/* Descriptors -- a new, flexible way to describe attributes */ #include "Python.h" #include "structmember.h" /* Why is this not included in Python.h? */ /* Various kinds of descriptor objects */ #define COMMON \ PyObject_HEAD \ PyTypeObject *d_type; \ PyObject *d_name typedef struct { COMMON; } PyDescrObject; typedef struct { COMMON; PyMethodDef *d_method; } PyMethodDescrObject; typedef struct { COMMON; struct memberlist *d_member; } PyMemberDescrObject; typedef struct { COMMON; struct getsetlist *d_getset; } PyGetSetDescrObject; typedef struct { COMMON; struct wrapperbase *d_base; void *d_wrapped; /* This can be any function pointer */ } PyWrapperDescrObject; static void descr_dealloc(PyDescrObject *descr) { Py_XDECREF(descr->d_type); Py_XDECREF(descr->d_name); PyObject_DEL(descr); } static char * descr_name(PyDescrObject *descr) { if (descr->d_name != NULL && PyString_Check(descr->d_name)) return PyString_AS_STRING(descr->d_name); else return "?"; } static PyObject * descr_repr(PyDescrObject *descr, char *format) { char buffer[500]; sprintf(buffer, format, descr_name(descr), descr->d_type->tp_name); return PyString_FromString(buffer); } static PyObject * method_repr(PyMethodDescrObject *descr) { return descr_repr((PyDescrObject *)descr, ""); } static PyObject * member_repr(PyMemberDescrObject *descr) { return descr_repr((PyDescrObject *)descr, ""); } static PyObject * getset_repr(PyGetSetDescrObject *descr) { return descr_repr((PyDescrObject *)descr, ""); } static PyObject * wrapper_repr(PyWrapperDescrObject *descr) { return descr_repr((PyDescrObject *)descr, ""); } static int descr_check(PyDescrObject *descr, PyObject *obj, PyTypeObject *type, PyObject **pres) { if (obj == NULL || (obj == Py_None && type != Py_None->ob_type)) { Py_INCREF(descr); *pres = (PyObject *)descr; return 1; } if (!PyObject_IsInstance(obj, (PyObject *)(descr->d_type))) { PyErr_Format(PyExc_TypeError, "descriptor '%.200s' for '%.100s' objects " "doesn't apply to '%.100s' object", descr_name((PyDescrObject *)descr), descr->d_type->tp_name, obj->ob_type->tp_name); *pres = NULL; return 1; } return 0; } static PyObject * method_get(PyMethodDescrObject *descr, PyObject *obj, PyTypeObject *type) { PyObject *res; if (descr_check((PyDescrObject *)descr, obj, type, &res)) return res; return PyCFunction_New(descr->d_method, obj); } static PyObject * member_get(PyMemberDescrObject *descr, PyObject *obj, PyTypeObject *type) { PyObject *res; if (descr_check((PyDescrObject *)descr, obj, type, &res)) return res; return PyMember_Get((char *)obj, descr->d_member, descr->d_member->name); } static PyObject * getset_get(PyGetSetDescrObject *descr, PyObject *obj, PyTypeObject *type) { PyObject *res; if (descr_check((PyDescrObject *)descr, obj, type, &res)) return res; if (descr->d_getset->get != NULL) return descr->d_getset->get(obj, descr->d_getset->closure); PyErr_Format(PyExc_TypeError, "attribute '%300s' of '%.100s' objects is not readable", descr_name((PyDescrObject *)descr), descr->d_type->tp_name); return NULL; } static PyObject * wrapper_get(PyWrapperDescrObject *descr, PyObject *obj, PyTypeObject *type) { PyObject *res; if (descr_check((PyDescrObject *)descr, obj, type, &res)) return res; return PyWrapper_New((PyObject *)descr, obj); } static int descr_setcheck(PyDescrObject *descr, PyObject *obj, PyObject *value, int *pres) { assert(obj != NULL); if (!PyObject_IsInstance(obj, (PyObject *)(descr->d_type))) { PyErr_Format(PyExc_TypeError, "descriptor '%.200s' for '%.100s' objects " "doesn't apply to '%.100s' object", descr_name(descr), descr->d_type->tp_name, obj->ob_type->tp_name); *pres = -1; return 1; } return 0; } static int member_set(PyMemberDescrObject *descr, PyObject *obj, PyObject *value) { int res; if (descr_setcheck((PyDescrObject *)descr, obj, value, &res)) return res; return PyMember_Set((char *)obj, descr->d_member, descr->d_member->name, value); } static int getset_set(PyGetSetDescrObject *descr, PyObject *obj, PyObject *value) { int res; if (descr_setcheck((PyDescrObject *)descr, obj, value, &res)) return res; if (descr->d_getset->set != NULL) return descr->d_getset->set(obj, value, descr->d_getset->closure); PyErr_Format(PyExc_TypeError, "attribute '%300s' of '%.100s' objects is not writable", descr_name((PyDescrObject *)descr), descr->d_type->tp_name); return -1; } static PyObject * methoddescr_call(PyMethodDescrObject *descr, PyObject *args, PyObject *kwds) { int argc; PyObject *self, *func, *result; /* Make sure that the first argument is acceptable as 'self' */ assert(PyTuple_Check(args)); argc = PyTuple_GET_SIZE(args); if (argc < 1) { PyErr_Format(PyExc_TypeError, "descriptor '%.300s' of '%.100s' " "object needs an argument", descr_name((PyDescrObject *)descr), descr->d_type->tp_name); return NULL; } self = PyTuple_GET_ITEM(args, 0); if (!PyObject_IsInstance(self, (PyObject *)(descr->d_type))) { PyErr_Format(PyExc_TypeError, "descriptor '%.200s' " "requires a '%.100s' object " "but received a '%.100s'", descr_name((PyDescrObject *)descr), descr->d_type->tp_name, self->ob_type->tp_name); return NULL; } func = PyCFunction_New(descr->d_method, self); if (func == NULL) return NULL; args = PyTuple_GetSlice(args, 1, argc); if (args == NULL) { Py_DECREF(func); return NULL; } result = PyEval_CallObjectWithKeywords(func, args, kwds); Py_DECREF(args); Py_DECREF(func); return result; } static PyObject * wrapperdescr_call(PyWrapperDescrObject *descr, PyObject *args, PyObject *kwds) { int argc; PyObject *self, *func, *result; /* Make sure that the first argument is acceptable as 'self' */ assert(PyTuple_Check(args)); argc = PyTuple_GET_SIZE(args); if (argc < 1) { PyErr_Format(PyExc_TypeError, "descriptor '%.300s' of '%.100s' " "object needs an argument", descr_name((PyDescrObject *)descr), descr->d_type->tp_name); return NULL; } self = PyTuple_GET_ITEM(args, 0); if (!PyObject_IsInstance(self, (PyObject *)(descr->d_type))) { PyErr_Format(PyExc_TypeError, "descriptor '%.200s' " "requires a '%.100s' object " "but received a '%.100s'", descr_name((PyDescrObject *)descr), descr->d_type->tp_name, self->ob_type->tp_name); return NULL; } func = PyWrapper_New((PyObject *)descr, self); if (func == NULL) return NULL; args = PyTuple_GetSlice(args, 1, argc); if (args == NULL) { Py_DECREF(func); return NULL; } result = PyEval_CallObjectWithKeywords(func, args, kwds); Py_DECREF(args); Py_DECREF(func); return result; } static PyObject * member_get_doc(PyMethodDescrObject *descr, void *closure) { if (descr->d_method->ml_doc == NULL) { Py_INCREF(Py_None); return Py_None; } return PyString_FromString(descr->d_method->ml_doc); } static struct memberlist descr_members[] = { {"__objclass__", T_OBJECT, offsetof(PyDescrObject, d_type), READONLY}, {"__name__", T_OBJECT, offsetof(PyDescrObject, d_name), READONLY}, {0} }; static struct getsetlist member_getset[] = { {"__doc__", (getter)member_get_doc}, {0} }; static PyObject * wrapper_get_doc(PyWrapperDescrObject *descr, void *closure) { if (descr->d_base->doc == NULL) { Py_INCREF(Py_None); return Py_None; } return PyString_FromString(descr->d_base->doc); } static struct getsetlist wrapper_getset[] = { {"__doc__", (getter)wrapper_get_doc}, {0} }; static PyTypeObject PyMethodDescr_Type = { PyObject_HEAD_INIT(&PyType_Type) 0, "method_descriptor", sizeof(PyMethodDescrObject), 0, (destructor)descr_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)method_repr, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ (ternaryfunc)methoddescr_call, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ descr_members, /* tp_members */ member_getset, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ (descrgetfunc)method_get, /* tp_descr_get */ 0, /* tp_descr_set */ }; static PyTypeObject PyMemberDescr_Type = { PyObject_HEAD_INIT(&PyType_Type) 0, "member_descriptor", sizeof(PyMemberDescrObject), 0, (destructor)descr_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)member_repr, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ (ternaryfunc)0, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ descr_members, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ (descrgetfunc)member_get, /* tp_descr_get */ (descrsetfunc)member_set, /* tp_descr_set */ }; static PyTypeObject PyGetSetDescr_Type = { PyObject_HEAD_INIT(&PyType_Type) 0, "getset_descriptor", sizeof(PyGetSetDescrObject), 0, (destructor)descr_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)getset_repr, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ (ternaryfunc)0, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ descr_members, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ (descrgetfunc)getset_get, /* tp_descr_get */ (descrsetfunc)getset_set, /* tp_descr_set */ }; static PyTypeObject PyWrapperDescr_Type = { PyObject_HEAD_INIT(&PyType_Type) 0, "wrapper_descriptor", sizeof(PyWrapperDescrObject), 0, (destructor)descr_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)wrapper_repr, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ (ternaryfunc)wrapperdescr_call, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ descr_members, /* tp_members */ wrapper_getset, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ (descrgetfunc)wrapper_get, /* tp_descr_get */ 0, /* tp_descr_set */ }; static PyDescrObject * descr_new(PyTypeObject *descrtype, PyTypeObject *type, char *name) { PyDescrObject *descr; descr = (PyDescrObject *)PyType_GenericAlloc(descrtype, 0); if (descr != NULL) { Py_XINCREF(type); descr->d_type = type; descr->d_name = PyString_InternFromString(name); if (descr->d_name == NULL) { Py_DECREF(descr); descr = NULL; } } return descr; } PyObject * PyDescr_NewMethod(PyTypeObject *type, PyMethodDef *method) { PyMethodDescrObject *descr; descr = (PyMethodDescrObject *)descr_new(&PyMethodDescr_Type, type, method->ml_name); if (descr != NULL) descr->d_method = method; return (PyObject *)descr; } PyObject * PyDescr_NewMember(PyTypeObject *type, struct memberlist *member) { PyMemberDescrObject *descr; descr = (PyMemberDescrObject *)descr_new(&PyMemberDescr_Type, type, member->name); if (descr != NULL) descr->d_member = member; return (PyObject *)descr; } PyObject * PyDescr_NewGetSet(PyTypeObject *type, struct getsetlist *getset) { PyGetSetDescrObject *descr; descr = (PyGetSetDescrObject *)descr_new(&PyGetSetDescr_Type, type, getset->name); if (descr != NULL) descr->d_getset = getset; return (PyObject *)descr; } PyObject * PyDescr_NewWrapper(PyTypeObject *type, struct wrapperbase *base, void *wrapped) { PyWrapperDescrObject *descr; descr = (PyWrapperDescrObject *)descr_new(&PyWrapperDescr_Type, type, base->name); if (descr != NULL) { descr->d_base = base; descr->d_wrapped = wrapped; } return (PyObject *)descr; } int PyDescr_IsData(PyObject *d) { return d->ob_type->tp_descr_set != NULL; } /* --- Readonly proxy for dictionaries (actually any mapping) --- */ /* This has no reason to be in this file except that adding new files is a bit of a pain */ typedef struct { PyObject_HEAD PyObject *dict; } proxyobject; static int proxy_len(proxyobject *pp) { return PyObject_Size(pp->dict); } static PyObject * proxy_getitem(proxyobject *pp, PyObject *key) { return PyObject_GetItem(pp->dict, key); } static PyMappingMethods proxy_as_mapping = { (inquiry)proxy_len, /* mp_length */ (binaryfunc)proxy_getitem, /* mp_subscript */ 0, /* mp_ass_subscript */ }; static int proxy_contains(proxyobject *pp, PyObject *key) { return PySequence_Contains(pp->dict, key); } static PySequenceMethods proxy_as_sequence = { 0, /* sq_length */ 0, /* sq_concat */ 0, /* sq_repeat */ 0, /* sq_item */ 0, /* sq_slice */ 0, /* sq_ass_item */ 0, /* sq_ass_slice */ (objobjproc)proxy_contains, /* sq_contains */ 0, /* sq_inplace_concat */ 0, /* sq_inplace_repeat */ }; static PyObject * proxy_has_key(proxyobject *pp, PyObject *key) { return PyInt_FromLong(PySequence_Contains(pp->dict, key)); } static PyObject * proxy_get(proxyobject *pp, PyObject *args) { PyObject *key, *def = Py_None; if (!PyArg_ParseTuple(args, "O|O:get", &key, &def)) return NULL; return PyObject_CallMethod(pp->dict, "get", "(OO)", key, def); } static PyObject * proxy_keys(proxyobject *pp) { return PyMapping_Keys(pp->dict); } static PyObject * proxy_values(proxyobject *pp) { return PyMapping_Values(pp->dict); } static PyObject * proxy_items(proxyobject *pp) { return PyMapping_Items(pp->dict); } static PyObject * proxy_copy(proxyobject *pp) { return PyObject_CallMethod(pp->dict, "copy", NULL); } static PyMethodDef proxy_methods[] = { {"has_key", (PyCFunction)proxy_has_key, METH_O, "XXX"}, {"get", (PyCFunction)proxy_get, METH_VARARGS, "XXX"}, {"keys", (PyCFunction)proxy_keys, METH_NOARGS, "XXX"}, {"values", (PyCFunction)proxy_values, METH_NOARGS, "XXX"}, {"items", (PyCFunction)proxy_items, METH_NOARGS, "XXX"}, {"copy", (PyCFunction)proxy_copy, METH_NOARGS, "XXX"}, {0} }; static void proxy_dealloc(proxyobject *pp) { Py_DECREF(pp->dict); PyObject_DEL(pp); } static PyObject * proxy_getiter(proxyobject *pp) { return PyObject_GetIter(pp->dict); } PyObject * proxy_str(proxyobject *pp) { return PyObject_Str(pp->dict); } PyTypeObject proxytype = { PyObject_HEAD_INIT(&PyType_Type) 0, /* ob_size */ "dict-proxy", /* tp_name */ sizeof(proxyobject), /* tp_basicsize */ 0, /* tp_itemsize */ /* methods */ (destructor)proxy_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ 0, /* tp_repr */ 0, /* tp_as_number */ &proxy_as_sequence, /* tp_as_sequence */ &proxy_as_mapping, /* tp_as_mapping */ 0, /* tp_hash */ 0, /* tp_call */ (reprfunc)proxy_str, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ (getiterfunc)proxy_getiter, /* tp_iter */ 0, /* tp_iternext */ proxy_methods, /* tp_methods */ 0, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ }; PyObject * PyDictProxy_New(PyObject *dict) { proxyobject *pp; pp = PyObject_NEW(proxyobject, &proxytype); if (pp != NULL) { Py_INCREF(dict); pp->dict = dict; } return (PyObject *)pp; } /* --- Wrapper object for "slot" methods --- */ /* This has no reason to be in this file except that adding new files is a bit of a pain */ typedef struct { PyObject_HEAD PyWrapperDescrObject *descr; PyObject *self; } wrapperobject; static void wrapper_dealloc(wrapperobject *wp) { Py_XDECREF(wp->descr); Py_XDECREF(wp->self); PyObject_DEL(wp); } static PyMethodDef wrapper_methods[] = { {0} }; static PyObject * wrapper_name(wrapperobject *wp) { char *s = wp->descr->d_base->name; return PyString_FromString(s); } static PyObject * wrapper_doc(wrapperobject *wp) { char *s = wp->descr->d_base->doc; if (s == NULL) { Py_INCREF(Py_None); return Py_None; } else { return PyString_FromString(s); } } static struct getsetlist wrapper_getsets[] = { {"__name__", (getter)wrapper_name}, {"__doc__", (getter)wrapper_doc}, {0} }; static PyObject * wrapper_call(wrapperobject *wp, PyObject *args, PyObject *kwds) { wrapperfunc wrapper = wp->descr->d_base->wrapper; PyObject *self = wp->self; return (*wrapper)(self, args, wp->descr->d_wrapped); } PyTypeObject wrappertype = { PyObject_HEAD_INIT(&PyType_Type) 0, /* ob_size */ "method-wrapper", /* tp_name */ sizeof(wrapperobject), /* tp_basicsize */ 0, /* tp_itemsize */ /* methods */ (destructor)wrapper_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ 0, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ (ternaryfunc)wrapper_call, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ 0, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ wrapper_methods, /* tp_methods */ 0, /* tp_members */ wrapper_getsets, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ }; PyObject * PyWrapper_New(PyObject *d, PyObject *self) { wrapperobject *wp; PyWrapperDescrObject *descr; assert(PyObject_TypeCheck(d, &PyWrapperDescr_Type)); descr = (PyWrapperDescrObject *)d; assert(PyObject_IsInstance(self, (PyObject *)(descr->d_type))); wp = PyObject_NEW(wrapperobject, &wrappertype); if (wp != NULL) { Py_INCREF(descr); wp->descr = descr; Py_INCREF(self); wp->self = self; } return (PyObject *)wp; }