[PATCH v5 7/8] sha1_file: do not access pack if unneeded
- From
- Jonathan Tan <jonathantanmy@google.com>
- Date
- Jun 22, 2017, 00:40 UTC
- Message-ID
- <ddbbc86204c131c83b3a1ff3b52789be9ed2a5b1.1498091579.git.jonathantanmy@google.com>
- In-Reply-To
- <cover.1498091579.git.jonathantanmy@google.com>
Currently, regardless of the contents of the "struct object_info" passed to sha1_object_info_extended(), that function always accesses the packfile whenever it returns information about a packed object, since it needs to populate "u.packed".
Add the ability to pass NULL, and use NULL-ness of the argument to activate an optimization in which sha1_object_info_extended() does not needlessly access the packfile. A subsequent patch will make use of this optimization.
A similar optimization is not made for the cached and loose cases as it would not cause a significant performance improvement.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- sha1_file.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/sha1_file.c b/sha1_file.c index b6bc02f09..bf6b64ec8 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -2977,12 +2977,16 @@ static int sha1_loose_object_info(const unsigned char *sha1, int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags) { + static struct object_info blank_oi = OBJECT_INFO_INIT; struct pack_entry e; int rtype; const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ? lookup_replace_object(sha1) : sha1; + if (!oi) + oi = &blank_oi; + if (!(flags & OBJECT_INFO_SKIP_CACHED)) { struct cached_object *co = find_cached_object(real); if (co) { @@ -3020,6 +3024,13 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, } } + if (oi == &blank_oi) + /* + * We know that the caller doesn't actually need the + * information below, so return early. + */ + return 0; + rtype = packed_object_info(e.p, e.offset, oi); if (rtype < 0) { mark_bad_packed_object(e.p, real);
-- 2.13.1.611.g7e3b11ae1-goog