[Libguestfs] [PATCH] New API: btrfs_device_stats

[Cao jin]

Hi

在 2015年06月18日 18:53, Pino Toscano 写道:
> On Thursday 18 June 2015 18:33:59 Cao jin wrote:
>> Hi, Pino
>>
>> 在 2015年06月18日 16:41, Pino Toscano 写道:
>>> Hi,
>>>
>>> On Thursday 18 June 2015 11:01:37 Cao jin wrote:
>>>>> Speaking of this: you said that you have a colleague working on
>>>>> btrfs-progs? What about suggesting to create some machine-parseable
>>>>> output (csv, xml, yaml, json, whatever) so extracting the results of
>>>>> btrfs tools is a lot more easy?
>>>>>
>>>>
>>>> Yes, I forward your suggestion and consult him, the result is not
>>>> surprised:( Here is what I learned from him:
>>>>      For the btrfs-progs cmds who output strings, the output are plain,
>>>> don`t have patterns. Seen some guys who want a formatted output, they do
>>>> a filter by themself, it not reasonable to ask btrfs-progs to output
>>>> formatted strings.
>>>
>>> This is exactly the issue here: every btrfs command has a totally
>>> different formatting for its output. Just let him take a look at all
>>> the commands implemented so far in libguestfs, you can easily spot
>>> that:
>>> - btrfs subvolume list
>>> - btrfs subvolume show
>>> - btrfs qgroup show
>>> - btrfs balance status
>>> - btrfs scrub status
>>> - btrfs device stats
>>> all have different custom parsers for each of their outputs.
>>>
>>> Compare that to e.g. the -m parameter for parted, so it outputs fields
>>> separated by semi-colon.
>>>
>>
>> Already forward your mail to my colleague. He think your comment is
>> interesting, and also forward your option to btrfs-progs mail-list.
>
> Great to hear that, thanks for it.
>
>> Speaking of btrfs device stats output, what do you suggest to do for
>> now? Since it may has multi devices.
>
> I see few options:
>
> (a) keep the current RHashTable
>
> (b) turn the statistics into a proper struct, and use RStructList
>
> (c) implement RHashTableList, and use it
>
> (d) something else I'm missing
>

OK, I prefer (a), its implementation seems easier and more clear than 
others. I will prepare a new patch, with commit message improved as you said

-- 
Yours Sincerely,

Cao Jin