+/* Scan 'path' for git repositories, save the resulting repolist in 'cached_rc'
+ * and return 0 on success.
+ */
+static int generate_cached_repolist(const char *path, const char *cached_rc)
+{
+ char *locked_rc;
+ int idx;
+ FILE *f;
+
+ locked_rc = xstrdup(fmt("%s.lock", cached_rc));
+ f = fopen(locked_rc, "wx");
+ if (!f) {
+ /* Inform about the error unless the lockfile already existed,
+ * since that only means we've got concurrent requests.
+ */
+ if (errno != EEXIST)
+ fprintf(stderr, "[cgit] Error opening %s: %s (%d)\n",
+ locked_rc, strerror(errno), errno);
+ return errno;
+ }
+ idx = cgit_repolist.count;
+ scan_tree(path, repo_config);
+ print_repolist(f, &cgit_repolist, idx);
+ if (rename(locked_rc, cached_rc))
+ fprintf(stderr, "[cgit] Error renaming %s to %s: %s (%d)\n",
+ locked_rc, cached_rc, strerror(errno), errno);
+ fclose(f);
+ return 0;
+}
+
+static void process_cached_repolist(const char *path)
+{
+ struct stat st;
+ char *cached_rc;
+ time_t age;
+
+ cached_rc = xstrdup(fmt("%s/rc-%8x", ctx.cfg.cache_root,
+ hash_str(path)));
+
+ if (stat(cached_rc, &st)) {
+ /* Nothing is cached, we need to scan without forking. And
+ * if we fail to generate a cached repolist, we need to
+ * invoke scan_tree manually.
+ */
+ if (generate_cached_repolist(path, cached_rc))
+ scan_tree(path, repo_config);
+ return;
+ }
+
+ parse_configfile(cached_rc, config_cb);
+
+ /* If the cached configfile hasn't expired, lets exit now */
+ age = time(NULL) - st.st_mtime;
+ if (age <= (ctx.cfg.cache_scanrc_ttl * 60))
+ return;
+
+ /* The cached repolist has been parsed, but it was old. So lets
+ * rescan the specified path and generate a new cached repolist
+ * in a child-process to avoid latency for the current request.
+ */
+ if (fork())
+ return;
+
+ exit(generate_cached_repolist(path, cached_rc));
+}