Added at_idmapper_flush to allow objects more control of their flush characteristics.

evennia/objects/models.py

@@ -51,10 +51,10 @@ class ContentsHandler(object):
         Re-initialize the content cache
 
         """
-        print "__init__", self.obj, calledby()
+        #print "__init__", self.obj, calledby()
         self._pkcache.update(dict((obj.pk, None) for obj in
                             ObjectDB.objects.filter(db_location=self.obj) if obj.pk))
-        print "init contentscache: self._pkcache:", self.obj, self._pkcache
+        #print "init contentscache: self._pkcache:", self.obj, self._pkcache, id(self._pkcache), id(self)
 
     def get(self, exclude=None):
         """
@@ -70,15 +70,15 @@ class ContentsHandler(object):
         if exclude:
             pks = [pk for pk in self._pkcache if pk not in [excl.pk for excl in make_iter(exclude)]]
         else:
-            print calledby()
+            #print calledby()
-            print "get: self._pkcache", self.obj, self._pkcache
+            #print "get: self._pkcache", self.obj, self._pkcache, id(self._pkcache), id(self)
             pks = self._pkcache
         try:
             return [self._idcache[pk] for pk in pks]
         except KeyError, err:
             # this can happen if the idmapper cache was cleared for an object
             # in the contents cache. If so we need to re-initialize and try again.
-            print "content_cache.get keyerror:", err, self._pkcache, self._idcache
+            #print "content_cache.get keyerror:", err, self._pkcache, self._idcache
             self.init()
             try:
                 return [self._idcache[pk] for pk in pks]
@@ -96,7 +96,7 @@ class ContentsHandler(object):
 
         """
         self._pkcache[obj.pk] = None
-        print "add self._pkcache:", self.obj, obj, obj.pk, self._pkcache
+        #print "add self._pkcache:", self.obj, obj, obj.pk, self._pkcache
 
     def remove(self, obj):
         """
@@ -107,7 +107,7 @@ class ContentsHandler(object):
 
         """
         self._pkcache.pop(obj.pk, None)
-        print "remove self._pkcache", self.obj, obj, obj.pk, self._pkcache
+        #print "remove self._pkcache", self.obj, obj, obj.pk, self._pkcache
 
     def clear(self):
         """
@@ -116,7 +116,7 @@ class ContentsHandler(object):
         """
         self._pkcache = {}
         self.init()
-        print "clear _pkcache", self.obj, self._pkcache
+        #print "clear _pkcache", self.obj, self._pkcache
 
 #------------------------------------------------------------
 #
@@ -272,12 +272,12 @@ class ObjectDB(TypedObject):
             # remove the safe flag
             del self._safe_contents_update
 
-            print "location_set:", self.key, old_location, self.db_location
+            #print "location_set:", self.key, old_location, self.db_location
             # update the contents cache
             if old_location:
                 old_location.contents_cache.remove(self)
             if self.db_location:
-                print "cache add:", self.db_location, self
+                #print "cache add:", self.db_location, self
                 self.db_location.contents_cache.add(self)
 
         except RuntimeError:

evennia/objects/objects.py

@@ -228,7 +228,7 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
 
         """
         con = self.contents_cache.get(exclude=exclude)
-        print "contents_get:", self, con, calledby()
+        #print "contents_get:", self, con, id(self), calledby()
         return con
     contents = property(contents_get)
 
@@ -267,7 +267,6 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
             return "{}(#{})".format(self.name, self.id)
         return self.name
 
-
     def search(self, searchdata,
                global_search=False,
                use_nicks=True,  # should this default to off?
@@ -1134,7 +1133,6 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
         """
         pass
 
-
     # hooks called when moving the object
 
     def at_before_move(self, destination):

evennia/typeclasses/attributes.py

@@ -325,6 +325,14 @@ class AttributeHandler(object):
         self._catcache.pop(catkey, None)
         self._cache_complete = False
 
+    def reset_cache(self):
+        """
+        Reset cache from the outside.
+        """
+        self._cache_complete = False
+        self._cache = {}
+        self._catcache = {}
+
     def has(self, key=None, category=None):
         """
         Checks if the given Attribute (or list of Attributes) exists on
@@ -910,7 +918,6 @@ class NAttributeHandler(object):
 
         """
         self._store[key] = value
-        self.obj.set_recache_protection()
 
     def remove(self, key):
         """
@@ -922,7 +929,6 @@ class NAttributeHandler(object):
         """
         if key in self._store:
             del self._store[key]
-        self.obj.set_recache_protection(self._store)
 
     def clear(self):
         """

evennia/typeclasses/models.py

@@ -376,6 +376,27 @@ class TypedObject(SharedMemoryModel):
         raise Exception("dbref cannot be deleted!")
     dbref = property(__dbref_get, __dbref_set, __dbref_del)
 
