MQTTStatus_t MQTT_SerializePublish()

in source/core_mqtt_serializer.c [1892:1973]
70 lines of code
15 McCabe index (conditional complexity)

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

    if( ( pFixedBuffer == NULL ) || ( pPublishInfo == NULL ) )
    {
        LogError( ( "Argument cannot be NULL: pFixedBuffer=%p, "
                    "pPublishInfo=%p.",
                    ( void * ) pFixedBuffer,
                    ( void * ) pPublishInfo ) );
        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;
    }

    /* For serializing a publish, if there exists a payload, then the buffer
     * cannot be NULL. */
    else if( ( pPublishInfo->payloadLength > 0U ) && ( pPublishInfo->pPayload == NULL ) )
    {
        LogError( ( "A nonzero payload length requires a non-NULL payload: "
                    "payloadLength=%lu, pPayload=%p.",
                    ( unsigned long ) pPublishInfo->payloadLength,
                    pPublishInfo->pPayload ) );
        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=%u.",
                    ( unsigned int ) 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. */
        packetSize = 1U + remainingLengthEncodedSize( remainingLength )
                     + remainingLength;
    }

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

    if( status == MQTTSuccess )
    {
        /* Serialize publish with header and payload. */
        serializePublishCommon( pPublishInfo,
                                remainingLength,
                                packetId,
                                pFixedBuffer,
                                true );
    }

    return status;
}