t/helper: add 'test-tool bitmap write' subcommand
In f16eb1c091 (pseudo-merge: fix disk reads from find_pseudo_merge(), 2026-03-31), we noted that `apply_pseudo_merges_for_commit()` is never triggered by the existing test suite, and that this bears further investigation. This patch is the first one to begin that investigation. The following patches will expose and fix a variety of bugs in the implementation of pseudo-merge bitmaps. In order to do so, however, many of these tests require very precise selection of which commits receive bitmaps and which do not. To date, there isn't a standard approach to easily facilitate this. Address this by introducing a `test-tool bitmap write` subcommand that writes a bitmap for a given packfile, reading the set of commits which should receive individual bitmaps from stdin like so: test-tool bitmap write <pack-basename> </path/to/commits.list , where "<pack-basename>" is the filename for a specific packfile (e.g., "pack-abc123.pack"), and "/path/to/commits.list" is a list of commit OIDs which will receive bitmaps. The helper respects `bitmapPseudoMerge.*` configuration for creating pseudo-merge bitmaps alongside the regular commit bitmaps. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau committed
May 11, 2026 at 20:46 UTC
bc2f6115693874b2e8feed80ff5539743d257920
2 files changed
+136
-1
t/helper/test-bitmap.c
+112
-1
@@ -2,7 +2,10 @@
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#include "test-tool.h"
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#include "git-compat-util.h"
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+#include "hex.h"
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+#include "odb.h"
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#include "pack-bitmap.h"
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+#include "pseudo-merge.h"
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#include "setup.h"
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static int bitmap_list_commits(void)
@@ -35,6 +38,111 @@ static int bitmap_dump_pseudo_merge_objects(uint32_t n)
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return test_bitmap_pseudo_merge_objects(the_repository, n);
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}
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+static int add_packed_object(const struct object_id *oid,
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+ struct packed_git *pack,
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+ uint32_t pos,
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+ void *_data)
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+{
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+ struct packing_data *packed = _data;
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+ struct object_entry *entry;
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+ struct object_info oi = OBJECT_INFO_INIT;
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+ enum object_type type;
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+
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+ oi.typep = &type;
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+
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+ entry = packlist_alloc(packed, oid);
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+ entry->idx.offset = nth_packed_object_offset(pack, pos);
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+ if (packed_object_info(pack, entry->idx.offset, &oi) < 0)
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+ die("could not get type of object %s",
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+ oid_to_hex(oid));
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+ oe_set_type(entry, type);
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+ oe_set_in_pack(packed, entry, pack);
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+
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+ return 0;
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+}
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+
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+static int idx_oid_cmp(const void *va, const void *vb)
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+{
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+ const struct pack_idx_entry *a = *(const struct pack_idx_entry **)va;
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+ const struct pack_idx_entry *b = *(const struct pack_idx_entry **)vb;
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+
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+ return oidcmp(&a->oid, &b->oid);
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+}
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+
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+static int bitmap_write(const char *basename)
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+{
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+ struct packed_git *p = NULL;
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+ struct packing_data packed = { 0 };
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+ struct bitmap_writer writer;
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+ struct pack_idx_entry **index;
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+ struct strbuf buf = STRBUF_INIT;
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+ uint32_t i;
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+
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+ prepare_repo_settings(the_repository);
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+ repo_for_each_pack(the_repository, p) {
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+ if (!strcmp(pack_basename(p), basename))
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+ break;
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+ }
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+
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+ if (!p)
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+ die("could not find pack '%s'", basename);
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+
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+ if (open_pack_index(p))
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+ die("cannot open pack index for '%s'", p->pack_name);
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+
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+ prepare_packing_data(the_repository, &packed);
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+
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+ for_each_object_in_pack(p, add_packed_object, &packed,
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+ ODB_FOR_EACH_OBJECT_PACK_ORDER);
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+
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+ /*
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+ * Build the index array now that data.packed.objects[] is
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+ * fully allocated (packlist_alloc() may have reallocated it
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+ * during the loop above).
