reftable/stack: refactor stack reloading to have common exit path

The `reftable_stack_reload_maybe_reuse()` function is responsible for
reloading the reftable list from disk. The function is quite hard to
follow though because it has a bunch of different exit paths, many of
which have to free the same set of resources.

Refactor the function to have a common exit path. While at it, touch up
the style of this function a bit to match our usual coding style better.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/reftable/stack.c b/reftable/stack.c
index 16bab82063d2b3e228abe05b3a8a26ffd310767c..bf869a6772f9e3230527bbc859c53f7c50da6c40 100644 (file)
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -304,69 +304,67 @@ static int tv_cmp(struct timeval *a, struct timeval *b)
 static int reftable_stack_reload_maybe_reuse(struct reftable_stack *st,
                                             int reuse_open)
 {
-       struct timeval deadline = { 0 };
-       int err = gettimeofday(&deadline, NULL);
+       char **names = NULL, **names_after = NULL;
+       struct timeval deadline;
        int64_t delay = 0;
-       int tries = 0;
-       if (err < 0)
-               return err;
+       int tries = 0, err;
 
+       err = gettimeofday(&deadline, NULL);
+       if (err < 0)
+               goto out;
        deadline.tv_sec += 3;
+
        while (1) {
-               char **names = NULL;
-               char **names_after = NULL;
-               struct timeval now = { 0 };
-               int err = gettimeofday(&now, NULL);
-               int err2 = 0;
-               if (err < 0) {
-                       return err;
-               }
+               struct timeval now;
 
-               /* Only look at deadlines after the first few times. This
-                  simplifies debugging in GDB */
+               err = gettimeofday(&now, NULL);
+               if (err < 0)
+                       goto out;
+
+               /*
+                * Only look at deadlines after the first few times. This
+                * simplifies debugging in GDB.
+                */
                tries++;
-               if (tries > 3 && tv_cmp(&now, &deadline) >= 0) {
-                       break;
-               }
+               if (tries > 3 && tv_cmp(&now, &deadline) >= 0)
+                       goto out;
 
                err = read_lines(st->list_file, &names);
-               if (err < 0) {
-                       free_names(names);
-                       return err;
-               }
+               if (err < 0)
+                       goto out;
+
                err = reftable_stack_reload_once(st, names, reuse_open);
-               if (err == 0) {
-                       free_names(names);
+               if (!err)
                        break;
-               }
-               if (err != REFTABLE_NOT_EXIST_ERROR) {
-                       free_names(names);
-                       return err;
-               }
-
-               /* err == REFTABLE_NOT_EXIST_ERROR can be caused by a concurrent
-                  writer. Check if there was one by checking if the name list
-                  changed.
-               */
-               err2 = read_lines(st->list_file, &names_after);
-               if (err2 < 0) {
-                       free_names(names);
-                       return err2;
-               }
-
+               if (err != REFTABLE_NOT_EXIST_ERROR)
+                       goto out;
+
+               /*
+                * REFTABLE_NOT_EXIST_ERROR can be caused by a concurrent
+                * writer. Check if there was one by checking if the name list
+                * changed.
+                */
+               err = read_lines(st->list_file, &names_after);
+               if (err < 0)
+                       goto out;
                if (names_equal(names_after, names)) {
-                       free_names(names);
-                       free_names(names_after);
-                       return err;
+                       err = REFTABLE_NOT_EXIST_ERROR;
+                       goto out;
                }
+
                free_names(names);
+               names = NULL;
                free_names(names_after);
+               names_after = NULL;
 
                delay = delay + (delay * rand()) / RAND_MAX + 1;
                sleep_millisec(delay);
        }
 
-       return 0;
+out:
+       free_names(names);
+       free_names(names_after);
+       return err;
 }
 
 /* -1 = error