diff --git a/dbus-node-red-pvinverter/pv_inverter.py b/dbus-node-red-pvinverter/pv_inverter.py new file mode 100644 index 0000000..6631753 --- /dev/null +++ b/dbus-node-red-pvinverter/pv_inverter.py @@ -0,0 +1,186 @@ +#!/usr/bin/env python + +# import normal packages +import platform +import logging +import sys +import os +import sys +if sys.version_info.major == 2: + import gobject +else: + from gi.repository import GLib as gobject +import sys +import time +import requests # for http GET + +# our own packages from victron +sys.path.insert(1, os.path.join(os.path.dirname(__file__), '/opt/victronenergy/dbus-systemcalc-py/ext/velib_python')) +from vedbus import VeDbusService + + +class NodeRedPVinverter: + def __init__(self, servicename, deviceinstance, paths, productname='PV-Inverter', connection='Node RED HTTP JSON service'): + self._dbusservice = VeDbusService("{}.http_{:02d}".format(servicename, deviceinstance)) + self._paths = paths + + logging.debug("%s /DeviceInstance = %d" % (servicename, deviceinstance)) + + # Create the management objects, as specified in the ccgx dbus-api document + self._dbusservice.add_path('/Mgmt/ProcessName', __file__) + self._dbusservice.add_path('/Mgmt/ProcessVersion', 'Python ' + platform.python_version()) + self._dbusservice.add_path('/Mgmt/Connection', connection) + + # Create the mandatory objects + self._dbusservice.add_path('/DeviceInstance', deviceinstance) + self._dbusservice.add_path('/ProductId', 0xFFFF) + self._dbusservice.add_path('/ProductName', productname) + self._dbusservice.add_path('/CustomName', productname) + self._dbusservice.add_path('/FirmwareVersion', 1.0) + self._dbusservice.add_path('/HardwareVersion', 0) + self._dbusservice.add_path('/Connected', 1) + self._dbusservice.add_path('/Position', 0) + self._dbusservice.add_path('/Serial', 12345678) + self._dbusservice.add_path('/UpdateIndex', 0) + self._dbusservice.add_path('/StatusCode', 0) + + # add path values to dbus + for path, settings in self._paths.items(): + self._dbusservice.add_path( + path, settings['initial'], gettextcallback=settings['textformat'], writeable=True, onchangecallback=self._handlechangedvalue) + + # last update + self._lastUpdate = 0 + + # add _update function 'timer' + gobject.timeout_add(500, self._update) # pause 500ms before the next request + + # add _Status 'timer' to get feedback in log every 5minutes + gobject.timeout_add(self._getStatusInterval()*60*1000, self._Status) + + def _getStatusInterval(self): + value = 1 + + if not value: + value = 0 + + return int(value) + + def _getNodeRedData(self): + URL = "http://localhost:1880/meters" + meter_r = requests.get(url = URL) + + # check for response + if not meter_r: + raise ConnectionError("No response from NodeRed - %s" % (URL)) + + meter_data = meter_r.json() + + # check for Json + if not meter_data: + raise ValueError("Converting response to JSON failed") + + + return meter_data + + + def _Status(self): + logging.debug("Last update: %s" % (self._lastUpdate)) + logging.debug("Last '/Ac/Power': %s" % (self._dbusservice['/Ac/Power'])) + return True + + def _update(self): + try: + #get data from NodeRed 3em + meter_data = self._getNodeRedData() + + #send data to DBus + self._dbusservice['/Ac/Voltage'] = meter_data['pv_inverter']['voltage'] + self._dbusservice['/Ac/L1/Voltage'] = meter_data['pv_inverter']['voltage'] + self._dbusservice['/Ac/Current'] = meter_data['pv_inverter']['current'] + self._dbusservice['/Ac/L1/Current'] = meter_data['pv_inverter']['current'] + self._dbusservice['/Ac/Power'] = meter_data['pv_inverter']['power'] + self._dbusservice['/Ac/L1/Power'] = meter_data['pv_inverter']['power'] + self._dbusservice['/Ac/Energy/Forward'] = meter_data['pv_inverter']['energy'] + self._dbusservice['/Ac/L1/Energy/Forward'] = meter_data['pv_inverter']['energy'] + + #logging + logging.debug("Inverter Power (/Ac/Power): %s" % (self._dbusservice['/Ac/Power'])) + logging.debug("Inverter Energy(/Ac/Energy/Forward): %s" % (self._dbusservice['/Ac/Energy/Forward'])) + logging.debug("---"); + + # increment UpdateIndex - to show that new data is available + index = self._dbusservice['/UpdateIndex'] + 1 # increment index + if index > 255: # maximum value of the index + index = 0 # overflow from 255 to 0 + self._dbusservice['/UpdateIndex'] = index + + #update lastupdate vars + self._lastUpdate = time.time() + except Exception as e: + logging.critical('Error