evennia/evennia/server/oobhandler.py
2015-11-02 00:19:04 +01:00

500 lines
19 KiB
Python

"""
OOBHandler - Out Of Band Handler
The OOBHandler.execute_cmd is called by the sessionhandler when it
detects an `oob` keyword in the outgoing data (usually called via
`msg(oob=...)`
How this works is that the handler executes an oobfunction, which is
defined in a user-supplied module. This function can then make use of
the oobhandler's functionality to return data, register a monitor on
an object's properties or start a repeating action.
"""
from builtins import object
from collections import defaultdict
from django.conf import settings
from evennia.server.models import ServerConfig
from evennia.server.sessionhandler import SESSIONS
from evennia.scripts.tickerhandler import TickerHandler
from evennia.utils.dbserialize import dbserialize, dbunserialize, pack_dbobj, unpack_dbobj
from evennia.utils import logger
from evennia.utils.utils import make_iter, mod_import
_SA = object.__setattr__
_GA = object.__getattribute__
_DA = object.__delattr__
# set at the bottom of this module
_OOB_FUNCS = None
_OOB_ERROR = None
#
# 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 OOBFieldMonitor(object):
"""
This object should be stored on the
tracked object as "_oob_at_<fieldname>_postsave".
the update() method w ill be called by the
save mechanism, which in turn will call the
user-customizable func()
"""
def __init__(self, obj):
"""
This initializes the monitor with the object it sits on.
Args:
obj (Object): object handler is defined on.
"""
self.obj = obj
self.subscribers = defaultdict(list)
def __call__(self, fieldname):
"""
Called by the save() mechanism when the given field has
updated.
Args:
fieldname (str): The field to monitor
"""
for sessid, oobtuples in self.subscribers.items():
# oobtuples is a list [(oobfuncname, args, kwargs), ...],
# a potential list of oob commands to call when this
# field changes.
for (oobfuncname, args, kwargs) in oobtuples:
OOB_HANDLER.execute_cmd(sessid, oobfuncname, fieldname, self.obj, *args, **kwargs)
def add(self, sessid, oobfuncname, *args, **kwargs):
"""
Add a specific tracking callback to monitor
Args:
sessid (int): Session id
oobfuncname (str): oob command to call when field updates
args,kwargs (any): arguments to pass to oob commjand
Notes:
Each sessid may have a list of (oobfuncname, args, kwargs)
tuples, all of which will be executed when the
field updates.
"""
self.subscribers[sessid].append((oobfuncname, args, kwargs))
def remove(self, sessid, oobfuncname=None):
"""
Remove a subscribing session from the monitor
Args:
sessid(int): Session id
oobfuncname (str, optional): Only delete this cmdname.
If not given, delete all.
"""
if oobfuncname:
self.subscribers[sessid] = [item for item in self.subscribers[sessid]
if item[0] != oobfuncname]
else:
self.subscribers.pop(sessid, None)
class OOBAtRepeater(object):
"""
This object is created and used by the `OOBHandler.repeat` method.
It will be assigned to a target object as a custom variable, e.g.:
`obj._oob_ECHO_every_20s_for_sessid_1 = AtRepater()`
It will be called every interval seconds by the OOBHandler,
triggering whatever OOB function it is set to use.
"""
def __call__(self, *args, **kwargs):
"Called at regular intervals. Calls the oob function"
OOB_HANDLER.execute_cmd(kwargs["_sessid"], kwargs["_oobfuncname"], *args, **kwargs)
# Main OOB Handler
class OOBHandler(TickerHandler):
"""
The OOBHandler manages all server-side OOB functionality
"""
def __init__(self, *args, **kwargs):
"""
Setup the tickerhandler wrapper.
"""
super(OOBHandler, self).__init__(*args, **kwargs)
self.save_name = "oob_ticker_storage"
self.oob_save_name = "oob_monitor_storage"
self.oob_monitor_storage = {}
def _get_repeater_hook_name(self, oobfuncname, interval, sessid):
"""
Get the unique repeater call hook name for this object
Args:
oobfuncname (str): OOB function to retrieve
interval (int): Repeat interval
sessid (int): The Session id.
