static void serializePublishCommon()

in source/core_mqtt_serializer.c [614:706]
62 lines of code
10 McCabe index (conditional complexity)

static void serializePublishCommon( const MQTTPublishInfo_t * pPublishInfo,
                                    size_t remainingLength,
                                    uint16_t packetIdentifier,
                                    const MQTTFixedBuffer_t * pFixedBuffer,
                                    bool serializePayload )
{
    uint8_t * pIndex = NULL;
    const uint8_t * pPayloadBuffer = NULL;

    /* The first byte of a PUBLISH packet contains the packet type and flags. */
    uint8_t publishFlags = MQTT_PACKET_TYPE_PUBLISH;

    assert( pPublishInfo != NULL );
    assert( pFixedBuffer != NULL );
    assert( pFixedBuffer->pBuffer != NULL );
    /* Packet Id should be non zero for Qos 1 and Qos 2. */
    assert( ( pPublishInfo->qos == MQTTQoS0 ) || ( packetIdentifier != 0U ) );
    /* Duplicate flag should be set only for Qos 1 or Qos 2. */
    assert( ( pPublishInfo->dup != true ) || ( pPublishInfo->qos != MQTTQoS0 ) );

    /* Get the start address of the buffer. */
    pIndex = pFixedBuffer->pBuffer;

    if( pPublishInfo->qos == MQTTQoS1 )
    {
        LogDebug( ( "Adding QoS as QoS1 in PUBLISH flags." ) );
        UINT8_SET_BIT( publishFlags, MQTT_PUBLISH_FLAG_QOS1 );
    }
    else if( pPublishInfo->qos == MQTTQoS2 )
    {
        LogDebug( ( "Adding QoS as QoS2 in PUBLISH flags." ) );
        UINT8_SET_BIT( publishFlags, MQTT_PUBLISH_FLAG_QOS2 );
    }
    else
    {
        /* Empty else MISRA 15.7 */
    }

    if( pPublishInfo->retain == true )
    {
        LogDebug( ( "Adding retain bit in PUBLISH flags." ) );
        UINT8_SET_BIT( publishFlags, MQTT_PUBLISH_FLAG_RETAIN );
    }

    if( pPublishInfo->dup == true )
    {
        LogDebug( ( "Adding dup bit in PUBLISH flags." ) );
        UINT8_SET_BIT( publishFlags, MQTT_PUBLISH_FLAG_DUP );
    }

    *pIndex = publishFlags;
    pIndex++;

    /* The "Remaining length" is encoded from the second byte. */
    pIndex = encodeRemainingLength( pIndex, remainingLength );

    /* The topic name is placed after the "Remaining length". */
    pIndex = encodeString( pIndex,
                           pPublishInfo->pTopicName,
                           pPublishInfo->topicNameLength );

    /* A packet identifier is required for QoS 1 and 2 messages. */
    if( pPublishInfo->qos > MQTTQoS0 )
    {
        LogDebug( ( "Adding packet Id in PUBLISH packet." ) );
        /* Place the packet identifier into the PUBLISH packet. */
        *pIndex = UINT16_HIGH_BYTE( packetIdentifier );
        *( pIndex + 1 ) = UINT16_LOW_BYTE( packetIdentifier );
        pIndex += 2;
    }

    /* The payload is placed after the packet identifier.
     * Payload is copied over only if required by the flag serializePayload.
     * This will help reduce an unnecessary copy of the payload into the buffer.
     */
    if( ( pPublishInfo->payloadLength > 0U ) &&
        ( serializePayload == true ) )
    {
        LogDebug( ( "Copying PUBLISH payload of length =%lu to buffer",
                    ( unsigned long ) pPublishInfo->payloadLength ) );

        /* Typecast const void * typed payload buffer to const uint8_t *.
         * This is to use same type buffers in memcpy. */
        pPayloadBuffer = ( const uint8_t * ) pPublishInfo->pPayload;

        ( void ) memcpy( pIndex, pPayloadBuffer, pPublishInfo->payloadLength );
        pIndex += pPublishInfo->payloadLength;
    }

    /* Ensure that the difference between the end and beginning of the buffer
     * is less than the buffer size. */
    assert( ( ( size_t ) ( pIndex - pFixedBuffer->pBuffer ) ) <= pFixedBuffer->size );
}