builtin/cat-file: support "blob:none" objects filter

Implement support for the "blob:none" filter in git-cat-file(1), which causes us to omit all blobs. Note that this new filter requires us to read the object type via `oid_object_info_extended()` in `batch_object_write()`. But as we try to optimize away reading objects from the database the `data->info.typep` pointer may not be set. We thus have to adapt the logic to conditionally set the pointer in cases where the filter is given. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Apr 2, 2025 at 13:13 UTC 3794e9bf982cde754a48b569a639bd2e180e754c
3 files changed +62 -4
Documentation/git-cat-file.adoc
+3 -1
@@ -88,7 +88,9 @@ OPTIONS
88 been explicitly requested via any of the batch modes that read objects
89 via standard input (`--batch`, `--batch-check`) will be reported as
90 "filtered". Excluded objects in `--batch-all-objects` mode will not be
91 - printed at all. No filters are supported yet.
91 + printed at all. The '<filter-spec>' may be one of the following:
92 ++
93 +The form '--filter=blob:none' omits all blobs.
94
95 --path=<path>::
96 For use with `--textconv` or `--filters`, to allow specifying an object
builtin/cat-file.c
+14 -1
@@ -482,7 +482,8 @@ static void batch_object_write(const char *obj_name,
482 if (!data->skip_object_info) {
483 int ret;
484
485 - if (use_mailmap)
485 + if (use_mailmap ||
486 + opt->objects_filter.choice == LOFC_BLOB_NONE)
487 data->info.typep = &data->type;
488
489 if (pack)
@@ -500,6 +501,14 @@ static void batch_object_write(const char *obj_name,
501 switch (opt->objects_filter.choice) {
502 case LOFC_DISABLED:
503 break;
504 + case LOFC_BLOB_NONE:
505 + if (data->type == OBJ_BLOB) {
506 + if (!opt->all_objects)
507 + report_object_status(opt, obj_name,
508 + &data->oid, "excluded");
509 + return;
510 + }
511 + break;
512 default:
513 BUG("unsupported objects filter");
514 }
@@ -1039,6 +1048,10 @@ int cmd_cat_file(int argc,
1048 switch (batch.objects_filter.choice) {
1049 case LOFC_DISABLED:
1050 break;
1051 + case LOFC_BLOB_NONE:
1052 + if (!batch.enabled)
1053 + usage(_("objects filter only supported in batch mode"));
1054 + break;
1055 default:
1056 usagef(_("objects filter not supported: '%s'"),
1057 list_object_filter_config_name(batch.objects_filter.choice));
t/t1006-cat-file.sh
+45 -2
@@ -1354,7 +1354,22 @@ test_expect_success PERL '--batch-command info is unbuffered by default' '
1354 '
1355
1356 test_expect_success 'setup for objects filter' '
1357 - git init repo
1357 + git init repo &&
1358 + (
1359 + # Seed the repository with three different sets of objects:
1360 + #
1361 + # - The first set is fully packed and has a bitmap.
1362 + # - The second set is packed, but has no bitmap.
1363 + # - The third set is loose.
1364 + #
1365 + # This ensures that we cover all these types as expected.
1366 + cd repo &&
1367 + test_commit first &&
1368 + git repack -Adb &&
1369 + test_commit second &&
1370 + git repack -d &&
1371 + test_commit third
1372 + )
1373 '
1374
1375 test_expect_success 'objects filter with unknown option' '
@@ -1365,7 +1380,7 @@ test_expect_success 'objects filter with unknown option' '
1380 test_cmp expect err
1381 '
1382
1368 -for option in blob:none blob:limit=1 object:type=tag sparse:oid=1234 tree:1 sparse:path=x
1383 +for option in blob:limit=1 object:type=tag sparse:oid=1234 tree:1 sparse:path=x
1384 do
1385 test_expect_success "objects filter with unsupported option $option" '
1386 case "$option" in
@@ -1393,4 +1408,32 @@ test_expect_success 'objects filter: disabled' '
1408 test_cmp expect.sorted actual.sorted
1409 '
1410
1411 +test_objects_filter () {
1412 + filter="$1"
1413 +
1414 + test_expect_success "objects filter: $filter" '
1415 + git -C repo cat-file --batch-check="%(objectname)" --batch-all-objects --filter="$filter" >actual &&
1416 + sort actual >actual.sorted &&
1417 + git -C repo rev-list --objects --no-object-names --all --filter="$filter" --filter-provided-objects >expect &&
1418 + sort expect >expect.sorted &&
1419 + test_cmp expect.sorted actual.sorted
1420 + '
1421 +
1422 + test_expect_success "objects filter prints excluded objects: $filter" '
1423 + # Find all objects that would be excluded by the current filter.
1424 + git -C repo rev-list --objects --no-object-names --all >all &&
1425 + git -C repo rev-list --objects --no-object-names --all --filter="$filter" --filter-provided-objects >filtered &&
1426 + sort all >all.sorted &&
1427 + sort filtered >filtered.sorted &&
1428 + comm -23 all.sorted filtered.sorted >expected.excluded &&
1429 + test_line_count -gt 0 expected.excluded &&
1430 +
1431 + git -C repo cat-file --batch-check="%(objectname)" --filter="$filter" <expected.excluded >actual &&
1432 + awk "/excluded/{ print \$1 }" actual | sort >actual.excluded &&
1433 + test_cmp expected.excluded actual.excluded
1434 + '
1435 +}
1436 +
1437 +test_objects_filter "blob:none"
1438 +
1439 test_done