From 12253ab6d0033aa8214c8a15bc2ea37ff052ff1c Mon Sep 17 00:00:00 2001 From: Emily Shaffer Date: Wed, 26 Oct 2022 17:32:43 -0400 Subject: [PATCH 1/2] gc: add tests for --cruft and friends In 5b92477f89 (builtin/gc.c: conditionally avoid pruning objects via loose, 2022-05-20) gc learned to respect '--cruft' and 'gc.cruftPacks'. '--cruft' is exercised in t5329-pack-objects-cruft.sh, but in a way that doesn't check whether a lone gc run generates these cruft packs. 'gc.cruftPacks' is never exercised. Add some tests to exercise these options to gc in the gc test suite. Signed-off-by: Emily Shaffer Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- t/t6500-gc.sh | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh index cd6c53360d..928a522194 100755 --- a/t/t6500-gc.sh +++ b/t/t6500-gc.sh @@ -202,6 +202,49 @@ test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "e grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out ' +prepare_cruft_history () { + test_commit base && + + test_commit --no-tag foo && + test_commit --no-tag bar && + git reset HEAD^^ +} + +assert_cruft_packs () { + find .git/objects/pack -name "*.mtimes" >mtimes && + sed -e 's/\.mtimes$/\.pack/g' mtimes >packs && + + test_file_not_empty packs && + while read pack + do + test_path_is_file "$pack" || return 1 + done Date: Wed, 26 Oct 2022 17:32:45 -0400 Subject: [PATCH 2/2] config: let feature.experimental imply gc.cruftPacks=true We are interested in exploring whether gc.cruftPacks=true should become the default value. To determine whether it is safe to do so, let's encourage more users to try it out. Users who have set feature.experimental=true have already volunteered to try new and possibly-breaking config changes, so let's try this new default with that set of users. Signed-off-by: Emily Shaffer Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- Documentation/config/feature.txt | 3 ++ builtin/gc.c | 7 +++-- repo-settings.c | 1 + repository.h | 1 + t/t6500-gc.sh | 53 ++++++++++++++++++++++++++++++++ 5 files changed, 63 insertions(+), 2 deletions(-) diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt index cdecd04e5b..95975e5091 100644 --- a/Documentation/config/feature.txt +++ b/Documentation/config/feature.txt @@ -14,6 +14,9 @@ feature.experimental:: + * `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by skipping more commits at a time, reducing the number of round trips. ++ +* `gc.cruftPacks=true` reduces disk space used by unreachable objects during +garbage collection, preventing loose object explosions. feature.manyFiles:: Enable config options that optimize for repos with many files in the diff --git a/builtin/gc.c b/builtin/gc.c index eeff2b760e..60a8f94c62 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -42,7 +42,7 @@ static const char * const builtin_gc_usage[] = { static int pack_refs = 1; static int prune_reflogs = 1; -static int cruft_packs = 0; +static int cruft_packs = -1; static int aggressive_depth = 50; static int aggressive_window = 250; static int gc_auto_threshold = 6700; @@ -600,6 +600,10 @@ int cmd_gc(int argc, const char **argv, const char *prefix) if (prune_expire && parse_expiry_date(prune_expire, &dummy)) die(_("failed to parse prune expiry value %s"), prune_expire); + prepare_repo_settings(the_repository); + if (cruft_packs < 0) + cruft_packs = the_repository->settings.gc_cruft_packs; + if (aggressive) { strvec_push(&repack, "-f"); if (aggressive_depth > 0) @@ -711,7 +715,6 @@ int cmd_gc(int argc, const char **argv, const char *prefix) clean_pack_garbage(); } - prepare_repo_settings(the_repository); if (the_repository->settings.gc_write_commit_graph == 1) write_commit_graph_reachable(the_repository->objects->odb, !quiet && !daemonized ? COMMIT_GRAPH_WRITE_PROGRESS : 0, diff --git a/repo-settings.c b/repo-settings.c index 43bc881bfc..a36b9411e1 100644 --- a/repo-settings.c +++ b/repo-settings.c @@ -43,6 +43,7 @@ void prepare_repo_settings(struct repository *r) /* Defaults modified by feature.* */ if (experimental) { r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING; + r->settings.gc_cruft_packs = 1; } if (manyfiles) { r->settings.index_version = 4; diff --git a/repository.h b/repository.h index 797f471cce..f235622a92 100644 --- a/repository.h +++ b/repository.h @@ -33,6 +33,7 @@ struct repo_settings { int commit_graph_generation_version; int commit_graph_read_changed_paths; int gc_write_commit_graph; + int gc_cruft_packs; int fetch_write_commit_graph; int command_requires_full_index; int sparse_index; diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh index 928a522194..d9acb63951 100755 --- a/t/t6500-gc.sh +++ b/t/t6500-gc.sh @@ -221,6 +221,11 @@ assert_cruft_packs () { done mtimes && + test_must_be_empty mtimes +} + test_expect_success 'gc --cruft generates a cruft pack' ' test_when_finished "rm -fr crufts" && git init crufts && @@ -245,6 +250,54 @@ test_expect_success 'gc.cruftPacks=true generates a cruft pack' ' ) ' +test_expect_success 'feature.experimental=true generates a cruft pack' ' + git init crufts && + test_when_finished "rm -fr crufts" && + ( + cd crufts && + + prepare_cruft_history && + git -c feature.experimental=true gc && + assert_cruft_packs + ) +' + +test_expect_success 'feature.experimental=false allows explicit cruft packs' ' + git init crufts && + test_when_finished "rm -fr crufts" && + ( + cd crufts && + + prepare_cruft_history && + git -c gc.cruftPacks=true -c feature.experimental=false gc && + assert_cruft_packs + ) +' + +test_expect_success 'feature.experimental=true can be overridden' ' + git init crufts && + test_when_finished "rm -fr crufts" && + ( + cd crufts && + + prepare_cruft_history && + git -c feature.expiremental=true -c gc.cruftPacks=false gc && + assert_no_cruft_packs + ) +' + +test_expect_success 'feature.experimental=false avoids cruft packs by default' ' + git init crufts && + test_when_finished "rm -fr crufts" && + ( + cd crufts && + + prepare_cruft_history && + git -c feature.experimental=false gc && + assert_no_cruft_packs + ) +' + run_and_wait_for_auto_gc () { # We read stdout from gc for the side effect of waiting until the # background gc process exits, closing its fd 9. Furthermore, the