MQTTStatus_t MQTTAgent_ResumeSession()

in source/core_mqtt_agent.c [1038:1077]

• 23 lines of code
• 4 McCabe index (conditional complexity)

MQTTStatus_t MQTTAgent_ResumeSession( MQTTAgentContext_t * pMqttAgentContext,
                                      bool sessionPresent )
{
    MQTTStatus_t statusResult = MQTTSuccess;

    /* If the packet ID is zero then the MQTT context has not been initialized as 0
     * is the initial value but not a valid packet ID. */
    if( ( pMqttAgentContext != NULL ) &&
        ( pMqttAgentContext->mqttContext.nextPacketId != MQTT_PACKET_ID_INVALID ) )
    {
        /* Resend publishes if session is present. NOTE: It's possible that some
         * of the operations that were in progress during the network interruption
         * were subscribes. In that case, we would want to mark those operations
         * as completing with error and remove them from the list of operations, so
         * that the calling task can try subscribing again. */
        if( sessionPresent )
        {
            /* The session has resumed, so clear any SUBSCRIBE/UNSUBSCRIBE operations
             * that were pending acknowledgments in the previous connection. */
            clearPendingAcknowledgments( pMqttAgentContext, true );

            statusResult = resendPublishes( pMqttAgentContext );
        }

        /* If we wanted to resume a session but none existed with the broker, we
         * should mark all in progress operations as errors so that the tasks that
         * created them can try again. */
        else
        {
            /* We have a clean session, so clear all operations pending acknowledgments. */
            clearPendingAcknowledgments( pMqttAgentContext, false );
        }
    }
    else
    {
        statusResult = MQTTBadParameter;
    }

    return statusResult;
}