descrobject.c

python s60 1.4.5版本的源代码

/* Portions Copyright (c) 2005 Nokia Corporation */
/* Descriptors -- a new, flexible way to describe attributes */

#include "Python.h"
#include "structmember.h" /* Why is this not included in Python.h? */

static void
descr_dealloc(PyDescrObject *descr)
{
	_PyObject_GC_UNTRACK(descr);
	Py_XDECREF(descr->d_type);
	Py_XDECREF(descr->d_name);
	PyObject_GC_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)
{
	return PyString_FromFormat(format, descr_name(descr),
				   descr->d_type->tp_name);
}

static PyObject *
method_repr(PyMethodDescrObject *descr)
{
	return descr_repr((PyDescrObject *)descr,
			  "<method '%s' of '%s' objects>");
}

static PyObject *
member_repr(PyMemberDescrObject *descr)
{
	return descr_repr((PyDescrObject *)descr,
			  "<member '%s' of '%s' objects>");
}

static PyObject *
getset_repr(PyGetSetDescrObject *descr)
{
	return descr_repr((PyDescrObject *)descr,
			  "<attribute '%s' of '%s' objects>");
}

static PyObject *
wrapper_repr(PyWrapperDescrObject *descr)
{
	return descr_repr((PyDescrObject *)descr,
			  "<slot wrapper '%s' of '%s' objects>");
}

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 '%s' for '%s' objects "
			     "doesn't apply to '%s' 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_GetOne((char *)obj, descr->d_member);
}

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_SetOne((char *)obj, descr->d_member, 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 *
method_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);
}

const static PyMemberDef descr_members[] = {
	{"__objclass__", T_OBJECT, offsetof(PyDescrObject, d_type), READONLY},
	{"__name__", T_OBJECT, offsetof(PyDescrObject, d_name), READONLY},
	{0}
};

const static PyGetSetDef method_getset[] = {
	{"__doc__", (getter)method_get_doc},
	{0}
};

static PyObject *
member_get_doc(PyMemberDescrObject *descr, void *closure)
{
	if (descr->d_member->doc == NULL) {
		Py_INCREF(Py_None);
		return Py_None;
	}
	return PyString_FromString(descr->d_member->doc);
}

const static PyGetSetDef member_getset[] = {
	{"__doc__", (getter)member_get_doc},
	{0}
};

static PyObject *
getset_get_doc(PyGetSetDescrObject *descr, void *closure)
{
	if (descr->d_getset->doc == NULL) {
		Py_INCREF(Py_None);
		return Py_None;
	}
	return PyString_FromString(descr->d_getset->doc);
}

const static PyGetSetDef getset_getset[] = {
	{"__doc__", (getter)getset_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);
}

const static PyGetSetDef wrapper_getset[] = {
	{"__doc__", (getter)wrapper_get_doc},
	{0}
};

static int
descr_traverse(PyObject *self, visitproc visit, void *arg)
{
	PyDescrObject *descr = (PyDescrObject *)self;
	int err;

	if (descr->d_type) {
		err = visit((PyObject *)(descr->d_type), arg);
		if (err)
			return err;
	}
	return 0;
}

#ifndef SYMBIAN
PyTypeObject PyMethodDescr_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyMethodDescr_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	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 | Py_TPFLAGS_HAVE_GC, /* tp_flags */
	0,					/* tp_doc */
	descr_traverse,				/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	0,					/* tp_methods */
	descr_members,				/* tp_members */
	method_getset,				/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	(descrgetfunc)method_get,		/* tp_descr_get */
	0,					/* tp_descr_set */
};

#ifndef SYMBIAN
PyTypeObject PyMemberDescr_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyMemberDescr_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	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 | Py_TPFLAGS_HAVE_GC, /* tp_flags */
	0,					/* tp_doc */
	descr_traverse,				/* 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)member_get,		/* tp_descr_get */
	(descrsetfunc)member_set,		/* tp_descr_set */
};

#ifndef SYMBIAN
PyTypeObject PyGetSetDescr_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyGetSetDescr_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	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 | Py_TPFLAGS_HAVE_GC, /* tp_flags */
	0,					/* tp_doc */
	descr_traverse,				/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	0,					/* tp_methods */
	descr_members,				/* tp_members */
	getset_getset,				/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	(descrgetfunc)getset_get,		/* tp_descr_get */
	(descrsetfunc)getset_set,		/* tp_descr_set */
};

#ifndef SYMBIAN
PyTypeObject PyWrapperDescr_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyWrapperDescr_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	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 | Py_TPFLAGS_HAVE_GC, /* tp_flags */
	0,					/* tp_doc */
	descr_traverse,				/* 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;
}

DL_EXPORT(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;
}

DL_EXPORT(PyObject *)
PyDescr_NewMember(PyTypeObject *type, PyMemberDef *member)
{
	PyMemberDescrObject *descr;

	descr = (PyMemberDescrObject *)descr_new(&PyMemberDescr_Type,
						 type, member->name);
	if (descr != NULL)
		descr->d_member = member;
	return (PyObject *)descr;
}

DL_EXPORT(PyObject *)
PyDescr_NewGetSet(PyTypeObject *type, PyGetSetDef *getset)
{
	PyGetSetDescrObject *descr;

	descr = (PyGetSetDescrObject *)descr_new(&PyGetSetDescr_Type,
						 type, getset->name);
	if (descr != NULL)
		descr->d_getset = getset;
	return (PyObject *)descr;
}

DL_EXPORT(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;