It can sometimes be useful to see which refs are contributing to the
overall repository size (e.g., does some branch have a bunch of objects
not found elsewhere in history, which indicates that deleting it would
shrink the size of a clone).
You can find that out by generating a list of objects, getting their
sizes from cat-file, and then summing them, like:
git rev-list --objects --no-object-names main..branch
git cat-file --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
Though note that the caveats from git-cat-file(1) apply here. We "blame"
base objects more than their deltas, even though the relationship could
easily be flipped. Still, it can be a useful rough measure.
But one problem is that it's slow to run. Teaching rev-list to sum up
the sizes can be much faster for two reasons:
1. It skips all of the piping of object names and sizes.
2. If bitmaps are in use, for objects that are in the
bitmapped packfile we can skip the oid_object_info()
lookup entirely, and just ask the revindex for the
on-disk size.
This patch implements a --disk-usage option which produces the same
answer in a fraction of the time. Here are some timings using a clone of
torvalds/linux:
[rev-list piped to cat-file, no bitmaps]
$ time git rev-list --objects --no-object-names --all |
git cat-file --buffer --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
1459938510
real 0m29.635s
user 0m38.003s
sys 0m1.093s
[internal, no bitmaps]
$ time git rev-list --disk-usage --objects --all
1459938510
real 0m31.262s
user 0m30.885s
sys 0m0.376s
Even though the wall-clock time is slightly worse due to parallelism,
notice the CPU savings between the two. We saved 21% of the CPU just by
avoiding the pipes.
But the real win is with bitmaps. If we use them without the new option:
[rev-list piped to cat-file, bitmaps]
$ time git rev-list --objects --no-object-names --all --use-bitmap-index |
git cat-file --batch-check='%(objectsize:disk)' |
perl -lne '$total += $_; END { print $total }'
1459938510
real 0m6.244s
user 0m8.452s
sys 0m0.311s
then we're faster to generate the list of objects, but we still spend a
lot of time piping and looking things up. But if we do both together:
[internal, bitmaps]
$ time git rev-list --disk-usage --objects --all --use-bitmap-index
1459938510
real 0m0.219s
user 0m0.169s
sys 0m0.049s
then we get the same answer much faster.
For "--all", that answer will correspond closely to "du objects/pack",
of course. But we're actually checking reachability here, so we're still
fast when we ask for more interesting things:
$ time git rev-list --disk-usage --use-bitmap-index v5.0..v5.10
374798628
real 0m0.429s
user 0m0.356s
sys 0m0.072s
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
Documentation/rev-list-options.txt | 9 ++++
builtin/rev-list.c | 46 +++++++++++++++++
pack-bitmap.c | 81 ++++++++++++++++++++++++++++++
pack-bitmap.h | 2 +
t/t6114-rev-list-du.sh | 51 +++++++++++++++++++
5 files changed, 189 insertions(+)
create mode 100755 t/t6114-rev-list-du.sh
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 96cc89d157..1238bfd915 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -227,6 +227,15 @@ ifdef::git-rev-list[]
test the exit status to see if a range of objects is fully
connected (or not). It is faster than redirecting stdout
to `/dev/null` as the output does not have to be formatted.
+
+--disk-usage::
+ Suppress normal output; instead, print the sum of the bytes used
+ for on-disk storage by the selected commits or objects. This is
+ equivalent to piping the output into `git cat-file
+ --batch-check='%(objectsize:disk)'`, except that it runs much
+ faster (especially with `--use-bitmap-index`). See the `CAVEATS`
+ section in linkgit:git-cat-file[1] for the limitations of what
+ "on-disk storage" means.
endif::git-rev-list[]
--cherry-mark::
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 25c6c3b38d..b4d8ea0a35 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -80,6 +80,19 @@ static int arg_show_object_names = 1;
#define DEFAULT_OIDSET_SIZE (16*1024)
+static int show_disk_usage;
+static off_t total_disk_usage;
+
+static off_t get_object_disk_usage(struct object *obj)
+{
+ off_t size;
+ struct object_info oi = OBJECT_INFO_INIT;
+ oi.disk_sizep = &size;
+ if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0)
+ die(_("unable to get disk usage of %s"), oid_to_hex(&obj->oid));
+ return size;
+}
+
static void finish_commit(struct commit *commit);
static void show_commit(struct commit *commit, void *data)
{
@@ -88,6 +101,9 @@ static void show_commit(struct commit *commit, void *data)
display_progress(progress, ++progress_counter);
+ if (show_disk_usage)
+ total_disk_usage += get_object_disk_usage(&commit->object);
+
if (info->flags & REV_LIST_QUIET) {
finish_commit(commit);
return;
@@ -258,6 +274,8 @@ static void show_object(struct object *obj, const char *name, void *cb_data)
if (finish_object(obj, name, cb_data))
return;
display_progress(progress, ++progress_counter);
+ if (show_disk_usage)
+ total_disk_usage += get_object_disk_usage(obj);
if (info->flags & REV_LIST_QUIET)
return;
@@ -452,6 +470,23 @@ static int try_bitmap_traversal(struct rev_info *revs,
return 0;
}
+static int try_bitmap_disk_usage(struct rev_info *revs,
+ struct list_objects_filter_options *filter)
+{
+ struct bitmap_index *bitmap_git;
+
+ if (!show_disk_usage)
+ return -1;
+
+ bitmap_git = prepare_bitmap_walk(revs, filter);
+ if (!bitmap_git)
+ return -1;
+
+ printf("%"PRIuMAX"\n",
+ (uintmax_t)get_disk_usage_from_bitmap(bitmap_git, revs));
+ return 0;
+}
+
int cmd_rev_list(int argc, const char **argv, const char *prefix)
{
struct rev_info revs;
@@ -584,6 +619,12 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
continue;
}
+ if (!strcmp(arg, "--disk-usage")) {
+ show_disk_usage = 1;
+ info.flags |= REV_LIST_QUIET;
+ continue;
+ }
+
usage(rev_list_usage);
}
@@ -626,6 +667,8 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
if (use_bitmap_index) {
if (!try_bitmap_count(&revs, &filter_options))
return 0;
+ if (!try_bitmap_disk_usage(&revs, &filter_options))
+ return 0;
if (!try_bitmap_traversal(&revs, &filter_options))
return 0;
}
@@ -690,5 +733,8 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
printf("%d\n", revs.count_left + revs.count_right);
}
+ if (show_disk_usage)
+ printf("%"PRIuMAX"\n", (uintmax_t)total_disk_usage);
+
return 0;
}
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 60fe20fb87..1f69b5fa85 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -1430,3 +1430,84 @@ int bitmap_has_oid_in_uninteresting(struct bitmap_index *bitmap_git,
return bitmap_git &&
bitmap_walk_contains(bitmap_git, bitmap_git->haves, oid);
}
+
+static off_t get_disk_usage_for_type(struct bitmap_index *bitmap_git,
+ enum object_type object_type)
+{
+ struct bitmap *result = bitmap_git->result;
+ struct packed_git *pack = bitmap_git->pack;
+ off_t total = 0;
+ struct ewah_iterator it;
+ eword_t filter;
+ size_t i;
+
+ init_type_iterator(&it, bitmap_git, object_type);
+ for (i = 0; i < result->word_alloc &&
+ ewah_iterator_next(&filter, &it); i++) {
+ eword_t word = result->words[i] & filter;
+ size_t base = (i * BITS_IN_EWORD);
+ unsigned offset;
+
+ if (!word)
+ continue;
+
+ for (offset = 0; offset < BITS_IN_EWORD; offset++) {
+ size_t pos;
+
+ if ((word >> offset) == 0)
+ break;
+
