Re: hfs patch (Re: State of GRUB on PowerPC)

[Michel Dänzer]

On Tue, 2009-02-10 at 15:47 +0100, Robert Millan wrote:
> On Tue, Feb 10, 2009 at 10:54:55AM +0100, Michel Dänzer wrote:
> 
> > > Michel may know better, but I think it's the order of characters.   
> > > Those with the lower order go first in the sorted binary tree.  Those  
> > > with the same order are equivalent on the filesystem level.  That is,  
> > > "foo" can only be between "bar" and "quux" in the node tree.  "foo"  
> > > and "Foo" are the same tree node and thus the same file.
> > 
> > I think that's a nice summary, thanks.
> 
> Ok. There's a pair of things that need to be cleaned up though.  If I
> understand correctly, the definition of caseorder[i] is such that given too
> distinct values of i, it can be used to sort them (if this is so, I think
> it should be explicitly mentioned in the comment).

Yes, for a given filename character value i, caseorder[i] is the
corresponding B-tree sort order.

> So if the table is basicaly storing values that enumerate something, why are
> we using hex to represent them?  Hex gives the impression they're an opaque
> sort of thing, like code, bitmasks or magic numbers.

Your guess is as good as mine.

> The reference to "the Macintosh" is a bit confusing, it usually means a
> computer, or an OS.  I assume it refers to HFS?

Yes. I think HFS used to be 'the Macintosh filesystem' before OS X.

> We'd also need to know what are these "'casefold' and 'order' tables from
> ARDI's code", and what exactly means this is a "composition" of them.

Your guess is as good as mine.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer