read-cache: unlink old sharedindex files

Everytime split index is turned on, it creates a "sharedindex.XXXX" file in the git directory. This change makes sure that shared index files that haven't been used for a long time are removed when a new shared index file is created. The new "splitIndex.sharedIndexExpire" config variable is created to tell the delay after which an unused shared index file can be deleted. It defaults to "2.weeks.ago". A previous commit made sure that each time a split index file is created the mtime of the shared index file it references is updated. This makes sure that recently used shared index file will not be deleted. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Christian Couder committed Mar 6, 2017 at 10:41 UTC b968372279d5c50df17f26afd9a9905285a73f37
1 file changed +63 -1
read-cache.c
+63 -1
@@ -2207,6 +2207,65 @@ static int write_split_index(struct index_state *istate,
2207 return ret;
2208 }
2209
2210 +static const char *shared_index_expire = "2.weeks.ago";
2211 +
2212 +static unsigned long get_shared_index_expire_date(void)
2213 +{
2214 + static unsigned long shared_index_expire_date;
2215 + static int shared_index_expire_date_prepared;
2216 +
2217 + if (!shared_index_expire_date_prepared) {
2218 + git_config_get_expiry("splitindex.sharedindexexpire",
2219 + &shared_index_expire);
2220 + shared_index_expire_date = approxidate(shared_index_expire);
2221 + shared_index_expire_date_prepared = 1;
2222 + }
2223 +
2224 + return shared_index_expire_date;
2225 +}
2226 +
2227 +static int should_delete_shared_index(const char *shared_index_path)
2228 +{
2229 + struct stat st;
2230 + unsigned long expiration;
2231 +
2232 + /* Check timestamp */
2233 + expiration = get_shared_index_expire_date();
2234 + if (!expiration)
2235 + return 0;
2236 + if (stat(shared_index_path, &st))
2237 + return error_errno(_("could not stat '%s"), shared_index_path);
2238 + if (st.st_mtime > expiration)
2239 + return 0;
2240 +
2241 + return 1;
2242 +}
2243 +
2244 +static int clean_shared_index_files(const char *current_hex)
2245 +{
2246 + struct dirent *de;
2247 + DIR *dir = opendir(get_git_dir());
2248 +
2249 + if (!dir)
2250 + return error_errno(_("unable to open git dir: %s"), get_git_dir());
2251 +
2252 + while ((de = readdir(dir)) != NULL) {
2253 + const char *sha1_hex;
2254 + const char *shared_index_path;
2255 + if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
2256 + continue;
2257 + if (!strcmp(sha1_hex, current_hex))
2258 + continue;
2259 + shared_index_path = git_path("%s", de->d_name);
2260 + if (should_delete_shared_index(shared_index_path) > 0 &&
2261 + unlink(shared_index_path))
2262 + warning_errno(_("unable to unlink: %s"), shared_index_path);
2263 + }
2264 + closedir(dir);
2265 +
2266 + return 0;
2267 +}
2268 +
2269 static struct tempfile temporary_sharedindex;
2270
2271 static int write_shared_index(struct index_state *istate,
@@ -2228,8 +2287,11 @@ static int write_shared_index(struct index_state *istate,
2287 }
2288 ret = rename_tempfile(&temporary_sharedindex,
2289 git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
2231 - if (!ret)
2290 + if (!ret) {
2291 hashcpy(si->base_sha1, si->base->sha1);
2292 + clean_shared_index_files(sha1_to_hex(si->base->sha1));
2293 + }
2294 +
2295 return ret;
2296 }
2297