Refcount tracked service types; ensure only the process that registers a service can change it; add support for updated service properties/published values

shell/Owner.py

@@ -1,9 +1,11 @@
 import os
 import random
 import base64
+import time
 
 import conf
 from sugar import env
+import logging
 from sugar.p2p import Stream
 from sugar.presence import PresenceService
 from Friends import Friends
@@ -15,7 +17,7 @@ class ShellOwner(object):
 	"""Class representing the owner of this machine/instance.  This class
 	runs in the shell and serves up the buddy icon and other stuff.  It's the
 	server portion of the Owner, paired with the client portion in Buddy.py."""
-	def __init__(self):
+	def __init__(self, shell):
 		profile = conf.get_profile()
 
 		self._nick = profile.get_nick_name()
@@ -34,6 +36,12 @@ class ShellOwner(object):
 		self._friends = Friends()
 		self._invites = Invites()
 
+		self._shell = shell
+		self._shell.connect('activity-changed', self.__activity_changed_cb)
+		self._last_activity_update = time.time()
+		self._pending_activity_update_timer = None
+		self._pending_activity_update = None
+
 	def get_friends(self):
 		return self._friends
 
@@ -43,10 +51,14 @@ class ShellOwner(object):
 	def announce(self):
 		# Create and announce our presence
 		color = conf.get_profile().get_color()
-		props = { 'color':  color.to_string() }
+		props = {'color':color.to_string()}
+		activity = self._shell.get_current_activity()
+		if activity is not None:
+			props['cur_activity':activity.get_id()]
+			self._last_activity_update = time.time()
 		self._service = self._pservice.register_service(self._nick,
 				PRESENCE_SERVICE_TYPE, properties=props)
-		print "Owner '%s' using port %d" % (self._nick, self._service.get_port())
+		logging.debug("Owner '%s' using port %d" % (self._nick, self._service.get_port()))
 		self._icon_stream = Stream.Stream.new_from_service(self._service)
 		self._icon_stream.register_reader_handler(self._handle_buddy_icon_request, "get_buddy_icon")
 		self._icon_stream.register_reader_handler(self._handle_invite, "invite")
@@ -61,3 +73,31 @@ class ShellOwner(object):
 		"""XMLRPC method, called when the owner is invited to an activity."""
 		self._invites.add_invite(issuer, bundle_id, activity_id)
 		return ''
+
+	def __update_advertised_current_activity_cb(self):
+		self._last_activity_update = time.time()
+		self._pending_activity_update_timer = None
+		logging.debug("*** Updating current activity to %s" % self._pending_activity_update)
+		return False
+
+	def __activity_changed_cb(self, shell, activity):
+		"""Update our presence service with the latest activity, but no
+		more frequently than every 30 seconds"""
+		self._pending_activity_update = activity.get_id()
+		# If there's no pending update, we must not have updated it in the
+		# last 30 seconds (except for the initial update, hence we also check
+		# for the last update)
+		if not self._pending_activity_update_timer or time.time() - self._last_activity_update > 30:
+			self.__update_advertised_current_activity_cb()
+			return
+
+		# If we have a pending update already, we have nothing left to do
+		if self._pending_activity_update_timer:
+			return
+
+		# Otherwise, we start a timer to update the activity at the next
+		# interval, which should be 30 seconds from the last update, or if that
+		# is in the past already, then now
+		next = 30 - max(30, time.time() - self._last_activity_update)
+		self._pending_activity_update_timer = gobject.timeout_add(next * 1000,
+				self.__update_advertised_current_activity_cb)

shell/PresenceService/PresenceService.py

@@ -56,6 +56,38 @@ class ServiceAdv(object):
 				raise ValueError("Can't reset to resolve pending from resolved.")
 		self._state = state
 
