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, 66 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_lib_remap.h b/source/blender/blenkernel/BKE_lib_remap.h
index d8842dbce7f..cc970342fbb 100644
--- a/source/blender/blenkernel/BKE_lib_remap.h
+++ b/source/blender/blenkernel/BKE_lib_remap.h
@@ -38,6 +38,9 @@
 extern "C" {
 #endif
 
+struct ID;
+struct IDRemapper;
+
 /* BKE_libblock_free, delete are declared in BKE_lib_id.h for convenience. */
 
 /* Also IDRemap->flag. */
@@ -98,6 +101,19 @@ enum {
 };
 
 /**
+ * Replace all references in given Main using the given \a mappings
+ *
+ * \note Is preferred over BKE_libblock_remap_locked due to performance.
+ */
+void BKE_libblock_remap_multiple_locked(struct Main *bmain,
+                                        const struct IDRemapper *mappings,
+                                        const short remap_flags);
+
+void BKE_libblock_remap_multiple(struct Main *bmain,
+                                 const struct IDRemapper *mappings,
+                                 const short remap_flags);
+
+/**
  * Replace all references in given Main to \a old_id by \a new_id
  * (if \a new_id is NULL, it unlinks \a old_id).
  *
@@ -146,12 +162,61 @@ void BKE_libblock_relink_to_newid(struct Main *bmain, struct ID *id, int remap_f
     ATTR_NONNULL();
 
 typedef void (*BKE_library_free_notifier_reference_cb)(const void *);
-typedef void (*BKE_library_remap_editor_id_reference_cb)(struct ID *, struct ID *);
+typedef void (*BKE_library_remap_editor_id_reference_cb)(const struct IDRemapper *mappings);
 
 void BKE_library_callback_free_notifier_reference_set(BKE_library_free_notifier_reference_cb func);
 void BKE_library_callback_remap_editor_id_reference_set(
     BKE_library_remap_editor_id_reference_cb func);
 
+/* IDRemapper */
+struct IDRemapper;
+typedef enum IDRemapperApplyResult {
+  /** No remapping rules available for the source. */
+  ID_REMAP_RESULT_SOURCE_UNAVAILABLE,
+  /** Source isn't mappable (e.g. NULL). */
+  ID_REMAP_RESULT_SOURCE_NOT_MAPPABLE,
+  /** Source has been remapped to a new pointer. */
+  ID_REMAP_RESULT_SOURCE_REMAPPED,
+  /** Source has been set to NULL. */
+  ID_REMAP_RESULT_SOURCE_UNASSIGNED,
+} IDRemapperApplyResult;
+
+typedef enum IDRemapperApplyOptions {
+  ID_REMAP_APPLY_UPDATE_REFCOUNT = (1 << 0),
+  ID_REMAP_APPLY_ENSURE_REAL = (1 << 1),
+
+  ID_REMAP_APPLY_DEFAULT = 0,
+} IDRemapperApplyOptions;
+
+typedef void (*IDRemapperIterFunction)(struct ID *old_id, struct ID *new_id, void *user_data);
+
+/**
+ * Create a new ID Remapper.
+ *
+ * An ID remapper stores multiple remapping rules.
+ */
+struct IDRemapper *BKE_id_remapper_create(void);
+
+void BKE_id_remapper_clear(struct IDRemapper *id_remapper);
+bool BKE_id_remapper_is_empty(const struct IDRemapper *id_remapper);
+/** Free the given ID Remapper. */
+void BKE_id_remapper_free(struct IDRemapper *id_remapper);
+/** Add a new remapping. */
+void BKE_id_remapper_add(struct IDRemapper *id_remapper, struct ID *old_id, struct ID *new_id);
+
+/**
+ * Apply a remapping.
+ *
+ * Update the id pointer stored in the given r_id_ptr if a remapping rule exists.
+ */
+IDRemapperApplyResult BKE_id_remapper_apply(const struct IDRemapper *id_remapper,
+                                            struct ID **r_id_ptr,
+                                            IDRemapperApplyOptions options);
+bool BKE_id_remapper_has_mapping_for(const struct IDRemapper *id_remapper, uint64_t type_filter);
+void BKE_id_remapper_iter(const struct IDRemapper *id_remapper,
+                          IDRemapperIterFunction func,
+                          void *user_data);
+
 #ifdef __cplusplus
 }
 #endif