""" OOBHandler - Out Of Band Handler The OOBHandler.execute_cmd is called by the sessionhandler when it detects an OOB instruction (exactly how this looked depends on the protocol; at this point all oob calls should look the same) The handler pieces of functionality: function execution - the oob protocol can execute a function directly on the server. The available functions must be defined as global functions in settings.OOB_PLUGIN_MODULES. repeat func execution - the oob protocol can request a given function be executed repeatedly at a regular interval. This uses an internal script pool. tracking - the oob protocol can request Evennia to track changes to fields on objects, as well as changes in Attributes. This is done by dynamically adding tracker-objects on entities. The behaviour of those objects can be customized by adding new tracker classes in settings.OOB_PLUGIN_MODULES. What goes into the OOB_PLUGIN_MODULES is a (list of) modules that contains the working server-side code available to the OOB system: oob functions and tracker classes. oob functions have the following call signature: function(caller, session, *args, **kwargs) oob trackers should inherit from the OOBTracker class (in this module) and implement a minimum of the same functionality. If a function named "oob_error" is given, this will be called with error messages. """ from inspect import isfunction from twisted.internet.defer import inlineCallbacks from django.conf import settings from src.server.models import ServerConfig from src.server.sessionhandler import SESSIONS #from src.scripts.scripts import Script #from src.utils.create import create_script from src.scripts.tickerhandler import Ticker, TickerPool, TickerHandler from src.utils.dbserialize import dbserialize, dbunserialize, pack_dbobj, unpack_dbobj from src.utils import logger from src.utils.utils import all_from_module, make_iter, to_str _SA = object.__setattr__ _GA = object.__getattribute__ _DA = object.__delattr__ # load resources from plugin module _OOB_FUNCS = {} for mod in make_iter(settings.OOB_PLUGIN_MODULES): _OOB_FUNCS.update(dict((key.lower(), func) for key, func in all_from_module(mod).items() if isfunction(func))) # get custom error method or use the default _OOB_ERROR = _OOB_FUNCS.get("oob_error", None) if not _OOB_ERROR: # create default oob error message function def oob_error(oobhandler, session, errmsg, *args, **kwargs): "Error wrapper" session.msg(oob=("err", ("ERROR ", errmsg))) _OOB_ERROR = oob_error # # TrackerHandler is assigned to objects that should notify themselves to # the OOB system when some property changes. This is never assigned manually # but automatically through the OOBHandler. # class TrackerHandler(object): """ This object is dynamically assigned to objects whenever one of its fields are to be tracked. It holds an internal dictionary mapping to the fields on that object. Each field can be tracked by any number of trackers (each tied to a different callback). """ def __init__(self, obj): """ This is initiated and stored on the object as a property _trackerhandler. """ self.obj = obj self.ntrackers = 0 # initiate store only with valid on-object fieldnames self.tracktargets = dict((key, {}) for key in _GA(_GA(self.obj, "_meta"), "get_all_field_names")()) def add(self, fieldname, tracker): """ Add tracker to the handler. Raises KeyError if fieldname does not exist. """ trackerkey = tracker.__class__.__name__ self.tracktargets[fieldname][trackerkey] = tracker self.ntrackers += 1 def remove(self, fieldname, trackerclass, *args, **kwargs): """ Remove identified tracker from TrackerHandler. Raises KeyError if tracker is not found. """ trackerkey = trackerclass.__name__ tracker = self.tracktargets[fieldname][trackerkey] try: tracker.at_remove(*args, **kwargs) except Exception: logger.log_trace() del self.tracktargets[fieldname][trackerkey] self.ntrackers -= 1 if self.ntrackers <= 0: # if there are no more trackers, clean this handler del self def update(self, fieldname, new_value): """ Called by the field when it updates to a new value """ for tracker in self.tracktargets[fieldname].values(): try: tracker.update(new_value) except Exception: logger.log_trace() # On-object Trackers to load with TrackerHandler class TrackerBase(object): """ Base class for OOB Tracker objects. Inherit from this to define custom trackers. """ def __init__(self, *args, **kwargs): pass def update(self, *args, **kwargs): "Called by tracked objects" pass def at_remove(self, *args, **kwargs): "Called when tracker is removed" pass class ReportFieldTracker(TrackerBase): """ Tracker that passively sends data to a stored sessid whenever a named database field changes. The TrackerHandler calls this with the correct arguments. """ def __init__(self, oobhandler, fieldname, sessid, *args, **kwargs): """ name - name of entity to track, such as "db_key" sessid - sessid of session to report to """ self.oobhandler = oobhandler self.fieldname = fieldname self.sessid = sessid def update(self, new_value, *args, **kwargs): "Called by cache when updating the tracked entitiy" # use oobhandler to relay data try: # we must never relay objects across the amp, only text data. new_value = new_value.key except AttributeError: new_value = to_str(new_value, force_string=True) kwargs[self.fieldname] = new_value # this is a wrapper call for sending oob data back to session self.oobhandler.msg(self.sessid, "report", *args, **kwargs) class ReportAttributeTracker(TrackerBase): """ Tracker that passively sends data to a stored sessid whenever the Attribute updates. Since the field here is always "db_key", we instead store the name of the attribute to return. """ def __init__(self, oobhandler, fieldname, sessid, attrname, *args, **kwargs): """ attrname - name of attribute to track sessid - sessid of session to report to """ self.oobhandler = oobhandler self.attrname = attrname self.sessid = sessid def update(self, new_value, *args, **kwargs): "Called by cache when attribute's db_value field updates" kwargs[self.attrname] = new_value # this is a wrapper call for sending oob data back to session self.oobhandler.msg(self.sessid, "report", *args, **kwargs) # Ticker of auto-updating objects class OOBTicker(Ticker): """ Version of Ticker that executes an executable rather than trying to call a hook method. """ @inlineCallbacks def _callback(self): "See original for more info" for key, (_, args, kwargs) in self.subscriptions.items(): # args = (sessid, callback_function) session = SESSIONS.session_from_sessid(args[0]) try: # execute the oob callback yield args[1](OOB_HANDLER, session, *args[2:], **kwargs) except Exception: logger.log_trace() class OOBTickerPool(TickerPool): ticker_class = OOBTicker class OOBTickerHandler(TickerHandler): ticker_pool_class = OOBTickerPool # Main OOB Handler class OOBHandler(object): """ The OOBHandler maintains all dynamic on-object oob hooks. It will store the creation instructions and and re-apply them at a server reload (but not after a server shutdown) """ def __init__(self): """ Initialize handler """ self.sessionhandler = SESSIONS self.oob_tracker_storage = {} self.tickerhandler = OOBTickerHandler("oob_ticker_storage") def save(self): """ Save the command_storage as a serialized string into a temporary ServerConf field """ if self.oob_tracker_storage: #print "saved tracker_storage:", self.oob_tracker_storage ServerConfig.objects.conf(key="oob_tracker_storage", value=dbserialize(self.oob_tracker_storage)) self.tickerhandler.save() def restore(self): """ Restore the command_storage from database and re-initialize the handler from storage.. This is only triggered after a server reload, not after a shutdown-restart """ # load stored command instructions and use them to re-initialize handler tracker_storage = ServerConfig.objects.conf(key="oob_tracker_storage") if tracker_storage: self.oob_tracker_storage = dbunserialize(tracker_storage) for (obj, sessid, fieldname, trackerclass, args, kwargs) in self.oob_tracker_storage.values(): #print "restoring tracking:",obj, sessid, fieldname, trackerclass self._track(unpack_dbobj(obj), sessid, fieldname, trackerclass, *args, **kwargs) # make sure to purge the storage ServerConfig.objects.conf(key="oob_tracker_storage", delete=True) self.tickerhandler.restore() def _track(self, obj, sessid, propname, trackerclass, *args, **kwargs): """ Create an OOB obj of class _oob_MAPPING[tracker_key] on obj. args, kwargs will be used to initialize the OOB hook before adding it to obj. If propname is not given, but the OOB has a class property named as propname, this will be used as the property name when assigning the OOB to obj, otherwise tracker_key is used as the property name. """ if not "_trackerhandler" in _GA(obj, "__dict__"): # assign trackerhandler to object _SA(obj, "_trackerhandler", TrackerHandler(obj)) # initialize object tracker = trackerclass(self, propname, sessid, *args, **kwargs) _GA(obj, "_trackerhandler").add(propname, tracker) # store calling arguments as a pickle for retrieval later obj_packed = pack_dbobj(obj) storekey = (obj_packed, sessid, propname) stored = (obj_packed, sessid, propname, trackerclass, args, kwargs) self.oob_tracker_storage[storekey] = stored #print "_track:", obj, id(obj), obj.