+class RegisteredServiceType(object):
+	def __init__(self, stype):
+		self._stype = stype
+		self._refcount = 1
+
+	def get_type(self):
+		return self._stype
+
+	def ref(self):
+		self._refcount += 1
+
+	def unref(self):
+		self._refcount -= 1
+		return self._refcount
+
+def _txt_to_dict(txt):
+	"""Convert an avahi-returned TXT record formatted
+	as nested arrays of integers (from dbus) into a dict
+	of key/value string pairs."""
+	prop_dict = {}
+	props = avahi.txt_array_to_string_array(txt)
+	for item in props:
+		key = value = None
+		if '=' not in item:
+			# No = means a boolean value of true
+			key = item
+			value = True
+		else:
+			(key, value) = item.split('=')
+		prop_dict[key] = value
+	return prop_dict
+
 
 _PRESENCE_SERVICE = "org.laptop.Presence"
 _PRESENCE_DBUS_INTERFACE = "org.laptop.Presence"
@@ -169,8 +201,9 @@ class PresenceServiceDBusHelper(dbus.service.Object):
 		return owner.object_path()
 
 	@dbus.service.method(_PRESENCE_DBUS_INTERFACE,
-						in_signature="os", out_signature="o")
-	def joinActivity(self, activity_op, stype):
+						in_signature="os", out_signature="o",
+						sender_keyword="sender")
+	def joinActivity(self, activity_op, stype, sender):
 		found_activity = None
 		acts = self._parent.get_activities()
 		for act in acts:
@@ -179,29 +212,34 @@ class PresenceServiceDBusHelper(dbus.service.Object):
 				break
 		if not found_activity:
 			raise NotFoundError("The activity %s was not found." % activity_op)
-		return self._parent.join_activity(found_activity, stype)
+		return self._parent.join_activity(found_activity, stype, sender)
 
 	@dbus.service.method(_PRESENCE_DBUS_INTERFACE,
-						in_signature="ssa{ss}sis", out_signature="o")
-	def shareActivity(self, activity_id, stype, properties, address, port, domain):
+						in_signature="ssa{ss}sis", out_signature="o",
+						sender_keyword="sender")
+	def shareActivity(self, activity_id, stype, properties, address, port,
+			domain, sender=None):
 		if not len(address):
 			address = None
 		service = self._parent.share_activity(activity_id, stype, properties, address,
-				port, domain)
+				port, domain, sender)
 		return service.object_path()
 
 	@dbus.service.method(_PRESENCE_DBUS_INTERFACE,
-						in_signature="ssa{ss}sis", out_signature="o")
-	def registerService(self, name, stype, properties, address, port, domain):
+						in_signature="ssa{ss}sis", out_signature="o",
+						sender_keyword="sender")
+	def registerService(self, name, stype, properties, address, port, domain,
+			sender=None):
 		if not len(address):
 			address = None
 		service = self._parent.register_service(name, stype, properties, address,
-				port, domain)
+				port, domain, sender)
 		return service.object_path()
 
 	@dbus.service.method(_PRESENCE_DBUS_INTERFACE,
-						in_signature="o", out_signature="")
-	def unregisterService(self, service_op):
+						in_signature="o", out_signature="",
+						sender_keyword="sender")
+	def unregisterService(self, service_op, sender):
 		found_serv = None
 		services = self._parent.get_services()
 		for serv in services:
@@ -210,7 +248,7 @@ class PresenceServiceDBusHelper(dbus.service.Object):
 				break
 		if not found_serv:
 			raise NotFoundError("The activity %s was not found." % service_op)
-		return self._parent.unregister_service(found_serv)
+		return self._parent.unregister_service(found_serv, sender)
 
