Merge eaf8672 into 1b67cdd

cachetools/keys.py

@@ -21,8 +21,22 @@ def __add__(self, other, add=tuple.__add__):
     def __radd__(self, other, add=tuple.__add__):
         return _HashedTuple(add(other, self))
 
+    def __getstate__(self):
+        return {}  # Don't pickle the runtime-dependent hashvalue
 
-_kwmark = (object(),)
+
+class _KeyWordMark(object):
+    # defines this class as singleton
+    def __new__(cls, *args, **kwargs):
+        it = cls.__dict__.get("__it__")
+        if it is not None:
+            return it
+        cls.__it__ = it = object.__new__(cls)
+        it.__init__(*args, **kwargs)
+        return it
+
+
+_kwmark = (_KeyWordMark(),)
 
 
 def hashkey(*args, **kwargs):

tests/test_method.py

@@ -3,6 +3,8 @@
 
 from cachetools import LRUCache, cachedmethod, keys
 
+import pytest
+
 
 class Cached(object):
 
@@ -44,6 +46,18 @@ def __exit__(self, *exc):
         pass
 
 
+class Pickled(object):
+    def __init__(self):
+        self.cache = {}
+
+    @cachedmethod(operator.attrgetter('cache'))
+    def calc(self, text, x, times_two=False):
+        result = 42*x
+        if times_two:
+            result *= 2
+        return result
+
+
 class CachedMethodTest(unittest.TestCase):
 
     def test_dict(self):
@@ -166,3 +180,28 @@ def test_locked_nospace(self):
         self.assertEqual(cached.get(1), 5)
         self.assertEqual(cached.get(1.0), 7)
         self.assertEqual(cached.get(1.0), 9)
+
+    def _call_pickle_obj(self, obj):
+        obj.calc("abc", 69)
+        obj.calc("abc", 72, times_two=True)
+
+    def test_pickle_hashvalue_store(self):
+        import pickle
+
+        obj = Pickled()
+        self._call_pickle_obj(obj)
+        with open('./pickle_test.pickle', 'bw') as fh:
+            pickle.dump(obj, fh)
+        assert len(obj.cache) == 2
+
+    @pytest.mark.pickle_restore()
+    def test_pickle_hashvalue_restore(self):
+        import pickle
+
+        with open('./pickle_test.pickle', 'br') as fh:
+            obj = pickle.load(fh)
+
+        # do the same calculations as in `test_pickle_hashvalue_store`
+        self._call_pickle_obj(obj)
+        # assure that there a no duplications due to new hash values
+        assert len(obj.cache) == 2

tox.ini

@@ -7,7 +7,8 @@ deps =
     pytest
     pytest-cov
 commands =
-    py.test --basetemp={envtmpdir} --cov=cachetools {posargs}
+    py.test --basetemp={envtmpdir} --cov=cachetools {posargs} -m "not pickle_restore"
+    py.test --basetemp={envtmpdir} --cov=cachetools {posargs} -m pickle_restore
 
 [testenv:check-manifest]
 deps =
@@ -36,3 +37,7 @@ deps =
 commands =
     flake8
 skip_install = true
+
+[pytest]
+markers =
+    pickle_restore: restoring a pickle from previous run