evennia/lib/typeclasses/attributes.py

515 lines
20 KiB
Python

"""
Attributes are arbitrary data stored on objects. Attributes supports
both pure-string values and pickled arbitrary data.
Attributes are also used to implement Nicks. This module also contains
the Attribute- and NickHandlers as well as the NAttributeHandler,
which is a non-db version of Attributes.
"""
import re
import weakref
from django.db import models
from django.conf import settings
from django.utils.encoding import smart_str
from src.locks.lockhandler import LockHandler
from src.utils.idmapper.models import SharedMemoryModel
from src.utils.dbserialize import to_pickle, from_pickle
from src.utils.picklefield import PickledObjectField
from src.utils.utils import lazy_property, to_str, make_iter
_TYPECLASS_AGGRESSIVE_CACHE = settings.TYPECLASS_AGGRESSIVE_CACHE
#------------------------------------------------------------
#
# Attributes
#
#------------------------------------------------------------
class Attribute(SharedMemoryModel):
"""
Attributes are things that are specific to different types of objects. For
example, a drink container needs to store its fill level, whereas an exit
needs to store its open/closed/locked/unlocked state. These are done via
attributes, rather than making different classes for each object type and
storing them directly. The added benefit is that we can add/remove
attributes on the fly as we like.
The Attribute class defines the following properties:
key - primary identifier
lock_storage - perm strings
obj - which object the attribute is defined on
date_created - when the attribute was created.
value - the data stored in the attribute, in pickled form
using wrappers to be able to store/retrieve models.
strvalue - string-only data. This data is not pickled and is
thus faster to search for in the database.
category - optional character string for grouping the Attribute
"""
#
# Attribute Database Model setup
#
# These database fields are all set using their corresponding properties,
# named same as the field, but withtout the db_* prefix.
db_key = models.CharField('key', max_length=255, db_index=True)
db_value = PickledObjectField(
'value', null=True,
help_text="The data returned when the attribute is accessed. Must be "
"written as a Python literal if editing through the admin "
"interface. Attribute values which are not Python literals "
"cannot be edited through the admin interface.")
db_strvalue = models.TextField(
'strvalue', null=True, blank=True,
help_text="String-specific storage for quick look-up")
db_category = models.CharField(
'category', max_length=128, db_index=True, blank=True, null=True,
help_text="Optional categorization of attribute.")
# Lock storage
db_lock_storage = models.TextField(
'locks', blank=True,
help_text="Lockstrings for this object are stored here.")
db_model = models.CharField(
'model', max_length=32, db_index=True, blank=True, null=True,
help_text="Which model of object this attribute is attached to (A "
"natural key like 'objects.dbobject'). You should not change "
"this value unless you know what you are doing.")
# subclass of Attribute (None or nick)
db_attrtype = models.CharField(
'attrtype', max_length=16, db_index=True, blank=True, null=True,
help_text="Subclass of Attribute (None or nick)")
# time stamp
db_date_created = models.DateTimeField(
'date_created', editable=False, auto_now_add=True)
# Database manager
#objects = managers.AttributeManager()
@lazy_property
def locks(self):
return LockHandler(self)
class Meta:
"Define Django meta options"
verbose_name = "Evennia Attribute"
# read-only wrappers
key = property(lambda self: self.db_key)
strvalue = property(lambda self: self.db_strvalue)
category = property(lambda self: self.db_category)
model = property(lambda self: self.db_model)
attrtype = property(lambda self: self.db_attrtype)
date_created = property(lambda self: self.db_date_created)
def __lock_storage_get(self):
return self.db_lock_storage
def __lock_storage_set(self, value):
self.db_lock_storage = value
self.save(update_fields=["db_lock_storage"])
def __lock_storage_del(self):
self.db_lock_storage = ""
self.save(update_fields=["db_lock_storage"])
lock_storage = property(__lock_storage_get, __lock_storage_set, __lock_storage_del)
# Wrapper properties to easily set database fields. These are
# @property decorators that allows to access these fields using
# normal python operations (without having to remember to save()
# etc). So e.g. a property 'attr' has a get/set/del decorator
# defined that allows the user to do self.attr = value,
# value = self.attr and del self.attr respectively (where self
# is the object in question).
# value property (wraps db_value)
#@property
def __value_get(self):
"""
Getter. Allows for value = self.value.
