Here is a reroll my topic to introduce pseudo-merge bitmaps. Much is
unchanged since last time, but notable changes (in response to Peff's
review of the first five or so patches of this topic) include:
- Rebased onto 2.45, so this is now based on 'master', which is at
786a3e4b8d (Git 2.45, 2024-04-29) at the time of writing.
- Dropped patch 2/24 from the first round as it is no longer
necessary.
- Introduced some documentation and fixed a couple of comments
around ewah_bitmap_is_subset() and bitmap_is_subset() to clarify
which argument is supposed to be a subset of the other.
Otherwise, a range-diff is included below for convenience. Thanks in
advance for your review!
Taylor Blau (23):
Documentation/technical: describe pseudo-merge bitmaps format
ewah: implement `ewah_bitmap_is_subset()`
pack-bitmap: drop unused `max_bitmaps` parameter
pack-bitmap: move some initialization to `bitmap_writer_init()`
pseudo-merge.ch: initial commit
pack-bitmap-write: support storing pseudo-merge commits
pack-bitmap: implement `bitmap_writer_has_bitmapped_object_id()`
pack-bitmap: make `bitmap_writer_push_bitmapped_commit()` public
pseudo-merge: implement support for selecting pseudo-merge commits
pack-bitmap-write.c: select pseudo-merge commits
pack-bitmap-write.c: write pseudo-merge table
pack-bitmap: extract `read_bitmap()` function
pseudo-merge: scaffolding for reads
pack-bitmap.c: read pseudo-merge extension
pseudo-merge: implement support for reading pseudo-merge commits
ewah: implement `ewah_bitmap_popcount()`
pack-bitmap: implement test helpers for pseudo-merge
t/test-lib-functions.sh: support `--date` in `test_commit_bulk()`
pack-bitmap.c: use pseudo-merges during traversal
pack-bitmap: extra trace2 information
ewah: `bitmap_equals_ewah()`
pseudo-merge: implement support for finding existing merges
t/perf: implement performace tests for pseudo-merge bitmaps
Documentation/config.txt | 2 +
Documentation/config/bitmap-pseudo-merge.txt | 75 ++
Documentation/technical/bitmap-format.txt | 205 +++++
Makefile | 1 +
builtin/pack-objects.c | 3 +-
ewah/bitmap.c | 76 ++
ewah/ewok.h | 8 +
midx-write.c | 3 +-
pack-bitmap-write.c | 275 ++++++-
pack-bitmap.c | 359 ++++++++-
pack-bitmap.h | 16 +-
pseudo-merge.c | 739 +++++++++++++++++++
pseudo-merge.h | 218 ++++++
t/helper/test-bitmap.c | 34 +-
t/perf/p5333-pseudo-merge-bitmaps.sh | 32 +
t/t5333-pseudo-merge-bitmaps.sh | 389 ++++++++++
t/test-lib-functions.sh | 12 +-
17 files changed, 2386 insertions(+), 61 deletions(-)
create mode 100644 Documentation/config/bitmap-pseudo-merge.txt
create mode 100644 pseudo-merge.c
create mode 100644 pseudo-merge.h
create mode 100755 t/perf/p5333-pseudo-merge-bitmaps.sh
create mode 100755 t/t5333-pseudo-merge-bitmaps.sh
Range-diff against v1:
1: 76e7e3b9cca = 1: 43fd5e35971 Documentation/technical: describe pseudo-merge bitmaps format
2: 21d8f9dc2b4 < -: ----------- config: repo_config_get_expiry()
3: 1347571ef4c ! 2: 290d928325d ewah: implement `ewah_bitmap_is_subset()`
@@ ewah/bitmap.c: void bitmap_or(struct bitmap *self, const struct bitmap *other)
+ * Otherwise, compare the next two pairs of
+ * words. If the word from `self` has bit(s) not
+ * in the word from `other`, `self` is not a
-+ * proper subset of `other`.
++ * subset of `other`.
+ */
+ return 0;
+ }
@@ ewah/bitmap.c: void bitmap_or(struct bitmap *self, const struct bitmap *other)
+ * If we got to this point, there may be zero or more words
+ * remaining in `self`, with no remaining words left in `other`.
+ * If there are any bits set in the remaining word(s) in `self`,
-+ * then `self` is not a proper subset of `other`.
++ * then `self` is not a subset of `other`.
+ */
+ while (ewah_iterator_next(&word, &it))
+ if (word)
@@ ewah/bitmap.c: void bitmap_or(struct bitmap *self, const struct bitmap *other)
size_t original_size = self->word_alloc;
## ewah/ewok.h ##
-@@ ewah/ewok.h: int bitmap_get(struct bitmap *self, size_t pos);
+@@ ewah/ewok.h: void bitmap_unset(struct bitmap *self, size_t pos);
+ int bitmap_get(struct bitmap *self, size_t pos);
void bitmap_free(struct bitmap *self);
int bitmap_equals(struct bitmap *self, struct bitmap *other);
++
++/*
++ * Both `bitmap_is_subset()` and `ewah_bitmap_is_subset()` return 1 if the set
++ * of bits in 'self' are a subset of the bits in 'other'. Returns 0 otherwise.