at %s', '_update', exc_info=e) + + # return true, otherwise add_timeout will be removed from GObject - see docs http://library.isr.ist.utl.pt/docs/pygtk2reference/gobject-functions.html#function-gobject--timeout-add + return True + + def _handlechangedvalue(self, path, value): + logging.debug("someone else updated %s to %s" % (path, value)) + return True # accept the change + + + +def main(): + #configure logging + logging.basicConfig( format='%(asctime)s,%(msecs)d %(name)s %(levelname)s %(message)s', + datefmt='%Y-%m-%d %H:%M:%S', + level=logging.INFO, + handlers=[ + logging.FileHandler("%s/current.log" % (os.path.dirname(os.path.realpath(__file__)))), + logging.StreamHandler() + ]) + + try: + logging.info("Start"); + + from dbus.mainloop.glib import DBusGMainLoop + # Have a mainloop, so we can send/receive asynchronous calls to and from dbus + DBusGMainLoop(set_as_default=True) + + #formatting + _kwh = lambda p, v: (str(round(v, 2)) + ' KWh') + _a = lambda p, v: (str(round(v, 1)) + ' A') + _w = lambda p, v: (str(round(v, 1)) + ' W') + _v = lambda p, v: (str(round(v, 1)) + ' V') + + #start our main-service + pvac_output = NodeRedPVinverter( + servicename='com.victronenergy.pvinverter', + deviceinstance=46, + paths={ + '/Ac/Energy/Forward': {'initial': None, 'textformat': _kwh}, # energy produced by pv inverter + '/Ac/Power': {'initial': 0, 'textformat': _w}, + + '/Ac/Current': {'initial': 0, 'textformat': _a}, + '/Ac/Voltage': {'initial': 0, 'textformat': _v}, + + '/Ac/L1/Voltage': {'initial': 0, 'textformat': _v}, + '/Ac/L2/Voltage': {'initial': 0, 'textformat': _v}, + '/Ac/L3/Voltage': {'initial': 0, 'textformat': _v}, + '/Ac/L1/Current': {'initial': 0, 'textformat': _a}, + '/Ac/L2/Current': {'initial': 0, 'textformat': _a}, + '/Ac/L3/Current': {'initial': 0, 'textformat': _a}, + '/Ac/L1/Power': {'initial': 0, 'textformat': _w}, + '/Ac/L2/Power': {'initial': 0, 'textformat': _w}, + '/Ac/L3/Power': {'initial': 0, 'textformat': _w}, + '/Ac/L1/Energy/Forward': {'initial': None, 'textformat': _kwh}, + '/Ac/L2/Energy/Forward': {'initial': None, 'textformat': _kwh}, + '/Ac/L3/Energy/Forward': {'initial': None, 'textformat': _kwh}, + }) + + logging.info('Connected to dbus, and switching over to gobject.MainLoop() (= event based)') + mainloop = gobject.MainLoop() + mainloop.run() + except Exception as e: + logging.critical('Error at %s', 'main', exc_info=e) +if __name__ == "__main__": + main() \ No newline at end of file diff --git a/dbus-node-red-pvinverter/service/run b/dbus-node-red-pvinverter/service/run new file mode 100644 index 0000000..aa0c5d7 --- /dev/null +++ b/dbus-node-red-pvinverter/service/run @@ -0,0 +1,3 @@ +#!/bin/sh +cd /data/dbus-node-red-pvinverter +python /data/dbus-node-red-pvinverter/pv_inverter.py \ No newline at end of file diff --git a/dbus-node-red-pvinverter/vedbus.py b/dbus-node-red-pvinverter/vedbus.py new file mode 100644 index 0000000..8c101ea --- /dev/null +++ b/dbus-node-red-pvinverter/vedbus.py @@ -0,0 +1,611 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- + +import dbus.service +import logging +import traceback +import os +import weakref +from collections import defaultdict +from ve_utils import wrap_dbus_value, unwrap_dbus_value + +# vedbus contains three classes: +# VeDbusItemImport -> use this to read data from the dbus, ie import +# VeDbusItemExport -> use this to export data to the dbus (one value) +# VeDbusService -> use that to create a service and export several values to the dbus + +# Code for VeDbusItemImport is copied from busitem.py and thereafter modified. +# All projects that used busitem.py need to migrate to this package. And some +# projects used to define there own equivalent of VeDbusItemExport. Better to +# use VeDbusItemExport, or even better the VeDbusService class that does it all for you. + +# TODOS +# 1 check for datatypes, it works now, but not sure if all is compliant with +# com.victronenergy.BusItem interface definition. See also the files in +# tests_and_examples. And see 'if type(v) == dbus.Byte:' on line 102. Perhaps +# something similar should also be done in VeDbusBusItemExport? +# 2 Shouldn't VeDbusBusItemExport inherit dbus.service.Object? +# 7 Make hard rules for services exporting data to the D-Bus, in order to make tracking +# changes possible. Does everybody first invalidate its data before leaving the bus? +# And what about before taking