Attachment 112098 Details for Bug 26903 – A patch to add properties support, fourth version

[patch] A patch to add properties support, fourth version

0001-Implement-dbus.service.property-decorator-and-Proper.patch (text/plain), 20.88 KB, created by Marko Kohtala on 2015-01-11 20:43:20 UTC

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Creator: Marko Kohtala

Created: 2015-01-11 20:43:20 UTC

Size: 20.88 KB

patch

obsolete

>From e65b269d101ac5fb687a1c9981596ea3ffd1baa3 Mon Sep 17 00:00:00 2001
>From: Marko Kohtala <marko.kohtala@gmail.com>
>Date: Sun, 11 Jan 2015 22:27:26 +0200
>Subject: [PATCH] Implement dbus.service.property decorator and
> PropertiesInterface
>
>This adds dbus server side support for properties using a decorator.
>The decorator automagically adds PropertiesInterface to the object.
>
>It also simplifies the _dbus_class_table shared by all derived classes
>and containing them to a _dbus_interface_table on each derived class.
>---
> dbus/decorators.py          | 102 ++++++++++++++++++++++++++
> dbus/exceptions.py          |  24 +++++++
> dbus/service.py             | 171 ++++++++++++++++++++++++++++++++++++++------
> examples/example-client.py  |  21 ++++--
> examples/example-service.py |  22 +++++-
> 5 files changed, 309 insertions(+), 31 deletions(-)
>
>diff --git a/dbus/decorators.py b/dbus/decorators.py
>index b164582..e04fd8a 100644
>--- a/dbus/decorators.py
>+++ b/dbus/decorators.py
>@@ -343,3 +343,105 @@ def signal(dbus_interface, signature=None, path_keyword=None,
>         return emit_signal
> 
>     return decorator
>+
>+
>+class property(object):
>+    """A decorator used to mark properties of a `dbus.service.Object`.
>+
>+    :Since: 1.3.0
>+    """
>+
>+    def __init__(self, dbus_interface, signature,
>+                 property_name=None, emits_changed_signal=None,
>+                 fget=None, fset=None, doc=None):
>+        """Initialize the decorator used to mark properties of a
>+        `dbus.service.Object`.
>+
>+        :Parameters:
>+            `dbus_interface` : str
>+                The D-Bus interface owning the property.
>+
>+            `signature` : str
>+                The signature of the property in the usual D-Bus
>+                notation.  It must be a single complete type,
>+                i.e. something that can be be suitable to be placed
>+                in a variant.
>+
>+            `property_name` : str
>+                A name for the property. Defaults to the name of the getter or
>+                setter function.
>+
>+            `emits_changed_signal` : True, False, "invalidates", or None
>+                Tells for introspection if the object emits PropertiesChanged
>+                signal.
>+
>+            `fget` : func or None
>+                Getter function taking the instance from which to read the
>+                property.
>+
>+            `fset` : func or None
>+                Setter function taking the instance to which set the property
>+                and the property value.
>+
>+            `doc` : str
>+                Documentation string for the property. Defaults to documentation
>+                string of getter function.
>+        """
>+        validate_interface_name(dbus_interface)
>+        self._dbus_interface = dbus_interface
>+
>+        # Keep the given name for later assignment of setter
>+        self._init_property_name = property_name
>+        if property_name is None:
>+            if fget is not None:
>+                property_name = fget.__name__
>+            elif fset is not None:
>+                property_name = fset.__name__
>+        if property_name is not None and not isinstance(property_name, str):
>+            if not is_py2 or not isinstance(property_name, unicode):
>+                raise TypeError("Invalid property name: '%s'" % property_name)
>+        self.__name__ = property_name
>+
>+        self._init_doc = doc
>+        if doc is None and fget is not None:
>+            doc = getattr(fget, "__doc__", None)
>+        self.fget = fget
>+        self.fset = fset
>+        self.__doc__ = doc
>+
>+        if emits_changed_signal not in (None, True, False, 'invalidates'):
>+            raise ValueError("emits_changed_signal invalid value: '%s'" %
>+                             emits_changed_signal)
>+        self._emits_changed_signal = emits_changed_signal
>+        if len(tuple(Signature(signature))) != 1:
>+            raise ValueError('signature must have only one item')
>+        self._dbus_signature = signature
>+
>+    def __get__(self, inst, type=None):
>+        if inst is None:
>+            return self
>+        if self.fget is None:
>+            raise AttributeError("unreadable attribute")
>+        return self.fget(inst)
>+
>+    def __set__(self, inst, value):
>+        if self.fset is None:
>+            raise AttributeError("can't set attribute")
>+        self.fset(inst, value)
>+
>+    def __call__(self, fget):
>+        return self.getter(fget)
>+
>+    def _copy(self, fget=None, fset=None):
>+        return property(dbus_interface=self._dbus_interface,
>+                        signature=self._dbus_signature,
>+                        property_name=self._init_property_name,
>+                        emits_changed_signal=self._emits_changed_signal,
>+                        fget=fget or self.fget, fset=fset or self.fset,
>+                        doc=self._init_doc)
>+
>+    def getter(self, fget):
>+        return self._copy(fget=fget)
>+
>+    def setter(self, fset):
>+        return self._copy(fset=fset)
>diff --git a/dbus/exceptions.py b/dbus/exceptions.py
>index 0930425..23d5bb2 100644
>--- a/dbus/exceptions.py
>+++ b/dbus/exceptions.py
>@@ -118,6 +118,14 @@ class IntrospectionParserException(DBusException):
>     def __init__(self, msg=''):
>         DBusException.__init__(self, "Error parsing introspect data: %s"%msg)
> 
>+class UnknownInterfaceException(DBusException):
>+
>+    include_traceback = True
>+    _dbus_error_name = 'org.freedesktop.DBus.Error.UnknownInterface'
>+
>+    def __init__(self, interface):
>+        DBusException.__init__(self, "Unknown interface: %s" % interface)
>+
> class UnknownMethodException(DBusException):
> 
>     include_traceback = True
>@@ -126,6 +134,22 @@ class UnknownMethodException(DBusException):
>     def __init__(self, method):
>         DBusException.__init__(self, "Unknown method: %s"%method)
> 
>+class UnknownPropertyException(DBusException):
>+
>+    include_traceback = True
>+    _dbus_error_name = 'org.freedesktop.DBus.Error.UnknownProperty'
>+
>+    def __init__(self, property):
>+        DBusException.__init__(self, "Unknown property: %s" % property)
>+
>+class PropertyReadOnlyException(DBusException):
>+
>+    include_traceback = True
>+    _dbus_error_name = 'org.freedesktop.DBus.Error.PropertyReadOnly'
>+
>+    def __init__(self, property):
>+        DBusException.__init__(self, "Property is read only: %s" % property)
>+
> class NameExistsException(DBusException):
> 
>     include_traceback = True
>diff --git a/dbus/service.py b/dbus/service.py
>index b1fc21d..4d5fcec 100644
>--- a/dbus/service.py
>+++ b/dbus/service.py
>@@ -23,7 +23,7 @@
> # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> # DEALINGS IN THE SOFTWARE.
> 
>-__all__ = ('BusName', 'Object', 'method', 'signal')
>+__all__ = ('BusName', 'Object', 'PropertiesInterface', 'method', 'property', 'signal')
> __docformat__ = 'restructuredtext'
> 
> import sys
>@@ -34,11 +34,14 @@ from collections import Sequence
> 
> import _dbus_bindings
> from dbus import (
>-    INTROSPECTABLE_IFACE, ObjectPath, SessionBus, Signature, Struct,
>-    validate_bus_name, validate_object_path)
>-from dbus.decorators import method, signal
>+    INTROSPECTABLE_IFACE, ObjectPath, PROPERTIES_IFACE, SessionBus, Signature,
>+    Struct, validate_bus_name, validate_object_path)
>+_builtin_property = property
>+from dbus.decorators import method, signal, property
> from dbus.exceptions import (
>-    DBusException, NameExistsException, UnknownMethodException)
>+    DBusException, NameExistsException, UnknownInterfaceException,
>+    UnknownMethodException, UnknownPropertyException,
>+    PropertyReadOnlyException)
> from dbus.lowlevel import ErrorMessage, MethodReturnMessage, MethodCallMessage
> from dbus.proxies import LOCAL_PATH
> from dbus._compat import is_py2
>@@ -297,20 +300,25 @@ def _method_reply_error(connection, message, exception):
> 
> 
> class InterfaceType(type):
>-    def __init__(cls, name, bases, dct):
>-        # these attributes are shared between all instances of the Interface
>-        # object, so this has to be a dictionary that maps class names to
>-        # the per-class introspection/interface data
>-        class_table = getattr(cls, '_dbus_class_table', {})
>-        cls._dbus_class_table = class_table
>-        interface_table = class_table[cls.__module__ + '.' + name] = {}
>+    def __new__(cls, name, bases, dct):
