Cache field types of the given model

Author: Tinitto

pydantic_redis/model.py

@@ -19,6 +19,7 @@ class Model(_AbstractModel):
     _nested_model_tuple_fields = {}
     _nested_model_list_fields = {}
     _nested_model_fields = {}
+    _field_types = {}
 
     @classmethod
     def __get_primary_key(cls, primary_key_value: Any):
@@ -37,13 +38,13 @@ def get_table_index_key(cls):
     @classmethod
     def initialize(cls):
         """Initializes class-wide variables for performance's reasons e.g. it caches the nested model fields"""
-        field_types = typing.get_type_hints(cls)
+        cls._field_types = typing.get_type_hints(cls)
 
         cls._nested_model_list_fields = {}
         cls._nested_model_tuple_fields = {}
         cls._nested_model_fields = {}
 
-        for field, field_type in field_types.items():
+        for field, field_type in cls._field_types.items():
             try:
                 # In case the annotation is Optional, an alias of Union[X, None], extract the X
                 is_generic = hasattr(field_type, "__origin__")
@@ -199,23 +200,22 @@ def __parse_dict_list(cls, data: List[Dict[bytes, Any]]) -> List[Dict[str, Any]]
             cls.deserialize_partially(record) for record in data if record != {}
         ]
         if len(parsed_data) > 0:
-            field_types = typing.get_type_hints(cls)
             keys = [*parsed_data[0].keys()]
 
             for k in keys:
                 if k.startswith(NESTED_MODEL_LIST_FIELD_PREFIX):
                     cls.__eager_load_nested_model_lists(
-                        prefixed_field=k, data=parsed_data, field_types=field_types
+                        prefixed_field=k, data=parsed_data
                     )
 
                 elif k.startswith(NESTED_MODEL_TUPLE_FIELD_PREFIX):
                     cls.__eager_load_nested_model_tuples(
-                        prefixed_field=k, data=parsed_data, field_types=field_types
+                        prefixed_field=k, data=parsed_data
                     )
 
                 elif k.startswith(NESTED_MODEL_PREFIX):
                     cls.__eager_load_nested_models(
-                        prefixed_field=k, data=parsed_data, field_types=field_types
+                        prefixed_field=k, data=parsed_data, field_types=cls._field_types
                     )
         return parsed_data
 
@@ -224,7 +224,6 @@ def __eager_load_nested_model_lists(
         cls,
         prefixed_field: str,
         data: List[Dict[str, Any]],
-        field_types: Dict[str, Any],
     ):
         """
         Eagerly loads any properties that have `List[Model]` or Optional[List[Model]]` as their type annotations
@@ -234,24 +233,17 @@ def __eager_load_nested_model_lists(
         [{"___books": ["id1", "id2"]}] becomes [{"books": [Book{"id": "id1", ...}, Book{"id": "id2", ...}]}]
         """
         field = strip_leading(prefixed_field, NESTED_MODEL_LIST_FIELD_PREFIX)
-        field_type = field_types.get(field)
-        model_type = field_type.__args__[0]
-
-        # in case the field is Optional e.g. books: Optional[List[Model]], an alias for Union[List[Model], None]
-        is_optional = field_type.__origin__ == Union
-        if is_optional:
-            model_type = model_type.__args__[0]
+        field_type = cls._nested_model_list_fields.get(field)
 
         for record in data:
             ids = record.pop(prefixed_field, None)
-            record[field] = model_type.select(ids=ids)
+            record[field] = field_type.select(ids=ids)
 
     @classmethod
     def __eager_load_nested_model_tuples(
         cls,
         prefixed_field: str,
         data: List[Dict[str, Any]],
-        field_types: Dict[str, Any],
     ):
         """
         Eagerly loads any properties that have `Tuple[Model]` or `Optional[Tuple[Model]]` as their type annotations
@@ -287,7 +279,7 @@ def __eager_load_nested_models(
         [{"__book": "id1"}] becomes [{"book": Book{"id": "id1", ...}}]
         """
         field = strip_leading(prefixed_field, NESTED_MODEL_PREFIX)
-        model_type = field_types.get(field)
+        model_type = cls._nested_model_fields.get(field)
 
         ids: List[str] = [record.pop(prefixed_field, None) for record in data]
         # a bulk network request might be faster than eagerly loading for each record for many records
@@ -400,7 +392,7 @@ def __get_select_fields(cls, columns: Optional[List[str]]) -> Optional[List[str]
         if columns is None:
             return None
 
-        field_types = typing.get_type_hints(cls)
+        field_types = cls._field_types
 
         fields = []
         for col in columns: