MQTTStatus_t MQTT_SerializePublishHeader()

in source/core_mqtt_serializer.c [1977:2056]
67 lines of code
14 McCabe index (conditional complexity)

MQTTStatus_t MQTT_SerializePublishHeader( const MQTTPublishInfo_t * pPublishInfo,
                                          uint16_t packetId,
                                          size_t remainingLength,
                                          const MQTTFixedBuffer_t * pFixedBuffer,
                                          size_t * pHeaderSize )
{
    MQTTStatus_t status = MQTTSuccess;
    size_t packetSize = 0;

    if( ( pFixedBuffer == NULL ) || ( pPublishInfo == NULL ) ||
        ( pHeaderSize == NULL ) )
    {
        LogError( ( "Argument cannot be NULL: pFixedBuffer=%p, "
                    "pPublishInfo=%p, pHeaderSize=%p.",
                    ( void * ) pFixedBuffer,
                    ( void * ) pPublishInfo,
                    ( void * ) pHeaderSize ) );
        status = MQTTBadParameter;
    }
    /* A buffer must be configured for serialization. */
    else if( pFixedBuffer->pBuffer == NULL )
    {
        LogError( ( "Argument cannot be NULL: pFixedBuffer->pBuffer is NULL." ) );
        status = MQTTBadParameter;
    }
    else if( ( pPublishInfo->pTopicName == NULL ) || ( pPublishInfo->topicNameLength == 0U ) )
    {
        LogError( ( "Invalid topic name for publish: pTopicName=%p, "
                    "topicNameLength=%hu.",
                    ( void * ) pPublishInfo->pTopicName,
                    ( unsigned short ) pPublishInfo->topicNameLength ) );
        status = MQTTBadParameter;
    }
    else if( ( pPublishInfo->qos != MQTTQoS0 ) && ( packetId == 0U ) )
    {
        LogError( ( "Packet Id is 0 for publish with QoS=%hu.",
                    ( unsigned short ) pPublishInfo->qos ) );
        status = MQTTBadParameter;
    }
    else if( ( pPublishInfo->dup == true ) && ( pPublishInfo->qos == MQTTQoS0 ) )
    {
        LogError( ( "Duplicate flag is set for PUBLISH with Qos 0." ) );
        status = MQTTBadParameter;
    }
    else
    {
        /* Length of serialized packet = First byte
         *                               + Length of encoded remaining length
         *                               + Remaining length
         *                               - Payload Length.
         */
        packetSize = 1U + remainingLengthEncodedSize( remainingLength )
                     + remainingLength
                     - pPublishInfo->payloadLength;
    }

    if( ( status == MQTTSuccess ) && ( packetSize > pFixedBuffer->size ) )
    {
        LogError( ( "Buffer size of %lu is not sufficient to hold "
                    "serialized PUBLISH header packet of size of %lu.",
                    ( unsigned long ) pFixedBuffer->size,
                    ( unsigned long ) ( packetSize - pPublishInfo->payloadLength ) ) );
        status = MQTTNoMemory;
    }

    if( status == MQTTSuccess )
    {
        /* Serialize publish without copying the payload. */
        serializePublishCommon( pPublishInfo,
                                remainingLength,
                                packetId,
                                pFixedBuffer,
                                false );

        /* Header size is the same as calculated packet size. */
        *pHeaderSize = packetSize;
    }

    return status;
}