pack-bitmap.c: teach `rev-list --test-bitmap` about incremental MIDXs
Implement support for the special `--test-bitmap` mode of `git rev-list` when using incremental MIDXs. The bitmap_test_data structure is extended to contain a "base" pointer that mirrors the structure of the bitmap chain that it is being used to test. When we find a commit to test, we first chase down the ->base pointer to find the appropriate bitmap_test_data for the bitmap layer that the given commit is contained within, and then perform the test on that bitmap. In order to implement this, light modifications are made to bitmap_for_commit() to reimplement it in terms of a new function, find_bitmap_for_commit(), which fills out a pointer which indicates the bitmap layer which contains the given commit. Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau committed
Mar 20, 2025 at 13:56 UTC
faab03f9a16cbca85415b73504eb95e6b8ed3d6b
1 file changed
+86
-21
pack-bitmap.c
+86
-21
@@ -938,8 +938,9 @@ corrupt:
938
return NULL;
939
}
940
941
-struct ewah_bitmap *bitmap_for_commit(struct bitmap_index *bitmap_git,
942
- struct commit *commit)
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+static struct ewah_bitmap *find_bitmap_for_commit(struct bitmap_index *bitmap_git,
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+ struct commit *commit,
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+ struct bitmap_index **found)
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{
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khiter_t hash_pos;
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if (!bitmap_git)
@@ -949,18 +950,30 @@ struct ewah_bitmap *bitmap_for_commit(struct bitmap_index *bitmap_git,
950
if (hash_pos >= kh_end(bitmap_git->bitmaps)) {
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struct stored_bitmap *bitmap = NULL;
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if (!bitmap_git->table_lookup)
952
- return bitmap_for_commit(bitmap_git->base, commit);
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+ return find_bitmap_for_commit(bitmap_git->base, commit,
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+ found);
955
956
/* this is a fairly hot codepath - no trace2_region please */
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/* NEEDSWORK: cache misses aren't recorded */
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bitmap = lazy_bitmap_for_commit(bitmap_git, commit);
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if (!bitmap)
958
- return bitmap_for_commit(bitmap_git->base, commit);
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+ return find_bitmap_for_commit(bitmap_git->base, commit,
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+ found);
962
+ if (found)
963
+ *found = bitmap_git;
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return lookup_stored_bitmap(bitmap);
965
}
966
+ if (found)
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+ *found = bitmap_git;
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return lookup_stored_bitmap(kh_value(bitmap_git->bitmaps, hash_pos));
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}
970
971
+struct ewah_bitmap *bitmap_for_commit(struct bitmap_index *bitmap_git,
972
+ struct commit *commit)
973
+{
974
+ return find_bitmap_for_commit(bitmap_git, commit, NULL);
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+}
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+
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static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
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const struct object_id *oid)
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{
@@ -2513,6 +2526,8 @@ struct bitmap_test_data {
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struct bitmap *tags;
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struct progress *prg;
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size_t seen;
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+
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+ struct bitmap_test_data *base_tdata;
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};
2532
2533
static void test_bitmap_type(struct bitmap_test_data *tdata,
@@ -2521,6 +2536,11 @@ static void test_bitmap_type(struct bitmap_test_data *tdata,
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enum object_type bitmap_type = OBJ_NONE;
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int bitmaps_nr = 0;
2538
2539
+ if (bitmap_is_midx(tdata->bitmap_git)) {
2540
+ while (pos < tdata->bitmap_git->midx->num_objects_in_base)
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+ tdata = tdata->base_tdata;
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+ }
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+
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if (bitmap_get(tdata->commits, pos)) {
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bitmap_type = OBJ_COMMIT;
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bitmaps_nr++;
@@ -2584,13 +2604,57 @@ static void test_show_commit(struct commit *commit, void *data)
2604
display_progress(tdata->prg, ++tdata->seen);
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}
2606
2607
+static uint32_t bitmap_total_entry_count(struct bitmap_index *bitmap_git)
