builtin/pack-refs: introduce new "--auto" flag
Calling git-pack-refs(1) will unconditionally cause it to pack all requested refs regardless of the current state of the ref database. For example: - With the "files" backend we will end up rewriting the complete "packed-refs" file even if only a single ref would require compaction. - With the "reftable" backend we will end up always compacting all tables into a single table. This behaviour can be completely unnecessary depending on the backend and is thus wasteful. With the introduction of the `PACK_REFS_AUTO` flag in the preceding commit we can improve this and let the backends decide for themselves whether to pack refs in the first place. Expose this functionality via a new "--auto" flag in git-pack-refs(1), which mirrors the same flag in both git-gc(1) and git-maintenance(1). Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt committed
Mar 25, 2024 at 11:03 UTC
6dcffc68f4cea97d4b4af8a9add0daae54a5c292
4 files changed
+57
-2
Documentation/git-pack-refs.txt
+14
-1
index 284956acb3..2dcabaf74c 100644
--- a/Documentation/git-pack-refs.txt
+++ b/Documentation/git-pack-refs.txt
@@ -8,7 +8,7 @@ git-pack-refs - Pack heads and tags for efficient repository access
SYNOPSIS
--------
[verse]
-'git pack-refs' [--all] [--no-prune] [--include <pattern>] [--exclude <pattern>]
+'git pack-refs' [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]
DESCRIPTION
-----------
@@ -60,6 +60,19 @@ with many branches of historical interests.
The command usually removes loose refs under `$GIT_DIR/refs`
hierarchy after packing them. This option tells it not to.
+--auto::
+
+Pack refs as needed depending on the current state of the ref database. The
+behavior depends on the ref format used by the repository and may change in the
+future.
++
+ - "files": No special handling for `--auto` has been implemented.
++
+ - "reftable": Tables are compacted such that they form a geometric
+ sequence. For two tables N and N+1, where N+1 is newer, this
+ maintains the property that N is at least twice as big as N+1. Only
+ tables that violate this property are compacted.
+
--include <pattern>::
Pack refs based on a `glob(7)` pattern. Repetitions of this option
builtin/pack-refs.c
+2
-1
index ea2baeec76..db40825666 100644
--- a/builtin/pack-refs.c
+++ b/builtin/pack-refs.c
@@ -7,7 +7,7 @@
#include "revision.h"
static char const * const pack_refs_usage[] = {
- N_("git pack-refs [--all] [--no-prune] [--include <pattern>] [--exclude <pattern>]"),
+ N_("git pack-refs [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]"),
NULL
};
@@ -28,6 +28,7 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix)
struct option opts[] = {
OPT_BOOL(0, "all", &pack_all, N_("pack everything")),
OPT_BIT(0, "prune", &pack_refs_opts.flags, N_("prune loose refs (default)"), PACK_REFS_PRUNE),
+ OPT_BIT(0, "auto", &pack_refs_opts.flags, N_("auto-pack refs as needed"), PACK_REFS_AUTO),
OPT_STRING_LIST(0, "include", pack_refs_opts.includes, N_("pattern"),
N_("references to include")),
OPT_STRING_LIST(0, "exclude", &option_excluded_refs, N_("pattern"),
t/t0601-reffiles-pack-refs.sh
+7
index b1cf587347..219a495451 100755
--- a/t/t0601-reffiles-pack-refs.sh
+++ b/t/t0601-reffiles-pack-refs.sh
@@ -164,6 +164,13 @@ test_expect_success 'test --exclude takes precedence over --include' '
git pack-refs --include "refs/heads/pack*" --exclude "refs/heads/pack*" &&
test -f .git/refs/heads/dont_pack5'
+test_expect_success '--auto packs and prunes refs as usual' '
+ git branch auto &&
+ test_path_is_file .git/refs/heads/auto &&
+ git pack-refs --auto --all &&
+ test_path_is_missing .git/refs/heads/auto
+'
+
test_expect_success 'see if up-to-date packed refs are preserved' '
git branch q &&
git pack-refs --all --prune &&
t/t0610-reftable-basics.sh
+34
index a53d1dc493..6de7529575 100755
--- a/t/t0610-reftable-basics.sh
+++ b/t/t0610-reftable-basics.sh
@@ -387,6 +387,40 @@ test_expect_success 'pack-refs: compaction raises locking errors' '
test_cmp expect err
'
+test_expect_success 'pack-refs: auto compaction' '
+ test_when_finished "rm -rf repo" &&
+ git init repo &&
+ (
+ cd repo &&
+
+ test_commit A &&
+
+ # The tables should have been auto-compacted, and thus auto
+ # compaction should not have to do anything.
+ ls -1 .git/reftable >tables-expect &&
+ test_line_count = 4 tables-expect &&
+ git pack-refs --auto &&
+ ls -1 .git/reftable >tables-actual &&
+ test_cmp tables-expect tables-actual &&
+
+ # Lock all tables write some refs. Auto-compaction will be
+ # unable to compact tables and thus fails gracefully, leaving
+ # the stack in a sub-optimal state.
+ ls .git/reftable/*.ref |
+ while read table
+ do
+ touch "$table.lock" || exit 1
+ done &&
+ git branch B &&
+ git branch C &&
+ rm .git/reftable/*.lock &&
+ test_line_count = 5 .git/reftable/tables.list &&
+
+ git pack-refs --auto &&
+ test_line_count = 1 .git/reftable/tables.list
+ )
+'
+
test_expect_success 'pack-refs: prunes stale tables' '
test_when_finished "rm -rf repo" &&
git init repo &&