one object away from the bus, instead of taking the +# whole service offline? +# They should! And after taking one value away, do we need to know that someone left +# the bus? Or we just keep that value in invalidated for ever? Result is that we can't +# see the difference anymore between an invalidated value and a value that was first on +# the bus and later not anymore. See comments above VeDbusItemImport as well. +# 9 there are probably more todos in the code below. + +# Some thoughts with regards to the data types: +# +# Text from: http://dbus.freedesktop.org/doc/dbus-python/doc/tutorial.html#data-types +# --- +# Variants are represented by setting the variant_level keyword argument in the +# constructor of any D-Bus data type to a value greater than 0 (variant_level 1 +# means a variant containing some other data type, variant_level 2 means a variant +# containing a variant containing some other data type, and so on). If a non-variant +# is passed as an argument but introspection indicates that a variant is expected, +# it'll automatically be wrapped in a variant. +# --- +# +# Also the different dbus datatypes, such as dbus.Int32, and dbus.UInt32 are a subclass +# of Python int. dbus.String is a subclass of Python standard class unicode, etcetera +# +# So all together that explains why we don't need to explicitly convert back and forth +# between the dbus datatypes and the standard python datatypes. Note that all datatypes +# in python are objects. Even an int is an object. + +# The signature of a variant is 'v'. + +# Export ourselves as a D-Bus service. +class VeDbusService(object): + def __init__(self, servicename, bus=None): + # dict containing the VeDbusItemExport objects, with their path as the key. + self._dbusobjects = {} + self._dbusnodes = {} + self._ratelimiters = [] + self._dbusname = None + + # dict containing the onchange callbacks, for each object. Object path is the key + self._onchangecallbacks = {} + + # Connect to session bus whenever present, else use the system bus + self._dbusconn = bus or (dbus.SessionBus() if 'DBUS_SESSION_BUS_ADDRESS' in os.environ else dbus.SystemBus()) + + # make the dbus connection available to outside, could make this a true property instead, but ach.. + self.dbusconn = self._dbusconn + + # Register ourselves on the dbus, trigger an error if already in use (do_not_queue) + self._dbusname = dbus.service.BusName(servicename, self._dbusconn, do_not_queue=True) + + # Add the root item that will return all items as a tree + self._dbusnodes['/'] = VeDbusRootExport(self._dbusconn, '/', self) + + logging.info("registered ourselves on D-Bus as %s" % servicename) + + # To force immediate deregistering of this dbus service and all its object paths, explicitly + # call __del__(). + def __del__(self): + for node in list(self._dbusnodes.values()): + node.__del__() + self._dbusnodes.clear() + for item in list(self._dbusobjects.values()): + item.__del__() + self._dbusobjects.clear() + if self._dbusname: + self._dbusname.__del__() # Forces call to self._bus.release_name(self._name), see source code + self._dbusname = None + + # @param callbackonchange function that will be called when this value is changed. First parameter will + # be the path of the object, second the new value. This callback should return + # True to accept the change, False to reject it. + def add_path(self, path, value, description="", writeable=False, + onchangecallback=None, gettextcallback=None, valuetype=None): + + if onchangecallback is not None: + self._onchangecallbacks[path] = onchangecallback + + item = VeDbusItemExport( + self._dbusconn, path, value, description, writeable, + self._value_changed, gettextcallback, deletecallback=self._item_deleted, valuetype=valuetype) + + spl = path.split('/') + for i in range(2, len(spl)): + subPath = '/'.join(spl[:i]) + if subPath not in self._dbusnodes and subPath not in self._dbusobjects: + self._dbusnodes[subPath] = VeDbusTreeExport(self._dbusconn, subPath, self) + self._dbusobjects[path] = item + logging.debug('added %s with start value %s. Writeable is %s' % (path, value, writeable)) + + # Add the mandatory paths, as per victron dbus api doc + def add_mandatory_paths(self, processname, processversion, connection, + deviceinstance, productid, productname, firmwareversion, hardwareversion, connected): + self.add_path('/Mgmt/ProcessName', processname) + self.add_path('/Mgmt/ProcessVersion', processversion) + self.add_path('/Mgmt/Connection', connection) + + # Create