diff options
author | Patrick Steinhardt <ps@pks.im> | 2020-04-02 07:10:02 (GMT) |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2020-04-02 18:09:49 (GMT) |
commit | e48cf33b61b8fecf1558fb32fcf5ee2987e82890 (patch) | |
tree | 39e57596523fdf5bc71b71e6f047a4e0f9f9f642 /t/t1400-update-ref.sh | |
parent | 94fd491a54b955990146f63e7283e9813dc85fef (diff) | |
download | git-e48cf33b61b8fecf1558fb32fcf5ee2987e82890.zip git-e48cf33b61b8fecf1558fb32fcf5ee2987e82890.tar.gz git-e48cf33b61b8fecf1558fb32fcf5ee2987e82890.tar.bz2 |
update-ref: implement interactive transaction handling
The git-update-ref(1) command can only handle queueing transactions
right now via its "--stdin" parameter, but there is no way for users to
handle the transaction itself in a more explicit way. E.g. in a
replicated scenario, one may imagine a coordinator that spawns
git-update-ref(1) for multiple repositories and only if all agree that
an update is possible will the coordinator send a commit. Such a
transactional session could look like
> start
< start: ok
> update refs/heads/master $OLD $NEW
> prepare
< prepare: ok
# All nodes have returned "ok"
> commit
< commit: ok
or
> start
< start: ok
> create refs/heads/master $OLD $NEW
> prepare
< fatal: cannot lock ref 'refs/heads/master': reference already exists
# On all other nodes:
> abort
< abort: ok
In order to allow for such transactional sessions, this commit
introduces four new commands for git-update-ref(1), which matches those
we have internally already with the exception of "start":
- start: start a new transaction
- prepare: prepare the transaction, that is try to lock all
references and verify their current value matches the
expected one
- commit: explicitly commit a session, that is update references to
match their new expected state
- abort: abort a session and roll back all changes
By design, git-update-ref(1) will commit as soon as standard input is
being closed. While fine in a non-transactional world, it is definitely
unexpected in a transactional world. Because of this, as soon as any of
the new transactional commands is used, the default will change to
aborting without an explicit "commit". To avoid a race between queueing
updates and the first "prepare" that starts a transaction, the "start"
command has been added to start an explicit transaction.
Add some tests to exercise this new functionality.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/t1400-update-ref.sh')
-rwxr-xr-x | t/t1400-update-ref.sh | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh index a6224ef..48d0d42 100755 --- a/t/t1400-update-ref.sh +++ b/t/t1400-update-ref.sh @@ -1404,4 +1404,135 @@ test_expect_success 'handle per-worktree refs in refs/bisect' ' ! test_cmp main-head worktree-head ' +test_expect_success 'transaction handles empty commit' ' + cat >stdin <<-EOF && + start + prepare + commit + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start prepare commit >expect && + test_cmp expect actual +' + +test_expect_success 'transaction handles empty commit with missing prepare' ' + cat >stdin <<-EOF && + start + commit + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start commit >expect && + test_cmp expect actual +' + +test_expect_success 'transaction handles sole commit' ' + cat >stdin <<-EOF && + commit + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" commit >expect && + test_cmp expect actual +' + +test_expect_success 'transaction handles empty abort' ' + cat >stdin <<-EOF && + start + prepare + abort + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start prepare abort >expect && + test_cmp expect actual +' + +test_expect_success 'transaction exits on multiple aborts' ' + cat >stdin <<-EOF && + abort + abort + EOF + test_must_fail git update-ref --stdin <stdin >actual 2>err && + printf "%s: ok\n" abort >expect && + test_cmp expect actual && + grep "fatal: transaction is closed" err +' + +test_expect_success 'transaction exits on start after prepare' ' + cat >stdin <<-EOF && + prepare + start + EOF + test_must_fail git update-ref --stdin <stdin 2>err >actual && + printf "%s: ok\n" prepare >expect && + test_cmp expect actual && + grep "fatal: prepared transactions can only be closed" err +' + +test_expect_success 'transaction handles empty abort with missing prepare' ' + cat >stdin <<-EOF && + start + abort + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start abort >expect && + test_cmp expect actual +' + +test_expect_success 'transaction handles sole abort' ' + cat >stdin <<-EOF && + abort + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" abort >expect && + test_cmp expect actual +' + +test_expect_success 'transaction can handle commit' ' + cat >stdin <<-EOF && + start + create $a HEAD + commit + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start commit >expect && + test_cmp expect actual && + git rev-parse HEAD >expect && + git rev-parse $a >actual && + test_cmp expect actual +' + +test_expect_success 'transaction can handle abort' ' + cat >stdin <<-EOF && + start + create $b HEAD + abort + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start abort >expect && + test_cmp expect actual && + test_path_is_missing .git/$b +' + +test_expect_success 'transaction aborts by default' ' + cat >stdin <<-EOF && + start + create $b HEAD + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start >expect && + test_cmp expect actual && + test_path_is_missing .git/$b +' + +test_expect_success 'transaction with prepare aborts by default' ' + cat >stdin <<-EOF && + start + create $b HEAD + prepare + EOF + git update-ref --stdin <stdin >actual && + printf "%s: ok\n" start prepare >expect && + test_cmp expect actual && + test_path_is_missing .git/$b +' + test_done |