refactor: move provider dict to a ProviderRegistry class

Signed-off-by: Federico Bond <federicobond@gmail.com>

openfeature/api.py

@@ -6,15 +6,13 @@
 from openfeature.hook import Hook
 from openfeature.provider import FeatureProvider
 from openfeature.provider.metadata import Metadata
-from openfeature.provider.no_op_provider import NoOpProvider
-
-_provider: FeatureProvider = NoOpProvider()
+from openfeature.provider.registry import ProviderRegistry
 
 _evaluation_context = EvaluationContext()
 
 _hooks: typing.List[Hook] = []
 
-_providers: typing.Dict[str, FeatureProvider] = {}
+_provider_registry: ProviderRegistry = ProviderRegistry()
 
 
 def get_client(
@@ -26,46 +24,18 @@ def get_client(
 def set_provider(
     provider: FeatureProvider, domain: typing.Optional[str] = None
 ) -> None:
-    if provider is None:
-        raise GeneralError(error_message="No provider")
-
-    if domain:
-        _set_domain_provider(domain, provider)
-        return
-
-    global _provider
-    if _provider:
-        _provider.shutdown()
-    _provider = provider
-    provider.initialize(_evaluation_context)
-
-
-def _set_domain_provider(domain: str, provider: FeatureProvider) -> None:
-    if domain in _providers:
-        old_provider = _providers[domain]
-        del _providers[domain]
-        if old_provider not in _providers.values():
-            old_provider.shutdown()
-    if provider not in _providers.values():
-        provider.initialize(_evaluation_context)
-    _providers[domain] = provider
-
-
-def _get_provider(domain: typing.Optional[str] = None) -> FeatureProvider:
-    global _provider
     if domain is None:
-        return _provider
-    return _providers.get(domain, _provider)
+        _provider_registry.set_default_provider(provider)
+    else:
+        _provider_registry.set_provider(domain, provider)
 
 
 def clear_providers() -> None:
-    for provider in _providers.values():
-        provider.shutdown()
-    _providers.clear()
+    return _provider_registry.clear_providers()
 
 
 def get_provider_metadata(domain: typing.Optional[str] = None) -> Metadata:
-    return _get_provider(domain).get_metadata()
+    return _provider_registry.get_provider(domain).get_metadata()
 
 
 def get_evaluation_context() -> EvaluationContext:
@@ -96,5 +66,4 @@ def get_hooks() -> typing.List[Hook]:
 
 
 def shutdown() -> None:
-    for provider in {_provider, *_providers.values()}:
-        provider.shutdown()
+    _provider_registry.shutdown()

openfeature/client.py

@@ -79,7 +79,7 @@ def __init__(
 
     @property
     def provider(self) -> FeatureProvider:
-        return api._get_provider(domain=self.domain)
+        return api._provider_registry.get_provider(self.domain)
 
     def get_metadata(self) -> ClientMetadata:
         return ClientMetadata(domain=self.domain)

openfeature/provider/registry.py

@@ -0,0 +1,59 @@
+import typing
+
+from openfeature.evaluation_context import EvaluationContext
+from openfeature.exception import GeneralError
+from openfeature.provider import FeatureProvider
+from openfeature.provider.no_op_provider import NoOpProvider
+
+
+class ProviderRegistry:
+    _default_provider: FeatureProvider
+    _providers: typing.Dict[str, FeatureProvider]
+
+    def __init__(self) -> None:
+        self._default_provider = NoOpProvider()
+        self._providers = {}
+
+    def set_provider(self, domain: str, provider: FeatureProvider) -> None:
+        if provider is None:
+            raise GeneralError(error_message="No provider")
+        providers = self._providers
+        if domain in providers:
+            old_provider = providers[domain]
+            del providers[domain]
+            if old_provider not in providers.values():
+                old_provider.shutdown()
+        if provider not in providers.values():
+            provider.initialize(self._get_evaluation_context())
+        providers[domain] = provider
+
+    def get_provider(self, domain: typing.Optional[str]) -> FeatureProvider:
+        if domain is None:
+            return self._default_provider
+        return self._providers.get(domain, self._default_provider)
+
+    def set_default_provider(self, provider: FeatureProvider) -> None:
+        if provider is None:
+            raise GeneralError(error_message="No provider")
+        if self._default_provider:
+            self._default_provider.shutdown()
+        self._default_provider = provider
+        provider.initialize(self._get_evaluation_context())
+
+    def get_default_provider(self) -> FeatureProvider:
+        return self._default_provider
+
+    def clear_providers(self) -> None:
+        for provider in self._providers.values():
+            provider.shutdown()
+        self._providers.clear()
+
+    def shutdown(self) -> None:
+        for provider in {self._default_provider, *self._providers.values()}:
+            provider.shutdown()
+
+    def _get_evaluation_context(self) -> EvaluationContext:
+        # imported here to avoid circular imports
+        from openfeature.api import get_evaluation_context  # noqa: PLC0415
+
+        return get_evaluation_context()