SF #1085304: Make array.array pickle-able

Lib/test/test_array.py

@@ -7,6 +7,10 @@ import unittest
 from test import test_support
 from weakref import proxy
 import array, cStringIO, math
+from cPickle import loads, dumps
+
+class ArraySubclass(array.array):
+    pass
 
 tests = [] # list to accumulate all tests
 typecodes = "cubBhHiIlLfd"
@@ -81,6 +85,21 @@ class BaseTest(unittest.TestCase):
         self.assertNotEqual(id(a), id(b))
         self.assertEqual(a, b)
 
+    def test_pickle(self):
+        for protocol in (0, 1, 2):
+            a = array.array(self.typecode, self.example)
+            b = loads(dumps(a, protocol))
+            self.assertNotEqual(id(a), id(b))
+            self.assertEqual(a, b)
+
+            a = ArraySubclass(self.typecode, self.example)
+            a.x = 10
+            b = loads(dumps(a, protocol))
+            self.assertNotEqual(id(a), id(b))
+            self.assertEqual(a, b)
+            self.assertEqual(a.x, b.x)
+            self.assertEqual(type(a), type(b))
+
     def test_insert(self):
         a = array.array(self.typecode, self.example)
         a.insert(0, self.example[0])

Misc/NEWS

@@ -17,6 +17,8 @@ Core and builtins
 Extension Modules
 -----------------
 
+- array.array objects are now picklable.
+
 - the cPickle module no longer accepts the deprecated None option in the
   args tuple returned by __reduce__().
 

Modules/arraymodule.c

@@ -1132,6 +1132,29 @@ PyDoc_STRVAR(byteswap_doc,
 Byteswap all items of the array.  If the items in the array are not 1, 2,\n\
 4, or 8 bytes in size, RuntimeError is raised.");
 
+static PyObject *
+array_reduce(arrayobject *array)
+{
+	PyObject *dict, *result;
+
+	dict = PyObject_GetAttrString((PyObject *)array, "__dict__");
+	if (dict == NULL) {
+		PyErr_Clear();
+		dict = Py_None;
+		Py_INCREF(dict);
+	}
+	result = Py_BuildValue("O(cs#)O", 
+		array->ob_type, 
+		array->ob_descr->typecode,
+		array->ob_item,
+		array->ob_size * array->ob_descr->itemsize,
+		dict);
+	Py_DECREF(dict);
+	return result;
+}
+
+PyDoc_STRVAR(array_doc, "Return state information for pickling.");
+
 static PyObject *
 array_reverse(arrayobject *self, PyObject *unused)
 {
@@ -1490,6 +1513,8 @@ PyMethodDef array_methods[] = {
 	 pop_doc},
 	{"read",	(PyCFunction)array_fromfile,	METH_VARARGS,
 	 fromfile_doc},
+	{"__reduce__",	(PyCFunction)array_reduce,	METH_NOARGS,
+	 array_doc},
 	{"remove",	(PyCFunction)array_remove,	METH_O,
 	 remove_doc},
 	{"reverse",	(PyCFunction)array_reverse,	METH_NOARGS,