read-cache: drop explicit CLOSE_LOCK-flag

`write_locked_index()` takes two flags: `COMMIT_LOCK` and `CLOSE_LOCK`.
At most one is allowed. But it is also possible to use no flag, i.e.,
`0`. But when `write_locked_index()` calls `do_write_index()`, the
temporary file, a.k.a. the lockfile, will be closed. So passing `0` is
effectively the same as `CLOSE_LOCK`, which seems like a bug.

We might feel tempted to restructure the code in order to close the file
later, or conditionally. It also feels a bit unfortunate that we simply
"happen" to close the lock by way of an implementation detail of
lockfiles. But note that we need to close the temporary file before
`stat`-ing it, at least on Windows. See 9f41c7a6b (read-cache: close
index.lock in do_write_index, 2017-04-26).

Drop `CLOSE_LOCK` and make it explicit that `write_locked_index()`
always closes the lock. Whether it is also committed is governed by the
remaining flag, `COMMIT_LOCK`.

This means we neither have nor suggest that we have a mode to write the
index and leave the file open. Whatever extra contents we might
eventually want to write, we should probably write it from within
`write_locked_index()` itself anyway.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Martin Ågren
2017-10-06 22:12:12 +02:00
committed by Junio C Hamano
parent 8dc3834610
commit 812d6b0075
3 changed files with 15 additions and 14 deletions

View File

@ -2187,6 +2187,13 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile
rollback_lock_file(lockfile);
}
/*
* On success, `tempfile` is closed. If it is the temporary file
* of a `struct lock_file`, we will therefore effectively perform
* a 'close_lock_file_gently()`. Since that is an implementation
* detail of lockfiles, callers of `do_write_index()` should not
* rely on it.
*/
static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
int strip_extensions)
{
@ -2343,14 +2350,9 @@ static int do_write_locked_index(struct index_state *istate, struct lock_file *l
int ret = do_write_index(istate, lock->tempfile, 0);
if (ret)
return ret;
assert((flags & (COMMIT_LOCK | CLOSE_LOCK)) !=
(COMMIT_LOCK | CLOSE_LOCK));
if (flags & COMMIT_LOCK)
return commit_locked_index(lock);
else if (flags & CLOSE_LOCK)
return close_lock_file_gently(lock);
else
return ret;
return close_lock_file_gently(lock);
}
static int write_split_index(struct index_state *istate,