writefile: reuse SDNA between writes

Avoids decoding the SDNA string every undo step.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_genfile.h b/source/blender/makesdna/DNA_genfile.h
index 27a3ff8f8cb..bc127ac2c82 100644
--- a/source/blender/makesdna/DNA_genfile.h
+++ b/source/blender/makesdna/DNA_genfile.h
@@ -80,6 +80,12 @@ struct SDNA *DNA_sdna_from_data(
         const char **r_error_message);
 void DNA_sdna_free(struct SDNA *sdna);
 
+/* Access for current Blender versions SDNA*/
+void               DNA_sdna_current_init(void);
+/* borrowed reference */
+const struct SDNA *DNA_sdna_current_get(void);
+void               DNA_sdna_current_free(void);
+
 int DNA_struct_find_nr_ex(const struct SDNA *sdna, const char *str, unsigned int *index_last);
 int DNA_struct_find_nr(const struct SDNA *sdna, const char *str);
 void DNA_struct_switch_endian(const struct SDNA *oldsdna, int oldSDNAnr, char *data);