import sys
import unittest
import weakref
from test_support import run_unittest
class C:
def method(self):
pass
class Callable:
bar = None
def __call__(self, x):
self.bar = x
def create_function():
def f(): pass
return f
def create_bound_method():
return C().method
def create_unbound_method():
return C.method
class TestBase(unittest.TestCase):
def setUp(self):
self.cbcalled = 0
def callback(self, ref):
self.cbcalled += 1
class ReferencesTestCase(TestBase):
def test_basic_ref(self):
self.check_basic_ref(C)
self.check_basic_ref(create_function)
self.check_basic_ref(create_bound_method)
self.check_basic_ref(create_unbound_method)
def test_basic_callback(self):
self.check_basic_callback(C)
self.check_basic_callback(create_function)
self.check_basic_callback(create_bound_method)
self.check_basic_callback(create_unbound_method)
def test_multiple_callbacks(self):
o = C()
ref1 = weakref.ref(o, self.callback)
ref2 = weakref.ref(o, self.callback)
del o
self.assert_(ref1() is None,
"expected reference to be invalidated")
self.assert_(ref2() is None,
"expected reference to be invalidated")
self.assert_(self.cbcalled == 2,
"callback not called the right number of times")
def test_multiple_selfref_callbacks(self):
"""Make sure all references are invalidated before callbacks
are called."""
#
# What's important here is that we're using the first
# reference in the callback invoked on the second reference
# (the most recently created ref is cleaned up first). This
# tests that all references to the object are invalidated
# before any of the callbacks are invoked, so that we only
# have one invocation of _weakref.c:cleanup_helper() active
# for a particular object at a time.
#
def callback(object, self=self):
self.ref()
c = C()
self.ref = weakref.ref(c, callback)
ref1 = weakref.ref(c, callback)
del c
def test_proxy_ref(self):
o = C()
o.bar = 1
ref1 = weakref.proxy(o, self.callback)
ref2 = weakref.proxy(o, self.callback)
del o
def check(proxy):
proxy.bar
self.assertRaises(weakref.ReferenceError, check, ref1)
self.assertRaises(weakref.ReferenceError, check, ref2)
self.assert_(self.cbcalled == 2)
def check_basic_ref(self, factory):
o = factory()
ref = weakref.ref(o)
self.assert_(ref() is not None,
"weak reference to live object should be live")
o2 = ref()
self.assert_(o is o2,
"<ref>() should return original object if live")
def check_basic_callback(self, factory):
self.cbcalled = 0
o = factory()
ref = weakref.ref(o, self.callback)
del o
self.assert_(self.cbcalled == 1,
"callback did not properly set 'cbcalled'")
self.assert_(ref() is None,
"ref2 should be dead after deleting object reference")
def test_ref_reuse(self):
o = C()
ref1 = weakref.ref(o)
# create a proxy to make sure that there's an intervening creation
# between these two; it should make no difference
proxy = weakref.proxy(o)
ref2 = weakref.ref(o)
self.assert_(ref1 is ref2,
"reference object w/out callback should be re-used")
o = C()
proxy = weakref.proxy(o)
ref1 = weakref.ref(o)
ref2 = weakref.ref(o)
self.assert_(ref1 is ref2,
"reference object w/out callback should be re-used")
self.assert_(weakref.getweakrefcount(o) == 2,
"wrong weak ref count for object")
del proxy
self.assert_(weakref.getweakrefcount(o) == 1,
"wrong weak ref count for object after deleting proxy")
def test_proxy_reuse(self):
o = C()
proxy1 = weakref.proxy(o)
ref = weakref.ref(o)
proxy2 = weakref.proxy(o)
self.assert_(proxy1 is proxy2,
"proxy object w/out callback should have been re-used")
def test_basic_proxy(self):
o = C()
self.check_proxy(o, weakref.proxy(o))
def test_callable_proxy(self):
o = Callable()
ref1 = weakref.proxy(o)
self.check_proxy(o, ref1)
self.assert_(type(ref1) is weakref.CallableProxyType,
"proxy is not of callable type")
ref1('twinkies!')
