RFC: startup time - again

[David Cournapeau]

John Arbash Meinel wrote:
>
> Actually, they do. Last I checked they had several required C
> extensions. (The
> diff and patch code is in C, I don't remember what else off-hand.)

I know that, but we have not talked about diff and patch in this thread
:) For what we are talking about here (slow startup, slow st on small
trees), I doubt that C is involved in the factor 2/3 between hg and bzr
for startup time (on Linux at least).

I see 5 files in C in mercurial 1.0.1:

./osutil.c
./mpatch.c
./bdiff.c
./base85.c
./diffhelpers.c

osutils implements one function to list directories (on posix only it
seems), I don't know what base85.c is about.

>
> Some of the other things, are arguable choices along the way. For
> example, bzr
> works in Unicode paths. This means that we take more time (and generally
> memory) as we decode from 8-bit strings into Unicode strings. On the flip
> side, it means that when I check it ",H,H.txt" on Linux, I get the
> same thing
> on Windows and Mac, rather than "جوجو.txt" (On Windows it will
> default to
> something like cp1250/latin-1 for 8-bit filenames, while on Linux it
> is UTF-8,
> even though Windows is actually a "wide-char" or UTF-16 filesystem.)

Yes, that's a great poinf of bzr here, but I fail to see how this
explains slow startup time.

cheers,

David