diff options
| -rw-r--r-- | update-cache.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/update-cache.c b/update-cache.c index 05d584ed48..893ba8679d 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; } |