentialNumber

(

)

The sequential number for notifications, as per specifications.

As per https://datatracker.ietf.org/doc/html/rfc7641#section-4.4, the sequence number MAY start at any value and MUST NOT increase so fast that it increases by more than 2^23 within less than 256 seconds.

As per implementation notes, using the local clock (e.g. millis()) is a simple way to meet this requirement.

Note

Only the least significant 24 bits are used.

getPort()

uint16_t Coap::Observer::getPort ( ) const

inline

Get the port of the observer.

Returns

The port number.

getToken()

const uint8_t * Coap::Observer::getToken ( ) const

inline

Get the token pointer used by the observer.

Returns

Pointer to the token.

getTokenLength()

uint8_t Coap::Observer::getTokenLength ( ) const

inline

Get the token length used by the observer.

Returns

The token length in bytes.

isActive()

bool Coap::Observer::isActive ( ) const

inline

Check if the observer is currently active.

Returns

True if the observer is active, false otherwise.

Inactive observers are ignored by the registry and their slot can be reused to store new observers.

isStale()

bool Coap::Observer::isStale

(

)

const

Check if the observer is stale.

Returns

True if the observer is stale, false otherwise.

An observer is considered stale if it is active AND has not been seen for 24 hours or more.

See also

https://datatracker.ietf.org/doc/html/rfc7641#section-4.5

---

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

• src/Observers.h
• src/Observers.cpp