Add utils module
The first utility is a class that uses the mapper to wait for a
list of dbus objects to appear on the bus.
The wait utility is non-blocking; a callback must be provided.
Change-Id: I12813b32df90090507c461f03d8c54bb71a7c332
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/obmc/mapper/utils.py b/obmc/mapper/utils.py
new file mode 100644
index 0000000..8ac9e55
--- /dev/null
+++ b/obmc/mapper/utils.py
@@ -0,0 +1,96 @@
+# Contributors Listed Below - COPYRIGHT 2016
+# [+] International Business Machines Corp.
+#
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License.
+
+import sys
+import dbus
+import dbus.mainloop.glib
+import gobject
+import obmc.mapper
+
+
+class Wait(object):
+ def __init__(self, bus, waitlist, *a, **kw):
+ self.bus = bus
+ self.waitlist = dict(zip(waitlist, [None]*len(waitlist)))
+ mapper = bus.get_object(
+ obmc.mapper.MAPPER_NAME,
+ obmc.mapper.MAPPER_PATH,
+ introspect=False)
+ self.mapper_iface = dbus.Interface(
+ mapper, dbus_interface=obmc.mapper.MAPPER_IFACE)
+ self.done = False
+ self.callback = kw.pop('callback', None)
+ self.callback_keyword = kw.pop('keyword', None)
+ self.callback_args = a
+ self.callback_kw = kw
+
+ self.bus.add_signal_receiver(
+ self.name_owner_changed_handler,
+ dbus_interface=dbus.BUS_DAEMON_IFACE,
+ signal_name='NameOwnerChanged')
+ self.bus.add_signal_receiver(
+ self.interfaces_added_handler,
+ dbus_interface=dbus.BUS_DAEMON_IFACE + '.ObjectManager',
+ sender_keyword='sender',
+ signal_name='InterfacesAdded')
+ gobject.idle_add(self.name_owner_changed_handler)
+
+ def check_done(self):
+ if not all(self.waitlist.values()) or self.done:
+ return
+
+ self.done = True
+ self.bus.remove_signal_receiver(
+ self.name_owner_changed_handler,
+ dbus_interface=dbus.BUS_DAEMON_IFACE,
+ signal_name='NameOwnerChanged')
+ self.bus.remove_signal_receiver(
+ self.interfaces_added_handler,
+ dbus_interface=dbus.BUS_DAEMON_IFACE + '.ObjectManager',
+ signal_name='InterfacesAdded')
+ if self.callback:
+ if self.callback_keyword:
+ self.callback_kw[self.callback_keyword] = self.waitlist
+ self.callback(*self.callback_args, **self.callback_kw)
+
+ def get_object_callback(self, path, info):
+ self.waitlist[path] = list(info)[0]
+ self.check_done()
+
+ def name_owner_changed_handler(self, *a, **kw):
+ class Callback(object):
+ def __init__(self, func, *args):
+ self.func = func
+ self.extra_args = args
+
+ def __call__(self, *a):
+ return self.func(*(self.extra_args + a))
+
+ if self.done:
+ return
+
+ for path in self.waitlist.keys():
+ method = getattr(self.mapper_iface, 'GetObject')
+ method.call_async(
+ path,
+ reply_handler=Callback(self.get_object_callback, path))
+
+ def interfaces_added_handler(self, path, *a, **kw):
+ if self.done:
+ return
+ if path in self.waitlist.keys():
+ self.waitlist[path] = kw['sender']
+ self.check_done()