>+        # Properties require the PropertiesInterface base.
>+        for func in dct.values():
>+            if isinstance(func, property):
>+                for b in bases:
>+                    if issubclass(b, PropertiesInterface):
>+                        break
>+                else:
>+                    bases += (PropertiesInterface,)
>+                break
>+
>+        interface_table = dct.setdefault('_dbus_interface_table', {})
> 
>         # merge all the name -> method tables for all the interfaces
>         # implemented by our base classes into our own
>         for b in bases:
>-            base_name = b.__module__ + '.' + b.__name__
>-            if getattr(b, '_dbus_class_table', False):
>-                for (interface, method_table) in class_table[base_name].items():
>+            base_interface_table = getattr(b, '_dbus_interface_table', False)
>+            if base_interface_table:
>+                for (interface, method_table) in base_interface_table.items():
>                     our_method_table = interface_table.setdefault(interface, {})
>                     our_method_table.update(method_table)
> 
>@@ -320,9 +328,9 @@ class InterfaceType(type):
>                 method_table = interface_table.setdefault(func._dbus_interface, {})
>                 method_table[func.__name__] = func
> 
>-        super(InterfaceType, cls).__init__(name, bases, dct)
>+        return type.__new__(cls, name, bases, dct)
> 
>-    # methods are different to signals, so we have two functions... :)
>+    # methods are different to signals and properties, so we have three functions... :)
>     def _reflect_on_method(cls, func):
>         args = func._dbus_args
> 
>@@ -370,12 +378,110 @@ class InterfaceType(type):
> 
>         return reflection_data
> 
>+    def _reflect_on_property(cls, descriptor):
>+        signature = descriptor._dbus_signature
>+
>+        if descriptor.fget:
>+            if descriptor.fset:
>+                access = "readwrite"
>+            else:
>+                access = "read"
>+        elif descriptor.fset:
>+            access = "write"
>+        else:
>+            return ""
>+        reflection_data = '    <property access="%s" type="%s" name="%s"' % (access, signature, descriptor.__name__)
>+        if descriptor._emits_changed_signal is not None:
>+            value = {True: "true", False: "false", "invalidates": "invalidates"}[descriptor._emits_changed_signal]
>+            reflection_data += '>\n      <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="%s"/>\n    </property>\n' % (value,)
>+        else:
>+            reflection_data += ' />\n'
>+        return reflection_data
>+
> 
> # Define Interface as an instance of the metaclass InterfaceType, in a way
> # that is compatible across both Python 2 and Python 3.
> Interface = InterfaceType('Interface', (object,), {})
> 
> 
>+class PropertiesInterface(Interface):
>+    """An object with properties must inherit from this interface.
>+
>+    This interface is added automatically to the class when the
>+    @\ `dbus.decorators.property` decorator is used.
>+
>+    :Since: 1.3.0
>+    """
>+
>+    def _get_decorator(self, interface_name, property_name):
>+        interfaces = self._dbus_interface_table
>+        if interface_name:
>+            interface = interfaces.get(interface_name)
>+            if interface is None:
>+                raise UnknownInterfaceException(interface_name)
>+            prop = interface.get(property_name)
>+            if prop is None or not isinstance(prop, property):
>+                raise UnknownPropertyException(property_name)
>+            return prop
>+        else:
>+            for interface in interfaces.itervalues():
>+                prop = interface.get(property_name)
>+                if prop and isinstance(prop, property):
>+                    return prop
>+            raise UnknownPropertyException(property_name)
>+
>+    @method(PROPERTIES_IFACE, in_signature="ss", out_signature="v")
>+    def Get(self, interface_name, property_name):
>+        """Get the value of the property on named interface. interface_name
>+        may be empty, but if there are many properties with the same name the
>+        behaviour is undefined.
>+        """
>+        prop = self._get_decorator(interface_name, property_name)
>+        if not prop.fget:
>+            raise DBusException("Property '%s' is not readable" % property_name,
>+                                name="org.freedesktop.DBus.Error.InvalidArgs")