Returns:
hook_name (str): The repeater hook, when created, is a
dynamically assigned function that gets assigned to a
variable with a name created by combining the arguments.
"""
return "_oob_%s_every_%ss_for_sessid_%s" % (oobfuncname, interval, sessid)
def _get_fieldmonitor_name(self, fieldname):
"""
Get the fieldmonitor name.
Args:
fieldname (str): The field monitored.
Returns:
fieldmonitor_name (str): A dynamic function name
created from the argument.
"""
return "_oob_at_%s_postsave" % fieldname
def _add_monitor(self, obj, sessid, fieldname, oobfuncname, *args, **kwargs):
"""
Helper method. Creates a fieldmonitor and store it on the
object. This tracker will be updated whenever the given field
changes.
Args:
obj (Object): The object on which to store the monitor.
sessid (int): The Session id associated with the monitor.
fieldname (str): The field to monitor
oobfuncname (str): The OOB callback function to trigger when
field `fieldname` changes.
args, kwargs (any): Arguments to pass on to the callback.
"""
fieldmonitorname = self._get_fieldmonitor_name(fieldname)
if not hasattr(obj, fieldmonitorname):
# assign a new fieldmonitor to the object
_SA(obj, fieldmonitorname, OOBFieldMonitor(obj))
# register the session with the monitor
_GA(obj, fieldmonitorname).add(sessid, oobfuncname, *args, **kwargs)
# store calling arguments as a pickle for retrieval at reload
storekey = (pack_dbobj(obj), sessid, fieldname, oobfuncname)
stored = (args, kwargs)
self.oob_monitor_storage[storekey] = stored
def _remove_monitor(self, obj, sessid, fieldname, oobfuncname=None):
"""
Helper method. Removes the OOB from obj.
Args:
obj (Object): The object from which to remove the monitor.
sessid (int): The Session id associated with the monitor.
fieldname (str): The monitored field from which to remove the monitor.
oobfuncname (str): The oob callback function.
"""
fieldmonitorname = self._get_fieldmonitor_name(fieldname)
try:
_GA(obj, fieldmonitorname).remove(sessid, oobfuncname=oobfuncname)
if not _GA(obj, fieldmonitorname).subscribers:
_DA(obj, fieldmonitorname)
except AttributeError:
pass
# remove the pickle from storage
store_key = (pack_dbobj(obj), sessid, fieldname, oobfuncname)
self.oob_monitor_storage.pop(store_key, None)
def save(self):
"""
Handles saving of the OOBHandler data when the server reloads.
Called from the Server process.
"""
# save ourselves as a tickerhandler
super(OOBHandler, self).save()
# handle the extra oob monitor store
if self.ticker_storage:
ServerConfig.objects.conf(key=self.oob_save_name,
value=dbserialize(self.oob_monitor_storage))
else:
# make sure we have nothing lingering in the database
ServerConfig.objects.conf(key=self.oob_save_name, delete=True)
def restore(self):
"""
Called when the handler recovers after a Server reload. Called
by the Server process as part of the reload upstart. Here we
overload the tickerhandler's restore method completely to make
sure we correctly re-apply and re-initialize the correct
monitor and repeater objecth on all saved objects.
