| From 69968dec867053e38de0b91d76ac41d5a5735e36 Mon Sep 17 00:00:00 2001 |
| From: Vendula Poncova <vponcova@redhat.com> |
| Date: Thu, 2 Aug 2018 15:31:56 +0800 |
| Subject: [PATCH 2/2] Support transformation between D-Bus errors and |
| exceptions. |
| |
| Exceptions can be registered with decorators, raised in a remote |
| method and recreated after return from the remote call. |
| |
| Upstream-Status: Backport [https://src.fedoraproject.org/cgit/rpms/python-pydbus.git/] |
| |
| Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> |
| --- |
| pydbus/error.py | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++ |
| pydbus/proxy_method.py | 18 ++++++++-- |
| pydbus/registration.py | 16 ++++++--- |
| 3 files changed, 123 insertions(+), 8 deletions(-) |
| create mode 100644 pydbus/error.py |
| |
| diff --git a/pydbus/error.py b/pydbus/error.py |
| new file mode 100644 |
| index 0000000..aaa3510 |
| --- /dev/null |
| +++ b/pydbus/error.py |
| @@ -0,0 +1,97 @@ |
| +from gi.repository import GLib, Gio |
| + |
| + |
| +def register_error(name, domain, code): |
| + """Register and map decorated exception class to a DBus error.""" |
| + def decorated(cls): |
| + error_registration.register_error(cls, name, domain, code) |
| + return cls |
| + |
| + return decorated |
| + |
| + |
| +def map_error(error_name): |
| + """Map decorated exception class to a DBus error.""" |
| + def decorated(cls): |
| + error_registration.map_error(cls, error_name) |
| + return cls |
| + |
| + return decorated |
| + |
| + |
| +def map_by_default(cls): |
| + """Map decorated exception class to all unknown DBus errors.""" |
| + error_registration.map_by_default(cls) |
| + return cls |
| + |
| + |
| +class ErrorRegistration(object): |
| + """Class for mapping exceptions to DBus errors.""" |
| + |
| + _default = None |
| + _map = dict() |
| + _reversed_map = dict() |
| + |
| + def map_by_default(self, exception_cls): |
| + """Set the exception class as a default.""" |
| + self._default = exception_cls |
| + |
| + def map_error(self, exception_cls, name): |
| + """Map the exception class to a DBus name.""" |
| + self._map[name] = exception_cls |
| + self._reversed_map[exception_cls] = name |
| + |
| + def register_error(self, exception_cls, name, domain, code): |
| + """Map and register the exception class to a DBus name.""" |
| + self.map_error(exception_cls, name) |
| + return Gio.DBusError.register_error(domain, code, name) |
| + |
| + def is_registered_exception(self, obj): |
| + """Is the exception registered?""" |
| + return obj.__class__ in self._reversed_map |
| + |
| + def get_dbus_name(self, obj): |
| + """Get the DBus name of the exception.""" |
| + return self._reversed_map.get(obj.__class__) |
| + |
| + def get_exception_class(self, name): |
| + """Get the exception class mapped to the DBus name.""" |
| + return self._map.get(name, self._default) |
| + |
| + def transform_message(self, name, message): |
| + """Transform the message of the exception.""" |
| + prefix = "{}:{}: ".format("GDBus.Error", name) |
| + |
| + if message.startswith(prefix): |
| + return message[len(prefix):] |
| + |
| + return message |
| + |
| + def transform_exception(self, e): |
| + """Transform the remote error to the exception.""" |
| + if not isinstance(e, GLib.Error): |
| + return e |
| + |
| + if not Gio.DBusError.is_remote_error(e): |
| + return e |
| + |
| + # Get DBus name of the error. |
| + name = Gio.DBusError.get_remote_error(e) |
| + # Get the exception class. |
| + exception_cls = self.get_exception_class(name) |
| + |
| + # Return the original exception. |
| + if not exception_cls: |
| + return e |
| + |
| + # Return new exception. |
| + message = self.transform_message(name, e.message) |
| + exception = exception_cls(message) |
| + exception.dbus_name = name |
| + exception.dbus_domain = e.domain |
| + exception.dbus_code = e.code |
| + return exception |
| + |
| + |
| +# Default error registration. |
| +error_registration = ErrorRegistration() |
| diff --git a/pydbus/proxy_method.py b/pydbus/proxy_method.py |
| index 4ea4304..e9496f5 100644 |
| --- a/pydbus/proxy_method.py |
| +++ b/pydbus/proxy_method.py |
| @@ -2,6 +2,7 @@ from gi.repository import GLib |
| from .generic import bound_method |
| from .identifier import filter_identifier |
| from .timeout import timeout_to_glib |
| +from .error import error_registration |
| |
| try: |
| from inspect import Signature, Parameter |
| @@ -87,9 +88,20 @@ class ProxyMethod(object): |
| call_args += (self._finish_async_call, (callback, callback_args)) |
| instance._bus.con.call(*call_args) |
| return None |
| + |
| else: |
| - ret = instance._bus.con.call_sync(*call_args) |
| - return self._unpack_return(ret) |
| + result = None |
| + error = None |
| + |
| + try: |
| + result = instance._bus.con.call_sync(*call_args) |
| + except Exception as e: |
| + error = error_registration.transform_exception(e) |
| + |
| + if error: |
| + raise error |
| + |
| + return self._unpack_return(result) |
| |
| def _unpack_return(self, values): |
| ret = values.unpack() |
| @@ -108,7 +120,7 @@ class ProxyMethod(object): |
| ret = source.call_finish(result) |
| return_args = self._unpack_return(ret) |
| except Exception as err: |
| - error = err |
| + error = error_registration.transform_exception(err) |
| |
| callback, callback_args = user_data |
| callback(*callback_args, returned=return_args, error=error) |
| diff --git a/pydbus/registration.py b/pydbus/registration.py |
| index f531539..1d2cbcb 100644 |
| --- a/pydbus/registration.py |
| +++ b/pydbus/registration.py |
| @@ -5,6 +5,7 @@ from . import generic |
| from .exitable import ExitableWithAliases |
| from functools import partial |
| from .method_call_context import MethodCallContext |
| +from .error import error_registration |
| import logging |
| |
| try: |
| @@ -91,11 +92,16 @@ class ObjectWrapper(ExitableWithAliases("unwrap")): |
| logger = logging.getLogger(__name__) |
| logger.exception("Exception while handling %s.%s()", interface_name, method_name) |
| |
| - #TODO Think of a better way to translate Python exception types to DBus error types. |
| - e_type = type(e).__name__ |
| - if not "." in e_type: |
| - e_type = "unknown." + e_type |
| - invocation.return_dbus_error(e_type, str(e)) |
| + if error_registration.is_registered_exception(e): |
| + name = error_registration.get_dbus_name(e) |
| + invocation.return_dbus_error(name, str(e)) |
| + else: |
| + logger.info("name is not registered") |
| + e_type = type(e).__name__ |
| + if not "." in e_type: |
| + e_type = "unknown." + e_type |
| + |
| + invocation.return_dbus_error(e_type, str(e)) |
| |
| def Get(self, interface_name, property_name): |
| type = self.readable_properties[interface_name + "." + property_name] |
| -- |
| 2.7.4 |
| |