self.assert_(o.bar == 'twinkies!',
"call through proxy not passed through to original")
# expect due to too few args
self.assertRaises(TypeError, ref1)
# expect due to too many args
self.assertRaises(TypeError, ref1, 1, 2, 3)
def check_proxy(self, o, proxy):
o.foo = 1
self.assert_(proxy.foo == 1,
"proxy does not reflect attribute addition")
o.foo = 2
self.assert_(proxy.foo == 2,
"proxy does not reflect attribute modification")
del o.foo
self.assert_(not hasattr(proxy, 'foo'),
"proxy does not reflect attribute removal")
proxy.foo = 1
self.assert_(o.foo == 1,
"object does not reflect attribute addition via proxy")
proxy.foo = 2
self.assert_(
o.foo == 2,
"object does not reflect attribute modification via proxy")
del proxy.foo
self.assert_(not hasattr(o, 'foo'),
"object does not reflect attribute removal via proxy")
def test_getweakrefcount(self):
o = C()
ref1 = weakref.ref(o)
ref2 = weakref.ref(o, self.callback)
self.assert_(weakref.getweakrefcount(o) == 2,
"got wrong number of weak reference objects")
proxy1 = weakref.proxy(o)
proxy2 = weakref.proxy(o, self.callback)
self.assert_(weakref.getweakrefcount(o) == 4,
"got wrong number of weak reference objects")
def test_getweakrefs(self):
o = C()
ref1 = weakref.ref(o, self.callback)
ref2 = weakref.ref(o, self.callback)
del ref1
self.assert_(weakref.getweakrefs(o) == [ref2],
"list of refs does not match")
o = C()
ref1 = weakref.ref(o, self.callback)
ref2 = weakref.ref(o, self.callback)
del ref2
self.assert_(weakref.getweakrefs(o) == [ref1],
"list of refs does not match")
class Object:
def __init__(self, arg):
self.arg = arg
def __repr__(self):
return "<Object %r>" % self.arg
class MappingTestCase(TestBase):
COUNT = 10
def test_weak_values(self):
dict = weakref.WeakValueDictionary()
objects = map(Object, range(self.COUNT))
for o in objects:
dict[o.arg] = o
for o in objects:
self.assert_(weakref.getweakrefcount(o) == 1,
"wrong number of weak references to %r!" % o)
self.assert_(o is dict[o.arg],
"wrong object returned by weak dict!")
items1 = dict.items()
items2 = dict.copy().items()
items1.sort()
items2.sort()
self.assert_(items1 == items2,
"cloning of weak-valued dictionary did not work!")
del items1, items2
self.assert_(len(dict) == self.COUNT)
del objects[0]
self.assert_(len(dict) == (self.COUNT - 1),
"deleting object did not cause dictionary update")
del objects, o
self.assert_(len(dict) == 0,
"deleting the values did not clear the dictionary")
def test_weak_keys(self):
dict = weakref.WeakKeyDictionary()
objects = map(Object, range(self.COUNT))
for o in objects:
dict[o] = o.arg
for o in objects:
self.assert_(weakref.getweakrefcount(o) == 1,
"wrong number of weak references to %r!" % o)
self.assert_(o.arg is dict[o],
"wrong object returned by weak dict!")
items1 = dict.items()
items2 = dict.copy().items()
items1.sort()
items2.sort()
self.assert_(items1 == items2,
"cloning of weak-keyed dictionary did not work!")
del items1, items2
self.assert_(len(dict) == self.COUNT)
del objects[0]
self.assert_(len(dict) == (self.COUNT - 1),
"deleting object did not cause dictionary update")
del objects, o
self.assert_(len(dict) == 0,
"deleting the keys did not clear the dictionary")
def check_setdefault(self, klass, key, value1, value2):
self.assert_(value1 is not value2,
"invalid test"
" -- value parameters must be distinct objects")
weakdict = klass()
o = weakdict.setdefault(key, value1)
self.assert_(o is value1)
self.assert_(weakdict.has_key(key))
self.assert_(weakdict.get(key) is value1)
self.assert_(weakdict[key] is value1)
o = weakdict.setdefault(key, value2)
self.assert_(o is value1)
self.assert_(weakdict.has_key(key))
self.assert_(weakdict.get(key) is value1)
self.assert_(weakdict[key] is value1)
def test_weak_valued_dict_setdefault(self):
self.check_setdefault(weakref.WeakValueDictionary,
"key", C(), C())
def test_weak_keyed_dict_setdefault(self):
self.check_setdefault(weakref.WeakKeyDictionary,
C(), "value 1", "value 2")
def check_update(self, klass, dict):
weakdict = klass()
weakdict.update(dict)
self.assert_(len(weakdict) == len(dict))
for k in weakdict.keys():
self.assert_(dict.has_key(k),
"mysterious new key appeared in weak dict")
v = dict.get(k)
self.assert_(v is weakdict[k])
self.assert_(v is weakdict.get(k))
for k in dict.keys():
self.assert_(weakdict.has_key(k),
"original key disappeared in weak dict")
v = dict[k]
self.assert_(v is weakdict[k])
self.assert_(v is weakdict.get(k))
def test_weak_valued_dict_update(self):
self.check_update(weakref.WeakValueDictionary,
{1: C(), 'a': C(), C(): C()})
def test_weak_keyed_dict_update(self):
self.check_update(weakref.WeakKeyDictionary,
{C(): 1, C(): 2, C(): 3})
run_unittest(ReferencesTestCase)
run_unittest(MappingTestCase)
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