From: Jeff King <peff@peff.net>
To: "René Scharfe" <l.s.r@web.de>
Cc: git@vger.kernel.org
Subject: Re: [PATCH 05/12] http: simplify parsing of remote objects/info/packs
Date: Fri, 5 Apr 2019 14:11:32 -0400 [thread overview]
Message-ID: <20190405181132.GA32401@sigill.intra.peff.net> (raw)
In-Reply-To: <83129937-dcd0-f16e-c8aa-97eceec9769a@web.de>
On Fri, Apr 05, 2019 at 12:41:27PM +0200, René Scharfe wrote:
> Am 05.04.2019 um 01:27 schrieb Jeff King:
> > We can use skip_prefix() and parse_oid_hex() to continuously increment
> > our pointer, rather than dealing with magic numbers. This also fixes a
> > few small shortcomings:
> >
> > - if we see a 'P' line that does not match our expectations, we'll
> > leave our "i" counter in the middle of the line. So we'll parse:
> > "P P P pack-1234.pack" as if there was just one "P" which was not
> > intentional (though probably not that harmful).
>
> How so? The default case, which we'd fall through to, skips the rest
> of such a line, doesn't it?
Oh, you're right. I didn't notice the fall-through, which is quite
subtle (I'm actually surprised -Wimplicit-fallthrough doesn't complain
about this).
I'll fix up the commit message (the cleanup is still very much worth it
for the garbage-oid issue, IMHO).
> > + while (*data) {
> > + if (skip_prefix(data, "P pack-", &data) &&
> > + !parse_oid_hex(data, &oid, &data) &&
> > + skip_prefix(data, ".pack", &data) &&
> > + (*data == '\n' || *data == '\0')) {
> > + fetch_and_setup_pack_index(packs_head, oid.hash, base_url);
> > + } else {
> > + data = strchrnul(data, '\n');
> > }
> > - i++;
> > + if (*data)
> > + data++; /* skip past newline */
>
> So much simpler, *and* converted to object_id -- I like it!
>
> Parsing "P" and "pack-" together crosses logical token boundaries,
> but that I don't mind it here.
Yeah, I was tempted to write:
if (skip_prefix(data, "P ", &data) &&
skip_prefix(data, "pack-", &data) &&
...
but that felt a little silly. I dunno. I guess it is probably not any
less efficient, because we'd expect skip_prefix() and its loop to get
inlined here anyway.
-Peff
next prev parent reply other threads:[~2019-04-05 18:11 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 23:21 [PATCH 0/12] a rabbit hole of update-server-info fixes Jeff King
2019-04-04 23:22 ` [PATCH 01/12] t5319: fix bogus cat-file argument Jeff King
2019-04-05 0:44 ` Ramsay Jones
2019-04-05 1:41 ` Jeff King
2019-04-05 1:46 ` Jeff King
2019-04-04 23:22 ` [PATCH 02/12] t5319: drop useless --buffer from cat-file Jeff King
2019-04-04 23:22 ` [PATCH 03/12] packfile: factor out .pack to .idx name conversion Jeff King
2019-04-04 23:25 ` [PATCH 04/12] packfile: check midx coverage with .idx rather than .pack Jeff King
2019-04-05 8:05 ` René Scharfe
2019-04-05 13:21 ` Jeff King
2019-04-05 13:30 ` Jeff King
2019-04-05 12:01 ` SZEDER Gábor
2019-04-05 13:40 ` Jeff King
2019-04-04 23:27 ` [PATCH 05/12] http: simplify parsing of remote objects/info/packs Jeff King
2019-04-05 10:41 ` René Scharfe
2019-04-05 18:11 ` Jeff King [this message]
2019-04-05 20:17 ` René Scharfe
2019-04-04 23:27 ` [PATCH 06/12] server-info: fix blind pointer arithmetic Jeff King
2019-04-04 23:28 ` [PATCH 07/12] server-info: simplify cleanup in parse_pack_def() Jeff King
2019-04-04 23:28 ` [PATCH 08/12] server-info: use strbuf to read old info/packs file Jeff King
2019-04-04 23:29 ` [PATCH 09/12] server-info: drop nr_alloc struct member Jeff King
2019-04-04 23:30 ` [PATCH 10/12] packfile.h: drop extern from function declarations Jeff King
2019-04-04 23:30 ` [PATCH 11/12] server-info: drop objdirlen pointer arithmetic Jeff King
2019-04-04 23:31 ` [PATCH 12/12] update_info_refs(): drop unused force parameter Jeff King
2019-04-05 5:46 ` [PATCH 0/12] a rabbit hole of update-server-info fixes Junio C Hamano
2019-04-05 18:03 ` [PATCH v2 0/13] a rabbit hole of update-server-info (and midx!) fixes Jeff King
2019-04-05 18:03 ` [PATCH v2 01/13] packfile.h: drop extern from function declarations Jeff King
2019-04-05 19:19 ` Ramsay Jones
2019-04-05 19:25 ` Jeff King
2019-04-08 5:13 ` Junio C Hamano
2019-04-08 20:32 ` Jeff King
2019-04-09 15:08 ` Junio C Hamano
2019-04-09 15:15 ` Jeff King
2019-04-05 18:04 ` [PATCH v2 02/13] pack-revindex: open index if necessary Jeff King
2019-04-05 18:04 ` [PATCH v2 03/13] t5319: fix bogus cat-file argument Jeff King
2019-04-05 18:05 ` [PATCH v2 04/13] t5319: drop useless --buffer from cat-file Jeff King
2019-04-05 18:06 ` [PATCH v2 05/13] midx: check both pack and index names for containment Jeff King
2019-04-05 20:18 ` René Scharfe
2019-04-05 18:06 ` [PATCH v2 06/13] packfile: fix pack basename computation Jeff King
2019-04-05 18:12 ` [PATCH v2 07/13] http: simplify parsing of remote objects/info/packs Jeff King
2019-04-05 18:13 ` [PATCH v2 08/13] server-info: fix blind pointer arithmetic Jeff King
2019-04-05 18:13 ` [PATCH v2 09/13] server-info: simplify cleanup in parse_pack_def() Jeff King
2019-04-05 18:16 ` Jeff King
2019-04-05 18:13 ` [PATCH v2 10/13] server-info: use strbuf to read old info/packs file Jeff King
2019-04-05 18:14 ` [PATCH v2 11/13] server-info: drop nr_alloc struct member Jeff King
2019-04-05 18:14 ` [PATCH v2 12/13] server-info: drop objdirlen pointer arithmetic Jeff King
2019-04-05 18:14 ` [PATCH v2 13/13] update_info_refs(): drop unused force parameter Jeff King
2019-04-05 18:19 ` [PATCH v2 0/13] a rabbit hole of update-server-info (and midx!) fixes Jeff King
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