On Sun, Mar 24 2019, Junio C Hamano wrote: > Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > >> The reason I'm raising this is that it seems like sweeping an existing >> issue under the rug. We document that the "sid" is "unique", and it's just: >> >> <nanotime / 1000 (i.e. *nix time in microseconds)>-<pid> > > If it is just that, then it cannot be unique, can it? > > Let's just fix the wrong doc and move on. I don't see why we wouldn't just fix the SID generation & move on if we're already carrying code purely as a work-around for it not being unique enough. Of course nothing is *guaranteed* to be unique, not even a 128-bit UUID. The point is to pick something that's "unique enough" given the problem space, which is already one where we'll ignore I/O errors on writing the file unless you opt-in to a warning. And it's a very useful property to have the SID be a) unique enough like that so you can use a unique index for "git events" b) fixed-width (which the current one *isn't*), so you can use fixed-with indexes in some logging databases c) as a bonus, be human-readable at a glance, hence spending slightly more space on the the YYYMM.. format in my suggested SID format. I can write that patch, but first it's useful to know if this is a case Josh is running into, or if it's just a guard out of paranoia.
