SF #1479988: add methods to allow access to weakrefs for the

weakref.WeakKeyDictionary and weakref.WeakValueDictionary
This commit is contained in:
Fred Drake 2006-05-02 06:53:59 +00:00
parent a6d01cec3f
commit 017e68c413
3 changed files with 125 additions and 0 deletions

View File

@ -147,6 +147,24 @@ information.
to vanish "by magic" (as a side effect of garbage collection).}
\end{classdesc}
\class{WeakKeyDictionary} objects have the following additional
methods. These expose the internal references directly. The
references are not guaranteed to be ``live'' at the time they are
used, so the result of calling the references needs to be checked
before being used. This can be used to avoid creating references that
will cause the garbage collector to keep the keys around longer than
needed.
\begin{methoddesc}{iterkeyrefs}{}
Return an iterator that yields the weak references to the keys.
\versionadded{2.5}
\end{methoddesc}
\begin{methoddesc}{keyrefs}{}
Return a list of weak references to the keys.
\versionadded{2.5}
\end{methoddesc}
\begin{classdesc}{WeakValueDictionary}{\optional{dict}}
Mapping class that references values weakly. Entries in the
dictionary will be discarded when no strong reference to the value
@ -160,6 +178,21 @@ information.
to vanish "by magic" (as a side effect of garbage collection).}
\end{classdesc}
\class{WeakValueDictionary} objects have the following additional
methods. These method have the same issues as the
\method{iterkeyrefs()} and \method{keyrefs()} methods of
\class{WeakKeyDictionary} objects.
\begin{methoddesc}{itervaluerefs}{}
Return an iterator that yields the weak references to the values.
\versionadded{2.5}
\end{methoddesc}
\begin{methoddesc}{valuerefs}{}
Return a list of weak references to the values.
\versionadded{2.5}
\end{methoddesc}
\begin{datadesc}{ReferenceType}
The type object for weak references objects.
\end{datadesc}

View File

@ -769,10 +769,54 @@ class MappingTestCase(TestBase):
dict, objects = self.make_weak_keyed_dict()
self.check_iters(dict)
# Test keyrefs()
refs = dict.keyrefs()
self.assertEqual(len(refs), len(objects))
objects2 = list(objects)
for wr in refs:
ob = wr()
self.assert_(dict.has_key(ob))
self.assert_(ob in dict)
self.assertEqual(ob.arg, dict[ob])
objects2.remove(ob)
self.assertEqual(len(objects2), 0)
# Test iterkeyrefs()
objects2 = list(objects)
self.assertEqual(len(list(dict.iterkeyrefs())), len(objects))
for wr in dict.iterkeyrefs():
ob = wr()
self.assert_(dict.has_key(ob))
self.assert_(ob in dict)
self.assertEqual(ob.arg, dict[ob])
objects2.remove(ob)
self.assertEqual(len(objects2), 0)
def test_weak_valued_iters(self):
dict, objects = self.make_weak_valued_dict()
self.check_iters(dict)
# Test valuerefs()
refs = dict.valuerefs()
self.assertEqual(len(refs), len(objects))
objects2 = list(objects)
for wr in refs:
ob = wr()
self.assertEqual(ob, dict[ob.arg])
self.assertEqual(ob.arg, dict[ob.arg].arg)
objects2.remove(ob)
self.assertEqual(len(objects2), 0)
# Test itervaluerefs()
objects2 = list(objects)
self.assertEqual(len(list(dict.itervaluerefs())), len(objects))
for wr in dict.itervaluerefs():
ob = wr()
self.assertEqual(ob, dict[ob.arg])
self.assertEqual(ob.arg, dict[ob.arg].arg)
objects2.remove(ob)
self.assertEqual(len(objects2), 0)
def check_iters(self, dict):
# item iterator:
items = dict.items()

View File

@ -118,6 +118,18 @@ class WeakValueDictionary(UserDict.UserDict):
def __iter__(self):
return self.data.iterkeys()
def itervaluerefs(self):
"""Return an iterator that yields the weak references to the values.
The references are not guaranteed to be 'live' at the time
they are used, so the result of calling the references needs
to be checked before being used. This can be used to avoid
creating references that will cause the garbage collector to
keep the values around longer than needed.
"""
return self.data.itervalues()
def itervalues(self):
for wr in self.data.itervalues():
obj = wr()
@ -162,6 +174,18 @@ class WeakValueDictionary(UserDict.UserDict):
if len(kwargs):
self.update(kwargs)
def valuerefs(self):
"""Return a list of weak references to the values.
The references are not guaranteed to be 'live' at the time
they are used, so the result of calling the references needs
to be checked before being used. This can be used to avoid
creating references that will cause the garbage collector to
keep the values around longer than needed.
"""
return self.data.values()
def values(self):
L = []
for wr in self.data.values():
@ -263,6 +287,18 @@ class WeakKeyDictionary(UserDict.UserDict):
if key is not None:
yield key, value
def iterkeyrefs(self):
"""Return an iterator that yields the weak references to the keys.
The references are not guaranteed to be 'live' at the time
they are used, so the result of calling the references needs
to be checked before being used. This can be used to avoid
creating references that will cause the garbage collector to
keep the keys around longer than needed.
"""
return self.data.iterkeys()
def iterkeys(self):
for wr in self.data.iterkeys():
obj = wr()
@ -275,6 +311,18 @@ class WeakKeyDictionary(UserDict.UserDict):
def itervalues(self):
return self.data.itervalues()
def keyrefs(self):
"""Return a list of weak references to the keys.
The references are not guaranteed to be 'live' at the time
they are used, so the result of calling the references needs
to be checked before being used. This can be used to avoid
creating references that will cause the garbage collector to
keep the keys around longer than needed.
"""
return self.data.keys()
def keys(self):
L = []
for wr in self.data.keys():