[PATCH] objects to be pruned immediately don't have to be loosened

From

Nicolas Pitre <nico@cam.org>

Date

Dec 15, 2008, 17:38 UTC

Message-ID

<alpine.LFD.2.00.0812151105100.30035@xanadu.home>

In-Reply-To

<20081215155610.GA11502@mit.edu>

Signed-off-by: Nicolas Pitre <nico@cam.org>
---

On Mon, 15 Dec 2008, Theodore Tso wrote:

> On Mon, Dec 15, 2008 at 03:08:34PM +0100, Björn Steinbrink wrote:
> > To clarify that a bit more: git gc keeps unreachable objects unpacked,
> > so that git prune can drop them. And git gc invokes git prune so that
> > only unreachable objects older than 2 weeks are dropped.
> 
> To be even more explicit, "git gc" will **unpack** objects that have
> become unreachable and were currently in packs.  As a result, the
> amount of disk space used by a git repository can actually go **up**
> dramatically after a "git gc" operation, which could be surprising for
> someone who is running close to full on their filesystem, deletes a
> number of branches from a tracking repository, and then does a "git
> gc" may get a very unpleasant surprise.
> 
> A really good repository which shows this is linux-next, since it is
> constantly getting rewound, and old branches are reserved via a tag
> such as next-20081204.  If you update the your local copy of the
> linux-next repository every day, you will accumulate a large number of
> these old branch tags.  If you then delete a whole series of them, and
> run git-gc, the operation will take quite a while, and the number of
> blocks and inodes used will grow significantly.  They will disappear
> after a "git prune", but when I do this housekeeping operation, I've
> often wished for a --yes-I-know-what-I-am-doing-and-it's-unsafe-but-
> just-drop-the-unreachable-objects-cause-this-is-just-a-tracking-repository
> option to "git gc".

What about this?

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 21ea165..ca45e71 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -702,7 +702,9 @@ gc.packrefs::
 
 gc.pruneexpire::
 	When 'git-gc' is run, it will call 'prune --expire 2.weeks.ago'.
-	Override the grace period with this config variable.
+	Override the grace period with this config variable.  The value
+	"now" may be used to disable this  grace period and always prune
+	unreachable objects immediately.
 
 gc.reflogexpire::
 	'git-reflog expire' removes reflog entries older than
diff --git a/builtin-gc.c b/builtin-gc.c
index 781df60..f8eae4a 100644
--- a/builtin-gc.c
+++ b/builtin-gc.c
@@ -188,7 +188,9 @@ static int need_to_gc(void)
 	 * there is no need.
 	 */
 	if (too_many_packs())
-		append_option(argv_repack, "-A", MAX_ADD);
+		append_option(argv_repack,
+			      !strcmp(prune_expire, "now") ? "-a" : "-A",
+			      MAX_ADD);
 	else if (!too_many_loose_objects())
 		return 0;
 
@@ -243,7 +245,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			"run \"git gc\" manually. See "
 			"\"git help gc\" for more information.\n");
 	} else
-		append_option(argv_repack, "-A", MAX_ADD);
+		append_option(argv_repack,
+			      !strcmp(prune_expire, "now") ? "-a" : "-A",
+			      MAX_ADD);
 
 	if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
 		return error(FAILED_RUN, argv_pack_refs[0]);