 	@dbus.service.method(_PRESENCE_DBUS_INTERFACE,
 						in_signature="s", out_signature="")
@@ -424,9 +462,10 @@ class PresenceService(object):
 		key = (full_name, stype)
 		if not self._services.has_key(key):
 			objid = self._get_next_object_id()
+			props = _txt_to_dict(txt)
 			service = Service.Service(self._bus_name, objid, name=full_name,
 					stype=stype, domain=domain, address=address, port=port,
-					properties=txt, source_address=address, local=adv.is_local())
+					properties=props, source_address=address, local=adv.is_local())
 			self._services[key] = service
 		else:
 			# Already tracking this service; likely we were the one that shared it
@@ -588,19 +627,22 @@ class PresenceService(object):
 	def _new_domain_cb_glue(self, interface, protocol, domain, flags=0):
 		gobject.idle_add(self._new_domain_cb, interface, protocol, domain, flags)
 
-	def join_activity(self, activity, stype):
+	def join_activity(self, activity, stype, sender):
 		services = activity.get_services_of_type(stype)
 		if not len(services):
-			raise NotFoundError("The service type %s was not present within the activity %s" % (stype, activity.object_path()))
+			raise NotFoundError("The service type %s was not present within " \
+					"the activity %s" % (stype, activity.object_path()))
 		act_service = services[0]
 		props = act_service.get_properties()
 		color = activity.get_color()
 		if color:
 			props['color'] = color
 		return self._share_activity(activity.get_id(), stype, properties,
-				act_service.get_address(), act_service.get_port(), act_service.get_domain())
+				act_service.get_address(), act_service.get_port(),
+				act_service.get_domain(), sender)
 
-	def share_activity(self, activity_id, stype, properties=None, address=None, port=-1, domain=u"local"):
+	def share_activity(self, activity_id, stype, properties=None, address=None,
+			port=-1, domain=u"local", sender=None):
 		"""Convenience function to share an activity with other buddies."""
 		if not util.validate_activity_id(activity_id):
 			raise ValueError("invalid activity id")
@@ -621,14 +663,19 @@ class PresenceService(object):
 		if color:
 			properties['color'] = color
 
-		logging.debug('Share activity %s, type %s, address %s, port %d, properties %s' % (activity_id, stype, address, port, properties))
-		return self.register_service(real_name, stype, properties, address, port, domain)
+		logging.debug('Share activity %s, type %s, address %s, port %d, " \
+				"properties %s' % (activity_id, stype, address, port,
+				properties))
+		return self.register_service(real_name, stype, properties, address,
+				port, domain, sender)
 
-	def register_service(self, name, stype, properties={}, address=None, port=-1, domain=u"local"):
+	def register_service(self, name, stype, properties={}, address=None,
+			port=-1, domain=u"local", sender=None):
 		"""Register a new service, advertising it to other Buddies on the network."""
 		(actid, person_name) = Service.decompose_service_name(name)
 		if self.get_owner() and person_name != self.get_owner().get_name():
-			raise RuntimeError("Tried to register a service that didn't have Owner nick as the service name!")
+			raise RuntimeError("Tried to register a service that didn't have" \
+					" Owner nick as the service name!")
 		if not domain or not len(domain):
 			domain = u"local"
 		if not port or port == -1:
@@ -647,12 +694,14 @@ class PresenceService(object):
 			objid = self._get_next_object_id()
 			service = Service.Service(self._bus_name, objid, name=name,
 					stype=stype, domain=domain, address=address, port=port,
-					properties=properties, source_address=None, local=True)
+					properties=properties, source_address=None, local=True,
+					local_publisher=sender)
 			self._services[(name, stype)] = service
 			port = service.get_port()
 
 			logging.debug("PS: Will register service with name='%s', stype='%s'," \
-					" domain='%s', address='%s', port=%d, info='%s'" % (name, stype, domain, address, port, info))
+					" domain='%s', address='%s', port=%d, info='%s'" % (name, stype,
+					domain, address, port, info))
 			group.AddService(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, 0, dbus.String(name),
 					dbus.String(stype), dbus.String(domain), dbus.String(""), # let Avahi figure the 'host' out
 					dbus.UInt16(port), info)
@@ -667,7 +716,10 @@ class PresenceService(object):
 		self.register_service_type(stype)
 		return service
 