"""
# load the oob monitors and initialize them
oob_storage = ServerConfig.objects.conf(key=self.oob_save_name)
if oob_storage:
self.oob_storage = dbunserialize(oob_storage)
for store_key, (args, kwargs) in self.oob_storage.items():
# re-create the monitors
obj, sessid, fieldname, oobfuncname = store_key
obj = unpack_dbobj(obj)
self._add_monitor(obj, sessid, fieldname, oobfuncname, *args, **kwargs)
# handle the tickers (same as in TickerHandler except we call
# the add_repeater method which makes sure to add the hooks before
# starting the tickerpool)
ticker_storage = ServerConfig.objects.conf(key=self.save_name)
if ticker_storage:
self.ticker_storage = dbunserialize(ticker_storage)
for store_key, (args, kwargs) in self.ticker_storage.items():
obj, interval, idstring = store_key
obj = unpack_dbobj(obj)
# we saved these in add_repeater before, can now retrieve them
sessid = kwargs["_sessid"]
oobfuncname = kwargs["_oobfuncname"]
self.add_repeater(obj, sessid, oobfuncname, interval, *args, **kwargs)
def add_repeater(self, obj, sessid, oobfuncname, interval=20, *args, **kwargs):
"""
Set an oob function to be repeatedly called.
Args:
obj (Object) - the object on which to register the repeat
sessid (int) - session id of the session registering
oobfuncname (str) - oob function name to call every interval seconds
interval (int, optional) - interval to call oobfunc, in seconds
Notes:
*args, **kwargs are used as extra arguments to the oobfunc.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
hook = OOBAtRepeater()
hookname = self._get_repeater_hook_name(oobfuncname, interval, sessid)
_SA(obj, hookname, hook)
# we store these in kwargs so that tickerhandler saves them with the rest
kwargs.update({"_sessid":sessid, "_oobfuncname":oobfuncname})
super(OOBHandler, self).add(obj, int(interval), oobfuncname, hookname, *args, **kwargs)
def remove_repeater(self, obj, sessid, oobfuncname, interval=20):
"""
Remove the repeatedly calling oob function
Args:
obj (Object): The object on which the repeater sits
sessid (int): Session id of the Session that registered the repeater
oobfuncname (str): Name of oob function to call at repeat
interval (int, optional): Number of seconds between repeats
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
super(OOBHandler, self).remove(obj, interval, idstring=oobfuncname)
hookname = self._get_repeater_hook_name(oobfuncname, interval, sessid)
try:
_DA(obj, hookname)
except AttributeError:
pass
def add_field_monitor(self, obj, sessid, field_name, oobfuncname, *args, **kwargs):
"""
Add a monitor tracking a database field
Args:
obj (Object): The object who'se field is to be monitored
sessid (int): Session if of the session monitoring
field_name (str): Name of database field to monitor. The db_* can optionally
be skipped (it will be automatically appended if missing)
oobfuncname (str): OOB function to call when field changes
Notes:
When the field updates the given oobfunction will be called as
`oobfuncname(session, fieldname, obj, *args, **kwargs)`
where `fieldname` is the name of the monitored field and
`obj` is the object on which the field sits. From this you
can also easily get the new field value if you want.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
# all database field names starts with db_*
field_name = field_name if field_name.startswith("db_") else "db_%s" % field_name
self._add_monitor(obj, sessid, field_name, oobfuncname, *args, **kwargs)
def remove_field_monitor(self, obj, sessid, field_name, oobfuncname=None):
"""
Un-tracks a database field
Args:
obj (Object): Entity with the monitored field
sessid (int): Session id of session that monitors
field_name (str): database field monitored (the db_* can optionally be
skipped (it will be auto-appended if missing)
oobfuncname (str, optional): OOB command to call on that field
Notes:
When the Attributes db_value updates the given oobfunction
will be called as
`oobfuncname(session, fieldname, obj, *args, **kwargs)`
where `fieldname` is the name of the monitored field and
`obj` is the object on which the field sits. From this you
can also easily get the new field value if you want.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
field_name = field_name if field_name.startswith("db_") else "db_%s" % field_name
self._remove_monitor(obj, sessid, field_name, oobfuncname=oobfuncname)
def add_attribute_monitor(self, obj, sessid, attr_name, oobfuncname, *args, **kwargs):
"""
Monitor the changes of an Attribute on an object. Will trigger when
the Attribute's `db_value` field updates.
