From: Jeff King <email@example.com> To: Jonathan Tan <firstname.lastname@example.org> Cc: email@example.com Subject: Re: Git in Outreachy December 2019? Date: Mon, 23 Sep 2019 15:15:10 -0400 [thread overview] Message-ID: <20190923191509.GC21344@sigill.intra.peff.net> (raw) In-Reply-To: <firstname.lastname@example.org> On Fri, Sep 20, 2019 at 10:04:48AM -0700, Jonathan Tan wrote: > > I'm happy to discuss possible projects if anybody has an idea but isn't > > sure how to develop it into a proposal. > > I'm new to Outreachy and programs like this, so does anyone have an > opinion on my draft proposal below? It does not have any immediate > user-facing benefit, but it does have a definite end point. > > Also let me know if an Outreachy proposal should have more detail, etc. > > Refactor "git index-pack" logic into library code > > Currently, whenever any Git code needs a pack to be indexed, it > needs to spawn a new "git index-pack" process, passing command-line > arguments and communicating with it using file descriptors (standard > input and output), much like an end-user would if invoking "git > index-pack" directly. Refactor the pack indexing logic into library > code callable from other Git code, make "git index-pack" a thin > wrapper around that library code, and (to demonstrate that the > refactoring works) change fetch-pack.c to use the library code > instead of spawning the "git index-pack" process. > > This allows the pack indexing code to communicate with its callers > with the full power of C (structs, callbacks, etc.) instead of being > restricted to command-line arguments and file descriptors. It also > simplifies debugging in that there will no longer be 2 > inter-communicating processes to deal with, only 1. I think this is an OK level of detail. I'm not sure quite sure about the goal of the project, though. In particular: - I'm not clear what we'd hope to gain. I.e., what richer information would we want to pass back and forth between index-pack and the other processes? It might also be more efficient, but I'm not sure it's measurably so (we save a single process, and we save some pipe traffic, but the sideband demuxer would probably end up passing it over a self-pipe anyway). - index-pack is prone to dying on bad input, and we wouldn't want it to take down the outer fetch-pack or receive-pack, which are what produce useful messages to the user. That's something that could be fixed as part of the libification, but I suspect the control flow might be a little tricky. - we don't always call index-pack, but sometimes call unpack-objects. I suppose we could continue to call an external unpack-objects in that path, but that eliminates the utility of having richer communication if we sometimes have to take the "dumb" path. A while ago I took a stab at teaching index-pack to unpack. It works, but there are a few ugly bits, as discussed in: https://github.com/peff/git/commit/7df82454a855281e9c147f3023225f8a6f72e303 Maybe that would be worth making part of the project? -Peff
next prev parent reply other threads:[~2019-09-23 19:15 UTC|newest] Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-27 5:17 Jeff King 2019-08-31 7:58 ` Christian Couder 2019-08-31 19:44 ` Olga Telezhnaya 2019-09-04 19:41 ` Jeff King 2019-09-05 7:24 ` Christian Couder 2019-09-05 19:39 ` Emily Shaffer 2019-09-06 11:55 ` Carlo Arenas 2019-09-07 6:39 ` Jeff King 2019-09-07 10:13 ` Carlo Arenas 2019-09-07 6:36 ` Jeff King 2019-09-08 14:56 ` Pratyush Yadav 2019-09-09 17:00 ` Jeff King 2019-09-23 18:07 ` SZEDER Gábor 2019-09-26 9:47 ` SZEDER Gábor 2019-09-26 19:32 ` Johannes Schindelin 2019-09-26 21:54 ` SZEDER Gábor 2019-09-26 11:42 ` Johannes Schindelin 2019-09-13 20:03 ` Jonathan Tan 2019-09-13 20:51 ` Jeff King 2019-09-16 18:42 ` Emily Shaffer 2019-09-16 21:33 ` Eric Wong 2019-09-16 21:44 ` SZEDER Gábor 2019-09-16 23:13 ` Jonathan Nieder 2019-09-17 0:59 ` Jeff King 2019-09-17 11:23 ` Johannes Schindelin 2019-09-17 12:02 ` SZEDER Gábor 2019-09-23 12:47 ` Johannes Schindelin 2019-09-23 16:58 ` SZEDER Gábor 2019-09-26 11:04 ` Johannes Schindelin 2019-09-26 13:28 ` SZEDER Gábor 2019-09-26 19:39 ` Johannes Schindelin 2019-09-26 21:44 ` SZEDER Gábor 2019-09-27 22:18 ` Jeff King 2019-10-09 17:25 ` SZEDER Gábor 2019-10-11 6:34 ` Jeff King 2019-09-23 18:19 ` Jeff King 2019-09-24 14:30 ` Johannes Schindelin 2019-09-17 15:10 ` Christian Couder 2019-09-23 12:50 ` Johannes Schindelin 2019-09-23 19:30 ` Jeff King 2019-09-23 18:07 ` Jeff King 2019-09-24 14:25 ` Johannes Schindelin 2019-09-24 15:33 ` Jeff King 2019-09-28 3:56 ` Junio C Hamano 2019-09-24 0:55 ` Eric Wong 2019-09-26 12:45 ` Johannes Schindelin 2019-09-30 8:55 ` Eric Wong 2019-09-28 4:01 ` Junio C Hamano 2019-09-20 17:04 ` Jonathan Tan 2019-09-21 1:47 ` Emily Shaffer 2019-09-23 14:23 ` Christian Couder 2019-09-23 19:40 ` Jeff King 2019-09-23 22:29 ` Philip Oakley 2019-10-22 21:16 ` Emily Shaffer 2019-09-23 11:49 ` Christian Couder 2019-09-23 17:58 ` Jonathan Tan 2019-09-23 19:27 ` Jeff King 2019-09-23 20:48 ` Jonathan Tan 2019-09-23 19:15 ` Jeff King [this message] 2019-09-23 20:38 ` Jonathan Tan 2019-09-23 21:28 ` Jeff King 2019-09-24 17:07 ` Jonathan Tan 2019-09-26 7:09 ` Jeff King
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style List information: http://vger.kernel.org/majordomo-info.html * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190923191509.GC21344@sigill.intra.peff.net \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --subject='Re: Git in Outreachy December 2019?' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Code repositories for project(s) associated with this inbox: https://80x24.org/mirrors/git.git This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).