gbproxy: Optimize gbprox_remove_stale_tllis
The current implementation of this function is O(N), where N is the
number of entries.
The new implementation is O(D), where D is the number of entries that
are going to be deleted.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index 435e8ed..203a15b 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -559,32 +559,50 @@
int gbprox_remove_stale_tllis(struct gbproxy_peer *peer, time_t now)
{
struct gbproxy_patch_state *state = &peer->patch_state;
- struct gbproxy_tlli_info *tlli_info = NULL, *nxt;
- int count = 0;
+ int exceeded_max_len = 0;
int deleted_count = 0;
+ int check_for_age;
- llist_for_each_entry_safe(tlli_info, nxt, &state->enabled_tllis, list) {
- int is_stale = 0;
- time_t age = now - tlli_info->timestamp;
+ if (peer->cfg->tlli_max_len > 0)
+ exceeded_max_len =
+ state->enabled_tllis_count - peer->cfg->tlli_max_len;
- count += 1;
+ check_for_age = peer->cfg->tlli_max_age > 0;
- if (peer->cfg->tlli_max_len > 0)
- is_stale = is_stale || count > peer->cfg->tlli_max_len;
-
- if (peer->cfg->tlli_max_age > 0)
- is_stale = is_stale || age > peer->cfg->tlli_max_age;
-
- if (!is_stale)
- continue;
-
+ for (; exceeded_max_len > 0; exceeded_max_len--) {
+ struct gbproxy_tlli_info *tlli_info;
+ OSMO_ASSERT(!llist_empty(&state->enabled_tllis));
+ tlli_info = llist_entry(state->enabled_tllis.prev,
+ struct gbproxy_tlli_info,
+ list);
LOGP(DGPRS, LOGL_INFO,
- "Removing TLLI %08x from list (stale)\n",
- tlli_info->tlli);
+ "Removing TLLI %08x from list "
+ "(stale, length %d, max_len exceeded)\n",
+ tlli_info->tlli, state->enabled_tllis_count);
gbprox_delete_tlli(peer, tlli_info);
- tlli_info = NULL;
+ deleted_count += 1;
+ }
+ while (check_for_age && !llist_empty(&state->enabled_tllis)) {
+ time_t age;
+ struct gbproxy_tlli_info *tlli_info;
+ tlli_info = llist_entry(state->enabled_tllis.prev,
+ struct gbproxy_tlli_info,
+ list);
+ age = now - tlli_info->timestamp;
+ /* age < 0 only happens after system time jumps, discard entry */
+ if (age <= peer->cfg->tlli_max_age && age >= 0) {
+ check_for_age = 0;
+ continue;
+ }
+
+ LOGP(DGPRS, LOGL_INFO,
+ "Removing TLLI %08x from list "
+ "(stale, age %d, max_age exceeded)\n",
+ tlli_info->tlli, (int)age);
+
+ gbprox_delete_tlli(peer, tlli_info);
deleted_count += 1;
}