rest of the mandatory objects + self.add_path('/DeviceInstance', deviceinstance) + self.add_path('/ProductId', productid) + self.add_path('/ProductName', productname) + self.add_path('/FirmwareVersion', firmwareversion) + self.add_path('/HardwareVersion', hardwareversion) + self.add_path('/Connected', connected) + + # Callback function that is called from the VeDbusItemExport objects when a value changes. This function + # maps the change-request to the onchangecallback given to us for this specific path. + def _value_changed(self, path, newvalue): + if path not in self._onchangecallbacks: + return True + + return self._onchangecallbacks[path](path, newvalue) + + def _item_deleted(self, path): + self._dbusobjects.pop(path) + for np in list(self._dbusnodes.keys()): + if np != '/': + for ip in self._dbusobjects: + if ip.startswith(np + '/'): + break + else: + self._dbusnodes[np].__del__() + self._dbusnodes.pop(np) + + def __getitem__(self, path): + return self._dbusobjects[path].local_get_value() + + def __setitem__(self, path, newvalue): + self._dbusobjects[path].local_set_value(newvalue) + + def __delitem__(self, path): + self._dbusobjects[path].__del__() # Invalidates and then removes the object path + assert path not in self._dbusobjects + + def __contains__(self, path): + return path in self._dbusobjects + + def __enter__(self): + l = ServiceContext(self) + self._ratelimiters.append(l) + return l + + def __exit__(self, *exc): + # pop off the top one and flush it. If with statements are nested + # then each exit flushes its own part. + if self._ratelimiters: + self._ratelimiters.pop().flush() + +class ServiceContext(object): + def __init__(self, parent): + self.parent = parent + self.changes = {} + + def __getitem__(self, path): + return self.parent[path] + + def __setitem__(self, path, newvalue): + c = self.parent._dbusobjects[path]._local_set_value(newvalue) + if c is not None: + self.changes[path] = c + + def flush(self): + if self.changes: + self.parent._dbusnodes['/'].ItemsChanged(self.changes) + +class TrackerDict(defaultdict): + """ Same as defaultdict, but passes the key to default_factory. """ + def __missing__(self, key): + self[key] = x = self.default_factory(key) + return x + +class VeDbusRootTracker(object): + """ This tracks the root of a dbus path and listens for PropertiesChanged + signals. When a signal arrives, parse it and unpack the key/value changes + into traditional events, then pass it to the original eventCallback + method. """ + def __init__(self, bus, serviceName): + self.importers = defaultdict(weakref.WeakSet) + self.serviceName = serviceName + self._match = bus.get_object(serviceName, '/', introspect=False).connect_to_signal( + "ItemsChanged", weak_functor(self._items_changed_handler)) + + def __del__(self): + self._match.remove() + self._match = None + + def add(self, i): + self.importers[i.path].add(i) + + def _items_changed_handler(self, items): + if not isinstance(items, dict): + return + + for path, changes in items.items(): + try: + v = changes['Value'] + except KeyError: + continue + + try: + t = changes['Text'] + except KeyError: + t = str(unwrap_dbus_value(v)) + + for i in self.importers.get(path, ()): + i._properties_changed_handler({'Value': v, 'Text': t}) + +""" +Importing basics: + - If when we power up, the D-Bus service does not exist, or it does exist and the path does not + yet exist, still subscribe to a signal: as soon as it comes online it will send a signal with its + initial value, which VeDbusItemImport will receive and use to update local cache. And, when set, + call the eventCallback. + - If when we power up, save it + - When using get_value, know that there is no difference between services (or object paths) that don't + exist and paths that are invalid (= empty array, see above). Both will return None. In case you do + really want to know ifa path exists or not, use the exists property. + - When a D-Bus service leaves the D-Bus, it will first invalidate all its values, and send signals + with that update, and only then leave the D-Bus. (or do we need to subscribe to the NameOwnerChanged- + signal!?!) To be discussed and make sure. Not really urgent, since all existing code that uses this + class already subscribes to the NameOwnerChanged signal, and subsequently removes instances of this + class. + +Read when using this class: +Note that when a service leaves that D-Bus without invalidating all its exported objects first, for +example because it is killed, VeDbusItemImport doesn't have a clue. So when using VeDbusItemImport, +make sure to also subscribe to the NamerOwnerChanged signal on bus-level. Or just use dbusmonitor, +because that takes care of all of that for you. +""" +class VeDbusItemImport(object): + def __new__(cls, bus, serviceName, path, eventCallback=None, createsignal=True): + instance = object.