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+ */
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+ ALLOC_ARRAY(index, p->num_objects);
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+ for (i = 0; i < p->num_objects; i++)
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+ index[i] = &packed.objects[i].idx;
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+
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+ bitmap_writer_init(&writer, the_repository, &packed, NULL);
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+ bitmap_writer_build_type_index(&writer, index);
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+
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+ while (strbuf_getline_lf(&buf, stdin) != EOF) {
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+ struct object_id oid;
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+ struct commit *c;
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+
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+ if (get_oid_hex(buf.buf, &oid))
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+ die("invalid OID: %s", buf.buf);
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+
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+ c = lookup_commit(the_repository, &oid);
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+ if (!c || repo_parse_commit(the_repository, c))
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+ die("could not parse commit %s", buf.buf);
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+
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+ bitmap_writer_push_commit(&writer, c, 0);
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+ }
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+
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+ select_pseudo_merges(&writer);
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+ if (bitmap_writer_build(&writer) < 0)
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+ die("failed to build bitmaps");
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+
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+ bitmap_writer_set_checksum(&writer, p->hash);
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+
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+ QSORT(index, p->num_objects, idx_oid_cmp);
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+
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+ strbuf_reset(&buf);
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+ strbuf_addstr(&buf, p->pack_name);
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+ strbuf_strip_suffix(&buf, ".pack");
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+ strbuf_addstr(&buf, ".bitmap");
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+ bitmap_writer_finish(&writer, index, buf.buf, 0);
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+
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+ bitmap_writer_free(&writer);
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+ strbuf_release(&buf);
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+ free(index);
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+ clear_packing_data(&packed);
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+
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+ return 0;
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+}
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+
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int cmd__bitmap(int argc, const char **argv)
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{
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setup_git_directory();
@@ -51,13 +159,16 @@ int cmd__bitmap(int argc, const char **argv)
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return bitmap_dump_pseudo_merge_commits(atoi(argv[2]));
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if (argc == 3 && !strcmp(argv[1], "dump-pseudo-merge-objects"))
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return bitmap_dump_pseudo_merge_objects(atoi(argv[2]));
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+ if (argc == 3 && !strcmp(argv[1], "write"))
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+ return bitmap_write(argv[2]);
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usage("\ttest-tool bitmap list-commits\n"
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"\ttest-tool bitmap list-commits-with-offset\n"
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"\ttest-tool bitmap dump-hashes\n"
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"\ttest-tool bitmap dump-pseudo-merges\n"
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"\ttest-tool bitmap dump-pseudo-merge-commits <n>\n"
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- "\ttest-tool bitmap dump-pseudo-merge-objects <n>");
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+ "\ttest-tool bitmap dump-pseudo-merge-objects <n>\n"
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+ "\ttest-tool bitmap write <pack-basename> < <commit-list>");
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return -1;
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}
t/t5310-pack-bitmaps.sh
+24
@@ -648,4 +648,28 @@ test_expect_success 'truncated bitmap fails gracefully (lookup table)' '
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test_grep corrupted.bitmap.index stderr
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'
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+test_expect_success 'test-tool bitmap write determines bitmap selection' '
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+ test_when_finished "rm -fr bitmap-write-helper" &&
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+ git init bitmap-write-helper &&
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+ (
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+ cd bitmap-write-helper &&
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+
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+ test_commit_bulk 64 &&
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+ git repack -ad &&
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+
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+ pack="$(ls .git/objects/pack/pack-*.pack)" &&
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+
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+ git rev-parse HEAD >in &&
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+ test-tool bitmap write "$(basename $pack)" <in &&
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+
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+ test-tool bitmap list-commits >bitmaps.raw &&
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+ sort bitmaps.raw >bitmaps &&
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+ test_cmp in bitmaps &&
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+
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+ git rev-list --count --objects --use-bitmap-index HEAD >actual &&
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+ git rev-list --count --objects HEAD >expect &&
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+ test_cmp expect actual
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+ )
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+'
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+
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test_done