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+{
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+ uint32_t total = 0;
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+ do {
2611
+ total = st_add(total, bitmap_git->entry_count);
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+ bitmap_git = bitmap_git->base;
2613
+ } while (bitmap_git);
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+
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+ return total;
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+}
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+
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+static void bitmap_test_data_prepare(struct bitmap_test_data *tdata,
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+ struct bitmap_index *bitmap_git)
2620
+{
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+ memset(tdata, 0, sizeof(struct bitmap_test_data));
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+
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+ tdata->bitmap_git = bitmap_git;
2624
+ tdata->base = bitmap_new();
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+ tdata->commits = ewah_to_bitmap(bitmap_git->commits);
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+ tdata->trees = ewah_to_bitmap(bitmap_git->trees);
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+ tdata->blobs = ewah_to_bitmap(bitmap_git->blobs);
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+ tdata->tags = ewah_to_bitmap(bitmap_git->tags);
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+
2630
+ if (bitmap_git->base) {
2631
+ tdata->base_tdata = xmalloc(sizeof(struct bitmap_test_data));
2632
+ bitmap_test_data_prepare(tdata->base_tdata, bitmap_git->base);
2633
+ }
2634
+}
2635
+
2636
+static void bitmap_test_data_release(struct bitmap_test_data *tdata)
2637
+{
2638
+ if (!tdata)
2639
+ return;
2640
+
2641
+ bitmap_test_data_release(tdata->base_tdata);
2642
+ free(tdata->base_tdata);
2643
+
2644
+ bitmap_free(tdata->base);
2645
+ bitmap_free(tdata->commits);
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+ bitmap_free(tdata->trees);
2647
+ bitmap_free(tdata->blobs);
2648
+ bitmap_free(tdata->tags);
2649
+}
2650
+
2651
void test_bitmap_walk(struct rev_info *revs)
2652
{
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struct object *root;
2654
struct bitmap *result = NULL;
2655
size_t result_popcnt;
2656
struct bitmap_test_data tdata;
2593
- struct bitmap_index *bitmap_git;
2657
+ struct bitmap_index *bitmap_git, *found;
2658
struct ewah_bitmap *bm;
2659
2660
if (!(bitmap_git = prepare_bitmap_git(revs->repo)))
@@ -2599,17 +2663,28 @@ void test_bitmap_walk(struct rev_info *revs)
2663
if (revs->pending.nr != 1)
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die(_("you must specify exactly one commit to test"));
2665
2602
- fprintf_ln(stderr, "Bitmap v%d test (%d entries%s)",
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+ fprintf_ln(stderr, "Bitmap v%d test (%d entries%s, %d total)",
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bitmap_git->version,
2668
bitmap_git->entry_count,
2605
- bitmap_git->table_lookup ? "" : " loaded");
2669
+ bitmap_git->table_lookup ? "" : " loaded",
2670
+ bitmap_total_entry_count(bitmap_git));
2671
2672
root = revs->pending.objects[0].item;
2608
- bm = bitmap_for_commit(bitmap_git, (struct commit *)root);
2673
+ bm = find_bitmap_for_commit(bitmap_git, (struct commit *)root, &found);
2674
2675
if (bm) {
2676
fprintf_ln(stderr, "Found bitmap for '%s'. %d bits / %08x checksum",
2612
- oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
2677
+ oid_to_hex(&root->oid),
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+ (int)bm->bit_size, ewah_checksum(bm));
2679
+
2680
+ if (bitmap_is_midx(found))
2681
+ fprintf_ln(stderr, "Located via MIDX '%s'.",
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+ hash_to_hex_algop(get_midx_checksum(found->midx),
2683
+ revs->repo->hash_algo));
2684
+ else
2685
+ fprintf_ln(stderr, "Located via pack '%s'.",
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+ hash_to_hex_algop(found->pack->hash,
2687
+ revs->repo->hash_algo));
2688
2689
result = ewah_to_bitmap(bm);
2690
}
@@ -2626,16 +2701,10 @@ void test_bitmap_walk(struct rev_info *revs)
2701
if (prepare_revision_walk(revs))
2702
die(_("revision walk setup failed"));
2703
2629
- tdata.bitmap_git = bitmap_git;
2630
- tdata.base = bitmap_new();
2631
- tdata.commits = ewah_to_bitmap(bitmap_git->commits);
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- tdata.trees = ewah_to_bitmap(bitmap_git->trees);
2633
- tdata.blobs = ewah_to_bitmap(bitmap_git->blobs);
2634
- tdata.tags = ewah_to_bitmap(bitmap_git->tags);
2704
+ bitmap_test_data_prepare(&tdata, bitmap_git);
2705
tdata.prg = start_progress(revs->repo,
2706
"Verifying bitmap entries",
2707
result_popcnt);
2638
- tdata.seen = 0;
2708
2709
traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
2710
@@ -2647,11 +2716,7 @@ void test_bitmap_walk(struct rev_info *revs)
2716
die(_("mismatch in bitmap results"));
2717
2718
bitmap_free(result);
2650
- bitmap_free(tdata.base);
2651
- bitmap_free(tdata.commits);
2652
- bitmap_free(tdata.trees);
2653
- bitmap_free(tdata.blobs);
2654
- bitmap_free(tdata.tags);
2719
+ bitmap_test_data_release(&tdata);
2720
free_bitmap_index(bitmap_git);
2721
}
2722