+    def at_idmapper_flush(self):
+        """
+        This is called when the idmapper cache is flushed and
+        allows customized actions when this happens.
+
+        Returns:
+            do_flush (bool): If True, flush this object as normal. If
+                False, don't flush and expect this object to handle
+                the flushing on its own.
+
+        """
+        if self.nattributes.all():
+            # we can't flush this object if we have non-persistent
+            # attributes stored - those would get lost! Nevertheless
+            # we try to flush as many references as we can.
+            self.attributes.reset_cache()
+            self.tags.reset_cache()
+            return False
+        # a normal flush
+        return True
+
     #
     # Object manipulation methods
     #

evennia/typeclasses/tags.py

@@ -212,6 +212,13 @@ class TagHandler(object):
         self._catcache.pop(catkey, None)
         self._cache_complete = False
 
+    def reset_cache(self):
+        """
+        Reset the cache from the outside.
+        """
+        self._cache_complete = False
+        self._cache = {}
+        self._catcache = {}
 
     def add(self, tag=None, category=None, data=None):
         """

evennia/utils/idmapper/models.py

@@ -79,7 +79,6 @@ class SharedMemoryModelBase(ModelBase):
         # the dbmodel is either the proxy base or ourselves
         dbmodel = cls._meta.proxy_for_model if cls._meta.proxy else cls
         cls.__dbclass__ = dbmodel
-        dbmodel._idmapper_recache_protection = False
         if not hasattr(dbmodel, "__instance_cache__"):
             # we store __instance_cache__ only on the dbmodel base
             dbmodel.__instance_cache__ = {}
@@ -291,8 +290,10 @@ class SharedMemoryModel(with_metaclass(SharedMemoryModelBase, Model)):
 
         """
         try:
-            if force or not cls._idmapper_recache_protection:
+            if force or cls.at_idmapper_flush():
                 del cls.__dbclass__.__instance_cache__[key]
+            else:
+                cls._dbclass__.__instance_cache__[key].refresh_from_db()
         except KeyError:
             pass
 
@@ -319,27 +320,37 @@ class SharedMemoryModel(with_metaclass(SharedMemoryModelBase, Model)):
             cls.__dbclass__.__instance_cache__ = {}
         else:
             cls.__dbclass__.__instance_cache__ = dict((key, obj) for key, obj in cls.__dbclass__.__instance_cache__.items()
-                                                      if obj._idmapper_recache_protection)
+                                                      if not obj.at_idmapper_flush())
+            for ins in cls.__dbclass__.__instance_cache__.itervalues():
+                ins.refresh_from_db()
     #flush_instance_cache = classmethod(flush_instance_cache)
 
     # per-instance methods
 
+    def at_idmapper_flush(self):
+        """
+        This is called when the idmapper cache is flushed and
+        allows customized actions when this happens.
+
+        Returns:
+            do_flush (bool): If True, flush this object as normal. If
+                False, don't flush and expect this object to handle
+                the flushing on its own.
+        """
+        return True
+
     def flush_from_cache(self, force=False):
         """
         Flush this instance from the instance cache. Use
-        `force` to override recache_protection for the object.
+        `force` to override the result of at_idmapper_flush() for the object.
 
         """
         pk = self._get_pk_val()
-        if pk and (force or not self._idmapper_recache_protection):
+        if pk:
+            if force or self.at_idmapper_flush():
                 self.__class__.__dbclass__.__instance_cache__.pop(pk, None)
-
+            else:
-    def set_recache_protection(self, mode=True):
+                self.refresh_from_db()
-        """
-        Set if this instance should be allowed to be recached.
-
-        """
-        self._idmapper_recache_protection = bool(mode)
 
     def delete(self, *args, **kwargs):
         """
@@ -415,7 +426,6 @@ class WeakSharedMemoryModelBase(SharedMemoryModelBase):
     def _prepare(cls):
         super(WeakSharedMemoryModelBase, cls)._prepare()
         cls.__dbclass__.__instance_cache__ = WeakValueDictionary()
-        cls._idmapper_recache_protection = False
 
 
 class WeakSharedMemoryModel(with_metaclass(WeakSharedMemoryModelBase, SharedMemoryModel)):
@@ -429,10 +439,9 @@ class WeakSharedMemoryModel(with_metaclass(WeakSharedMemoryModelBase, SharedMemo
 
 def flush_cache(**kwargs):
     """
-    Flush idmapper cache. When doing so the cache will
+    Flush idmapper cache. When doing so the cache will fire the
-    look for a property `_idmapper_cache_flush_safe` on the
+    at_idmapper_flush hook to allow the object to optionally handle
-    class/subclass instance and only flush if this
+    its own flushing.
-    is `True`.
 
     Uses a signal so we make sure to catch cascades.