__dict__ def _untrack(self, obj, sessid, propname, trackerclass, *args, **kwargs): """ Remove the OOB from obj. If oob implements an at_delete hook, this will be called with args, kwargs """ try: # call at_remove hook on the trackerclass _GA(obj, "_trackerhandler").remove(propname, trackerclass, *args, **kwargs) except AttributeError: pass # remove the pickle from storage store_key = (pack_dbobj(obj), sessid, propname) self.oob_tracker_storage.pop(store_key, None) def get_all_tracked(self, session): """ Get the names of all variables this session is tracking. """ sessid = session.sessid return [stored for key, stored in self.oob_tracker_storage.items() if key[1] == sessid] def track_field(self, obj, sessid, field_name, trackerclass=ReportFieldTracker): """ Shortcut wrapper method for specifically tracking a database field. Takes the tracker class as argument. """ # all database field names starts with db_* field_name = field_name if field_name.startswith("db_") else "db_%s" % field_name self._track(obj, sessid, field_name, trackerclass, field_name) def untrack_field(self, obj, sessid, field_name, trackerclass=ReportFieldTracker): """ Shortcut for untracking a database field. Uses OOBTracker by defualt """ field_name = field_name if field_name.startswith("db_") else "db_%s" % field_name self._untrack(obj, sessid, field_name, trackerclass) def track_attribute(self, obj, sessid, attr_name, trackerclass=ReportAttributeTracker): """ Shortcut wrapper method for specifically tracking the changes of an Attribute on an object. Will create a tracker on the Attribute Object and name in a way the Attribute expects. """ # get the attribute object if we can attrobj = obj.attributes.get(attr_name, return_obj=True) #print "track_attribute attrobj:", attrobj, id(attrobj) if attrobj: self._track(attrobj, sessid, "db_value", trackerclass, attr_name) def untrack_attribute(self, obj, sessid, attr_name, trackerclass=ReportAttributeTracker): """ Shortcut for deactivating tracking for a given attribute. """ attrobj = obj.attributes.get(attr_name, return_obj=True) if attrobj: self._untrack(attrobj, sessid, "db_value", trackerclass, attr_name) def repeat(self, obj, sessid, interval=20, callback=None, *args, **kwargs): """ Start a repeating action. Every interval seconds, trigger callback(*args, **kwargs). The callback is called with args and kwargs; note that *args and **kwargs may not contain anything un-picklable (use dbrefs if wanting to use objects). """ self.tickerhandler.add(obj, interval, sessid, callback, *args, **kwargs) def unrepeat(self, obj, sessid, interval=20): """ Stop a repeating action """ self.tickerhandler.remove(obj, interval) # access method - called from session.msg() def execute_cmd(self, session, func_key, *args, **kwargs): """ Retrieve oobfunc from OOB_FUNCS and execute it immediately using *args and **kwargs """ oobfunc = _OOB_FUNCS.get(func_key, None) if not oobfunc: # function not found errmsg = "OOB Error: function '%s' not recognized." % func_key if _OOB_ERROR: _OOB_ERROR(self, session, errmsg, *args, **kwargs) logger.log_trace() else: logger.log_trace(errmsg) return # execute the found function try: #print "OOB execute_cmd:", session, func_key, args, kwargs, _OOB_FUNCS.keys() oobfunc(self, session, *args, **kwargs) except Exception, err: errmsg = "OOB Error: Exception in '%s'(%s, %s):\n%s" % (func_key, args, kwargs, err) if _OOB_ERROR: _OOB_ERROR(self, session, errmsg, *args, **kwargs) logger.log_trace(errmsg) raise Exception(errmsg) def msg(self, sessid, funcname, *args, **kwargs): "Shortcut to force-send an OOB message through the oobhandler to a session" session = self.sessionhandler.session_from_sessid(sessid) #print "oobhandler msg:", sessid, session, funcname, args, kwargs if session: session.msg(oob=(funcname, args, kwargs)) # access object OOB_HANDLER = OOBHandler()