diff options
| author | René Scharfe <l.s.r@web.de> | 2019-01-06 17:45:52 +0100 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2019-01-08 18:40:19 +0100 |
| commit | 4cea1ce0f69d079819f2a189febcea215045dabf (patch) | |
| tree | 45a878f31890e63ee18602a49eb1c998a1399ea1 /object-store.h | |
| parent | object-store: factor out odb_clear_loose_cache() (diff) | |
| download | git-4cea1ce0f69d079819f2a189febcea215045dabf.tar.xz git-4cea1ce0f69d079819f2a189febcea215045dabf.zip | |
object-store: use one oid_array per subdirectory for loose cache
The loose objects cache is filled one subdirectory at a time as needed.
It is stored in an oid_array, which has to be resorted after each add
operation. So when querying a wide range of objects, the partially
filled array needs to be resorted up to 255 times, which takes over 100
times longer than sorting once.
Use one oid_array for each subdirectory. This ensures that entries have
to only be sorted a single time. It also avoids eight binary search
steps for each cache lookup as a small bonus.
The cache is used for collision checks for the log placeholders %h, %t
and %p, and we can see the change speeding them up in a repository with
ca. 100 objects per subdirectory:
$ git count-objects
26733 objects, 68808 kilobytes
Test HEAD^ HEAD
--------------------------------------------------------------------
4205.1: log with %H 0.51(0.47+0.04) 0.51(0.49+0.02) +0.0%
4205.2: log with %h 0.84(0.82+0.02) 0.60(0.57+0.03) -28.6%
4205.3: log with %T 0.53(0.49+0.04) 0.52(0.48+0.03) -1.9%
4205.4: log with %t 0.84(0.80+0.04) 0.60(0.59+0.01) -28.6%
4205.5: log with %P 0.52(0.48+0.03) 0.51(0.50+0.01) -1.9%
4205.6: log with %p 0.85(0.78+0.06) 0.61(0.56+0.05) -28.2%
4205.7: log with %h-%h-%h 0.96(0.92+0.03) 0.69(0.64+0.04) -28.1%
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'object-store.h')
| -rw-r--r-- | object-store.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/object-store.h b/object-store.h index 709bf856b6..2fb6c0e4db 100644 --- a/object-store.h +++ b/object-store.h @@ -20,7 +20,7 @@ struct object_directory { * Be sure to call odb_load_loose_cache() before using. */ char loose_objects_subdir_seen[256]; - struct oid_array loose_objects_cache; + struct oid_array loose_objects_cache[256]; /* * Path to the alternative object store. If this is a relative path, |