>+        return prop.fget(self)
>+
>+    @method(PROPERTIES_IFACE, in_signature="ssv")
>+    def Set(self, interface_name, property_name, value):
>+        """Set value of property on named interface to value. interface_name
>+        may be empty, but if there are many properties with the same name the
>+        behaviour is undefined.
>+        """
>+        prop = self._get_decorator(interface_name, property_name)
>+        if not prop.fset:
>+            raise PropertyReadOnlyException(property_name)
>+        return prop.fset(self, value)
>+
>+    @method(PROPERTIES_IFACE, in_signature="s", out_signature="a{sv}")
>+    def GetAll(self, interface_name):
>+        """Return a dictionary of all property names and values. Returns only
>+        readable properties.
>+        """
>+        interfaces = self._dbus_interface_table
>+        if interface_name:
>+            iface = interfaces.get(interface_name)
>+            if iface is None:
>+                raise UnknownInterfaceException(interface_name)
>+            ifaces = [iface]
>+        else:
>+            ifaces = interfaces.values()
>+        properties = {}
>+        for iface in ifaces:
>+            for name, prop in iface.items():
>+                if not isinstance(prop, property):
>+                    continue
>+                if not prop.fget or name in properties:
>+                    continue
>+                properties[name] = prop.fget(self)
>+        return properties
>+
>+    @signal(PROPERTIES_IFACE, signature='sa{sv}as')
>+    def PropertiesChanged(self, interface_name, changed_properties,
>+                          invalidated_properties):
>+        pass
>+
>+
> #: A unique object used as the value of Object._object_path and
> #: Object._connection if it's actually in more than one place
> _MANY = object()
>@@ -384,11 +490,12 @@ class Object(Interface):
>     r"""A base class for exporting your own Objects across the Bus.
> 
>     Just inherit from Object and mark exported methods with the
>-    @\ `dbus.service.method` or @\ `dbus.service.signal` decorator.
>+    @\ `dbus.service.method`, @\ `dbus.service.signal` or
>+    @\ `dbus.service.property` decorator.
> 
>     Example::
> 
>-        class Example(dbus.service.object):
>+        class Example(dbus.service.Object):
>             def __init__(self, object_path):
>                 dbus.service.Object.__init__(self, dbus.SessionBus(), path)
>                 self._last_input = None
>@@ -397,6 +504,8 @@ class Object(Interface):
>                                  in_signature='v', out_signature='s')
>             def StringifyVariant(self, var):
>                 self.LastInputChanged(var)      # emits the signal
>+                # Emit the property changed signal
>+                self.PropertiesChanged('com.example.Sample', {'LastInput': var}, [])
>                 return str(var)
> 
>             @dbus.service.signal(interface='com.example.Sample',
>@@ -410,6 +519,20 @@ class Object(Interface):
>                                  in_signature='', out_signature='v')
>             def GetLastInput(self):
>                 return self._last_input
>+
>+            @dbus.service.property(interface='com.example.Sample',
>+                                   signature='s')
>+            def LastInput(self):
>+                return self._last_input
>+
>+            @LastInput.setter
>+            def LastInput(self, value):
>+                self._last_input = value
>+                # By default a property is expected to send the
>+                # PropertiesChanged signal when value changes.
>+                self.PropertiesChanged('com.example.Sample',
>+                                       {'LastInput': var}, [])
>+
>     """
> 
>     #: If True, this object can be made available at more than one object path.
>@@ -484,7 +607,7 @@ class Object(Interface):
>         if conn is not None and object_path is not None:
>             self.add_to_connection(conn, object_path)
> 
>-    @property
>+    @_builtin_property
>     def __dbus_object_path__(self):
>         """The object-path at which this object is available.
>         Access raises AttributeError if there is no object path, or more than
>@@ -500,7 +623,7 @@ class Object(Interface):
>         else:
>             return self._object_path
> 
>-    @property
>+    @_builtin_property
>     def connection(self):
>         """The Connection on which this object is available.
