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authorJunio C Hamano <junkio@cox.net>2005-05-05 22:29:06 (GMT)
committerJunio C Hamano <junkio@cox.net>2005-05-05 22:29:06 (GMT)
commitc4b83e618f1df7d8ecc9392fa40e5bebccbe6b5a (patch)
treedfb527d0821f06e8fb1c08eaedd150a4530ab8e7 /update-cache.c
parented4eeaf203d0f293bd5ffc2a0ad8711f052db1f3 (diff)
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Do not write out new index if nothing has changed.
The git-update-cache command, especially with --refresh, may not change anything. In such a case, writing 1.6MB of the same thing is a waste. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'update-cache.c')
-rw-r--r--update-cache.c44
1 files changed, 41 insertions, 3 deletions
diff --git a/update-cache.c b/update-cache.c
index 05d584e..893ba86 100644
--- a/update-cache.c
+++ b/update-cache.c
@@ -15,6 +15,12 @@
*/
static int allow_add = 0, allow_remove = 0, not_new = 0;
+/*
+ * update-cache --refresh may not touch anything at all, in which case
+ * writing 1.6MB of the same thing is a waste.
+ */
+static int cache_changed = 0;
+
/* Three functions to allow overloaded pointer return; see linux/err.h */
static inline void *ERR_PTR(long error)
{
@@ -51,7 +57,7 @@ static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
ce->ce_size = htonl(st->st_size);
}
-static int add_file_to_cache(char *path)
+static int add_file_to_cache_1(char *path)
{
int size, namelen;
struct cache_entry *ce;
@@ -93,9 +99,35 @@ static int add_file_to_cache(char *path)
default:
return -1;
}
+ if (!cache_changed) {
+ /* If we have not smudged the cache, be careful
+ * to keep it clean. Find out if we have a matching
+ * cache entry that add_cache_entry would replace with,
+ * and if it matches then do not bother calling it.
+ */
+ int pos = cache_name_pos(ce->name, namelen);
+ if ((0 <= pos) &&
+ !memcmp(active_cache[pos], ce, sizeof(*ce))) {
+ free(ce);
+ /* magic to tell add_file_to_cache that
+ * we have not updated anything.
+ */
+ return 999;
+ }
+ }
return add_cache_entry(ce, allow_add);
}
+static int add_file_to_cache(char *path)
+{
+ int ret = add_file_to_cache_1(path);
+ if (ret == 0)
+ cache_changed = 1;
+ else if (ret == 999)
+ ret = 0;
+ return ret;
+}
+
static int match_data(int fd, void *buffer, unsigned long size)
{
while (size) {
@@ -165,6 +197,7 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
if (compare_data(ce, st.st_size))
return ERR_PTR(-EINVAL);
+ cache_changed = 1;
size = ce_size(ce);
updated = xmalloc(size);
memcpy(updated, ce, size);
@@ -245,6 +278,7 @@ static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
if (!verify_path(arg3))
return -1;
+ cache_changed = 1;
len = strlen(arg3);
size = cache_entry_size(len);
ce = xmalloc(size);
@@ -339,9 +373,13 @@ int main(int argc, char **argv)
if (add_file_to_cache(path))
die("Unable to add %s to database", path);
}
- if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
+
+ if (!cache_changed)
+ unlink(lockfile);
+ else if (write_cache(newfd, active_cache, active_nr) ||
+ rename(lockfile, indexfile))
die("Unable to write new cachefile");
lockfile_name = NULL;
- return has_errors;
+ return has_errors ? 1 : 0;
}