Re: repost for readdir

[Hans Reiser <reiser@namesys.com>]

Vladimir V. Saveliev wrote:

> Hello
>
> jenn sirp wrote:
>
>> Hi,
>>
>> I'd like to thank you guys for your help earlier this year with the
>> initial phase of my project. I was able to implement FIFO queueing
>> functionality in Reiser v3. It is not very elegant, but I am still
>> learning. I was able to steer my supervisor in the direction of Reiser4.
>> It appears that the design principles of the new system will make it 
>> very
>> valuable for many at the Lab.
>>
>> That said, and back to Hans' suggestion of a readdir implementation for
>> FIFO and LIFO file queuing... I have some questions. If anyone can 
>> answer
>> them, has advice, or suggestions that would be so great.
>>
>> Here's where I am at, and what I don't know:
>>
>>> From what I can tell, files in the reiserfs 'Directory Item' aren't 
>>> preserved in
>>
>> the order they are written due to deletes and other operations. So if I
>> were to access the Directory Item to generate a list for readdir I 
>> couldn't be certain that they would be in first
>> created -to- last created order.
>
We sort in hash order, not creation order.

>>
>> If readdir has to sort the files in the directory every time it is 
>> called
>> it seems like it would be a bit of a performance hit.
>
>
> Do you mean readdir library function? It reads directory and fills 
> dirent structures. It does not sort anything. It even does not stat 
> files names of which it reads.
>
> Should another
>
>> structure be maintained that preserves the order as the files are
>> written... and should readdir use that as it's basis for returning the
>> directory contents?
>>
>
> Are you trying to optimize ls -l?
>
> Please describe in more details what are you trying to do.
>
>> If this is a question that doesn't belong here... please let me know 
>> and I apologize.
>>
>> Thanks,
>>
>> Jenn
>>
>>
>>
>
>
>
>
Please consider working with V4, it will be easier and more useful I think.