BUFFER_HANDLE mqtt_codec_unsubscribe()

in src/mqtt_codec.c [990:1052]

• 57 lines of code
• 11 McCabe index (conditional complexity)

BUFFER_HANDLE mqtt_codec_unsubscribe(uint16_t packetId, const char** unsubscribeList, size_t count, STRING_HANDLE trace_log)
{
    BUFFER_HANDLE result;
    /* Codes_SRS_MQTT_CODEC_07_027: [If the parameters unsubscribeList is NULL or if count is 0 then mqtt_codec_unsubscribe shall return NULL.] */
    if (unsubscribeList == NULL || count == 0)
    {
        result = NULL;
    }
    else
    {
        /* Codes_SRS_MQTT_CODEC_07_030: [mqtt_codec_unsubscribe shall return a BUFFER_HANDLE that represents a MQTT SUBSCRIBE message.] */
        result = BUFFER_new();
        if (result != NULL)
        {
            if (constructSubscibeTypeVariableHeader(result, packetId) != 0)
            {
                /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
                BUFFER_delete(result);
                result = NULL;
            }
            else
            {
                STRING_HANDLE unsub_trace = NULL;
                if (trace_log != NULL)
                {
                    unsub_trace = STRING_construct_sprintf(" | PACKET_ID: %"PRIu16, packetId);
                }
                /* Codes_SRS_MQTT_CODEC_07_028: [mqtt_codec_unsubscribe shall iterate through count items in the unsubscribeList.] */
                if (addListItemsToUnsubscribePacket(result, unsubscribeList, count, unsub_trace) != 0)
                {
                    /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
                    BUFFER_delete(result);
                    result = NULL;
                }
                else
                {
                    if (trace_log != NULL)
                    {
                        (void)STRING_copy(trace_log, "UNSUBSCRIBE");
                    }
                    if (constructFixedHeader(result, UNSUBSCRIBE_TYPE, UNSUBSCRIBE_FIXED_HEADER_FLAG) != 0)
                    {
                        /* Codes_SRS_MQTT_CODEC_07_029: [If any error is encountered then mqtt_codec_unsubscribe shall return NULL.] */
                        BUFFER_delete(result);
                        result = NULL;
                    }
                    else
                    {
                        if (trace_log != NULL)
                        {
                            (void)STRING_concat_with_STRING(trace_log, unsub_trace);
                        }
                    }
                }
                if (unsub_trace != NULL)
                {
                    STRING_delete(unsub_trace);
                }
            }
        }
    }
    return result;
}