-	def unregister_service(self, service):
+	def unregister_service(self, service, sender=None):
+		local_publisher = service.get_local_publisher()
+		if sender is not None and local_publisher != sender:
+			raise ValueError("Service was not not registered by requesting process!")
 		group = service.get_avahi_entry_group()
 		if not group:
 			raise ValueError("Service was not a local service provided by this laptop!")
@@ -678,9 +730,16 @@ class PresenceService(object):
 		a certain mDNS service types."""
 		if type(stype) != type(u""):
 			raise ValueError("service type must be a unicode string.")
-		if stype in self._registered_service_types:
-			return
-		self._registered_service_types.append(stype)
+
+		# If we've already registered it as a service type, ref it and return
+		for item in self._registered_service_types:
+			if item.get_type() == stype:
+				item.ref()
+				return
+
+		# Otherwise track this type now
+		obj = RegisteredServiceType(stype)
+		self._registered_service_types.append(obj)
 
 		# Find unresolved services that match the service type
 		# we're now interested in, and resolve them
@@ -698,8 +757,15 @@ class PresenceService(object):
 		"""Stop tracking a certain mDNS service."""
 		if type(stype) != type(u""):
 			raise ValueError("service type must be a unicode string.")
-		if stype in self._registered_service_types:
-			self._registered_service_types.remove(stype)
+		item = None
+		for item in self._registered_service_types:
+			if item.get_type() == stype:
+				break
+		# if it was found, unref it and possibly remove it
+		if item is not None:
+			if item.unref() <= 0:
+				self._registered_service_types.remove(item)
+				del item
 
 
 def main():

shell/PresenceService/Service.py

@@ -5,23 +5,6 @@ from sugar import util
 import dbus, dbus.service
 import random
 
-def _txt_to_dict(txt):
-	"""Convert an avahi-returned TXT record formatted
-	as nested arrays of integers (from dbus) into a dict
-	of key/value string pairs."""
-	prop_dict = {}
-	props = avahi.txt_array_to_string_array(txt)
-	for item in props:
-		key = value = None
-		if '=' not in item:
-			# No = means a boolean value of true
-			key = item
-			value = True
-		else:
-			(key, value) = item.split('=')
-		prop_dict[key] = value
-	return prop_dict
-
 def compose_service_name(name, activity_id):
 	if type(name) == type(""):
 		name = unicode(name)
@@ -67,6 +50,11 @@ class ServiceDBusHelper(dbus.service.Object):
 		self._object_path = object_path
 		dbus.service.Object.__init__(self, bus_name, self._object_path)
 
+	@dbus.service.signal(SERVICE_DBUS_INTERFACE,
+						signature="as")
+	def PublishedValueChanged(self, keylist):
+		pass
+
 	@dbus.service.method(SERVICE_DBUS_INTERFACE,
 						in_signature="", out_signature="a{sv}")
 	def getProperties(self):
@@ -90,14 +78,33 @@ class ServiceDBusHelper(dbus.service.Object):
 		return pary
 
 	@dbus.service.method(SERVICE_DBUS_INTERFACE,
-						in_signature="s", out_signature="s")
+						in_signature="s")
 	def getPublishedValue(self, key):
 		"""Return the value belonging to the requested key from the
 		service's TXT records."""
-		value = self._parent.get_one_property(key)
-		if type(value) == type(True):
-			value = str(value)
-		return value
+		val = self._parent.get_one_property(key)
+		if not val:
+			raise KeyError("Value was not found.")
+		return val
+
+	@dbus.service.method(SERVICE_DBUS_INTERFACE,
+						in_signature="", out_signature="a{sv}")
+	def getPublishedValues(self):
+		pary = {}
+		props = self._parent.get_properties()
+		for key, value in props.items():
+			pary[key] = str(value)
+		return dbus.Dictionary(pary)
+
+	@dbus.service.method(SERVICE_DBUS_INTERFACE,
+						sender_keyword="sender")
+	def setPublishedValue(self, key, value, sender):
+		self._parent.set_property(key, value, sender)
+
+	@dbus.service.method(SERVICE_DBUS_INTERFACE,
+						in_signature="a{sv}", sender_keyword="sender")
+	def setPublishedValues(self, values, sender):
+		self._parent.set_properties(values, sender)
 
