BlenRead: Add GHash-based search for already read linked IDs.

Ths commit adds a new `IDNameLibMap` to `Main`, used during file reading
to quickly find already read linked IDs.

Without that, search would use string-based search over list of linked
data, which becomes extremely slow and inneficient in cases where a lot
of IDs are linked from a same library. See also {T89194}.

Extrem-usecase reported in T89194 is now about 4 times faster in linked
data reading (about 2 times faster for the whole .blend file loading).

More normal cases (like Sprites studio production files) have barely
measurable speed improvements, a few percents at best.

NOTE: `main_idmap` API was extended to support insertion and removal of
IDs from the mapping, avoids having to re-create the whole thing several
time during libraries expansion in readcode.

Differential Revision: https://developer.blender.org/D11757

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_main.h b/source/blender/blenkernel/BKE_main.h
index ed930fe539d..ae60a5563b5 100644
--- a/source/blender/blenkernel/BKE_main.h
+++ b/source/blender/blenkernel/BKE_main.h
@@ -48,6 +48,7 @@ struct BLI_mempool;
 struct BlendThumbnail;
 struct GHash;
 struct GSet;
+struct IDNameLib_Map;
 struct ImBuf;
 struct Library;
 struct MainLock;
@@ -191,6 +192,9 @@ typedef struct Main {
    */
   struct MainIDRelations *relations;
 
+  /* IDMap of IDs. Currently used when reading (expanding) libraries. */
+  struct IDNameLib_Map *id_map;
+
   struct MainLock *lock;
 } Main;