We cannot cache here since it makes certain cases (such
as storing a dbobj which is then deleted elsewhere) out-of-sync.
The overhead of unpickling seems hard to avoid.
"""
return from_pickle(self.db_value, db_obj=self)
#@value.setter
def __value_set(self, new_value):
"""
Setter. Allows for self.value = value. We cannot cache here,
see self.__value_get.
"""
self.db_value = to_pickle(new_value)
self.save(update_fields=["db_value"])
#@value.deleter
def __value_del(self):
"Deleter. Allows for del attr.value. This removes the entire attribute."
self.delete()
value = property(__value_get, __value_set, __value_del)
#
#
# Attribute methods
#
#
def __str__(self):
return smart_str("%s(%s)" % (self.db_key, self.id))
def __unicode__(self):
return u"%s(%s)" % (self.db_key,self.id)
def access(self, accessing_obj, access_type='read', default=False, **kwargs):
"""
Determines if another object has permission to access.
accessing_obj - object trying to access this one
access_type - type of access sought
default - what to return if no lock of access_type was found
**kwargs - passed to at_access hook along with result.
"""
result = self.locks.check(accessing_obj, access_type=access_type, default=default)
#self.at_access(result, **kwargs)
return result
#
# Handlers making use of the Attribute model
#
class AttributeHandler(object):
"""
Handler for adding Attributes to the object.
"""
_m2m_fieldname = "db_attributes"
_attrcreate = "attrcreate"
_attredit = "attredit"
_attrread = "attrread"
_attrtype = None
def __init__(self, obj):
"Initialize handler"
self.obj = obj
self._objid = obj.id
self._model = to_str(obj.__dbclass__.__name__.lower())
self._cache = None
def _recache(self):
"Cache all attributes of this object"
query = {"%s__id" % self._model : self._objid,
"attribute__db_attrtype" : self._attrtype}
attrs = [conn.attribute for conn in getattr(self.obj, self._m2m_fieldname).through.objects.filter(**query)]
self._cache = dict(("%s-%s" % (to_str(attr.db_key).lower(),
attr.db_category.lower() if conn.attribute.db_category else None),
attr) for attr in attrs)
def has(self, key, category=None):
"""
Checks if the given Attribute (or list of Attributes) exists on
the object.
If an iterable is given, returns list of booleans.
"""
if self._cache is None or not _TYPECLASS_AGGRESSIVE_CACHE:
self._recache()
key = [k.strip().lower() for k in make_iter(key) if k]
category = category.strip().lower() if category is not None else None
searchkeys = ["%s-%s" % (k, category) for k in make_iter(key)]
ret = [self._cache.get(skey) for skey in searchkeys if skey in self._cache]
return ret[0] if len(ret) == 1 else ret
def get(self, key=None, category=None, default=None, return_obj=False,
strattr=False, raise_exception=False, accessing_obj=None,
default_access=True, not_found_none=False):
"""
Returns the value of the given Attribute or list of Attributes.
strattr will cause the string-only value field instead of the normal
pickled field data. Use to get back values from Attributes added with
the strattr keyword.
If return_obj=True, return the matching Attribute object
instead. Returns default if no matches (or [ ] if key was a list
with no matches). If raise_exception=True, failure to find a
match will raise AttributeError instead.
If accessing_obj is given, its "attrread" permission lock will be
checked before displaying each looked-after Attribute. If no
accessing_obj is given, no check will be done.
