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| author | Michael Haggerty <mhagger@alum.mit.edu> | 2017-05-22 14:17:49 (GMT) |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2017-05-23 05:29:55 (GMT) |
| commit | 28ed9830b1dc65df37bdb3c9b8ef743f1f266262 (patch) | |
| tree | df1ea10365753071d455725a73d7c46ca8060d34 /refs | |
| parent | 531cc4a56da1eff87cb57d90012197eb6d721edd (diff) | |
| download | git-28ed9830b1dc65df37bdb3c9b8ef743f1f266262.zip git-28ed9830b1dc65df37bdb3c9b8ef743f1f266262.tar.gz git-28ed9830b1dc65df37bdb3c9b8ef743f1f266262.tar.bz2 | |
get_packed_ref_cache(): assume "packed-refs" won't change while locked
If we've got the "packed-refs" file locked, then it can't change;
there's no need to keep calling `stat_validity_check()` on it.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'refs')
| -rw-r--r-- | refs/files-backend.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c index 2951439..c4bc955 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -342,13 +342,18 @@ static void files_ref_path(struct files_ref_store *refs, /* * Get the packed_ref_cache for the specified files_ref_store, - * creating it if necessary. + * creating and populating it if it hasn't been read before or if the + * file has been changed (according to its `validity` field) since it + * was last read. On the other hand, if we hold the lock, then assume + * that the file hasn't been changed out from under us, so skip the + * extra `stat()` call in `stat_validity_check()`. */ static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs) { const char *packed_refs_file = files_packed_refs_path(refs); if (refs->packed && + !is_lock_file_locked(&refs->packed_refs_lock) && !stat_validity_check(&refs->packed->validity, packed_refs_file)) clear_packed_ref_cache(refs); @@ -1288,10 +1293,11 @@ static int lock_packed_refs(struct files_ref_store *refs, int flags) flags, timeout_value) < 0) return -1; /* - * Get the current packed-refs while holding the lock. If the - * packed-refs file has been modified since we last read it, - * this will automatically invalidate the cache and re-read - * the packed-refs file. + * Get the current packed-refs while holding the lock. It is + * important that we call `get_packed_ref_cache()` before + * setting `packed_ref_cache->lock`, because otherwise the + * former will see that the file is locked and assume that the + * cache can't be stale. */ packed_ref_cache = get_packed_ref_cache(refs); /* Increment the reference count to prevent it from being freed: */ |