>         Access raises AttributeError if there is no Connection, or more than
>@@ -516,7 +639,7 @@ class Object(Interface):
>         else:
>             return self._connection
> 
>-    @property
>+    @_builtin_property
>     def locations(self):
>         """An iterable over tuples representing locations at which this
>         object is available.
>@@ -762,7 +885,7 @@ class Object(Interface):
>         reflection_data = _dbus_bindings.DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE
>         reflection_data += '<node name="%s">\n' % object_path
> 
>-        interfaces = self._dbus_class_table[self.__class__.__module__ + '.' + self.__class__.__name__]
>+        interfaces = self._dbus_interface_table
>         for (name, funcs) in interfaces.items():
>             reflection_data += '  <interface name="%s">\n' % (name)
> 
>@@ -771,6 +894,8 @@ class Object(Interface):
>                     reflection_data += self.__class__._reflect_on_method(func)
>                 elif getattr(func, '_dbus_is_signal', False):
>                     reflection_data += self.__class__._reflect_on_signal(func)
>+                elif isinstance(func, property):
>+                    reflection_data += self.__class__._reflect_on_property(func)
> 
>             reflection_data += '  </interface>\n'
> 
>diff --git a/examples/example-client.py b/examples/example-client.py
>index 262f892..29281ed 100644
>--- a/examples/example-client.py
>+++ b/examples/example-client.py
>@@ -1,4 +1,5 @@
> #!/usr/bin/env python
>+# -*- coding: utf-8 -*-
> 
> usage = """Usage:
> python example-service.py &
>@@ -46,30 +47,38 @@ def main():
>             dbus_interface = "com.example.SampleInterface")
>     except dbus.DBusException:
>         print_exc()
>-        print usage
>+        print(usage)
>         sys.exit(1)
> 
>-    print (hello_reply_list)
>+    print(hello_reply_list)
> 
>     # ... or create an Interface wrapper for the remote object
>     iface = dbus.Interface(remote_object, "com.example.SampleInterface")
> 
>     hello_reply_tuple = iface.GetTuple()
> 
>-    print hello_reply_tuple
>+    print(hello_reply_tuple)
> 
>     hello_reply_dict = iface.GetDict()
> 
>-    print hello_reply_dict
>+    print(hello_reply_dict)
> 
>     # D-Bus exceptions are mapped to Python exceptions
>     try:
>         iface.RaiseException()
>     except dbus.DBusException as e:
>-        print str(e)
>+        print(str(e))
>+
>+    # D-Bus properties are implemented on server, but client needs to access
>+    # them directly.
>+    properties = dbus.Interface(remote_object, dbus.PROPERTIES_IFACE)
>+    property_value = properties.Get("com.example.SampleInterface", "Property")
>+    print(property_value)
>+
>+    print(properties.Get("com.example.SampleInterface", "PÃ¶Ã¶"))
> 
>     # introspection is automatically supported
>-    print remote_object.Introspect(dbus_interface="org.freedesktop.DBus.Introspectable")
>+    print(remote_object.Introspect(dbus_interface="org.freedesktop.DBus.Introspectable"))
> 
>     if sys.argv[1:] == ['--exit-service']:
>         iface.Exit()
>diff --git a/examples/example-service.py b/examples/example-service.py
>index c42b526..c4ac3f7 100644
>--- a/examples/example-service.py
>+++ b/examples/example-service.py
>@@ -1,4 +1,5 @@
> #!/usr/bin/env python
>+# -*- coding: utf-8 -*-
> 
> usage = """Usage:
> python example-service.py &
>@@ -69,6 +70,23 @@ class SomeObject(dbus.service.Object):
>     def Exit(self):
>         mainloop.quit()
> 
>+    _property_default = "Hello world!"
>+    @dbus.service.property("com.example.SampleInterface",
>+                           signature='s')
>+    def Property(self):
>+        """Sample property"""
>+        return self._property_default
>+
>+    @Property.setter
>+    def Property(self, value):
>+        self._property_default = value
>+
>+    @dbus.service.property("com.example.SampleInterface", 's',
>+                           property_name=u"PÃ¶Ã¶")
>+    def Property_unicode_name(self):
>+        """Sample property"""
>+        return "Unicode property"
>+
> 
> if __name__ == '__main__':
>     dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
>@@ -78,6 +96,6 @@ if __name__ == '__main__':
>     object = SomeObject(session_bus, '/SomeObject')
> 
>     mainloop = gobject.MainLoop()
>-    print "Running example service."
>-    print usage
>+    print("Running example service.")
>+    print(usage)
>     mainloop.run()
>-- 
>1.9.1
>

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