"""
class RetDefault(object):
"Holds default values"
def __init__(self):
self.value = default
self.strvalue = str(default) if default is not None else None
if self._cache is None or not _TYPECLASS_AGGRESSIVE_CACHE:
self._recache()
ret = []
key = [k.strip().lower() for k in make_iter(key) if k]
category = category.strip().lower() if category is not None else None
#print "cache:", self._cache.keys(), key
if not key:
# return all with matching category (or no category)
catkey = "-%s" % category if category is not None else None
ret = [attr for key, attr in self._cache.items() if key and key.endswith(catkey)]
else:
for searchkey in ("%s-%s" % (k, category) for k in key):
attr_obj = self._cache.get(searchkey)
if attr_obj:
ret.append(attr_obj)
else:
if raise_exception:
raise AttributeError
else:
ret.append(RetDefault())
if accessing_obj:
# check 'attrread' locks
ret = [attr for attr in ret if attr.access(accessing_obj, self._attrread, default=default_access)]
if strattr:
ret = ret if return_obj else [attr.strvalue for attr in ret if attr]
else:
ret = ret if return_obj else [attr.value for attr in ret if attr]
if not ret:
return ret if len(key) > 1 else default
return ret[0] if len(ret)==1 else ret
def add(self, key, value, category=None, lockstring="",
strattr=False, accessing_obj=None, default_access=True):
"""
Add attribute to object, with optional lockstring.
If strattr is set, the db_strvalue field will be used (no pickling).
Use the get() method with the strattr keyword to get it back.
If accessing_obj is given, self.obj's 'attrcreate' lock access
will be checked against it. If no accessing_obj is given, no check
will be done.
"""
if accessing_obj and not self.obj.access(accessing_obj,
self._attrcreate, default=default_access):
# check create access
return
if self._cache is None:
self._recache()
if not key:
return
category = category.strip().lower() if category is not None else None
keystr = key.strip().lower()
cachekey = "%s-%s" % (keystr, category)
attr_obj = self._cache.get(cachekey)
if attr_obj:
# update an existing attribute object
if strattr:
# store as a simple string (will not notify OOB handlers)
attr_obj.db_strvalue = value
attr_obj.save(update_fields=["db_strvalue"])
else:
# store normally (this will also notify OOB handlers)
attr_obj.value = value
else:
# create a new Attribute (no OOB handlers can be notified)
kwargs = {"db_key" : keystr, "db_category" : category,
"db_model" : self._model, "db_attrtype" : self._attrtype,
"db_value" : None if strattr else to_pickle(value),
"db_strvalue" : value if strattr else None}
new_attr = Attribute(**kwargs)
new_attr.save()
getattr(self.obj, self._m2m_fieldname).add(new_attr)
self._cache[cachekey] = new_attr
def batch_add(self, key, value, category=None, lockstring="",
strattr=False, accessing_obj=None, default_access=True):
"""
Batch-version of add(). This is more efficient than
repeat-calling add.
key and value must be sequences of the same length, each
representing a key-value pair.
"""
if accessing_obj and not self.obj.access(accessing_obj,
self._attrcreate, default=default_access):
# check create access
return
if self._cache is None:
self._recache()
if not key:
return
keys, values= make_iter(key), make_iter(value)
if len(keys) != len(values):
raise RuntimeError("AttributeHandler.add(): key and value of different length: %s vs %s" % key, value)
category = category.strip().lower() if category is not None else None
new_attrobjs = []
for ikey, keystr in enumerate(keys):
keystr = keystr.strip().lower()
new_value = values[ikey]
cachekey = "%s-%s" % (keystr, category)
attr_obj = self._cache.get(cachekey)
if attr_obj:
# update an existing attribute object
if strattr:
# store as a simple string (will not notify OOB handlers)
attr_obj.db_strvalue = new_value
attr_obj.save(update_fields=["db_strvalue"])
else:
# store normally (this will also notify OOB handlers)
attr_obj.value = new_value
else:
# create a new Attribute (no OOB handlers can be notified)
kwargs = {"db_key" : keystr, "db_category" : category,
"db_attrtype" : self._attrtype,
"db_value" : None if strattr else to_pickle(new_value),
"db_strvalue" : value if strattr else None}
new_attr = Attribute(**kwargs)
new_attr.save()
new_attrobjs.append(new_attr)
if new_attrobjs:
# Add new objects to m2m field all at once
getattr(self.obj, self._m2m_fieldname).add(*new_attrobjs)
self._recache()
def remove(self, key, raise_exception=False, category=None,
accessing_obj=None, default_access=True):
"""Remove attribute or a list of attributes from object.
If accessing_obj is given, will check against the 'attredit' lock.
If not given, this check is skipped.
