Performance: Remap multiple items in UI

During sprite fright loading of complex scenes would spend a long time in remapping ID's
The remapping process is done on a per ID instance that resulted in a very time consuming
process that goes over every possible ID reference to find out if it needs to be updated.

If there are N of references to ID blocks and there are M ID blocks that needed to be remapped
it would take N*M checks. These checks are scattered around the place and memory.
Each reference would only be updated at most once, but most of the time no update is needed at all.

Idea: By grouping the changes together will reduce the number of checks resulting in improved performance.
This would only require N checks. Additional benefits is improved data locality as data is only loaded once
in the L2 cache.

It has be implemented for the resyncing process and UI editors.
On an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz 16Gig the resyncing process went
from 170 seconds to 145 seconds (during hotspot recording).

After this patch has been applied we could add similar approach
to references (references between data blocks) and functionality (tagged deletion).
In my understanding this could reduce the resyncing process to less than a second.
Opening the village production file between 10 and 20 seconds.

Flame graphs showing that UI remapping isn't visible anymore (`WM_main_remap_editor_id_reference`)
* Master {F12769210 size=full}
* This patch {F12769211 size=full}

Reviewed By: mont29

Maniphest Tasks: T94185

Differential Revision: https://developer.blender.org/D13615

1 files changed, 25 insertions, 14 deletions

diff --git a/source/blender/blenkernel/intern/lib_id_delete.c b/source/blender/blenkernel/intern/lib_id_delete.c
index 6d2e89187f7..f4dd67cac28 100644
--- a/source/blender/blenkernel/intern/lib_id_delete.c
+++ b/source/blender/blenkernel/intern/lib_id_delete.c
@@ -154,7 +154,10 @@ void BKE_id_free_ex(Main *bmain, void *idv, int flag, const bool use_flag_from_i
     }
 
     if (remap_editor_id_reference_cb) {
-      remap_editor_id_reference_cb(id, NULL);
+      struct IDRemapper *remapper = BKE_id_remapper_create();
+      BKE_id_remapper_add(remapper, id, NULL);
+      remap_editor_id_reference_cb(remapper);
+      BKE_id_remapper_free(remapper);
     }
   }
 
@@ -292,32 +295,40 @@ static size_t id_delete(Main *bmain, const bool do_tagged_deletion)
      * Note that we go forward here, since we want to check dependencies before users
      * (e.g. meshes before objects).
      * Avoids to have to loop twice. */
+    struct IDRemapper *remapper = BKE_id_remapper_create();
     for (i = 0; i < base_count; i++) {
       ListBase *lb = lbarray[i];
       ID *id, *id_next;
+      BKE_id_remapper_clear(remapper);
 
       for (id = lb->first; id; id = id_next) {
         id_next = id->next;
         /* NOTE: in case we delete a library, we also delete all its datablocks! */
         if ((id->tag & tag) || (id->lib != NULL && (id->lib->id.tag & tag))) {
           id->tag |= tag;
-
-          /* Will tag 'never NULL' users of this ID too.
-           * Note that we cannot use BKE_libblock_unlink() here, since it would ignore indirect
-           * (and proxy!) links, this can lead to nasty crashing here in second,
-           * actual deleting loop.
-           * Also, this will also flag users of deleted data that cannot be unlinked
-           * (object using deleted obdata, etc.), so that they also get deleted. */
-          BKE_libblock_remap_locked(bmain,
-                                    id,
-                                    NULL,
-                                    (ID_REMAP_FLAG_NEVER_NULL_USAGE |
-                                     ID_REMAP_FORCE_NEVER_NULL_USAGE |
-                                     ID_REMAP_FORCE_INTERNAL_RUNTIME_POINTERS));
+          BKE_id_remapper_add(remapper, id, NULL);
         }
       }
+
+      if (BKE_id_remapper_is_empty(remapper)) {
+        continue;
+      }
+
+      /* Will tag 'never NULL' users of this ID too.
+       * Note that we cannot use BKE_libblock_unlink() here, since it would ignore indirect
+       * (and proxy!) links, this can lead to nasty crashing here in second,
+       * actual deleting loop.
+       * Also, this will also flag users of deleted data that cannot be unlinked
+       * (object using deleted obdata, etc.), so that they also get deleted. */
+      BKE_libblock_remap_multiple_locked(bmain,
+                                         remapper,
+                                         (ID_REMAP_FLAG_NEVER_NULL_USAGE |
+                                          ID_REMAP_FORCE_NEVER_NULL_USAGE |
+                                          ID_REMAP_FORCE_INTERNAL_RUNTIME_POINTERS));
     }
+    BKE_id_remapper_free(remapper);
   }
+
   BKE_main_unlock(bmain);
 
   /* In usual reversed order, such that all usage of a given ID, even 'never NULL' ones,