FreeLists / openbeos / [openbeos] Re: kernel mime_table module

["Axel Dörfler" <axeld@xxxxxxxxxxxxxxxx>]

Ingo Weinhold <bonefish@xxxxxxxxxxxxxxx> wrote:
> > If I understand you correctly, you would fix BNodeInfo to ask the
> > roster about the type for the given file - I am not sure if it's a 
> > good
> > idea to do a full lookup there, though (again, speed 
> > considerations).
> No, I don't think I would change BNodeInfo. For a node on a FS that 
> doesn't 
> support attributes or MIME types, the Tracker shouldn't even try to 
> get 
> data from a BNodeInfo object, but instead sniff the type and get the 
> info 
> from BMimeType.

I would chose BNodeInfo as a starting point, as this class is the one 
that abstracts the file type stuff from the implementation. 
Whenever a file does not have the BEOS:TYPE attribute set (for whatever 
reason), it could get the type via the file extension only.

This way, all applications would benefit from this -- why should we aim 
for a Tracker only solution here (or at least have all applications do 
this extra work)?

> > If I open up a folder with thousand files, how much slower will it 
> > get
> > because of that?
> Don't know. But, unless I'm mistaken here, the Tracker currently 
> lazily 
> gets the information when needed (i.e. when an entry is about to be 
> displayed). So I wouldn't expect a significant slow-down when opening 
> a 
> large folder, since there's only overhead for the visible entries. 
> But to 
> be sure this needs to be verified by tests. If it is slow indeed, the 
> sniffing can as well be done as a background task.

I am not sure when Tracker does this; I would guess that it only loads 
additional attributes on demand, but not determine the file type this 
way.

> > Anyway, in whatever way we will solve this, I think this is 
> > something
> > we should definitely do before R1.
> Yep.

After R1, I want to introduce file system layers, so that we can just 
plug in generic attribute support for all file systems that don't 
support them natively. That should also simplify a couple of things :)

Bye,
   Axel.