Optimize response formatter application hot path

web3/middleware/formatting.py

@@ -3,7 +3,6 @@
     Any,
     Callable,
     Coroutine,
-    Literal,
     Union,
     cast,
 )
@@ -55,46 +54,37 @@ def _apply_response_formatters(
     error_formatters: Formatters,
     response: RPCResponse,
 ) -> RPCResponse:
-    def _format_response(
-        response_type: Literal["result", "error", "params"],
-        method_response_formatter: Callable[..., Any],
-    ) -> RPCResponse:
-        appropriate_response = response[response_type]
-
-        if response_type == "params":
-            appropriate_response = cast(EthSubscriptionParams, response[response_type])
+    if not isinstance(response, dict):
+        raise BadResponseFormat(
+            "Malformed response: expected a valid JSON-RPC response object, got: "
+            "`{}`".format(response)
+        )
+
+    result_formatter = result_formatters.get(method)
+    if result_formatter is not None:
+        result = response.get("result")
+        if result is not None:
+            return assoc(response, "result", result_formatter(result))
+
+        params = response.get("params")
+        if params is not None and params.get("result") is not None:
+            # eth_subscription responses
+            subscription_params = cast(EthSubscriptionParams, params)
             return assoc(
                 response,
-                response_type,
+                "params",
                 assoc(
-                    response["params"],
+                    params,
                     "result",
-                    method_response_formatter(appropriate_response["result"]),
+                    result_formatter(subscription_params["result"]),
                 ),
             )
-        else:
-            return assoc(
-                response, response_type, method_response_formatter(appropriate_response)
-            )
 
-    if not isinstance(response, dict):
-        raise BadResponseFormat(
-            "Malformed response: expected a valid JSON-RPC response object, got: "
-            "`{}`".format(response)
-        )
-    elif response.get("result") is not None and method in result_formatters:
-        return _format_response("result", result_formatters[method])
-    elif (
-        # eth_subscription responses
-        response.get("params") is not None
-        and response["params"].get("result") is not None
-        and method in result_formatters
-    ):
-        return _format_response("params", result_formatters[method])
-    elif "error" in response and method in error_formatters:
-        return _format_response("error", error_formatters[method])
-    else:
-        return response
+    error_formatter = error_formatters.get(method)
+    if error_formatter is not None and "error" in response:
+        return assoc(response, "error", error_formatter(response["error"]))
+
+    return response
 
 
 SYNC_FORMATTERS_BUILDER = Callable[["Web3", RPCEndpoint], FormattersDict]