From: Michael Haggerty <mhagger@alum.mit.edu>
To: Junio C Hamano <gitster@pobox.com>
Cc: Jeff King <peff@peff.net>, Johan Herland <johan@herland.net>,
Ramsay Jones <ramsay@ramsay1.demon.co.uk>,
git@vger.kernel.org, Michael Haggerty <mhagger@alum.mit.edu>
Subject: [PATCH v2 12/12] refs: do not invalidate the packed-refs cache unnecessarily
Date: Wed, 19 Jun 2013 09:51:33 +0200 [thread overview]
Message-ID: <1371628293-28824-13-git-send-email-mhagger@alum.mit.edu> (raw)
In-Reply-To: <1371628293-28824-1-git-send-email-mhagger@alum.mit.edu>
Now that we keep track of the packed-refs file metadata, we can detect
when the packed-refs file has been modified since we last read it, and
we do so automatically every time that get_packed_ref_cache() is
called. So there is no need to invalidate the cache automatically
when lock_packed_refs() is called; usually the old copy will still be
valid.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
refs.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/refs.c b/refs.c
index 350054c..4b989b0 100644
--- a/refs.c
+++ b/refs.c
@@ -2133,11 +2133,14 @@ int lock_packed_refs(struct lock_file *lock, int flags)
{
struct packed_ref_cache *packed_ref_cache;
- /* Discard the old cache because it might be invalid: */
- clear_packed_ref_cache(&ref_cache);
if (hold_lock_file_for_update(lock, git_path("packed-refs"), flags) < 0)
return -1;
- /* Read the current packed-refs while holding the lock: */
+ /*
+ * 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.
+ */
packed_ref_cache = get_packed_ref_cache(&ref_cache);
packed_ref_cache->lock = lock;
/* Increment the reference count to prevent it from being freed: */
--
1.8.3.1
next prev parent reply other threads:[~2013-06-19 7:52 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-19 7:51 [PATCH v2 00/12] Fix some reference-related races Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 01/12] repack_without_ref(): split list curation and entry writing Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 02/12] pack_refs(): split creation of packed refs " Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 03/12] refs: wrap the packed refs cache in a level of indirection Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 04/12] refs: implement simple transactions for the packed-refs file Michael Haggerty
2013-06-19 19:18 ` Junio C Hamano
2013-06-20 7:49 ` Michael Haggerty
2013-06-20 11:55 ` Jeff King
2013-06-20 18:03 ` Michael Haggerty
2013-06-20 19:55 ` Jeff King
2013-06-20 17:11 ` Junio C Hamano
2013-06-20 17:58 ` Michael Haggerty
2013-06-20 18:36 ` Junio C Hamano
2013-06-19 7:51 ` [PATCH v2 05/12] refs: manage lifetime of packed refs cache via reference counting Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 06/12] do_for_each_entry(): increment the packed refs cache refcount Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 07/12] packed_ref_cache: increment refcount when locked Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 08/12] Extract a struct stat_data from cache_entry Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 09/12] add a stat_validity struct Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 10/12] get_packed_ref_cache: reload packed-refs file when it changes Michael Haggerty
2013-06-19 7:51 ` [PATCH v2 11/12] for_each_ref: load all loose refs before packed refs Michael Haggerty
2013-06-19 7:51 ` Michael Haggerty [this message]
2013-06-19 18:56 ` [PATCH v2 00/12] Fix some reference-related races Jeff King
2013-06-20 9:09 ` Michael Haggerty
2013-06-20 11:52 ` Jeff King
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