feat: speed up run time constructed method handlers (#275)

src/dbus_fast/message_bus.pxd

@@ -57,3 +57,11 @@ cdef class BaseMessageBus:
     cpdef _call(self, Message msg, object callback)
 
     cpdef next_serial(self)
+
+    cpdef void _callback_method_handler(
+        self,
+        ServiceInterface interface,
+        _Method method,
+        Message msg,
+        object send_reply
+    )

src/dbus_fast/message_bus.py

@@ -865,67 +865,64 @@ class BaseMessageBus:
                 return_handler(msg, None)
             del self._method_return_handlers[msg.reply_serial]
 
+    def _callback_method_handler(
+        self,
+        interface: ServiceInterface,
+        method: _Method,
+        msg: Message,
+        send_reply: Callable[[Message], None],
+    ) -> None:
+        """This is the callback that will be called when a method call is."""
+        args = ServiceInterface._c_msg_body_to_args(msg) if msg.unix_fds else msg.body
+        result = method.fn(interface, *args)
+        if send_reply is BLOCK_UNEXPECTED_REPLY or _expects_reply(msg) is False:
+            return
+        body, fds = ServiceInterface._c_fn_result_to_body(
+            result,
+            signature_tree=method.out_signature_tree,
+            replace_fds=self._negotiate_unix_fd,
+        )
+        send_reply(
+            Message(
+                message_type=MessageType.METHOD_RETURN,
+                reply_serial=msg.serial,
+                destination=msg.sender,
+                signature=method.out_signature,
+                body=body,
+                unix_fds=fds,
+            )
+        )
+
     def _make_method_handler(
         self, interface: ServiceInterface, method: _Method
     ) -> Callable[[Message, Callable[[Message], None]], None]:
-        method_fn = method.fn
+        return partial(self._callback_method_handler, interface, method)
-        out_signature_tree = method.out_signature_tree
-        negotiate_unix_fd = self._negotiate_unix_fd
-        out_signature = method.out_signature
-        message_type_method_return = MessageType.METHOD_RETURN
-        msg_body_to_args = ServiceInterface._msg_body_to_args
-        fn_result_to_body = ServiceInterface._fn_result_to_body
-
-        def _callback_method_handler(
-            msg: Message, send_reply: Callable[[Message], None]
-        ) -> None:
-            """This is the callback that will be called when a method call is."""
-            args = msg_body_to_args(msg) if msg.unix_fds else msg.body
-            result = method_fn(interface, *args)
-            if send_reply is BLOCK_UNEXPECTED_REPLY or _expects_reply(msg) is False:
-                return
-            body, fds = fn_result_to_body(
-                result,
-                signature_tree=out_signature_tree,
-                replace_fds=negotiate_unix_fd,
-            )
-            send_reply(
-                Message(
-                    message_type=message_type_method_return,
-                    reply_serial=msg.serial,
-                    destination=msg.sender,
-                    signature=out_signature,
-                    body=body,
-                    unix_fds=fds,
-                )
-            )
-
-        return _callback_method_handler
 
     def _find_message_handler(
         self, msg: _Message
     ) -> Optional[Callable[[Message, Callable[[Message], None]], None]]:
-        if (
+        if msg.interface.startswith("org.freedesktop.DBus."):
-            msg.interface == "org.freedesktop.DBus.Introspectable"
+            if (
-            and msg.member == "Introspect"
+                msg.interface == "org.freedesktop.DBus.Introspectable"
-            and msg.signature == ""
+                and msg.member == "Introspect"
-        ):
+                and msg.signature == ""
-            return self._default_introspect_handler
+            ):
+                return self._default_introspect_handler
 
-        if msg.interface == "org.freedesktop.DBus.Properties":
+            if msg.interface == "org.freedesktop.DBus.Properties":
-            return self._default_properties_handler
+                return self._default_properties_handler
 
-        if msg.interface == "org.freedesktop.DBus.Peer":
+            if msg.interface == "org.freedesktop.DBus.Peer":
-            if msg.member == "Ping" and msg.signature == "":
+                if msg.member == "Ping" and msg.signature == "":
-                return self._default_ping_handler
+                    return self._default_ping_handler
-            elif msg.member == "GetMachineId" and msg.signature == "":
+                elif msg.member == "GetMachineId" and msg.signature == "":
-                return self._default_get_machine_id_handler
+                    return self._default_get_machine_id_handler
 