__new__(cls) + + # If signal tracking should be done, also add to root tracker + if createsignal: + if "_roots" not in cls.__dict__: + cls._roots = TrackerDict(lambda k: VeDbusRootTracker(bus, k)) + + return instance + + ## Constructor + # @param bus the bus-object (SESSION or SYSTEM). + # @param serviceName the dbus-service-name (string), for example 'com.victronenergy.battery.ttyO1' + # @param path the object-path, for example '/Dc/V' + # @param eventCallback function that you want to be called on a value change + # @param createSignal only set this to False if you use this function to one time read a value. When + # leaving it to True, make sure to also subscribe to the NameOwnerChanged signal + # elsewhere. See also note some 15 lines up. + def __init__(self, bus, serviceName, path, eventCallback=None, createsignal=True): + # TODO: is it necessary to store _serviceName and _path? Isn't it + # stored in the bus_getobjectsomewhere? + self._serviceName = serviceName + self._path = path + self._match = None + # TODO: _proxy is being used in settingsdevice.py, make a getter for that + self._proxy = bus.get_object(serviceName, path, introspect=False) + self.eventCallback = eventCallback + + assert eventCallback is None or createsignal == True + if createsignal: + self._match = self._proxy.connect_to_signal( + "PropertiesChanged", weak_functor(self._properties_changed_handler)) + self._roots[serviceName].add(self) + + # store the current value in _cachedvalue. When it doesn't exists set _cachedvalue to + # None, same as when a value is invalid + self._cachedvalue = None + try: + v = self._proxy.GetValue() + except dbus.exceptions.DBusException: + pass + else: + self._cachedvalue = unwrap_dbus_value(v) + + def __del__(self): + if self._match is not None: + self._match.remove() + self._match = None + self._proxy = None + + def _refreshcachedvalue(self): + self._cachedvalue = unwrap_dbus_value(self._proxy.GetValue()) + + ## Returns the path as a string, for example '/AC/L1/V' + @property + def path(self): + return self._path + + ## Returns the dbus service name as a string, for example com.victronenergy.vebus.ttyO1 + @property + def serviceName(self): + return self._serviceName + + ## Returns the value of the dbus-item. + # the type will be a dbus variant, for example dbus.Int32(0, variant_level=1) + # this is not a property to keep the name consistant with the com.victronenergy.busitem interface + # returns None when the property is invalid + def get_value(self): + return self._cachedvalue + + ## Writes a new value to the dbus-item + def set_value(self, newvalue): + r = self._proxy.SetValue(wrap_dbus_value(newvalue)) + + # instead of just saving the value, go to the dbus and get it. So we have the right type etc. + if r == 0: + self._refreshcachedvalue() + + return r + + ## Resets the item to its default value + def set_default(self): + self._proxy.SetDefault() + self._refreshcachedvalue() + + ## Returns the text representation of the value. + # For example when the value is an enum/int GetText might return the string + # belonging to that enum value. Another example, for a voltage, GetValue + # would return a float, 12.0Volt, and GetText could return 12 VDC. + # + # Note that this depends on how the dbus-producer has implemented this. + def get_text(self): + return self._proxy.GetText() + + ## Returns true of object path exists, and false if it doesn't + @property + def exists(self): + # TODO: do some real check instead of this crazy thing. + r = False + try: + r = self._proxy.GetValue() + r = True + except dbus.exceptions.DBusException: + pass + + return r + + ## callback for the trigger-event. + # @param eventCallback the event-callback-function. + @property + def eventCallback(self): + return self._eventCallback + + @eventCallback.setter + def eventCallback(self, eventCallback): + self._eventCallback = eventCallback + + ## Is called when the value of the imported bus-item changes. + # Stores the new value in our local cache, and calls the eventCallback, if set. + def _properties_changed_handler(self, changes): + if "Value" in changes: + changes['Value'] = unwrap_dbus_value(changes['Value']) + self._cachedvalue = changes['Value'] + if self._eventCallback: + # The reason behind this try/except is to prevent errors silently ending up the an error + # handler in the dbus code. + try: + self._eventCallback(self._serviceName, self._path, changes) + except: + traceback.print_exc() + os._exit(1) # sys.exit() is not used, since that also throws an exception + + +class VeDbusTreeExport(dbus.service.Object): + def __init__(self, bus, objectPath, service): + dbus.service.Object.__init__(self, bus, objectPath) + self._service = service + logging.debug("VeDbusTreeExport %s has been created" % objectPath) + + def __del__(self): + # self._get_path() will raise an exception when retrieved after the call to .remove_from_connection, + # so we need a copy. + path = self._get_path() + if path is None: + return + self.remove_from_connection() + logging.debug("VeDbusTreeExport %s has been removed" % path) + + def _get_path(self): + if len(self._locations) == 0: + return None + return self._locations[0][1] + + def _get_value_handler(self, path, get_text=False): + logging.debug("_get_value_handler called for %s" % path) + r = {} + px = path + if not px.endswith('/'): + px += '/' + for p, item in self._service._dbusobjects.items(): + if p.startswith(px): + v = item.GetText() if get_text else wrap_dbus_value(item.local_get_value()) + r[p[len(px):]] = v + logging.debug(r) + return r + + @dbus.service.method('com.victronenergy.BusItem', out_signature='v') + def GetValue(self): + value = self._get_value_handler(self._get_path()) + return dbus.Dictionary(value, signature=dbus.Signature('sv'), variant_level=1) + + @dbus.service.method('com.victronenergy.BusItem', out_signature='v') + def GetText(self): + return self._get_value_handler(self._get_path(), True) + + def local_get_value(self): + return self._get_value_handler(self.path) + +class VeDbusRootExport(VeDbusTreeExport): + @dbus.service.signal('com.victronenergy.BusItem', signature='a{sa{sv}}') + def ItemsChanged(self, changes): + pass + + @dbus.service.method('com.victronenergy.BusItem', out_signature='a{sa{sv}}') + def GetItems(self): + return { + path: { + 'Value': wrap_dbus_value(item.local_get_value()), + 'Text': item.GetText() } + for path, item in self._service._dbusobjects.items() + } + + +class VeDbusItemExport(dbus.service.Object): + ## Constructor of VeDbusItemExport + # + # Use this object to export (publish), values on the dbus + # Creates the dbus-object under the given dbus-service-name. + # @param bus The dbus object. + # @param objectPath The dbus-object-path. + # @param value Value to initialize ourselves with, defaults to None which means Invalid + # @param description String containing a description. Can be called over the dbus with GetDescription() + # @param writeable what would this do!? :). + # @param callback Function that will be called when someone else changes the value of this VeBusItem + # over the dbus. First parameter passed to callback will be our path, second the new + # value. This callback should return True to accept the change, False to reject it. + def __init__(self, bus, objectPath, value=None, description=None, writeable=False, + onchangecallback=None, gettextcallback=None, deletecallback=None, + valuetype=None): + dbus.service.Object.__init__(self, bus, objectPath) + self._onchangecallback = onchangecallback + self._gettextcallback = gettextcallback + self._value = value + self._description = description + self._writeable = writeable + self._deletecallback = deletecallback + self._type = valuetype + + # To force immediate deregistering of this dbus object, explicitly call __del__(). + def __del__(self): + # self._get_path() will raise an exception when retrieved after the + # call to .remove_from_connection, so we need a copy. + path = self._get_path() + if path == None: + return + if self._deletecallback is not None: + self._deletecallback(path) + self.remove_from_connection() + logging.debug("VeDbusItemExport %s has been removed" % path) + + def _get_path(self): + if len(self._locations) == 0: + return None + return