[ECOS] 答复: Re: [ECOS] A question about function readdir and stat

[eCos at sunnorth dot com dot cn]

Thanks very much for your answer.
We can't use the first method, though it is a very good idea. The reason 
is that our application is DPF(Digital Photo Frame), a directory structure 
fixed is almost impossible. Users copy and delete photo(jpeg/bmp and so 
on) files to a DPF device by their own, so actually we can't control what 
the users do and the directory structure is not controllable at all. 


> Why not impose a directory structure. eg my camera has a directory for
> every 100 images. That would mean you only need a maximum of 100
> comparisons for the last file in the directory and for 10000 files you
> need 100 directories.

> Another option which would give a speed up is not to use numbers, but
> a more dense naming scheme. eg fAA, fAB, fAC, ..., fAZ, fAa, ... fAz,
> You still end up doing 10000 comparisons, but the strings you are
> comparing are shorted so there is less work to do.


> I assume you are using fatfs? Looking at fatfs_fo_dirread, this would
> be easy to implement. You have the information you need in dentry. So
> just add the new member d_type and fill it in.

>     Andrew


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