Subscriber

Description:

Defines the subscriber for external interfaces to subsribe to events and data of a topic.

Summary

Description:

Adds a specified topic to the Broadcast service.

The specified topic is added by the subscriber. A topic can be subscribed to only after being added.

Parameters:

Returns:

Returns EC_SUCCESS if the topic is successfully added; returns other error codes if the topic fails to be added.

Description:

Modifies the consumer of a specified topic.

Parameters:

Returns:

Returns the pointer of the original consumer if the modification is successful; returns NULL otherwise.

Subscribes to a specified topic for consumers.

Call this function on the subscriber. The topic to be subscribed to must have been added to the Broadcast service.

Parameters:

Returns:

Returns EC_SUCCESS if the subscription is successful; returns other error codes if the subscription fails.

Description:

Unsubscribes from a specified topic.

This function cancels the subscription relationship between the specified topic and consumer.

Parameters:

Returns:

Returns the pointer of the consumer if the unsubscription is successful; returns NULL otherwise.