refs: handle the main ref_cache specially
Hold the ref_cache instance for the main repository in a dedicated, statically-allocated instance to avoid the need for a function call and a linked-list traversal when it is needed. Suggested by: Heiko Voigt <hvoigt@hvoigt.net> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Michael Haggerty committed
Apr 22, 2013 at 21:52 UTC
9da31cb027aa5dac3d4914a88faa8830f0578c88
1 file changed
+31
-29
refs.c
+31
-29
@@ -811,9 +811,13 @@ static struct ref_cache {
811
struct ref_cache *next;
812
struct ref_entry *loose;
813
struct ref_entry *packed;
814
- /* The submodule name, or "" for the main repo. */
815
- char name[FLEX_ARRAY];
816
-} *ref_cache;
814
+ /*
815
+ * The submodule name, or "" for the main repo. We allocate
816
+ * length 1 rather than FLEX_ARRAY so that the main ref_cache
817
+ * is initialized correctly.
818
+ */
819
+ char name[1];
820
+} ref_cache, *submodule_ref_caches;
821
822
static void clear_packed_ref_cache(struct ref_cache *refs)
823
{
@@ -851,18 +855,18 @@ static struct ref_cache *create_ref_cache(const char *submodule)
855
*/
856
static struct ref_cache *get_ref_cache(const char *submodule)
857
{
854
- struct ref_cache *refs = ref_cache;
855
- if (!submodule)
856
- submodule = "";
857
- while (refs) {
858
+ struct ref_cache *refs;
859
+
860
+ if (!submodule || !*submodule)
861
+ return &ref_cache;
862
+
863
+ for (refs = submodule_ref_caches; refs; refs = refs->next)
864
if (!strcmp(submodule, refs->name))
865
return refs;
860
- refs = refs->next;
861
- }
866
867
refs = create_ref_cache(submodule);
864
- refs->next = ref_cache;
865
- ref_cache = refs;
868
+ refs->next = submodule_ref_caches;
869
+ submodule_ref_caches = refs;
870
return refs;
871
}
872
@@ -1011,8 +1015,8 @@ static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1015
1016
void add_packed_ref(const char *refname, const unsigned char *sha1)
1017
{
1014
- add_ref(get_packed_refs(get_ref_cache(NULL)),
1015
- create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1018
+ add_ref(get_packed_refs(&ref_cache),
1019
+ create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1020
}
1021
1022
/*
@@ -1187,7 +1191,7 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sh
1191
*/
1192
static struct ref_entry *get_packed_ref(const char *refname)
1193
{
1190
- return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
1194
+ return find_ref(get_packed_refs(&ref_cache), refname);
1195
}
1196
1197
const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
@@ -1592,7 +1596,7 @@ int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1596
1597
int for_each_ref(each_ref_fn fn, void *cb_data)
1598
{
1595
- return do_for_each_ref(get_ref_cache(NULL), "", fn, 0, 0, cb_data);
1599
+ return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1600
}
1601
1602
int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
@@ -1602,7 +1606,7 @@ int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1606
1607
int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1608
{
1605
- return do_for_each_ref(get_ref_cache(NULL), prefix, fn, strlen(prefix), 0, cb_data);
1609
+ return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1610
}
1611
1612
int for_each_ref_in_submodule(const char *submodule, const char *prefix,
@@ -1643,7 +1647,7 @@ int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *c
1647
1648
int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1649
{
1646
- return do_for_each_ref(get_ref_cache(NULL), "refs/replace/", fn, 13, 0, cb_data);
1650
+ return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1651
}
1652
1653
int head_ref_namespaced(each_ref_fn fn, void *cb_data)
@@ -1666,7 +1670,7 @@ int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1670
struct strbuf buf = STRBUF_INIT;
1671
int ret;
1672
strbuf_addf(&buf, "%srefs/", get_git_namespace());
1669
- ret = do_for_each_ref(get_ref_cache(NULL), buf.buf, fn, 0, 0, cb_data);
1673
+ ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1674
strbuf_release(&buf);
1675
return ret;
1676
}
@@ -1708,7 +1712,7 @@ int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1712
1713
int for_each_rawref(each_ref_fn fn, void *cb_data)
1714
{
1711
- return do_for_each_ref(get_ref_cache(NULL), "", fn, 0,
1715
+ return do_for_each_ref(&ref_cache, "", fn, 0,
1716
DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1717
}
1718
@@ -1914,7 +1918,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1918
* name is a proper prefix of our refname.
1919
*/
1920
if (missing &&
1917
- !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
1921
+ !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
1922
last_errno = ENOTDIR;
1923
goto error_return;
1924
}
@@ -2103,7 +2107,7 @@ int pack_refs(unsigned int flags)
2107
2108
write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2109
2106
- do_for_each_entry(get_ref_cache(NULL), "", pack_one_ref, &cbdata);
2110
+ do_for_each_entry(&ref_cache, "", pack_one_ref, &cbdata);
2111
if (commit_lock_file(&packlock) < 0)
2112
die_errno("unable to overwrite old ref-pack file");
2113
prune_refs(cbdata.ref_to_prune);
@@ -2161,7 +2165,6 @@ static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
2165
static int repack_without_ref(const char *refname)
2166
{
2167
int fd;
2164
- struct ref_cache *refs = get_ref_cache(NULL);
2168
struct ref_dir *packed;
2169
2170
if (!get_packed_ref(refname))
@@ -2172,8 +2175,8 @@ static int repack_without_ref(const char *refname)
2175
unable_to_lock_error(git_path("packed-refs"), errno);
2176
return error("cannot delete '%s' from packed refs", refname);
2177
}
2175
- clear_packed_ref_cache(refs);
2176
- packed = get_packed_refs(refs);
2178
+ clear_packed_ref_cache(&ref_cache);
2179
+ packed = get_packed_refs(&ref_cache);
2180
/* Remove refname from the cache. */
2181
if (remove_entry(packed, refname) == -1) {
2182
/*
@@ -2213,7 +2216,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2216
ret |= repack_without_ref(lock->ref_name);
2217
2218
unlink_or_warn(git_path("logs/%s", lock->ref_name));
2216
- clear_loose_ref_cache(get_ref_cache(NULL));
2219
+ clear_loose_ref_cache(&ref_cache);
2220
unlock_ref(lock);
2221
return ret;
2222
}
@@ -2235,7 +2238,6 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
2238
struct stat loginfo;
2239
int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2240
const char *symref = NULL;
2238
- struct ref_cache *refs = get_ref_cache(NULL);
2241
2242
if (log && S_ISLNK(loginfo.st_mode))
2243
return error("reflog for %s is a symlink", oldrefname);
@@ -2247,10 +2249,10 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
2249
if (!symref)
2250
return error("refname %s not found", oldrefname);
2251
2250
- if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
2252
+ if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2253
return 1;
2254
2253
- if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
2255
+ if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2256
return 1;
2257
2258
if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
@@ -2506,7 +2508,7 @@ int write_ref_sha1(struct ref_lock *lock,
2508
unlock_ref(lock);
2509
return -1;
2510
}
2509
- clear_loose_ref_cache(get_ref_cache(NULL));
2511
+ clear_loose_ref_cache(&ref_cache);
2512
if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2513
(strcmp(lock->ref_name, lock->orig_ref_name) &&
2514
log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {