Commit ccc1297226b184c40459e9d373cc9eebfb7bd898 changed the behavior
of 'git repack -A' so unreachable objects are stored as loose objects.
However it did so in a naive and inn efficient way by making packs
about to be deleted inaccessible and feeding their content through
'git unpack-objects'. While this works, there are major flaws with
this approach:
- It is unacceptably sloooooooooooooow.
In the Linux kernel repository with no actual unreachable objects,
doing 'git repack -A -d' before:
real 2m33.220s
user 2m21.675s
sys 0m3.510s
And with this change:
real 0m36.849s
user 0m24.365s
sys 0m1.950s
For reference, here's the timing for 'git repack -a -d':
real 0m35.816s
user 0m22.571s
sys 0m2.011s
This is explained by the fact that 'git unpack-objects' was used to
unpack _every_ objects even if (almost) 100% of them were thrown away.
- There is a black out period.
Between the removal of the .idx file for the redundant pack and the
completion of its unpacking, the unreachable objects become completely
unaccessible. This is not a big issue as we're talking about unreachable
objects, but some consistency is always good.
- There is no way to easily set a sensible mtime for the newly created
unreachable loose objects.
So, while having a command called "pack-objects" to perform object
unpacking looks really odd, this is probably the best compromize to be
able to solve the above issues in an efficient way.
Signed-off-by: Nicolas Pitre <nico@xxxxxxx>
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index e20851e..f43eb67 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -28,7 +28,8 @@ git-pack-objects [{ -q | --progress | --all-progress }] \n\
[--window=N] [--window-memory=N] [--depth=N] \n\
[--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
[--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
- [--stdout | base-name] [--include-tag] [--keep-unreachable] \n\
+ [--stdout | base-name] [--include-tag] \n\
+ [--keep-unreachable | --unpack-unreachable] \n\
[<ref-list | <object-list]";
struct object_entry {
@@ -67,7 +68,7 @@ static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
static int non_empty;
static int reuse_delta = 1, reuse_object = 1;
-static int keep_unreachable, include_tag;
+static int keep_unreachable, unpack_unreachable, include_tag;
static int local;
static int incremental;
static int allow_ofs_delta;
@@ -1946,6 +1947,32 @@ static void add_objects_in_unpacked_packs(struct rev_info *revs)
free(in_pack.array);
}
+static void loosen_unused_packed_objects(struct rev_info *revs)
+{
+ struct packed_git *p;
+ uint32_t i;
+ const unsigned char *sha1;
+
+ for (p = packed_git; p; p = p->next) {
+ for (i = 0; i < revs->num_ignore_packed; i++) {
+ if (matches_pack_name(p, revs->ignore_packed[i]))
+ break;
+ }
+ if (revs->num_ignore_packed <= i)
+ continue;
+
+ if (open_pack_index(p))
+ die("cannot open pack index");
+
+ for (i = 0; i < p->num_objects; i++) {
+ sha1 = nth_packed_object_sha1(p, i);
+ if (!locate_object_entry(sha1))
+ if (force_object_loose(sha1, p->mtime))
+ die("unable to force loose object");
+ }
+ }
+}
+
static void get_object_list(int ac, const char **av)
{
struct rev_info revs;
@@ -1980,6 +2007,8 @@ static void get_object_list(int ac, const char **av)
if (keep_unreachable)
add_objects_in_unpacked_packs(&revs);
+ if (unpack_unreachable)
+ loosen_unused_packed_objects(&revs);
}
static int adjust_perm(const char *path, mode_t mode)
@@ -2114,6 +2143,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
keep_unreachable = 1;
continue;
}
+ if (!strcmp("--unpack-unreachable", arg)) {
+ unpack_unreachable = 1;
+ continue;
+ }
if (!strcmp("--include-tag", arg)) {
include_tag = 1;
continue;
@@ -2179,6 +2212,9 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
if (!pack_to_stdout && thin)
die("--thin cannot be used to build an indexable pack.");
+ if (keep_unreachable && unpack_unreachable)
+ die("--keep-unreachable and --unpack-unreachable are incompatible.");
+
#ifdef THREADED_DELTA_SEARCH
if (!delta_search_threads) /* --threads=0 means autodetect */
delta_search_threads = online_cpus();
diff --git a/git-repack.sh b/git-repack.sh
index 0aede89..10f735c 100755
--- a/git-repack.sh
+++ b/git-repack.sh
@@ -8,7 +8,7 @@ OPTIONS_SPEC="\
git-repack [options]
--
a pack everything in a single pack
-A same as -a, and keep unreachable objects too
+A same as -a, and turn unreachable objects loose
d remove redundant packs, and run git-prune-packed
f pass --no-reuse-delta to git-pack-objects
n do not run git-update-server-info
@@ -23,7 +23,7 @@ max-pack-size= maximum size of each packfile
SUBDIRECTORY_OK='Yes'
. git-sh-setup
-no_update_info= all_into_one= remove_redundant= keep_unreachable=
+no_update_info= all_into_one= remove_redundant= unpack_unreachable=
local= quiet= no_reuse= extra=
while test $# != 0
do
@@ -31,7 +31,7 @@ do
-n) no_update_info=t ;;
-a) all_into_one=t ;;
-A) all_into_one=t
- keep_unreachable=t ;;
+ unpack_unreachable=--unpack-unreachable ;;
-d) remove_redundant=t ;;
-q) quiet=-q ;;
-f) no_reuse=--no-reuse-object ;;
@@ -79,6 +79,9 @@ case ",$all_into_one," in
if test -z "$args"
then
args='--unpacked --incremental'
+ elif test -n "$unpack_unreachable"
+ then
+ args="$args $unpack_unreachable"
fi
;;
esac
@@ -128,18 +131,7 @@ then
do
case " $fullbases " in
*" $e "*) ;;
- *)
- rm -f "$e.idx" "$e.keep"
- if test -n "$keep_unreachable" &&
- test -f "$e.pack"
- then
- git unpack-objects < "$e.pack" || {
- echo >&2 "Failed unpacking unreachable objects from redundant pack file $e.pack"
- exit 1
- }
- fi
- rm -f "$e.pack"
- ;;
+ *) rm -f "$e.pack" "$e.idx" "$e.keep" ;;
esac
done
)
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