]> granicus.if.org Git - python/commitdiff
Implementing the salient parts of __reduce_ex__ in C.
authorGuido van Rossum <guido@python.org>
Fri, 21 Feb 2003 22:02:54 +0000 (22:02 +0000)
committerGuido van Rossum <guido@python.org>
Fri, 21 Feb 2003 22:02:54 +0000 (22:02 +0000)
This still falls back to helpers in copy_reg for:
   - pickle protocols < 2
   - calculating the list of slot names (done only once per class)
   - the __newobj__ function (which is used as a token but never called)

Objects/typeobject.c

index a1e5b88ad77c7a142641cf8de70718791d17e38e..e61eae882c2b1d5848da0e55591f7e18e014af49 100644 (file)
@@ -2440,27 +2440,249 @@ static PyGetSetDef object_getsets[] = {
        {0}
 };
 
+
+/* Stuff to implement __reduce_ex__ for pickle protocols >= 2.
+   We fall back to helpers in copy_reg for:
+   - pickle protocols < 2
+   - calculating the list of slot names (done only once per class)
+   - the __newobj__ function (which is used as a token but never called)
+*/
+
+static PyObject *
+import_copy_reg(void)
+{
+       static PyObject *copy_reg_str;
+
+       if (!copy_reg_str) {
+               copy_reg_str = PyString_InternFromString("copy_reg");
+               if (copy_reg_str == NULL)
+                       return NULL;
+       }
+
+       return PyImport_Import(copy_reg_str);
+}
+
+static PyObject *
+slotnames(PyObject *cls)
+{
+       PyObject *clsdict;
+       PyObject *copy_reg;
+       PyObject *slotnames;
+
+       if (!PyType_Check(cls)) {
+               Py_INCREF(Py_None);
+               return Py_None;
+       }
+
+       clsdict = ((PyTypeObject *)cls)->tp_dict;
+       slotnames = PyDict_GetItemString(clsdict, "__slotnames__");
+       if (slotnames != NULL) {
+               Py_INCREF(slotnames);
+               return slotnames;
+       }
+
+       copy_reg = import_copy_reg();
+       if (copy_reg == NULL)
+               return NULL;
+
+       slotnames = PyObject_CallMethod(copy_reg, "_slotnames", "O", cls);
+       Py_DECREF(copy_reg);
+       if (slotnames != NULL &&
+           slotnames != Py_None &&
+           !PyList_Check(slotnames))
+       {
+               PyErr_SetString(PyExc_TypeError,
+                       "copy_reg._slotnames didn't return a list or None");
+               Py_DECREF(slotnames);
+               slotnames = NULL;
+       }
+
+       return slotnames;
+}
+
+static PyObject *
+reduce_2(PyObject *obj)
+{
+       PyObject *cls, *getnewargs;
+       PyObject *args = NULL, *args2 = NULL;
+       PyObject *getstate = NULL, *state = NULL, *names = NULL;
+       PyObject *slots = NULL, *listitems = NULL, *dictitems = NULL;
+       PyObject *copy_reg = NULL, *newobj = NULL, *res = NULL;
+       int i, n;
+
+       cls = PyObject_GetAttrString(obj, "__class__");
+       if (cls == NULL)
+               return NULL;
+
+       getnewargs = PyObject_GetAttrString(obj, "__getnewargs__");
+       if (getnewargs != NULL) {
+               args = PyObject_CallObject(getnewargs, NULL);
+               Py_DECREF(getnewargs);
+               if (args != NULL && !PyTuple_Check(args)) {
+                       PyErr_SetString(PyExc_TypeError,
+                               "__getnewargs__ should return a tuple");
+                       goto end;
+               }
+       }
+       else {
+               PyErr_Clear();
+               args = PyTuple_New(0);
+       }
+       if (args == NULL)
+               goto end;
+
+       getstate = PyObject_GetAttrString(obj, "__getstate__");
+       if (getstate != NULL) {
+               state = PyObject_CallObject(getstate, NULL);
+               Py_DECREF(getstate);
+       }
+       else {
+               state = PyObject_GetAttrString(obj, "__dict__");
+               if (state == NULL) {
+                       PyErr_Clear();
+                       state = Py_None;
+                       Py_INCREF(state);
+               }
+               names = slotnames(cls);
+               if (names == NULL)
+                       goto end;
+               if (names != Py_None) {
+                       assert(PyList_Check(names));
+                       slots = PyDict_New();
+                       if (slots == NULL)
+                               goto end;
+                       n = 0;
+                       /* Can't pre-compute the list size; the list
+                          is stored on the class so accessible to other
+                          threads, which may be run by DECREF */
+                       for (i = 0; i < PyList_GET_SIZE(names); i++) {
+                               PyObject *name, *value;
+                               name = PyList_GET_ITEM(names, i);
+                               value = PyObject_GetAttr(obj, name);
+                               if (value == NULL)
+                                       PyErr_Clear();
+                               else {
+                                       int err = PyDict_SetItem(slots, name,
+                                                                value);
+                                       Py_DECREF(value);
+                                       if (err)
+                                               goto end;
+                                       n++;
+                               }
+                       }
+                       if (n) {
+                               state = Py_BuildValue("(NO)", state, slots);
+                               if (state == NULL)
+                                       goto end;
+                       }
+               }
+       }
+
+       if (!PyList_Check(obj)) {
+               listitems = Py_None;
+               Py_INCREF(listitems);
+       }
+       else {
+               listitems = PyObject_GetIter(obj);
+               if (listitems == NULL)
+                       goto end;
+       }
+
+       if (!PyDict_Check(obj)) {
+               dictitems = Py_None;
+               Py_INCREF(dictitems);
+       }
+       else {
+               dictitems = PyObject_CallMethod(obj, "iteritems", "");
+               if (dictitems == NULL)
+                       goto end;
+       }
+
+       copy_reg = import_copy_reg();
+       if (copy_reg == NULL)
+               goto end;
+       newobj = PyObject_GetAttrString(copy_reg, "__newobj__");
+       if (newobj == NULL)
+               goto end;
+
+       n = PyTuple_GET_SIZE(args);
+       args2 = PyTuple_New(n+1);
+       if (args2 == NULL)
+               goto end;
+       PyTuple_SET_ITEM(args2, 0, cls);
+       cls = NULL;
+       for (i = 0; i < n; i++) {
+               PyObject *v = PyTuple_GET_ITEM(args, i);
+               Py_INCREF(v);
+               PyTuple_SET_ITEM(args2, i+1, v);
+       }
+
+       res = Py_BuildValue("(OOOOO)",
+                           newobj, args2, state, listitems, dictitems);
+
+  end:
+       Py_XDECREF(cls);
+       Py_XDECREF(args);
+       Py_XDECREF(args2);
+       Py_XDECREF(state);
+       Py_XDECREF(names);
+       Py_XDECREF(listitems);
+       Py_XDECREF(dictitems);
+       Py_XDECREF(copy_reg);
+       Py_XDECREF(newobj);
+       return res;
+}
+
 static PyObject *
 object_reduce_ex(PyObject *self, PyObject *args)
 {
        /* Call copy_reg._reduce_ex(self, proto) */
-       static PyObject *copy_reg_str;
-       PyObject *copy_reg, *res;
+       PyObject *reduce, *copy_reg, *res;
        int proto = 0;
 
