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.

3 files changed, 57 insertions, 2 deletions

diff --git a/source/blender/makesrna/intern/rna_cachefile.c b/source/blender/makesrna/intern/rna_cachefile.c
index 7249ebd5feb..09fdeb15b10 100644
--- a/source/blender/makesrna/intern/rna_cachefile.c
+++ b/source/blender/makesrna/intern/rna_cachefile.c
@@ -37,6 +37,8 @@
 #include "BKE_cachefile.h"
 #include "BKE_depsgraph.h"
 
+#include "BLI_string.h"
+
 #include "DEG_depsgraph.h"
 
 #include "WM_api.h"
@@ -60,6 +62,12 @@ static void rna_CacheFile_update_handle(Main *bmain, Scene *scene, PointerRNA *p
 {
 	CacheFile *cache_file = ptr->data;
 
+	if ((cache_file->flag & CACHEFILE_DIRTY) != 0) {
+		BKE_cachefile_clean(scene, cache_file);
+		BLI_freelistN(&cache_file->object_paths);
+		cache_file->flag &= ~CACHEFILE_DIRTY;
+	}
+
 	BKE_cachefile_reload(bmain, cache_file);
 
 	rna_CacheFile_update(bmain, scene, ptr);
@@ -71,6 +79,20 @@ static void rna_CacheFile_object_paths_begin(CollectionPropertyIterator *iter, P
 	rna_iterator_listbase_begin(iter, &cache_file->object_paths, NULL);
 }
 
+static void rna_CacheFile_filename_set(PointerRNA *ptr, const char *value)
+{
+	CacheFile *cache_file = ptr->data;
+
+	if (STREQ(cache_file->filepath, value)) {
+		return;
+	}
+
+	/* Different file is opened, close all readers. */
+	cache_file->flag |= CACHEFILE_DIRTY;
+
+	BLI_strncpy(cache_file->filepath, value, sizeof(cache_file->filepath));
+}
+
 #else
 
 /* cachefile.object_paths */
@@ -103,6 +125,7 @@ static void rna_def_cachefile(BlenderRNA *brna)
 	RNA_def_struct_ui_icon(srna, ICON_FILE);
 
 	PropertyRNA *prop = RNA_def_property(srna, "filepath", PROP_STRING, PROP_FILEPATH);
+	RNA_def_property_string_funcs(prop, NULL, NULL, "rna_CacheFile_filename_set");
 	RNA_def_property_ui_text(prop, "File Path", "Path to external displacements file");
 	RNA_def_property_update(prop, 0, "rna_CacheFile_update_handle");
 
diff --git a/source/blender/makesrna/intern/rna_constraint.c b/source/blender/makesrna/intern/rna_constraint.c
index db3f76f3cfc..ad037af943d 100644
--- a/source/blender/makesrna/intern/rna_constraint.c
+++ b/source/blender/makesrna/intern/rna_constraint.c
@@ -148,12 +148,17 @@ static EnumPropertyItem space_object_items[] = {
 	{0, NULL, 0, NULL, NULL}
 };
 
+#include "DNA_cachefile_types.h"
+
 #include "BKE_animsys.h"
 #include "BKE_action.h"
 #include "BKE_constraint.h"
 #include "BKE_context.h"
 #include "BKE_depsgraph.h"
 
+#ifdef WITH_ALEMBIC
+#  include "ABC_alembic.h"
+#endif
 
 static StructRNA *rna_ConstraintType_refine(struct PointerRNA *ptr)
 {
@@ -471,6 +476,20 @@ static void rna_Constraint_objectSolver_camera_set(PointerRNA *ptr, PointerRNA v
 	}
 }
 
+static void rna_Constraint_transformCache_object_path_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+	bConstraint *con = (bConstraint *)ptr->data;
+	bTransformCacheConstraint *data = (bTransformCacheConstraint *)con->data;
+	Object *ob = (Object *)ptr->id.data;
+
+	data->reader = CacheReader_open_alembic_object(data->cache_file->handle,
+	                                               data->reader,
+	                                               ob,
+	                                               data->object_path);
+
+	rna_Constraint_update(bmain, scene, ptr);
+}
+
 #else
 
 static EnumPropertyItem constraint_distance_items[] = {
@@ -2593,7 +2612,7 @@ static void rna_def_constraint_transform_cache(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "object_path", PROP_STRING, PROP_NONE);
 	RNA_def_property_ui_text(prop, "Object Path", "Path to the object in the Alembic archive used to lookup the transform matrix");
-	RNA_def_property_update(prop, 0, "rna_Constraint_update");
+	RNA_def_property_update(prop, 0, "rna_Constraint_transformCache_object_path_update");
 }
 
 /* base struct for constraints */
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 39f6298ca61..b30c156a88c 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1131,6 +1131,19 @@ static int rna_CorrectiveSmoothModifier_is_bind_get(PointerRNA *ptr)
 	return (csmd->bind_coords != NULL);
 }
 
+static void rna_MeshSequenceCache_object_path_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+	MeshSeqCacheModifierData *mcmd = (MeshSeqCacheModifierData *)ptr->data;
+	Object *ob = (Object *)ptr->id.data;
+
+	mcmd->reader = CacheReader_open_alembic_object(mcmd->cache_file->handle,
+	                                               mcmd->reader,
+	                                               ob,
+	                                               mcmd->object_path);
+
+	rna_Modifier_update(bmain, scene, ptr);
+}
+
 #else
 
 static PropertyRNA *rna_def_property_subdivision_common(StructRNA *srna, const char type[])
@@ -4257,7 +4270,7 @@ static void rna_def_modifier_meshseqcache(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "object_path", PROP_STRING, PROP_NONE);
 	RNA_def_property_ui_text(prop, "Object Path", "Path to the object in the Alembic archive used to lookup geometric data");
-	RNA_def_property_update(prop, 0, "rna_Modifier_update");
+	RNA_def_property_update(prop, 0, "rna_MeshSequenceCache_object_path_update");
 
 	static EnumPropertyItem read_flag_items[] = {
 		{MOD_MESHSEQ_READ_VERT,  "VERT", 0, "Vertex", ""},