-        if (
+            if (
-            msg.interface == "org.freedesktop.DBus.ObjectManager"
+                msg.interface == "org.freedesktop.DBus.ObjectManager"
-            and msg.member == "GetManagedObjects"
+                and msg.member == "GetManagedObjects"
-        ):
+            ):
-            return self._default_get_managed_objects_handler
+                return self._default_get_managed_objects_handler
 
         msg_path = msg.path
         if msg_path:

src/dbus_fast/service.pxd

@@ -2,6 +2,7 @@
 
 import cython
 
+from .message cimport Message
 from .signature cimport SignatureTree
 
 
@@ -16,6 +17,14 @@ cdef class _Method:
     cdef public SignatureTree in_signature_tree
     cdef public SignatureTree out_signature_tree
 
+
+
+cdef tuple _real_fn_result_to_body(
+    object result,
+    SignatureTree signature_tree,
+    bint replace_fds
+)
+
 cdef class ServiceInterface:
 
     cdef public str name
@@ -30,3 +39,13 @@ cdef class ServiceInterface:
 
     @staticmethod
     cdef object _c_get_handler(ServiceInterface interface, _Method method, object bus)
+
+    @staticmethod
+    cdef list _c_msg_body_to_args(Message msg)
+
+    @staticmethod
+    cdef tuple _c_fn_result_to_body(
+        object result,
+        SignatureTree signature_tree,
+        bint replace_fds,
+    )

src/dbus_fast/service.py

@@ -326,6 +326,35 @@ def dbus_property(
     return decorator
 
 
+def _real_fn_result_to_body(
+    result: Optional[Any],
+    signature_tree: SignatureTree,
+    replace_fds: bool,
+) -> Tuple[List[Any], List[int]]:
+    out_len = len(signature_tree.types)
+    if result is None:
+        final_result = []
+    else:
+        if out_len == 1:
+            final_result = [result]
+        else:
+            result_type = type(result)
+            if result_type is not list and result_type is not tuple:
+                raise SignatureBodyMismatchError(
+                    "Expected signal to return a list or tuple of arguments"
+                )
+            final_result = result
+
+    if out_len != len(final_result):
+        raise SignatureBodyMismatchError(
+            f"Signature and function return mismatch, expected {len(signature_tree.types)} arguments but got {len(result)}"
+        )
+
+    if not replace_fds:
+        return final_result, []
+    return replace_fds_with_idx(signature_tree, final_result)
+
+
 class ServiceInterface:
     """An abstract class that can be extended by the user to define DBus services.
 
@@ -505,6 +534,11 @@ class ServiceInterface:
 
     @staticmethod
     def _msg_body_to_args(msg: Message) -> List[Any]:
+        return ServiceInterface._c_msg_body_to_args(msg)
+
+    @staticmethod
+    def _c_msg_body_to_args(msg: Message) -> List[Any]:
+        # https://github.com/cython/cython/issues/3327
         if not signature_contains_type(msg.signature_tree, msg.body, "h"):
             return msg.body
 
@@ -520,31 +554,20 @@ class ServiceInterface:
         result: Optional[Any],
         signature_tree: SignatureTree,
         replace_fds: bool = True,
+    ) -> Tuple[List[Any], List[int]]:
+        return _real_fn_result_to_body(result, signature_tree, replace_fds)
+
+    @staticmethod
+    def _c_fn_result_to_body(
+        result: Optional[Any],
+        signature_tree: SignatureTree,
+        replace_fds: bool,
     ) -> Tuple[List[Any], List[int]]:
         """The high level interfaces may return single values which may be
         wrapped in a list to be a message body. Also they may return fds
         directly for type 'h' which need to be put into an external list."""
-        out_len = len(signature_tree.types)
+        # https://github.com/cython/cython/issues/3327
-        if result is None:
+        return _real_fn_result_to_body(result, signature_tree, replace_fds)
-            result = []
-        else:
-            if out_len == 1:
-                result = [result]
-            else:
-                result_type = type(result)
-                if result_type is not list and result_type is not tuple:
-                    raise SignatureBodyMismatchError(
-                        "Expected signal to return a list or tuple of arguments"
-                    )
-
-        if out_len != len(result):
-            raise SignatureBodyMismatchError(
-                f"Signature and function return mismatch, expected {len(signature_tree.types)} arguments but got {len(result)}"
-            )
-
-        if not replace_fds:
-            return result, []
-        return replace_fds_with_idx(signature_tree, result)
 
     @staticmethod
     def _handle_signal(