"""
if self._cache is None or not _TYPECLASS_AGGRESSIVE_CACHE:
self._recache()
key = [k.strip().lower() for k in make_iter(key) if k]
category = category.strip().lower() if category is not None else None
for searchstr in ("%s-%s" % (k, category) for k in key):
attr_obj = self._cache.get(searchstr)
if attr_obj:
if not (accessing_obj and not attr_obj.access(accessing_obj,
self._attredit, default=default_access)):
attr_obj.delete()
elif not attr_obj and raise_exception:
raise AttributeError
self._recache()
def clear(self, category=None, accessing_obj=None, default_access=True):
"""
Remove all Attributes on this object. If accessing_obj is
given, check the 'attredit' lock on each Attribute before
continuing. If not given, skip check.
"""
if self._cache is None or not _TYPECLASS_AGGRESSIVE_CACHE:
self._recache()
if accessing_obj:
[attr.delete() for attr in self._cache.values()
if attr.access(accessing_obj, self._attredit, default=default_access)]
else:
[attr.delete() for attr in self._cache.values()]
self._recache()
def all(self, accessing_obj=None, default_access=True):
"""
Return all Attribute objects on this object.
If accessing_obj is given, check the "attrread" lock on
each attribute before returning them. If not given, this
check is skipped.
"""
if self._cache is None or not _TYPECLASS_AGGRESSIVE_CACHE:
self._recache()
attrs = sorted(self._cache.values(), key=lambda o: o.id)
if accessing_obj:
return [attr for attr in attrs
if attr.access(accessing_obj, self._attredit, default=default_access)]
else:
return attrs
class NickHandler(AttributeHandler):
"""
Handles the addition and removal of Nicks
(uses Attributes' strvalue and category fields)
Nicks are stored as Attributes
with categories nick_<nicktype>
"""
_attrtype = "nick"
def has(self, key, category="inputline"):
return super(NickHandler, self).has(key, category=category)
def get(self, key=None, category="inputline", **kwargs):
"Get the replacement value matching the given key and category"
return super(NickHandler, self).get(key=key, category=category, strattr=True, **kwargs)
def add(self, key, replacement, category="inputline", **kwargs):
"Add a new nick"
super(NickHandler, self).add(key, replacement, category=category, strattr=True, **kwargs)
def remove(self, key, category="inputline", **kwargs):
"Remove Nick with matching category"
super(NickHandler, self).remove(key, category=category, **kwargs)
def nickreplace(self, raw_string, categories=("inputline", "channel"), include_player=True):
"Replace entries in raw_string with nick replacement"
raw_string
obj_nicks, player_nicks = [], []
for category in make_iter(categories):
obj_nicks.extend([n for n in make_iter(self.get(category=category, return_obj=True)) if n])
if include_player and self.obj.has_player:
for category in make_iter(categories):
player_nicks.extend([n for n in make_iter(self.obj.player.nicks.get(category=category, return_obj=True)) if n])
for nick in obj_nicks + player_nicks:
# make a case-insensitive match here
match = re.match(re.escape(nick.db_key), raw_string, re.IGNORECASE)
if match:
raw_string = raw_string.replace(match.group(), nick.db_strvalue, 1)
break
return raw_string
class NAttributeHandler(object):
"""
This stand-alone handler manages non-database saving.
It is similar to AttributeHandler and is used
by the .ndb handler in the same way as .db does
for the AttributeHandler.
"""
def __init__(self, obj):
"initialized on the object"
self._store = {}
self.obj = weakref.proxy(obj)
def has(self, key):
"Check if object has this attribute or not"
return key in self._store
def get(self, key):
"Returns named key value"
return self._store.get(key, None)
def add(self, key, value):
"Add new key and value"
self._store[key] = value
self.obj.set_recache_protection()
def remove(self, key):
"Remove key from storage"
if key in self._store:
del self._store[key]
self.obj.set_recache_protection(self._store)
def clear(self):
"Remove all nattributes from handler"
self._store = {}
def all(self, return_tuples=False):
"List all keys or (keys, values) stored, except _keys"
if return_tuples:
return [(key, value) for (key, value) in self._store.items() if not key.startswith("_")]
return [key for key in self._store if not key.startswith("_")]