Add gc header size to returned sizeof information

Python/sysmodule.c

Index: Python/sysmodule.c
===================================================================
--- Python/sysmodule.c	(revision 64518)
+++ Python/sysmodule.c	(working copy)
@@ -640,10 +640,18 @@
 #endif /* USE_MALLOPT */
 
 static PyObject *
-sys_getsizeof(PyObject *self, PyObject *args)
+sys_getsizeof(PyObject *self, PyObject *args, PyObject *kwds)
 {
-	static PyObject * str__sizeof__ = NULL;
+	PyObject *res = NULL;
+	static PyObject *str__sizeof__, *gc_head_size = NULL;
+	static char *kwlist[] = {"object", "default", "gc_head", 0};
+	PyObject *o, *dflt = NULL;
+	int gc_head;
 
+	if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|Oi:getsizeof",
+					 kwlist, &o, &dflt, &gc_head))
+		return NULL;
+
 	/* Initialize static variable needed by _PyType_Lookup */
 	if (str__sizeof__ == NULL) {
 		str__sizeof__ = PyString_InternFromString("__sizeof__");
@@ -651,30 +659,54 @@
 			return NULL;
 	}
 
-	/* Type objects */
-	if (PyType_Check(args)){
-		PyObject *method = _PyType_Lookup(Py_TYPE(args),
-						  str__sizeof__);
-		if (method == NULL) {
+        /* Initialize static variable for GC head size */
+	if (gc_head_size == NULL) {
+		gc_head_size = PyInt_FromSsize_t(sizeof(PyGC_Head));
+		if (gc_head_size == NULL)
+			return NULL;
+	}
+	
+	/* Make sure the type is initialized. float gets initialized late */
+	if (PyType_Ready(Py_TYPE(o)) < 0)
+		return NULL;
+	
+	/* non-type objects */
+	else if (!PyType_Check(o))
+		res = PyObject_CallMethod(o, "__sizeof__", NULL);
+	/* type objects and objects which do not have the __sizeof__ attribute */
+	if (PyType_Check(o) ||
+	    (res == NULL && PyErr_ExceptionMatches(PyExc_AttributeError))) {
+		PyObject *method = _PyType_Lookup(Py_TYPE(o), str__sizeof__);
+		if (method == NULL)
 			PyErr_Format(PyExc_TypeError,
 				     "Type %.100s doesn't define __sizeof__",
-				     Py_TYPE(args)->tp_name);
-			return NULL;
-		}
-		return PyObject_CallFunctionObjArgs(method, args, NULL);
-	} 
-	/* Instance of old-style classes */
-	else if (PyInstance_Check(args))
-		return PyInt_FromSsize_t(PyInstance_Type.tp_basicsize);
-	/* Old-style classes */
-	else if (PyClass_Check(args))
-		return PyInt_FromSsize_t(PyClass_Type.tp_basicsize);
-	else
-		return PyObject_CallMethod(args, "__sizeof__", NULL);
+				     Py_TYPE(o)->tp_name);
+		else
+			res = PyObject_CallFunctionObjArgs(method, o, NULL);
+	}
+
+	/* failed. is default value is given? */

[Martin v. Löwis, 2008/07/07 05:24:06]

"Has a default value been given" or "Was a default value requested"?

+	if ((res == NULL) && (dflt != NULL) &&
+	    PyErr_ExceptionMatches(PyExc_TypeError))
+	{
+		PyErr_Clear();
+		Py_INCREF(dflt);
+		return dflt;
+	}
+	else if (res == NULL)
+		return res;
+	
+	/* add gc_head size if object is tracked by gc */
+	if (gc_head && PyObject_IS_GC(o)) {
+		PyObject *tmp = res;
+		res = PyNumber_Add(tmp, gc_head_size);
+		Py_DECREF(tmp);
+	}
+	return res;
 }
 
 PyDoc_STRVAR(getsizeof_doc,
-"getsizeof(object) -> int\n\
+"getsizeof(object, default, gc_head=True) -> int\n\
 \n\
 Return the size of object in bytes.");
 
@@ -889,7 +921,8 @@
 	{"getrefcount",	(PyCFunction)sys_getrefcount, METH_O, getrefcount_doc},
 	{"getrecursionlimit", (PyCFunction)sys_getrecursionlimit, METH_NOARGS,
 	 getrecursionlimit_doc},
- 	{"getsizeof",	sys_getsizeof,  METH_O, getsizeof_doc},
+	{"getsizeof",   (PyCFunction)sys_getsizeof,
+	 METH_VARARGS | METH_KEYWORDS, getsizeof_doc},
 	{"_getframe", sys_getframe, METH_VARARGS, getframe_doc},
 #ifdef MS_WINDOWS
 	{"getwindowsversion", (PyCFunction)sys_getwindowsversion, METH_NOARGS,