AzureIoTResult_t AzureIoTHubClient_SubscribeProperties()

in source/azure_iot_hub_client.c [1197:1253]

• 52 lines of code
• 5 McCabe index (conditional complexity)

AzureIoTResult_t AzureIoTHubClient_SubscribeProperties( AzureIoTHubClient_t * pxAzureIoTHubClient,
                                                        AzureIoTHubClientPropertiesCallback_t xCallback,
                                                        void * prvCallbackContext,
                                                        uint32_t ulTimeoutMilliseconds )
{
    AzureIoTMQTTSubscribeInfo_t xMqttSubscription[ 2 ] = { { 0 }, { 0 } };
    AzureIoTMQTTResult_t xMQTTResult;
    AzureIoTResult_t xResult;
    uint16_t usSubscribePacketIdentifier;
    AzureIoTHubClientReceiveContext_t * pxContext;

    if( ( pxAzureIoTHubClient == NULL ) ||
        ( xCallback == NULL ) )
    {
        AZLogError( ( "AzureIoTHubClient_SubscribeProperties failed: invalid argument" ) );
        xResult = eAzureIoTErrorInvalidArgument;
    }
    else
    {
        pxContext = &pxAzureIoTHubClient->_internal.xReceiveContext[ azureiothubRECEIVE_CONTEXT_INDEX_PROPERTIES ];
        xMqttSubscription[ 0 ].xQoS = eAzureIoTMQTTQoS0;
        xMqttSubscription[ 0 ].pcTopicFilter = ( const uint8_t * ) AZ_IOT_HUB_CLIENT_PROPERTIES_MESSAGE_SUBSCRIBE_TOPIC;
        xMqttSubscription[ 0 ].usTopicFilterLength = ( uint16_t ) sizeof( AZ_IOT_HUB_CLIENT_PROPERTIES_MESSAGE_SUBSCRIBE_TOPIC ) - 1;
        xMqttSubscription[ 1 ].xQoS = eAzureIoTMQTTQoS0;
        xMqttSubscription[ 1 ].pcTopicFilter = ( const uint8_t * ) AZ_IOT_HUB_CLIENT_PROPERTIES_WRITABLE_UPDATES_SUBSCRIBE_TOPIC;
        xMqttSubscription[ 1 ].usTopicFilterLength = ( uint16_t ) sizeof( AZ_IOT_HUB_CLIENT_PROPERTIES_WRITABLE_UPDATES_SUBSCRIBE_TOPIC ) - 1;
        usSubscribePacketIdentifier = AzureIoTMQTT_GetPacketId( &( pxAzureIoTHubClient->_internal.xMQTTContext ) );

        AZLogDebug( ( "Attempting to subscribe to the MQTT topics: %s and %s",
                      AZ_IOT_HUB_CLIENT_PROPERTIES_MESSAGE_SUBSCRIBE_TOPIC, AZ_IOT_HUB_CLIENT_PROPERTIES_WRITABLE_UPDATES_SUBSCRIBE_TOPIC ) );

        if( ( xMQTTResult = AzureIoTMQTT_Subscribe( &( pxAzureIoTHubClient->_internal.xMQTTContext ),
                                                    xMqttSubscription, 2,
                                                    usSubscribePacketIdentifier ) ) != eAzureIoTMQTTSuccess )
        {
            AZLogError( ( "Properties subscribe failed: MQTT error=0x%08x", xMQTTResult ) );
            xResult = eAzureIoTErrorSubscribeFailed;
        }
        else
        {
            pxContext->_internal.usState = azureiothubTOPIC_SUBSCRIBE_STATE_SUB;
            pxContext->_internal.usMqttSubPacketID = usSubscribePacketIdentifier;
            pxContext->_internal.pxProcessFunction = prvAzureIoTHubClientPropertiesProcess;
            pxContext->_internal.callbacks.xPropertiesCallback = xCallback;
            pxContext->_internal.pvCallbackContext = prvCallbackContext;

            if( ( xResult = prvWaitForSubAck( pxAzureIoTHubClient, pxContext,
                                              ulTimeoutMilliseconds ) ) != eAzureIoTSuccess )
            {
                AZLogError( ( "Wait for properties sub ack failed: error=0x%08x", xResult ) );
                memset( pxContext, 0, sizeof( AzureIoTHubClientReceiveContext_t ) );
            }
        }
    }

    return xResult;
}