share hashcode implementation

yacv_server/tessellate.py

@@ -1,7 +1,7 @@
 import hashlib
 import io
 import re
-from typing import List, Dict, Tuple
+from typing import List, Dict, Tuple, Union
 
 from OCP.BRep import BRep_Tool
 from OCP.BRepAdaptor import BRepAdaptor_Curve
@@ -123,18 +123,24 @@ def _tessellate_vertex(mgr: GLTFMgr, ocp_vertex: TopoDS_Vertex, faces: List[Topo
     mgr.add_vertex(_push_point((c.X, c.Y, c.Z), faces))
 
 
-def _hashcode(obj: TopoDS_Shape) -> str:
+def _hashcode(obj: Union[bytes, TopoDS_Shape], **extras) -> str:
     """Utility to compute the hash code of a shape recursively without the need to tessellate it"""
     # NOTE: obj.HashCode(MAX_HASH_CODE) is not stable across different runs of the same program
     # This is best-effort and not guaranteed to be unique
     map_of_shapes = TopTools_IndexedMapOfShape()
     TopExp.MapShapes_s(obj, map_of_shapes)
     hasher = hashlib.md5(usedforsecurity=False)
-    for i in range(1, map_of_shapes.Extent() + 1):
-        sub_shape = map_of_shapes.FindKey(i)
-        sub_data = io.BytesIO()
-        TopoDS_Shape.DumpJson(sub_shape, sub_data)
-        val = sub_data.getvalue()
-        val = re.sub(b'"this": "[^"]*"', b'', val)  # Remove memory address
-        hasher.update(val)
+    for k, v in extras.items():
+        hasher.update(str(k).encode())
+        hasher.update(str(v).encode())
+    if isinstance(obj, bytes):
+        hasher.update(obj)
+    else:
+        for i in range(1, map_of_shapes.Extent() + 1):
+            sub_shape = map_of_shapes.FindKey(i)
+            sub_data = io.BytesIO()
+            TopoDS_Shape.DumpJson(sub_shape, sub_data)
+            val = sub_data.getvalue()
+            val = re.sub(b'"this": "[^"]*"', b'', val)  # Remove memory address
+            hasher.update(val)
     return hasher.hexdigest()