platform: improve way to prune dirty route-manager entries

The general idea is that when we have entries tracked by the
route-manager, that we can mark them all as dirty. Then, calling the
"track" function will reset the dirty flag. Finally, there is a method
to delete all dirty entries.

As we can lookup an entry with O(1) (using dictionaries), we can
sync the list of tracked objects with O(n). We just need to track
all the ones we care about, and then delete those that were not touched
(that is, are still dirty).

Previously, we had to explicitly mark all entries as dirty. We can do
better. Just let nmp_route_manager_untrack_all() mark the survivors as
dirty right away. This way, we can save iterating the list once.

It also makes sense because the only purpose of the dirty flag is to
aid this prune mechanism with track/untrack-all. So, untrack-all can
just help out, and leave the remaining entries dirty, so that the next
track does the right thing.

3 files changed, 9 insertions, 7 deletions

diff --git a/src/core/devices/nm-device.c b/src/core/devices/nm-device.c
index 30e0fe8fef..5cb3d27065 100644
--- a/src/core/devices/nm-device.c
+++ b/src/core/devices/nm-device.c
@@ -9301,9 +9301,6 @@ _routing_rules_sync(NMDevice *self, NMTernary set_mode)
         int                is_ipv4;
 
         untrack_only_dirty = TRUE;
-        nmp_route_manager_set_dirty(route_manager, user_tag_1);
-        if (klass->get_extra_rules)
-            nmp_route_manager_set_dirty(route_manager, user_tag_2);
 
         applied_connection = nm_device_get_applied_connection(self);
 
@@ -9350,9 +9347,9 @@ _routing_rules_sync(NMDevice *self, NMTernary set_mode)
         }
     }
 
-    nmp_route_manager_untrack_all(route_manager, user_tag_1, !untrack_only_dirty);
+    nmp_route_manager_untrack_all(route_manager, user_tag_1, !untrack_only_dirty, TRUE);
     if (klass->get_extra_rules)
-        nmp_route_manager_untrack_all(route_manager, user_tag_2, !untrack_only_dirty);
+        nmp_route_manager_untrack_all(route_manager, user_tag_2, !untrack_only_dirty, TRUE);
 
     keep_deleted_rules = FALSE;
     if (set_mode == NM_TERNARY_DEFAULT) {
diff --git a/src/libnm-platform/nmp-route-manager.c b/src/libnm-platform/nmp-route-manager.c
index c5ca02600c..c31c9806a5 100644
--- a/src/libnm-platform/nmp-route-manager.c
+++ b/src/libnm-platform/nmp-route-manager.c
@@ -514,7 +514,8 @@ nmp_route_manager_set_dirty(NMPRouteManager *self, gconstpointer user_tag)
 gboolean
 nmp_route_manager_untrack_all(NMPRouteManager *self,
                               gconstpointer    user_tag,
-                              gboolean         all /* or only dirty */)
+                              gboolean         all /* or only dirty */,
+                              gboolean         make_survivors_dirty)
 {
     TrackData        *track_data;
     TrackData        *track_data_safe;
@@ -535,7 +536,10 @@ nmp_route_manager_untrack_all(NMPRouteManager *self,
         if (all || track_data->dirty) {
             _track_data_untrack(self, track_data, FALSE, FALSE);
             changed = TRUE;
+            continue;
         }
+        if (make_survivors_dirty)
+            track_data->dirty = TRUE;
     }
     if (c_list_is_empty(&user_tag_data->user_tag_lst_head))
         g_hash_table_remove(self->by_user_tag, user_tag_data);
diff --git a/src/libnm-platform/nmp-route-manager.h b/src/libnm-platform/nmp-route-manager.h
index a61a68ca98..97ec3840df 100644
--- a/src/libnm-platform/nmp-route-manager.h
+++ b/src/libnm-platform/nmp-route-manager.h
@@ -69,7 +69,8 @@ void nmp_route_manager_set_dirty(NMPRouteManager *self, gconstpointer user_tag);
 
 gboolean nmp_route_manager_untrack_all(NMPRouteManager *self,
                                        gconstpointer    user_tag,
-                                       gboolean         all /* or only dirty */);
+                                       gboolean         all /* or only dirty */,
+                                       gboolean         make_survivors_dirty);
 
 void nmp_route_manager_sync(NMPRouteManager *self, NMPObjectType obj_type, gboolean keep_deleted);