 
 class Service(object):
@@ -105,7 +112,7 @@ class Service(object):
 	service as advertised on the network."""
 	def __init__(self, bus_name, object_id, name, stype, domain=u"local",
 				address=None, port=-1, properties=None, source_address=None,
-				local=False):
+				local=False, local_publisher=None):
 		if not bus_name:
 			raise ValueError("DBus bus name must be valid")
 		if not object_id or type(object_id) != type(1):
@@ -137,7 +144,7 @@ class Service(object):
 		self._port = -1
 		self.set_port(port)
 		self._properties = {}
-		self.set_properties(properties)
+		self._internal_set_properties(properties, first_time=True)
 		self._avahi_entry_group = None
 		self._local = local
 
@@ -159,13 +166,19 @@ class Service(object):
 		if self._properties.has_key(_ACTIVITY_ID_TAG):
 			prop_actid = self._properties[_ACTIVITY_ID_TAG]
 			if (prop_actid and not actid) or (prop_actid != actid):
-				raise ValueError("ActivityID property specified, but the service names's activity ID didn't match it: %s, %s" % (prop_actid, actid))
+				raise ValueError("ActivityID property specified, but the " \
+						"service names's activity ID didn't match it: %s," \
+						" %s" % (prop_actid, actid))
 		self._activity_id = actid
 		if actid and not self._properties.has_key(_ACTIVITY_ID_TAG):
 			self._properties[_ACTIVITY_ID_TAG] = actid
 
 		self._owner = None
 
+		# ID of the D-Bus connection that published this service, if any.
+		# We only let the local publisher modify the service.
+		self._local_publisher = local_publisher
+
 		# register ourselves with dbus
 		self._object_id = object_id
 		self._object_path = SERVICE_DBUS_OBJECT_PATH + str(self._object_id)
@@ -182,6 +195,9 @@ class Service(object):
 			raise RuntimeError("Can only set a service's owner once")
 		self._owner = owner
 
+	def get_local_publisher(self):
+		return self._local_publisher
+
 	def is_local(self):
 		return self._local
 
@@ -207,19 +223,55 @@ class Service(object):
 		properties."""
 		return self._properties
 
-	def set_properties(self, properties):
+	def set_property(self, key, value, sender=None):
+		"""Set one service property"""
+		if sender is not None and self._local_publisher != sender:
+			raise ValueError("Service was not not registered by requesting process!")
+
+		if type(key) != type(u""):
+			raise ValueError("Key must be a unicode string.")
+		if type(value) != type(u"") or type(value) != type(True):
+			raise ValueError("Key must be a unicode string or a boolean.")
+
+		# Ignore setting the key to it's current value
+		if self._properties.has_key(key):
+			if self._properties[key] == value:
+				return
+
+		# Blank value means remove key
+		remove = False
+		if type(value) == type(u"") and len(value) == 0:
+			remove = True
+		if type(value) == type(False) and value == False:
+			remove = True
+
+		if remove:
+			# If the key wasn't present, return without error
+			if self._properties.has_key(key):
+				del self._properties[key]
+		else:
+			# Otherwise set it
+			if type(value) == type(True):
+				value = ""
+			self._properties[key] = value
+		self._dbus_helper.PublishedValueChanged(key)
+
+	def set_properties(self, properties, sender=None):
+		"""Set all service properties in one call"""
+		if sender is not None and self._local_publisher != sender:
+			raise ValueError("Service was not not registered by requesting process!")
+		self._internal_set_properties(properties)
+
+	def _internal_set_properties(self, properties, first_time=False):
 		"""Set the service's properties from either an Avahi
 		TXT record (a list of lists of integers), or a
 		python dictionary."""
+		if type(properties) != type({}):
+			raise ValueError("Properties must be a dictionary.")
 		self._properties = {}
-		props = {}
-		if type(properties) == type([]):
-			props = _txt_to_dict(properties)
-		elif type(properties) == type({}):
-			props = properties
 
