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Amaury Forgeot d'Arc committed a5bb40b

cpyext: implement PyString_InternInPlace()

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Files changed (3)

pypy/module/cpyext/stringobject.py

     s = rffi.charp2str(string)
     return space.new_interned_str(s)
 
+@cpython_api([PyObjectP], lltype.Void)
+def PyString_InternInPlace(space, string):
+    """Intern the argument *string in place.  The argument must be the
+    address of a pointer variable pointing to a Python string object.
+    If there is an existing interned string that is the same as
+    *string, it sets *string to it (decrementing the reference count
+    of the old string object and incrementing the reference count of
+    the interned string object), otherwise it leaves *string alone and
+    interns it (incrementing its reference count).  (Clarification:
+    even though there is a lot of talk about reference counts, think
+    of this function as reference-count-neutral; you own the object
+    after the call if and only if you owned it before the call.)
+
+    This function is not available in 3.x and does not have a PyBytes
+    alias."""
+    w_str = from_ref(space, string[0])
+    w_str = space.new_interned_w_str(w_str)
+    string[0] = make_ref(space, w_str)
+
 @cpython_api([PyObject, rffi.CCHARP, rffi.CCHARP], PyObject)
 def PyString_AsEncodedObject(space, w_str, encoding, errors):
     """Encode a string object using the codec registered for encoding and return

pypy/module/cpyext/stubs.py

     """Empty an existing set of all elements."""
     raise NotImplementedError
 
-@cpython_api([PyObjectP], lltype.Void)
-def PyString_InternInPlace(space, string):
-    """Intern the argument *string in place.  The argument must be the address of a
-    pointer variable pointing to a Python string object.  If there is an existing
-    interned string that is the same as *string, it sets *string to it
-    (decrementing the reference count of the old string object and incrementing the
-    reference count of the interned string object), otherwise it leaves *string
-    alone and interns it (incrementing its reference count).  (Clarification: even
-    though there is a lot of talk about reference counts, think of this function as
-    reference-count-neutral; you own the object after the call if and only if you
-    owned it before the call.)
-
-    This function is not available in 3.x and does not have a PyBytes alias."""
-    raise NotImplementedError
-
 @cpython_api([rffi.CCHARP, Py_ssize_t, rffi.CCHARP, rffi.CCHARP], PyObject)
 def PyString_Decode(space, s, size, encoding, errors):
     """Create an object by decoding size bytes of the encoded buffer s using the

pypy/module/cpyext/test/test_stringobject.py

         res = module.test_string_format(1, "xyz")
         assert res == "bla 1 ble xyz\n"
 
+    def test_intern_inplace(self):
+        module = self.import_extension('foo', [
+            ("test_intern_inplace", "METH_O",
+             '''
+                 PyObject *s = args;
+                 Py_INCREF(s);
+                 PyString_InternInPlace(&s);
+                 return s;
+             '''
+             )
+            ])
+        # This does not test much, but at least the refcounts are checked.
+        assert module.test_intern_inplace('s') == 's'
+
 class TestString(BaseApiTest):
     def test_string_resize(self, space, api):
         py_str = new_empty_str(space, 10)