Re: [Qemu-devel] [PATCHv4 6/6] ui/vnc: disable adaptive update calculations if not needed

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2014/1/11 6:28, Peter Lieven 写道:
> Am 10.01.2014 04:09, schrieb Wenchao Xia:
>> 于 2014/1/10 0:25, Peter Lieven 写道:
>>> Am 09.01.2014 09:29, schrieb Wenchao Xia:
>>>> 于 2014/1/8 17:08, Peter Lieven 写道:
>>>>> Signed-off-by: Peter Lieven <pl@kamp.de>
>>>>> ---
>>>>>     ui/vnc.c |    9 +++++++++
>>>>>     1 file changed, 9 insertions(+)
>>>>>
>>>>> diff --git a/ui/vnc.c b/ui/vnc.c
>>>>> index da552fe..a742d32 100644
>>>>> --- a/ui/vnc.c
>>>>> +++ b/ui/vnc.c
>>>>> @@ -3170,7 +3170,9 @@ void vnc_display_open(DisplayState *ds, const char *display, Error **errp)
>>>>>                 acl = 1;
>>>>>     #endif
>>>>>             } else if (strncmp(options, "lossy", 5) == 0) {
>>>>> +#ifdef CONFIG_VNC_JPEG
>>>>>                 vs->lossy = true;
>>>>> +#endif
>>>>>             } else if (strncmp(options, "non-adaptive", 12) == 0) {
>>>>>                 vs->non_adaptive = true;
>>>>>             } else if (strncmp(options, "share=", 6) == 0) {
>>>>> @@ -3187,6 +3189,13 @@ void vnc_display_open(DisplayState *ds, const char *display, Error **errp)
>>>>>             }
>>>>>         }
>>>>>
>>>>> +    /* adaptive updates are only used with tight encoding and
>>>>> +     * if lossy updates are enabled so we can disable all the
>>>>> +     * calculations otherwise */
>>>>> +    if (!vs->lossy) {
>>>>> +        vs->non_adaptive = true;
>>>>> +    }
>>>>> +
>>>>     The code seems: if vs->loosy == false, then vs->non_adaptive = true,
>>>> translate as: if loosy update is not used, then don't do adaptive
>>>> update., which doesn't conform with the comments. I am not sure if this
>>>> is on expectation.
>>> It don't see the logic break. The option means non_adaptive, not adaptive.
>>>
>>> I write "adaptive updates are only used ... with lossy updates...". Which
>>    So tight encoding means loosy updates?
> It means you can only enable lossy updates if you have tight encoding. So if you are
> missing tight encoding or lossy is false then you can set non_adaptive to true.
> 
> Peter
> 
  I see the logic, guess I punctuated the comments in a wrong way, the
real meaning may be:

    /* Adaptive updates are only used with tight encoding and
     * if lossy updates are enabled, so we can disable all the
     * calculations otherwise */