 		# Set key/value pairs on internal property list
-		for key, value in props.items():
+		for key, value in properties.items():
 			if len(key) == 0:
 				continue
 			tmp_key = key
@@ -230,6 +282,9 @@ class Service(object):
 				tmp_val = unicode(tmp_val)
 			self._properties[tmp_key] = tmp_val
 
+		if not first_time:
+			self._dbus_helper.PublishedValueChanged(self._properties.keys())
+
 	def get_type(self):
 		"""Return the service's service type."""
 		return self._stype

shell/Shell.py

@@ -73,7 +73,7 @@ class Shell(gobject.GObject):
 		PresenceService.start()
 		self._pservice = PresenceService.get_instance()
 
-		self._owner = ShellOwner()
+		self._owner = ShellOwner(self)
 		self._owner.announce()
 
 		self._home_window.set_owner(self._owner)

sugar/presence/Service.py

@@ -2,11 +2,29 @@ import gobject
 import dbus
 
 
+def __one_dict_differs(dict1, dict2):
+	for key, value in dict1.items():
+		if not dict2.has_key(key) or dict2[key] != value:
+			return True
+	return False
+
+def __dicts_differ(dict1, dict2):
+	if __one_dict_differs(dict1, dict2):
+		return True
+	if __one_dict_differs(dict2, dict1):
+		return True
+	return False
+
 class Service(gobject.GObject):
 
 	_PRESENCE_SERVICE = "org.laptop.Presence"
 	_SERVICE_DBUS_INTERFACE = "org.laptop.Presence.Service"
 
+	__gsignals__ = {
+		'published-value-changed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
+								   ([gobject.TYPE_PYOBJECT]))
+	}
+
 	def __init__(self, bus, new_obj_cb, del_obj_cb, object_path):
 		gobject.GObject.__init__(self)
 		self._object_path = object_path
@@ -14,17 +32,40 @@ class Service(gobject.GObject):
 		self._ps_del_object = del_obj_cb
 		sobj = bus.get_object(self._PRESENCE_SERVICE, object_path)
 		self._service = dbus.Interface(sobj, self._SERVICE_DBUS_INTERFACE)
-		self._service.connect_to_signal('PropertyChanged', self._property_changed_cb)
+		self._service.connect_to_signal('PropertyChanged', self.__property_changed_cb)
+		self._service.connect_to_signal('PublishedValueChanged',
+				self.__published_value_changed_cb)
 		self._props = self._service.getProperties()
+		self._pubvals = self._service.getPublishedValues()
 
 	def object_path(self):
 		return self._object_path
 
-	def _property_changed_cb(self, prop_list):
+	def __property_changed_cb(self, prop_list):
 		self._props = self._service.getProperties()
 
 	def get_published_value(self, key):
-		return self._service.getPublishedValue(key)
+		return self._pubvals[key]
+
+	def get_published_values(self):
+		self._pubvals = self._service.getPublishedValues()
+
+	def set_published_value(self, key, value):
+		if self._pubvals.has_key(key):
+			if self._pubvals[key] == value:
+				return
+		self._pubvals[key] = value
+		self._service.setPublishedValue(key, value)
+
+	def set_published_values(self, vals):
+		self._service.setPublishedValues(vals)
+		self._pubvals = vals
+
+	def __published_value_changed_cb(self, keys):
+		oldvals = self._pubvals
+		self.get_published_values()
+		if __dicts_differ(oldvals, self._pubvals):
+			self.emit('published-value-changed', keys)
 
 	def get_name(self):
 		return self._props['name']