        if (!PyArg_ParseTuple(args, "|i:__reduce_ex__", &proto))
                return NULL;
 
-       if (!copy_reg_str) {
-               copy_reg_str = PyString_InternFromString("copy_reg");
-               if (copy_reg_str == NULL)
+       reduce = PyObject_GetAttrString(self, "__reduce__");
+       if (reduce == NULL)
+               PyErr_Clear();
+       else {
+               PyObject *cls, *clsreduce, *objreduce;
+               int override;
+               cls = PyObject_GetAttrString(self, "__class__");
+               if (cls == NULL) {
+                       Py_DECREF(reduce);
                        return NULL;
+               }
+               clsreduce = PyObject_GetAttrString(cls, "__reduce__");
+               Py_DECREF(cls);
+               if (clsreduce == NULL) {
+                       Py_DECREF(reduce);
+                       return NULL;
+               }
+               objreduce = PyDict_GetItemString(PyBaseObject_Type.tp_dict,
+                                                "__reduce__");
+               override = (clsreduce != objreduce);
+               Py_DECREF(clsreduce);
+               if (override) {
+                       res = PyObject_CallObject(reduce, NULL);
+                       Py_DECREF(reduce);
+                       return res;
+               }
+               else
+                       Py_DECREF(reduce);
        }
-       copy_reg = PyImport_Import(copy_reg_str);
+
+       if (proto >= 2)
+               return reduce_2(self);
+
+       copy_reg = import_copy_reg();
        if (!copy_reg)
                return NULL;
+
        res = PyEval_CallMethod(copy_reg, "_reduce_ex", "(Oi)", self, proto);
        Py_DECREF(copy_reg);
+
        return res;
 }
 
@@ -2472,6 +2694,7 @@ static PyMethodDef object_methods[] = {
        {0}
 };
 
+
 PyTypeObject PyBaseObject_Type = {
        PyObject_HEAD_INIT(&PyType_Type)
        0,                                      /* ob_size */