++ */
int bitmap_is_subset(struct bitmap *self, struct bitmap *other);
+int ewah_bitmap_is_subset(struct ewah_bitmap *self, struct bitmap *other);
4: c6a08dae037 ! 3: 5160859f7f3 pack-bitmap: drop unused `max_bitmaps` parameter
@@ builtin/pack-objects.c: static void write_pack_file(void)
die(_("failed to write bitmap index"));
bitmap_writer_finish(written_list, nr_written,
- ## midx.c ##
-@@ midx.c: static int write_midx_bitmap(const char *midx_name,
+ ## midx-write.c ##
+@@ midx-write.c: static int write_midx_bitmap(const char *midx_name,
for (i = 0; i < pdata->nr_objects; i++)
index[pack_order[i]] = &pdata->objects[i].idx;
5: a6531656739 ! 4: 3d7d930b1c5 pack-bitmap: move some initialization to `bitmap_writer_init()`
@@ builtin/pack-objects.c: static void write_pack_file(void)
bitmap_writer_build_type_index(
&to_pack, written_list, nr_written);
- ## midx.c ##
-@@ midx.c: static int write_midx_bitmap(const char *midx_name,
+ ## midx-write.c ##
+@@ midx-write.c: static int write_midx_bitmap(const char *midx_name,
for (i = 0; i < pdata->nr_objects; i++)
index[i] = &pdata->objects[i].idx;
6: c6f9170af0f = 5: e7a87cf7d4e pseudo-merge.ch: initial commit
7: 7acdee2b5f2 = 6: ee33a703245 pack-bitmap-write: support storing pseudo-merge commits
8: 4fdd7dda274 = 7: 9c6d09bf874 pack-bitmap: implement `bitmap_writer_has_bitmapped_object_id()`
9: d74cf3e484d = 8: dfd4b73d12e pack-bitmap: make `bitmap_writer_push_bitmapped_commit()` public
10: 323e1250b24 = 9: 86a1e4b8b9b pseudo-merge: implement support for selecting pseudo-merge commits
11: bf6b0d8601e = 10: 12b432e3a8a pack-bitmap-write.c: select pseudo-merge commits
12: 4c594f3faa8 = 11: 6ce805d061e pack-bitmap-write.c: write pseudo-merge table
13: 7a31a932ab3 = 12: 60f6b310213 pack-bitmap: extract `read_bitmap()` function
14: 7e4d051f37a = 13: 9465313691b pseudo-merge: scaffolding for reads
15: 7bb644b2b0c = 14: 5894f3d5369 pack-bitmap.c: read pseudo-merge extension
16: 792cc863154 = 15: 7dbee8bcbdf pseudo-merge: implement support for reading pseudo-merge commits
17: 8fb7f7ab37b = 16: 09650aa53e9 ewah: implement `ewah_bitmap_popcount()`
18: c839e1fed15 = 17: 7b5ea56d053 pack-bitmap: implement test helpers for pseudo-merge
19: 7d3b88e6fd6 = 18: 006abdd1698 t/test-lib-functions.sh: support `--date` in `test_commit_bulk()`
20: c18694ade2a = 19: 3f85e5b90f5 pack-bitmap.c: use pseudo-merges during traversal
21: d38ebeba419 = 20: 5fac186df64 pack-bitmap: extra trace2 information
22: 1eb10c190ba ! 21: b5aea8e57f8 ewah: `bitmap_equals_ewah()`
@@ ewah/ewok.h: void bitmap_unset(struct bitmap *self, size_t pos);
void bitmap_free(struct bitmap *self);
int bitmap_equals(struct bitmap *self, struct bitmap *other);
+int bitmap_equals_ewah(struct bitmap *self, struct ewah_bitmap *other);
- int bitmap_is_subset(struct bitmap *self, struct bitmap *other);
- int ewah_bitmap_is_subset(struct ewah_bitmap *self, struct bitmap *other);
+ /*
+ * Both `bitmap_is_subset()` and `ewah_bitmap_is_subset()` return 1 if the set
23: 4ae4f0eaae5 = 22: 61ddb574285 pseudo-merge: implement support for finding existing merges
24: a05ad42202d = 23: 2bd830d35dd t/perf: implement performace tests for pseudo-merge bitmaps
base-commit: 786a3e4b8d754d2b14b1208b98eeb0a554ef19a8
--
2.45.0.23.gc6f94b99219
