Alembic: store a pointer to the object reader in the cache modifiers and

constraints.

This avoids traversing the archive everytime object data is needed and
gives an overall consistent ~2x speedup here with files containing
between 136 and 500 Alembic objects. Also this somewhat nicely de-
duplicates code between data creation (upon import) and data streaming
(modifiers and constraints).

The only worying part is what happens when a CacheFile is deleted and/or
has its path changed. For now, we traverse the whole scene and for each
object using the CacheFile we free the pointer and NULL-ify it (see
BKE_cachefile_clean), but at some point this should be re-considered and
make use of the dependency graph.

1 files changed, 12 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index c4afa58b7d3..c7750707cc4 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -4364,8 +4364,14 @@ static void transformcache_evaluate(bConstraint *con, bConstraintOb *cob, ListBa
 
 	BKE_cachefile_ensure_handle(G.main, cache_file);
 
-	ABC_get_transform(cache_file->handle, cob->ob, data->object_path,
-	                  cob->matrix, time, cache_file->scale);
+	if (!data->reader) {
+		data->reader = CacheReader_open_alembic_object(cache_file->handle,
+		                                               data->reader,
+		                                               cob->ob,
+		                                               data->object_path);
+	}
+
+	ABC_get_transform(data->reader, cob->matrix, time, cache_file->scale);
 #else
 	UNUSED_VARS(con, cob);
 #endif
@@ -4393,6 +4399,10 @@ static void transformcache_free(bConstraint *con)
 	if (data->cache_file) {
 		id_us_min(&data->cache_file->id);
 	}
+
+	if (data->reader) {
+		CacheReader_free(data->reader);
+	}
 }
 
 static void transformcache_new_data(void *cdata)