Refactor: Use StringRef for attribute API and BMesh CustomData functions

Replace `const char *` with `StringRef` for the API in `BKE_attribute.h`.
The benefits are slightly simpler code and possibly slightly improved
performance through avoiding the need to measure string length.

Pull Request: https://projects.blender.org/blender/blender/pulls/134183

intern/cycles/blender/mesh.cpp

@@ -281,7 +281,8 @@ static void attr_create_generic(Scene *scene,
   const blender::bke::AttributeAccessor b_attributes = b_mesh.attributes();
   AttributeSet &attributes = (subdivision) ? mesh->subd_attributes : mesh->attributes;
   static const ustring u_velocity("velocity");
-  const ustring default_color_name{BKE_id_attributes_default_color_name(&b_mesh.id)};
+  const ustring default_color_name{
+      std::string_view(BKE_id_attributes_default_color_name(&b_mesh.id).value_or(""))};
 
   b_attributes.foreach_attribute([&](const blender::bke::AttributeIter &iter) {
     const ustring name{std::string_view(iter.name)};

source/blender/blenkernel/BKE_attribute.h

@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include <optional>
 #include <string>
 
 #include "BLI_string_ref.hh"
@@ -81,50 +82,52 @@ class AttributeOwner {
  * Create a new attribute layer.
  */
 struct CustomDataLayer *BKE_attribute_new(AttributeOwner &owner,
-                                          const char *name,
+                                          blender::StringRef name,
                                           eCustomDataType type,
                                           blender::bke::AttrDomain domain,
                                           struct ReportList *reports);
-bool BKE_attribute_remove(AttributeOwner &owner, const char *name, struct ReportList *reports);
+bool BKE_attribute_remove(AttributeOwner &owner,
+                          blender::StringRef name,
+                          struct ReportList *reports);
 
 /**
  * Creates a duplicate attribute layer.
  */
 struct CustomDataLayer *BKE_attribute_duplicate(AttributeOwner &owner,
-                                                const char *name,
+                                                blender::StringRef name,
                                                 struct ReportList *reports);
 
 struct CustomDataLayer *BKE_attribute_find(const AttributeOwner &owner,
-                                           const char *name,
+                                           blender::StringRef name,
                                            eCustomDataType type,
                                            blender::bke::AttrDomain domain);
 
 const struct CustomDataLayer *BKE_attribute_search(const AttributeOwner &owner,
-                                                   const char *name,
+                                                   blender::StringRef name,
                                                    eCustomDataMask type,
                                                    AttrDomainMask domain_mask);
 
 struct CustomDataLayer *BKE_attribute_search_for_write(AttributeOwner &owner,
-                                                       const char *name,
+                                                       blender::StringRef name,
                                                        eCustomDataMask type,
                                                        AttrDomainMask domain_mask);
 
 blender::bke::AttrDomain BKE_attribute_domain(const AttributeOwner &owner,
                                               const struct CustomDataLayer *layer);
 int BKE_attribute_domain_size(const AttributeOwner &owner, int domain);
 int BKE_attribute_data_length(AttributeOwner &owner, struct CustomDataLayer *layer);
-bool BKE_attribute_required(const AttributeOwner &owner, const char *name);
+bool BKE_attribute_required(const AttributeOwner &owner, blender::StringRef name);
 bool BKE_attribute_rename(AttributeOwner &owner,
-                          const char *old_name,
-                          const char *new_name,
+                          blender::StringRef old_name,
+                          blender::StringRef new_name,
                           struct ReportList *reports);
 
 int BKE_attributes_length(const AttributeOwner &owner,
                           AttrDomainMask domain_mask,
                           eCustomDataMask mask);
 
 struct CustomDataLayer *BKE_attributes_active_get(AttributeOwner &owner);
-void BKE_attributes_active_set(AttributeOwner &owner, const char *name);
+void BKE_attributes_active_set(AttributeOwner &owner, blender::StringRef name);
 void BKE_attributes_active_clear(AttributeOwner &owner);
 int *BKE_attributes_active_index_p(AttributeOwner &owner);
 
@@ -141,18 +144,22 @@ int BKE_attribute_to_index(const AttributeOwner &owner,
                            AttrDomainMask domain_mask,
                            eCustomDataMask layer_mask);
 
-const char *BKE_id_attributes_active_color_name(const struct ID *id);
-const char *BKE_id_attributes_default_color_name(const struct ID *id);
-void BKE_id_attributes_active_color_set(struct ID *id, const char *name);
+std::optional<blender::StringRef> BKE_id_attributes_active_color_name(const struct ID *id);
+std::optional<blender::StringRef> BKE_id_attributes_default_color_name(const struct ID *id);
+void BKE_id_attributes_active_color_set(struct ID *id, std::optional<blender::StringRef> name);
 void BKE_id_attributes_active_color_clear(struct ID *id);
-void BKE_id_attributes_default_color_set(struct ID *id, const char *name);
+void BKE_id_attributes_default_color_set(struct ID *id, std::optional<blender::StringRef> name);
 
