From: Duy Nguyen Date: Mon, 20 Jan 2014 01:38:25 GMT Subject: Re: [PATCH/WIP v2 02/14] read-cache: new extension to mark what file is watched Message-ID: In-Reply-To: <87fvojewaf.fsf@thomasrast.ch> On Mon, Jan 20, 2014 at 12:06 AM, Thomas Rast wrote: > Nguyễn Thái Ngọc Duy writes: > >> If an entry is "watched", git lets an external program decide if the >> entry is modified or not. It's more like --assume-unchanged, but >> designed to be controlled by machine. >> >> We are running out of on-disk ce_flags, so instead of extending >> on-disk entry format again, "watched" flags are in-core only and >> stored as extension instead. > > I wonder if this would be a good use-case for EWAH bitmaps? Presumably > most users would end up having only a few large ranges of files that are > being watched. Quite possibly most users would watch *all* files. Oh yeah. I edited my commit message locally to this a while ago On webkit.git with 182k entries, that's 364k more to be SHA-1'd on current index versions, compared to 22k in this format (and even less when jk/pack-bitmap ewah graduates and we can use ewah compression) -- Duy