+ offset += ewah_bit_ctz64(word >> offset);
+ pos = base + offset;
+ total += pack_pos_to_offset(pack, pos + 1) -
+ pack_pos_to_offset(pack, pos);
+ }
+ }
+
+ return total;
+}
+
+static off_t get_disk_usage_for_extended(struct bitmap_index *bitmap_git)
+{
+ struct bitmap *result = bitmap_git->result;
+ struct packed_git *pack = bitmap_git->pack;
+ struct eindex *eindex = &bitmap_git->ext_index;
+ off_t total = 0;
+ struct object_info oi = OBJECT_INFO_INIT;
+ off_t object_size;
+ size_t i;
+
+ oi.disk_sizep = &object_size;
+
+ for (i = 0; i < eindex->count; i++) {
+ struct object *obj = eindex->objects[i];
+
+ if (!bitmap_get(result, pack->num_objects + i))
+ continue;
+
+ if (oid_object_info_extended(the_repository, &obj->oid, &oi, 0) < 0)
+ die(_("unable to get disk usage of %s"),
+ oid_to_hex(&obj->oid));
+
+ total += object_size;
+ }
+ return total;
+}
+
+off_t get_disk_usage_from_bitmap(struct bitmap_index *bitmap_git,
+ struct rev_info *revs)
+{
+ off_t total = 0;
+
+ total += get_disk_usage_for_type(bitmap_git, OBJ_COMMIT);
+ if (revs->tree_objects)
+ total += get_disk_usage_for_type(bitmap_git, OBJ_TREE);
+ if (revs->blob_objects)
+ total += get_disk_usage_for_type(bitmap_git, OBJ_BLOB);
+ if (revs->tag_objects)
+ total += get_disk_usage_for_type(bitmap_git, OBJ_TAG);
+
+ total += get_disk_usage_for_extended(bitmap_git);
+
+ return total;
+}
diff --git a/pack-bitmap.h b/pack-bitmap.h
index 25dfcf5615..36d99930d8 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -68,6 +68,8 @@ int bitmap_walk_contains(struct bitmap_index *,
*/
int bitmap_has_oid_in_uninteresting(struct bitmap_index *, const struct object_id *oid);
+off_t get_disk_usage_from_bitmap(struct bitmap_index *, struct rev_info *);
+
void bitmap_writer_show_progress(int show);
void bitmap_writer_set_checksum(unsigned char *sha1);
void bitmap_writer_build_type_index(struct packing_data *to_pack,
diff --git a/t/t6114-rev-list-du.sh b/t/t6114-rev-list-du.sh
new file mode 100755
index 0000000000..b4aef32b71
--- /dev/null
+++ b/t/t6114-rev-list-du.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+
+test_description='basic tests of rev-list --disk-usage'
+. ./test-lib.sh
+
+# we want a mix of reachable and unreachable, as well as
+# objects in the bitmapped pack and some outside of it
+test_expect_success 'set up repository' '
+ test_commit --no-tag one &&
+ test_commit --no-tag two &&
+ git repack -adb &&
+ git reset --hard HEAD^ &&
+ test_commit --no-tag three &&
+ test_commit --no-tag four &&
+ git reset --hard HEAD^
+'
+
+# We don't want to hardcode sizes, because they depend on the exact details of
+# packing, zlib, etc. We'll assume that the regular rev-list and cat-file
+# machinery works and compare the --disk-usage output to that.
+disk_usage_slow () {
+ git rev-list --no-object-names "$@" |
+ git cat-file --batch-check="%(objectsize:disk)" |
+ perl -lne '$total += $_; END { print $total}'
+}
+
+# check behavior with given rev-list options; note that
+# whitespace is not preserved in args
+check_du () {
+ args=$*
+
+ test_expect_success "generate expected size ($args)" "
+ disk_usage_slow $args >expect
+ "
+
+ test_expect_success "rev-list --disk-usage without bitmaps ($args)" "
+ git rev-list --disk-usage $args >actual &&
+ test_cmp expect actual
+ "
+
+ test_expect_success "rev-list --disk-usage with bitmaps ($args)" "
+ git rev-list --disk-usage --use-bitmap-index $args >actual &&
+ test_cmp expect actual
+ "
+}
+
+check_du HEAD
+check_du --objects HEAD
+check_du --objects HEAD^..HEAD
+
+test_done
--
2.30.1.887.ge7d57fcab0