Args:
obj (Object): Object with the Attribute to monitor.
sessid (int): Session id of monitoring Session.
attr_name (str): Name (key) of Attribute to monitor.
oobfuncname (str): OOB function to call when Attribute updates.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
# get the attribute object if we can
attrobj = obj.attributes.get(attr_name, return_obj=True)
if attrobj:
self._add_monitor(attrobj, sessid, "db_value", oobfuncname)
def remove_attribute_monitor(self, obj, sessid, attr_name, oobfuncname):
"""
Deactivate tracking for a given object's Attribute
Args:
obj (Object): Object monitored.
sessid (int): Session id of monitoring Session.
attr_name (str): Name of Attribute monitored.
oobfuncname (str): OOB function name called when Attribute updates.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
attrobj = obj.attributes.get(attr_name, return_obj=True)
if attrobj:
self._remove_monitor(attrobj, sessid, "db_value", oobfuncname)
def get_all_monitors(self, sessid):
"""
Get the names of all variables this session is tracking.
Args:
sessid (id): Session id of monitoring Session
Returns:
stored monitors (tuple): A list of tuples
`(obj, fieldname, args, kwargs)` representing all
the monitoring the Session with the given sessid is doing.
"""
# check so we didn't get a session instead of a sessid
if not isinstance(sessid, int):
sessid = sessid.sessid
# [(obj, fieldname, args, kwargs), ...]
return [(unpack_dbobj(key[0]), key[2], stored[0], stored[1])
for key, stored in self.oob_monitor_storage.items() if key[1] == sessid]
# access method - called from session.msg()
def execute_cmd(self, session, oobfuncname, *args, **kwargs):
"""
Execute an oob command
Args:
session (Session or int): Session or Session.sessid calling
the oob command
oobfuncname (str): The name of the oob command (case sensitive)
Notes:
If the oobfuncname is a valid oob function, `args` and
`kwargs` are passed into the oob command.
"""
if isinstance(session, int):
# a sessid. Convert to a session
session = SESSIONS.session_from_sessid(session)
if not session:
errmsg = "OOB Error: execute_cmd(%s,%s,%s,%s) - no valid session" % \
(session, oobfuncname, args, kwargs)
raise RuntimeError(errmsg)
try:
oobfunc = _OOB_FUNCS[oobfuncname]
except Exception:
errmsg = "'%s' is not a valid OOB command. Commands available:\n %s" % (oobfuncname, ", ".join(_OOB_FUNCS))
if _OOB_ERROR:
_OOB_ERROR(session, errmsg, *args, **kwargs)
errmsg = "OOB ERROR: %s" % errmsg
logger.log_trace(errmsg)
return
# we found an oob command. Execute it.
try:
oobfunc(session, *args, **kwargs)
except Exception as err:
errmsg = "Exception in %s(*%s, **%s):\n%s" % (oobfuncname, args, kwargs, err)
if _OOB_ERROR:
_OOB_ERROR(session, errmsg, *args, **kwargs)
errmsg = "OOB ERROR: %s" % errmsg
logger.log_trace(errmsg)
# access object
OOB_HANDLER = OOBHandler()
# load resources from plugin module. This must happen
# AFTER the OOB_HANDLER has been initialized since the
# commands will want to import it.
_OOB_FUNCS = {}
for modname in make_iter(settings.OOB_PLUGIN_MODULES):
_OOB_FUNCS.update(mod_import(modname).CMD_MAP)
# get the command to receive eventual error strings
_OOB_ERROR = _OOB_FUNCS.get("oob_error", None)
if not _OOB_ERROR:
# no custom error set; create default oob error message function
def oob_error(session, errmsg, *args, **kwargs):
"""
Fallback error handler. This will be used if no custom
oob_error is defined and just echoes the error back to the
session.
Args:
errmsg (str): Error message to echo.
args, kwargs (any): Not used.
"""
session.msg(oob=("err", ("ERROR ", errmsg)))
_OOB_ERROR = oob_error