From 9bfb82927447a15a9486bf4a5df433dbe151497d Mon Sep 17 00:00:00 2001
From: Griatch <griatch@gmail.com>
Date: Sun, 11 May 2014 15:23:11 +0200
Subject: [PATCH] Implemented WeakSharedMemoryModel for Attributes.

---
 src/commands/cmdhandler.py   | 12 ++++++++++--
 src/typeclasses/models.py    |  6 +++---
 src/utils/idmapper/base.py   | 21 +++++++++++++++++++++
 src/utils/idmapper/models.py |  2 +-
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/commands/cmdhandler.py b/src/commands/cmdhandler.py
index 0511ad7c92..33116d915e 100644
--- a/src/commands/cmdhandler.py
+++ b/src/commands/cmdhandler.py
@@ -35,6 +35,7 @@ command line. The process is as follows:
 
 """
 
+from weakref import WeakValueDictionary
 from copy import copy
 from traceback import format_exc
 from twisted.internet.defer import inlineCallbacks, returnValue
@@ -42,13 +43,13 @@ from django.conf import settings
 from src.comms.channelhandler import CHANNELHANDLER
 from src.utils import logger, utils
 from src.commands.cmdparser import at_multimatch_cmd
-from src.utils.utils import string_suggestions, make_iter, to_unicode
+from src.utils.utils import string_suggestions, to_unicode
 
 from django.utils.translation import ugettext as _
 
 __all__ = ("cmdhandler",)
 _GA = object.__getattribute__
-_CMDSET_MERGE_CACHE = {}
+_CMDSET_MERGE_CACHE = WeakValueDictionary()
 
 # This decides which command parser is to be used.
 # You have to restart the server for changes to take effect.
@@ -408,6 +409,13 @@ def cmdhandler(called_by, raw_string, testing=False, callertype="session", sessi
                 caller.ndb.last_cmd = yield copy(cmd)
             else:
                 caller.ndb.last_cmd = None
+
+            # cleanup
+            del cmd.caller
+            del cmd.player
+            del cmd.session
+            del cmd.cmdset
+
             # Done! This returns a deferred. By default, Evennia does
             # not use this at all.
             returnValue(ret)
diff --git a/src/typeclasses/models.py b/src/typeclasses/models.py
index 00bb2a745d..2d36e16609 100644
--- a/src/typeclasses/models.py
+++ b/src/typeclasses/models.py
@@ -35,7 +35,7 @@ from django.conf import settings
 from django.utils.encoding import smart_str
 from django.contrib.contenttypes.models import ContentType
 
-from src.utils.idmapper.models import SharedMemoryModel
+from src.utils.idmapper.models import SharedMemoryModel, WeakSharedMemoryModel
 from src.server.caches import get_prop_cache, set_prop_cache
 #from src.server.caches import set_attr_cache
 
@@ -44,7 +44,7 @@ from src.server.models import ServerConfig
 from src.typeclasses import managers
 from src.locks.lockhandler import LockHandler
 from src.utils import logger
-from src.utils.utils import make_iter, is_iter, to_str, inherits_from, LazyLoadHandler, NonWeakLazyLoadHandler
+from src.utils.utils import make_iter, is_iter, to_str, inherits_from, LazyLoadHandler
 from src.utils.dbserialize import to_pickle, from_pickle
 from src.utils.picklefield import PickledObjectField
 
@@ -66,7 +66,7 @@ _DA = object.__delattr__
 #------------------------------------------------------------
 
 #class Attribute(SharedMemoryModel):
-class Attribute(models.Model):
+class Attribute(WeakSharedMemoryModel):
     """
     Abstract django model.
 
diff --git a/src/utils/idmapper/base.py b/src/utils/idmapper/base.py
index 832b5d1929..cbf17b4063 100755
--- a/src/utils/idmapper/base.py
+++ b/src/utils/idmapper/base.py
@@ -271,6 +271,27 @@ class SharedMemoryModel(Model):
             #blockingCallFromThread(reactor, _save_callback, cls, *args, **kwargs)
             callFromThread(_save_callback, cls, *args, **kwargs)
 
+
+class WeakSharedMemoryModelBase(SharedMemoryModelBase):
+    """
+    Uses a WeakValue dictionary for caching instead of a regular one
+    """
+    def _prepare(cls):
+        cls.__instance_cache__ = WeakValueDictionary()
+        super(WeakSharedMemoryModelBase, cls)._prepare()
+
+class WeakSharedMemoryModel(SharedMemoryModel):
+    """
+    Uses a WeakValue dictionary for caching instead of a regular one
+    """
+    __metaclass__ = WeakSharedMemoryModelBase
+    class Meta:
+        abstract = True
+    def flush_instance_cache(cls):
+        cls.__instance_cache__ = WeakValueDictionary()
+    flush_instance_cache = classmethod(flush_instance_cache)
+
+
 # Use a signal so we make sure to catch cascades.
 def flush_cache(**kwargs):
     def class_hierarchy(root):
diff --git a/src/utils/idmapper/models.py b/src/utils/idmapper/models.py
index 7f67eb5660..c70fd19092 100755
--- a/src/utils/idmapper/models.py
+++ b/src/utils/idmapper/models.py
@@ -1,2 +1,2 @@
 from django.db.models import *
-from base import SharedMemoryModel
\ No newline at end of file
+from base import SharedMemoryModel, WeakSharedMemoryModel