Observe Subscription

Internal API for handling CoAP Observe Subscriptions (RFC7641) More...

Collaboration diagram for Observe Subscription:

Data Structures
struct	coap_subscription_t
	Number of notifications that may be sent non-confirmable before a confirmable message is sent to detect if observers are alive. More...

Functions
void	coap_subscription_init (coap_subscription_t *)
void	coap_handle_failed_notify (coap_context_t *context, coap_session_t *session, const coap_binary_t *token)
	Handles a failed observe notify. More...
void	coap_check_notify (coap_context_t *context)
	Checks all known resources to see if they are dirty and then notifies subscribed observers. More...
coap_subscription_t *	coap_add_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token, const coap_pdu_t *pdu)
	Adds the specified peer as observer for resource. More...
coap_subscription_t *	coap_find_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token)
	Returns a subscription object for given peer. More...
void	coap_touch_observer (coap_context_t *context, coap_session_t *session, const coap_binary_t *token)
	Flags that data is ready to be sent to observers. More...
int	coap_delete_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token)
	Removes any subscription for observer from resource and releases the allocated storage. More...
void	coap_delete_observers (coap_context_t *context, coap_session_t *session)
	Removes any subscription for session and releases the allocated storage. More...

Detailed Description

Internal API for handling CoAP Observe Subscriptions (RFC7641)

Function Documentation

coap_add_observer()

coap_subscription_t * coap_add_observer	(	coap_resource_t *	resource,
		coap_session_t *	session,
		const coap_binary_t *	token,
		const coap_pdu_t *	pdu
	)

Adds the specified peer as observer for resource.

The subscription is identified by the given token. This function returns the registered subscription information if the observer has been added, or NULL on error.

Parameters

resource	The observed resource.
session	The observer's session
token	The token that identifies this subscription.
pdu	The requesting pdu.

Returns

A pointer to the added/updated subscription information or NULL on error.

coap_check_notify()

void coap_check_notify

(

coap_context_t *

context

)

Checks all known resources to see if they are dirty and then notifies subscribed observers.

Parameters

context

The context to check for dirty resources.

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coap_delete_observer()

int coap_delete_observer	(	coap_resource_t *	resource,
		coap_session_t *	session,
		const coap_binary_t *	token
	)

Removes any subscription for observer from resource and releases the allocated storage.

The result is 1 if an observation relationship with observer and token existed, 0 otherwise.

Parameters

resource	The observed resource.
session	The observer's session.
token	The token that identifies this subscription or NULL for any token.

Returns

1 if the observer has been deleted, 0 otherwise.

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coap_delete_observers()

void coap_delete_observers	(	coap_context_t *	context,
		coap_session_t *	session
	)

Removes any subscription for session and releases the allocated storage.

Parameters

context	The CoAP context to use.
session	The observer's session.

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coap_find_observer()

coap_subscription_t * coap_find_observer	(	coap_resource_t *	resource,
		coap_session_t *	session,
		const coap_binary_t *	token
	)

Returns a subscription object for given peer.

Parameters

resource	The observed resource.
session	The observer's session
token	The token that identifies this subscription or NULL for any token.

Returns

A valid subscription if exists or NULL otherwise.

coap_handle_failed_notify()

void coap_handle_failed_notify	(	coap_context_t *	context,
		coap_session_t *	session,
		const coap_binary_t *	token
	)

Handles a failed observe notify.

Parameters

context	The context holding the resource.
session	The session that the observe notify failed on.
token	The token used when the observe notify failed.

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coap_subscription_init()

void coap_subscription_init

(

coap_subscription_t *

)

coap_touch_observer()

void coap_touch_observer	(	coap_context_t *	context,
		coap_session_t *	session,
		const coap_binary_t *	token
	)

Flags that data is ready to be sent to observers.

Parameters

context	The CoAP context to use.
session	The observer's session
token	The corresponding token that has been used for the subscription.

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