[Owncloud] OwnClouds Future

[Evgeniy Ivanov]

On Mon, Mar 22, 2010 at 2:46 AM, Cosmin Gorgovan <cosmin at linux-geek.org> wrote:
> On 03/21/2010 11:13 PM, Evgeniy Ivanov wrote:
>>
>> On Mon, Mar 22, 2010 at 2:10 AM, Evgeniy Ivanov<lolkaantimat at gmail.com>
>>  wrote:
>>
>>>>
>>>>   * from what I've read, it doesn't do read-ahead
>>>>
>>>
>>> Well, I'm not sure if it can be done via http. AFAIK you can only
>>> request some file and that's all since server can do path-->file
>>> (data) only. Of course there is a way to get only parts of file using
>>> special convention (but here you fell into trouble with limitations to
>>> directory structure and some other things) and it's done in python
>>> very quickly (but here again you will have server side application).
>>>
>>>
>>
>> Btw, since AFAIK http can provide only full files (not random blocks)
>>
>
> HTTP supports getting limited ranges of a file. The server's reponse code is
> 206 Partial content in case you want to look into that. Just to make sure,

Didn't know it, thanks.


>> read-ahead can's be done for http-based filesystem, since all you can
>> is either get full file or get nothing. You don't know what to read
>> ahead.
>>
> What I'd do would be to get all the files as long as there is disk space and
> there isn't any file activity.

It's something like locality principle. I don't think using disk space
is good option in this case. Nobody wants application to consume much
memory, disk space or network bandwidth. Just imagine, that our
application took last disk space (sure, quota might be set, but...)
and user needs additional space too. So here we came to something very
complicated (quotas and managing free space, probably deallocation on
demand, caching policies, ...). And it's just about reading. Writing
is more complicated process.

Cosmin, I really enjoy discussion, but in my opinion it's beyond this
project. If you really willing to write user-space filesystem, I would
recommend you to focus on it as separate GSoC project (MINIX 3
organization is a good place for this).


-- 
Evgeniy Ivanov