[darcs-users] always long comment

Juliusz Chroboczek jch at pps.jussieu.fr
Tue Jul 13 16:21:22 UTC 2004


> > That's a pet peeve of mine.  Hashtables have been known since the
> > 1960s, B-trees since the early 70s.  Why are there still filesystems
> > that use linear search in directories?

> Because linear searches [...] do not consume nearly the amount of
> space that even a hashtable would.

Huh?  A hashtable lookup is hashing followed by an array reference,
which requires no stack space to speak of.  A hashtable insertion
might, once in a blue moon, require rehashing and hence reallocation,
but so does extending a linear array.

Similar things can be said of B-trees (which might actually be a
better choice for a filesystem).

> There is NO need to always have to refer to a file by name.  inode
> number is plenty sufficient,

That's the old Unix vs. MacOS debate again.  Too much ink has been
wasted on the subject already.

> Thus, to achieve this kind of flexibility without sacrificing the
> ability to move/copy whole files around, you end up once again
> having a filesystem inside a file.

No, you don't.  MacOS solves this problem.

                                        Juliusz




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