-const struct CustomDataLayer *BKE_id_attributes_color_find(const struct ID *id, const char *name);
+const struct CustomDataLayer *BKE_id_attributes_color_find(const struct ID *id,
+                                                           blender::StringRef name);
 bool BKE_color_attribute_supported(const struct Mesh &mesh, const blender::StringRef name);
 
 std::string BKE_attribute_calc_unique_name(const AttributeOwner &owner,
                                            const blender::StringRef name);
 
-const char *BKE_uv_map_vert_select_name_get(const char *uv_map_name, char *buffer);
-const char *BKE_uv_map_edge_select_name_get(const char *uv_map_name, char *buffer);
-const char *BKE_uv_map_pin_name_get(const char *uv_map_name, char *buffer);
+[[nodiscard]] blender::StringRef BKE_uv_map_vert_select_name_get(blender::StringRef uv_map_name,
+                                                                 char *buffer);
+[[nodiscard]] blender::StringRef BKE_uv_map_edge_select_name_get(blender::StringRef uv_map_name,
+                                                                 char *buffer);
+[[nodiscard]] blender::StringRef BKE_uv_map_pin_name_get(blender::StringRef uv_map_name,
+                                                         char *buffer);

source/blender/blenkernel/BKE_curves.h

@@ -6,6 +6,8 @@
 
 #include "DNA_curves_types.h"
 
+#include "BLI_string_ref.hh"
+
 /** \file
  * \ingroup bke
  * \brief Low-level operations for curves that cannot be defined in the C++ header yet.
@@ -23,7 +25,7 @@ struct Scene;
 
 struct Curves *BKE_curves_add(struct Main *bmain, const char *name);
 
-bool BKE_curves_attribute_required(const struct Curves *curves, const char *name);
+bool BKE_curves_attribute_required(const struct Curves *curves, blender::StringRef name);
 
 /* Depsgraph */
 

source/blender/blenkernel/BKE_grease_pencil.hh

@@ -1061,7 +1061,8 @@ inline bool GreasePencil::has_active_group() const
   return (this->active_node != nullptr) && (this->active_node->wrap().is_group());
 }
 
-bool BKE_grease_pencil_drawing_attribute_required(const GreasePencilDrawing *, const char *name);
+bool BKE_grease_pencil_drawing_attribute_required(const GreasePencilDrawing *,
+                                                  blender::StringRef name);
 
 GreasePencil *BKE_grease_pencil_add(Main *bmain, const char *name);
 GreasePencil *BKE_grease_pencil_new_nomain();

source/blender/blenkernel/BKE_mesh.h

@@ -10,6 +10,7 @@
 #include <cstdint>
 
 #include "BLI_array.hh"
+#include "BLI_string_ref.hh"
 
 #include "DNA_mesh_types.h"
 
@@ -137,7 +138,7 @@ Mesh *BKE_mesh_copy_for_eval(const Mesh &source);
 Mesh *BKE_mesh_new_nomain_from_curve(const Object *ob);
 Mesh *BKE_mesh_new_nomain_from_curve_displist(const Object *ob, const ListBase *dispbase);
 
-bool BKE_mesh_attribute_required(const char *name);
+bool BKE_mesh_attribute_required(blender::StringRef name);
 
 blender::Array<blender::float3> BKE_mesh_orco_verts_get(const Object *ob);
 void BKE_mesh_orco_verts_transform(Mesh *mesh,

source/blender/blenkernel/BKE_pointcloud.hh

@@ -12,6 +12,7 @@
 #include "BLI_bounds_types.hh"
 #include "BLI_math_vector_types.hh"
 #include "BLI_shared_cache.hh"
+#include "BLI_string_ref.hh"
 
 #include "DNA_pointcloud_types.h"
 
@@ -53,7 +54,7 @@ PointCloud *BKE_pointcloud_add_default(Main *bmain, const char *name);
 PointCloud *BKE_pointcloud_new_nomain(int totpoint);
 void BKE_pointcloud_nomain_to_pointcloud(PointCloud *pointcloud_src, PointCloud *pointcloud_dst);
 
-bool BKE_pointcloud_attribute_required(const PointCloud *pointcloud, const char *name);
+bool BKE_pointcloud_attribute_required(const PointCloud *pointcloud, blender::StringRef name);
 
 /* Dependency Graph */