ThrottledDevice: speed up quick reactivation

[~helmut/onoff.git] / onoff / dbusutils.py

diff --git a/onoff/dbusutils.py b/onoff/dbusutils.py
index 5654c95..c248ed5 100644 (file)
--- a/onoff/dbusutils.py
+++ b/onoff/dbusutils.py
@@ -1,6 +1,7 @@
 import argparse
 import logging
 import socket
+import xml.parsers.expat
 
 import dbus
 import dbus.service
@@ -18,21 +19,31 @@ dbus_options.add_argument("--bus", default="session",
 dbus_options.add_argument("--busname", type=str, default=default_busname,
                           help="which busname (i.e. client) to use " +
                                "(default: %(default)s)")
-dbus_options.add_argument("--device", type=str, required=True,
+dbus_options.add_argument("--device", type=str,
                           help="which device to control")
 
-def get_dbus_proxy(namespace):
+def get_dbus(namespace):
     """
     @param namespace: a namespace returned from a dbus_options argument parser
-    @returns: a dbus object proxy
+    @rtype: dbus.Bus
+    @returns: the requested bus
     """
     if namespace.bus == "session":
-        bus = dbus.SessionBus()
+        return dbus.SessionBus()
     elif namespace.bus == "system":
-        bus = dbus.SystemBus()
+        return dbus.SystemBus()
     else:
         raise AssertionError("namespace.bus %r is neither session nor system",
                              namespace.bus)
+
+def get_dbus_proxy(namespace):
+    """
+    @param namespace: a namespace returned from a dbus_options argument parser
+    @returns: a dbus object proxy
+    """
+    bus = get_dbus(namespace)
+    if not namespace.device:
+        raise ValueError("no --device given")
     objname = "%s/%s" % (object_prefix, namespace.device)
     return bus.get_object(namespace.busname, objname)
 
@@ -47,6 +58,35 @@ def socketpair():
     s2.close()
     return s1, s3
 
+def list_objects(bus, busname, path=None):
+    """List objects on the given bus and busname starting with path. Only the
+    trailing components after the slash are returned.
+
+    @type bus: dbus.Bus
+    @type busname: str
+    @type path: None or str
+    @param path: prefix for searching objects. Defaults to
+        dbusutils.object_prefix.
+    @rtype: [str]
+    @returns: the trailing components of the objects found
+    """
+    if path is None:
+        path = object_prefix
+    xmlstring = bus.get_object(busname, path).Introspect()
+    parser = xml.parsers.expat.ParserCreate()
+    nodes = []
+    def start_element(name, attrs):
+        if name != "node":
+            return
+        try:
+            value = attrs["name"]
+        except KeyError:
+            return
+        nodes.append(value)
+    parser.StartElementHandler = start_element
+    parser.Parse(xmlstring)
+    return nodes
+
 class OnoffControl(dbus.service.Object):
     domain = default_busname
     path = object_prefix