perf: avoid deep copy (#702)

Author: adhtruong

polyfactory/factories/base.py

@@ -260,7 +260,10 @@ def _get_build_context(cls, build_context: BuildContext | None) -> BuildContext:
         if build_context is None:
             return {"seen_models": set()}
 
-        return copy.deepcopy(build_context)
+        return {
+            **build_context,
+            "seen_models": copy.copy(build_context["seen_models"]),
+        }
 
     @classmethod
     def _infer_model_type(cls) -> type[T] | None:

polyfactory/factories/pydantic_factory.py

@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import copy
 from contextlib import suppress
 from datetime import timezone
 from functools import partial
@@ -529,15 +528,11 @@ def _get_build_context(cls, build_context: BaseBuildContext | PydanticBuildConte
         :returns: PydanticBuildContext
 
         """
-        if build_context is None:
-            return {"seen_models": set(), "factory_use_construct": False}
+        build_context = cast("PydanticBuildContext", super()._get_build_context(build_context))
+        if build_context.get("factory_use_construct") is None:
+            build_context["factory_use_construct"] = False
 
-        factory_use_construct = bool(build_context.get("factory_use_construct", False))
-
-        return {
-            "seen_models": copy.deepcopy(build_context["seen_models"]),
-            "factory_use_construct": factory_use_construct,
-        }
+        return build_context
 
     @classmethod
     def _create_model(cls, _build_context: PydanticBuildContext, **kwargs: Any) -> T:
@@ -549,7 +544,7 @@ def _create_model(cls, _build_context: PydanticBuildContext, **kwargs: Any) -> T
         :returns: An instance of type T.
 
         """
-        if cls._get_build_context(_build_context).get("factory_use_construct"):
+        if _build_context.get("factory_use_construct"):
             if _is_pydantic_v1_model(cls.__model__):
                 return cls.__model__.construct(**kwargs)  # type: ignore[return-value]
             return cls.__model__.model_construct(**kwargs)