static int constructPublishVariableHeader()

in src/mqtt_codec.c [226:280]

• 49 lines of code
• 8 McCabe index (conditional complexity)

static int constructPublishVariableHeader(BUFFER_HANDLE ctrlPacket, const PUBLISH_HEADER_INFO* publishHeader, STRING_HANDLE trace_log)
{
    int result = 0;
    size_t topicLen = 0;
    size_t spaceLen = 0;
    size_t idLen = 0;

    size_t currLen = BUFFER_length(ctrlPacket);

    topicLen = strlen(publishHeader->topicName);
    spaceLen += 2;

    if (publishHeader->qualityOfServiceValue != DELIVER_AT_MOST_ONCE)
    {
        // Packet Id is only set if the QOS is not 0
        idLen = 2;
    }

    if (topicLen > USHRT_MAX)
    {
        result = MU_FAILURE;
    }
    else if (BUFFER_enlarge(ctrlPacket, topicLen + idLen + spaceLen) != 0)
    {
        result = MU_FAILURE;
    }
    else
    {
        uint8_t* iterator = BUFFER_u_char(ctrlPacket);
        if (iterator == NULL)
        {
            result = MU_FAILURE;
        }
        else
        {
            iterator += currLen;
            /* The Topic Name MUST be present as the first field in the PUBLISH Packet Variable header.It MUST be 792 a UTF-8 encoded string [MQTT-3.3.2-1] as defined in section 1.5.3.*/
            byteutil_writeUTF(&iterator, publishHeader->topicName, (uint16_t)topicLen);
            if (trace_log != NULL)
            {
                STRING_sprintf(trace_log, " | TOPIC_NAME: %s", publishHeader->topicName);
            }
            if (idLen > 0)
            {
                if (trace_log != NULL)
                {
                    STRING_sprintf(trace_log, " | PACKET_ID: %"PRIu16, publishHeader->packetId);
                }
                byteutil_writeInt(&iterator, publishHeader->packetId);
            }
            result = 0;
        }
    }
    return result;
}