BUFFER_HANDLE mqtt_codec_publish()

in src/mqtt_codec.c [745:860]

• 103 lines of code
• 21 McCabe index (conditional complexity)

BUFFER_HANDLE mqtt_codec_publish(QOS_VALUE qosValue, bool duplicateMsg, bool serverRetain, uint16_t packetId, const char* topicName, const uint8_t* msgBuffer, size_t buffLen, STRING_HANDLE trace_log)
{
    BUFFER_HANDLE result;
    /* Codes_SRS_MQTT_CODEC_07_005: [If the parameters topicName is NULL then mqtt_codec_publish shall return NULL.] */
    if (topicName == NULL)
    {
        result = NULL;
    }
    /* Codes_SRS_MQTT_CODEC_07_036: [mqtt_codec_publish shall return NULL if the buffLen variable is greater than the MAX_SEND_SIZE (0xFFFFFF7F).] */
    else if (buffLen > MAX_SEND_SIZE)
    {
        /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
        result = NULL;
    }
    else
    {
        PUBLISH_HEADER_INFO publishInfo ={ 0 };
        publishInfo.topicName = topicName;
        publishInfo.packetId = packetId;
        publishInfo.qualityOfServiceValue = qosValue;

        uint8_t headerFlags = 0;
        if (duplicateMsg) headerFlags |= PUBLISH_DUP_FLAG;
        if (serverRetain) headerFlags |= PUBLISH_QOS_RETAIN;
        if (qosValue != DELIVER_AT_MOST_ONCE)
        {
            if (qosValue == DELIVER_AT_LEAST_ONCE)
            {
                headerFlags |= PUBLISH_QOS_AT_LEAST_ONCE;
            }
            else
            {
                headerFlags |= PUBLISH_QOS_EXACTLY_ONCE;
            }
        }

        /* Codes_SRS_MQTT_CODEC_07_007: [mqtt_codec_publish shall return a BUFFER_HANDLE that represents a MQTT PUBLISH message.] */
        result = BUFFER_new();
        if (result != NULL)
        {
            STRING_HANDLE varible_header_log = NULL;
            if (trace_log != NULL)
            {
                varible_header_log = STRING_construct_sprintf(" | IS_DUP: %s | RETAIN: %d | QOS: %s", duplicateMsg ? TRUE_CONST : FALSE_CONST,
                    serverRetain ? 1 : 0,
                    retrieve_qos_value(publishInfo.qualityOfServiceValue) );
            }

            if (constructPublishVariableHeader(result, &publishInfo, varible_header_log) != 0)
            {
                /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
                BUFFER_delete(result);
                result = NULL;
            }
            else
            {
                size_t payloadOffset = BUFFER_length(result);
                if (buffLen > 0)
                {
                    if (BUFFER_enlarge(result, buffLen) != 0)
                    {
                        /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
                        BUFFER_delete(result);
                        result = NULL;
                    }
                    else
                    {
                        uint8_t* iterator = BUFFER_u_char(result);
                        if (iterator == NULL)
                        {
                            /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
                            BUFFER_delete(result);
                            result = NULL;
                        }
                        else
                        {
                            iterator += payloadOffset;
                            // Write Message
                            (void)memcpy(iterator, msgBuffer, buffLen);
                            if (trace_log)
                            {
                                STRING_sprintf(varible_header_log, " | PAYLOAD_LEN: %lu", (unsigned long)buffLen);
                            }
                        }
                    }
                }

                if (result != NULL)
                {
                    if (trace_log != NULL)
                    {
                        (void)STRING_copy(trace_log, "PUBLISH");
                    }
                    if (constructFixedHeader(result, PUBLISH_TYPE, headerFlags) != 0)
                    {
                        /* Codes_SRS_MQTT_CODEC_07_006: [If any error is encountered then mqtt_codec_publish shall return NULL.] */
                        BUFFER_delete(result);
                        result = NULL;
                    }
                    else
                    {
                        if (trace_log != NULL)
                        {
                            (void)STRING_concat_with_STRING(trace_log, varible_header_log);
                        }
                    }
                }
            }
            if (varible_header_log != NULL)
            {
                STRING_delete(varible_header_log);
            }
        }
    }
    return result;
}