From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Junio C Hamano <gitster@pobox.com>
Cc: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>,
git@vger.kernel.org, Jeff King <peff@peff.net>
Subject: Re: [PATCH 4/4] get_oid(): when an object was not found, try harder
Date: Thu, 14 Mar 2019 14:17:18 +0100 (STD) [thread overview]
Message-ID: <nycvar.QRO.7.76.6.1903141410360.41@tvgsbejvaqbjf.bet> (raw)
In-Reply-To: <xmqqa7hyckfm.fsf@gitster-ct.c.googlers.com>
Hi Junio & Peff,
On Thu, 14 Mar 2019, Junio C Hamano wrote:
> "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
>
> > @@ -442,6 +442,18 @@ static enum get_oid_result get_short_oid(const char *name, int len,
> > find_short_packed_object(&ds);
> > status = finish_object_disambiguation(&ds, oid);
> >
> > + /*
> > + * If we didn't find it, do the usual reprepare() slow-path,
> > + * since the object may have recently been added to the repository
> > + * or migrated from loose to packed.
> > + */
> > + if (status == MISSING_OBJECT) {
> > + reprepare_packed_git(the_repository);
> > + find_short_object_filename(&ds);
> > + find_short_packed_object(&ds);
> > + status = finish_object_disambiguation(&ds, oid);
> > + }
> > +
>
> This looks obviously correct, but two things that made me wonder
> briefly were:
>
> 1. is reprepare_packed_git() a bit too heavy-weight, if the only
> thing we are addressing is the loose-object cache going stale?
>
> 2. is there a way to cleanly avoid the three-line duplicate?
>
> My tentative answers are (1) even if it is, but get_short_oid() is
> already heavy-weight enough; it won't be worth restructuring the
> code to make it possible to clear only the loose-object cache, and
> (2) a loop that runs twice when the first result is MISSING_OBJECT
> and otherwise leaves after once would need an extra variable, its
> iniialization, check and increment, which is more than what we might
> save with such a restructuring, so it won't be worth pursuing.
>
> But others may have better ideas, as always ;-)
Peff tried with a function, but I think that this would actually be a
really appropriate occasion for a well-placed `goto`:
-- snip --
diff --git a/sha1-name.c b/sha1-name.c
index 6dda2c16df10..36a66026964a 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -415,7 +415,7 @@ static enum get_oid_result get_short_oid(const char *name, int len,
struct object_id *oid,
unsigned flags)
{
- int status;
+ int status, attempts = 0;
struct disambiguate_state ds;
int quietly = !!(flags & GET_OID_QUIETLY);
@@ -438,10 +438,21 @@ static enum get_oid_result get_short_oid(const char *name, int len,
else
ds.fn = default_disambiguate_hint;
+try_again:
find_short_object_filename(&ds);
find_short_packed_object(&ds);
status = finish_object_disambiguation(&ds, oid);
+ /*
+ * If we did not find it, do the usual reprepare() slow-path, since the
+ * object may have recently been added to the repository or migrated
+ * from loose to packed.
+ */
+ if (status == MISSING_OBJECT && !attempts++) {
+ reprepare_packed_git(the_repository);
+ goto try_again;
+ }
+
if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) {
struct oid_array collect = OID_ARRAY_INIT;
-- snap --
Granted, it's 11 lines inserted and one changed as opposed to 12 lines
inserted, but it does make the code DRYer (and therefore slightly safer to
modify in the future). I pushed this to the GitGitGadget PR.
Thanks,
Dscho
next prev parent reply other threads:[~2019-03-14 13:17 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-13 10:16 [PATCH 0/4] get_oid: cope with a possibly stale loose object cache Johannes Schindelin via GitGitGadget
2019-03-13 10:16 ` [PATCH 1/4] rebase -i: demonstrate obscure loose object cache bug Johannes Schindelin via GitGitGadget
2019-03-13 16:11 ` Ævar Arnfjörð Bjarmason
2019-03-13 16:35 ` Jeff King
2019-03-13 16:53 ` Jeff King
2019-03-13 22:40 ` Johannes Schindelin
2019-03-14 0:07 ` Jeff King
2019-03-13 22:27 ` Johannes Schindelin
2019-03-14 0:05 ` Jeff King
2019-03-14 6:40 ` Johannes Sixt
2019-03-14 13:06 ` Johannes Schindelin
2019-03-14 1:12 ` Junio C Hamano
2019-03-14 12:44 ` Johannes Schindelin
2019-03-13 10:16 ` [PATCH 2/4] sequencer: improve error message when an OID could not be parsed Johannes Schindelin via GitGitGadget
2019-03-14 1:14 ` Junio C Hamano
2019-03-13 10:16 ` [PATCH 3/4] sequencer: move stale comment into correct location Johannes Schindelin via GitGitGadget
2019-03-13 10:16 ` [PATCH 4/4] get_oid(): when an object was not found, try harder Johannes Schindelin via GitGitGadget
2019-03-14 1:29 ` Junio C Hamano
2019-03-14 2:22 ` Jeff King
2019-03-14 2:40 ` Jeff King
2019-03-14 4:05 ` Junio C Hamano
2019-03-14 18:55 ` Jeff King
2019-03-14 3:49 ` Junio C Hamano
2019-03-14 13:17 ` Johannes Schindelin [this message]
2019-03-14 18:57 ` Jeff King
2019-03-14 19:55 ` Johannes Schindelin
2019-03-13 15:33 ` [PATCH 0/4] get_oid: cope with a possibly stale loose object cache Jeff King
2019-03-14 15:33 ` [PATCH v2 0/4] get_short_oid: " Johannes Schindelin via GitGitGadget
2019-03-14 15:33 ` [PATCH v2 1/4] rebase -i: demonstrate obscure loose object cache bug Johannes Schindelin via GitGitGadget
2019-03-14 15:33 ` [PATCH v2 2/4] sequencer: improve error message when an OID could not be parsed Johannes Schindelin via GitGitGadget
2019-03-14 15:33 ` [PATCH v2 3/4] sequencer: move stale comment into correct location Johannes Schindelin via GitGitGadget
2019-03-14 15:33 ` [PATCH v2 4/4] get_oid(): when an object was not found, try harder Johannes Schindelin via GitGitGadget
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=nycvar.QRO.7.76.6.1903141410360.41@tvgsbejvaqbjf.bet \
--to=johannes.schindelin@gmx.de \
--cc=git@vger.kernel.org \
--cc=gitgitgadget@gmail.com \
--cc=gitster@pobox.com \
--cc=peff@peff.net \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public 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).