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
@@ -8,7 +8,7 @@ git-pack-refs - Pack heads and tags for efficient repository access
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SYNOPSIS
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--------
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[verse]
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-'git pack-refs' [--all] [--no-prune] [--include <pattern>] [--exclude <pattern>]
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+'git pack-refs' [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]
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DESCRIPTION
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-----------
@@ -60,6 +60,19 @@ with many branches of historical interests.
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The command usually removes loose refs under `$GIT_DIR/refs`
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hierarchy after packing them. This option tells it not to.
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+--auto::
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+
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+Pack refs as needed depending on the current state of the ref database. The
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+behavior depends on the ref format used by the repository and may change in the
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+future.
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++
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+ - "files": No special handling for `--auto` has been implemented.
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++
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+ - "reftable": Tables are compacted such that they form a geometric
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+ sequence. For two tables N and N+1, where N+1 is newer, this
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+ maintains the property that N is at least twice as big as N+1. Only
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+ tables that violate this property are compacted.
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+
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--include <pattern>::
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Pack refs based on a `glob(7)` pattern. Repetitions of this option
builtin/pack-refs.c
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-1
@@ -7,7 +7,7 @@
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#include "revision.h"
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static char const * const pack_refs_usage[] = {
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- N_("git pack-refs [--all] [--no-prune] [--include <pattern>] [--exclude <pattern>]"),
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+ N_("git pack-refs [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]"),
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NULL
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};
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@@ -28,6 +28,7 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix)
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struct option opts[] = {
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OPT_BOOL(0, "all", &pack_all, N_("pack everything")),
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OPT_BIT(0, "prune", &pack_refs_opts.flags, N_("prune loose refs (default)"), PACK_REFS_PRUNE),
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+ OPT_BIT(0, "auto", &pack_refs_opts.flags, N_("auto-pack refs as needed"), PACK_REFS_AUTO),
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OPT_STRING_LIST(0, "include", pack_refs_opts.includes, N_("pattern"),
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N_("references to include")),
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OPT_STRING_LIST(0, "exclude", &option_excluded_refs, N_("pattern"),
t/t0601-reffiles-pack-refs.sh
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@@ -164,6 +164,13 @@ test_expect_success 'test --exclude takes precedence over --include' '
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git pack-refs --include "refs/heads/pack*" --exclude "refs/heads/pack*" &&
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test -f .git/refs/heads/dont_pack5'
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+test_expect_success '--auto packs and prunes refs as usual' '
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+ git branch auto &&
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+ test_path_is_file .git/refs/heads/auto &&
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+ git pack-refs --auto --all &&
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+ test_path_is_missing .git/refs/heads/auto
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+'
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+
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test_expect_success 'see if up-to-date packed refs are preserved' '
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git branch q &&
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git pack-refs --all --prune &&
t/t0610-reftable-basics.sh
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@@ -387,6 +387,40 @@ test_expect_success 'pack-refs: compaction raises locking errors' '
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test_cmp expect err
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'
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+test_expect_success 'pack-refs: auto compaction' '
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+ test_when_finished "rm -rf repo" &&
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+ git init repo &&
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+ (
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+ cd repo &&
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+
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+ test_commit A &&
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+
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+ # The tables should have been auto-compacted, and thus auto
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+ # compaction should not have to do anything.
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+ ls -1 .git/reftable >tables-expect &&
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+ test_line_count = 4 tables-expect &&
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+ git pack-refs --auto &&
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+ ls -1 .git/reftable >tables-actual &&
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+ test_cmp tables-expect tables-actual &&
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+
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+ # Lock all tables write some refs. Auto-compaction will be
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+ # unable to compact tables and thus fails gracefully, leaving
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+ # the stack in a sub-optimal state.
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+ ls .git/reftable/*.ref |
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+ while read table
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+ do
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+ touch "$table.lock" || exit 1
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+ done &&
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+ git branch B &&
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+ git branch C &&
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+ rm .git/reftable/*.lock &&
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+ test_line_count = 5 .git/reftable/tables.list &&
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+
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+ git pack-refs --auto &&
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+ test_line_count = 1 .git/reftable/tables.list
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+ )
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+'
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+
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test_expect_success 'pack-refs: prunes stale tables' '
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test_when_finished "rm -rf repo" &&
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git init repo &&