self._locations[0][1] + + ## Sets the value. And in case the value is different from what it was, a signal + # will be emitted to the dbus. This function is to be used in the python code that + # is using this class to export values to the dbus. + # set value to None to indicate that it is Invalid + def local_set_value(self, newvalue): + changes = self._local_set_value(newvalue) + if changes is not None: + self.PropertiesChanged(changes) + + def _local_set_value(self, newvalue): + if self._value == newvalue: + return None + + self._value = newvalue + return { + 'Value': wrap_dbus_value(newvalue), + 'Text': self.GetText() + } + + def local_get_value(self): + return self._value + + # ==== ALL FUNCTIONS BELOW THIS LINE WILL BE CALLED BY OTHER PROCESSES OVER THE DBUS ==== + + ## Dbus exported method SetValue + # Function is called over the D-Bus by other process. It will first check (via callback) if new + # value is accepted. And it is, stores it and emits a changed-signal. + # @param value The new value. + # @return completion-code When successful a 0 is return, and when not a -1 is returned. + @dbus.service.method('com.victronenergy.BusItem', in_signature='v', out_signature='i') + def SetValue(self, newvalue): + if not self._writeable: + return 1 # NOT OK + + newvalue = unwrap_dbus_value(newvalue) + + # If value type is enforced, cast it. If the type can be coerced + # python will do it for us. This allows ints to become floats, + # or bools to become ints. Additionally also allow None, so that + # a path may be invalidated. + if self._type is not None and newvalue is not None: + try: + newvalue = self._type(newvalue) + except (ValueError, TypeError): + return 1 # NOT OK + + if newvalue == self._value: + return 0 # OK + + # call the callback given to us, and check if new value is OK. + if (self._onchangecallback is None or + (self._onchangecallback is not None and self._onchangecallback(self.__dbus_object_path__, newvalue))): + + self.local_set_value(newvalue) + return 0 # OK + + return 2 # NOT OK + + ## Dbus exported method GetDescription + # + # Returns the a description. + # @param language A language code (e.g. ISO 639-1 en-US). + # @param length Lenght of the language string. + # @return description + @dbus.service.method('com.victronenergy.BusItem', in_signature='si', out_signature='s') + def GetDescription(self, language, length): + return self._description if self._description is not None else 'No description given' + + ## Dbus exported method GetValue + # Returns the value. + # @return the value when valid, and otherwise an empty array + @dbus.service.method('com.victronenergy.BusItem', out_signature='v') + def GetValue(self): + return wrap_dbus_value(self._value) + + ## Dbus exported method GetText + # Returns the value as string of the dbus-object-path. + # @return text A text-value. '---' when local value is invalid + @dbus.service.method('com.victronenergy.BusItem', out_signature='s') + def GetText(self): + if self._value is None: + return '---' + + # Default conversion from dbus.Byte will get you a character (so 'T' instead of '84'), so we + # have to convert to int first. Note that if a dbus.Byte turns up here, it must have come from + # the application itself, as all data from the D-Bus should have been unwrapped by now. + if self._gettextcallback is None and type(self._value) == dbus.Byte: + return str(int(self._value)) + + if self._gettextcallback is None and self.__dbus_object_path__ == '/ProductId': + return "0x%X" % self._value + + if self._gettextcallback is None: + return str(self._value) + + return self._gettextcallback(self.__dbus_object_path__, self._value) + + ## The signal that indicates that the value has changed. + # Other processes connected to this BusItem object will have subscribed to the + # event when they want to track our state. + @dbus.service.signal('com.victronenergy.BusItem', signature='a{sv}') + def PropertiesChanged(self, changes): + pass + +## This class behaves like a regular reference to a class method (eg. self.foo), but keeps a weak reference +## to the object which method is to be called. +## Use this object to break circular references. +class weak_functor: + def __init__(self, f): + self._r = weakref.ref(f.__self__) + self._f = weakref.ref(f.__func__) + + def __call__(self, *args, **kargs): + r = self._r() + f = self._f() + if r == None or f == None: + return + f(r, *args, **kargs)