Add caching for resolve (#3549)

* Use cached property for .type

* More granular cache

* Added a comment for later

* Remove old cache and fix a bug noted by San

Let's see what happens if I remove the cache

* Add tweet and release files

* Fix name

* Remove comment

`resolve` is called every time we get the field type, which, turns out,
is called a lot of times, even when creating the dataclass, maybe
there's some opportunity for improvements here, but we would need
to call `resolve` anyway, so it's probably not worth changing how this
works

RELEASE.md

@@ -0,0 +1,4 @@
+Release type: patch
+
+This release improves the performance when returning a lot of data, especially
+when using generic inputs (where we got a 7x speedup in our benchmark!).

TWEET.md

@@ -0,0 +1,6 @@
+🆕 Release $version is out! Thanks to $contributor for the PR 👏
+
+This release improves the performance when returning a lot of data, especially
+when using generic inputs (where we got a 7x speedup in our benchmark!).
+
+Get it here 👉 $release_url

strawberry/annotation.py

@@ -54,7 +54,7 @@
 
 
 class StrawberryAnnotation:
-    __slots__ = "raw_annotation", "namespace", "__eval_cache__"
+    __slots__ = "raw_annotation", "namespace", "__resolve_cache__"
 
     def __init__(
         self,
@@ -65,7 +65,7 @@ def __init__(
         self.raw_annotation = annotation
         self.namespace = namespace
 
-        self.__eval_cache__: Optional[Type[Any]] = None
+        self.__resolve_cache__: Optional[Union[StrawberryType, type]] = None
 
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, StrawberryAnnotation):
@@ -101,19 +101,17 @@ def annotation(self) -> Union[object, str]:
     def annotation(self, value: Union[object, str]) -> None:
         self.raw_annotation = value
 
+        self.__resolve_cache__ = None
+
     def evaluate(self) -> type:
         """Return evaluated annotation using `strawberry.util.typing.eval_type`."""
-        evaled_type = self.__eval_cache__
-        if evaled_type:
-            return evaled_type
-
         annotation = self.raw_annotation
+
         if isinstance(annotation, str):
             annotation = ForwardRef(annotation)
 
         evaled_type = eval_type(annotation, self.namespace, None)
 
-        self.__eval_cache__ = evaled_type
         return evaled_type
 
     def _get_type_with_args(
@@ -131,6 +129,12 @@ def _get_type_with_args(
 
     def resolve(self) -> Union[StrawberryType, type]:
         """Return resolved (transformed) annotation."""
+        if self.__resolve_cache__ is None:
+            self.__resolve_cache__ = self._resolve()
+
+        return self.__resolve_cache__
+
+    def _resolve(self) -> Union[StrawberryType, type]:
         evaled_type = cast(Any, self.evaluate())
 
         if is_private(evaled_type):
@@ -172,7 +176,7 @@ def set_namespace_from_field(self, field: StrawberryField) -> None:
         module = sys.modules[field.origin.__module__]
         self.namespace = module.__dict__
 
-        self.__eval_cache__ = None  # Invalidate cache to allow re-evaluation
+        self.__resolve_cache__ = None  # Invalidate cache to allow re-evaluation
 
     def create_concrete_type(self, evaled_type: type) -> type:
         if has_object_definition(evaled_type):

strawberry/arguments.py

@@ -129,7 +129,6 @@ def type(self) -> Union[StrawberryType, type]:
 
     @property
     def is_graphql_generic(self) -> bool:
-        # TODO: double check this
         from strawberry.schema.compat import is_graphql_generic
 
         return is_graphql_generic(self.type)