view Python/structmember.c @ 37756:7b2e436a4a21 legacy-trunk

Use Py_VISIT in all tp_traverse methods, instead of traversing manually or using a custom, nearly-identical macro. This probably changes how some of these functions are compiled, which may result in fractionally slower (or faster) execution. Considering the nature of traversal, visiting much of the address space in unpredictable patterns, I'd argue the code readability and maintainability is well worth it ;P
author Thomas Wouters <thomas@python.org>
date Sat, 15 Apr 2006 21:47:09 +0000
parents e9a10f74cf88
children 8bc4a7e5fef8
line wrap: on
line source


/* Map C struct members to Python object attributes */

#include "Python.h"

#include "structmember.h"

static PyObject *
listmembers(struct memberlist *mlist)
{
	int i, n;
	PyObject *v;
	for (n = 0; mlist[n].name != NULL; n++)
		;
	v = PyList_New(n);
	if (v != NULL) {
		for (i = 0; i < n; i++)
			PyList_SetItem(v, i,
				       PyString_FromString(mlist[i].name));
		if (PyErr_Occurred()) {
			Py_DECREF(v);
			v = NULL;
		}
		else {
			PyList_Sort(v);
		}
	}
	return v;
}

PyObject *
PyMember_Get(const char *addr, struct memberlist *mlist, const char *name)
{
	struct memberlist *l;

	if (strcmp(name, "__members__") == 0)
		return listmembers(mlist);
	for (l = mlist; l->name != NULL; l++) {
		if (strcmp(l->name, name) == 0) {
			PyMemberDef copy;
			copy.name = l->name;
			copy.type = l->type;
			copy.offset = l->offset;
			copy.flags = l->flags;
			copy.doc = NULL;
			return PyMember_GetOne(addr, &copy);
		}
	}
	PyErr_SetString(PyExc_AttributeError, name);
	return NULL;
}

PyObject *
PyMember_GetOne(const char *addr, PyMemberDef *l)
{
	PyObject *v;
	if ((l->flags & READ_RESTRICTED) &&
	    PyEval_GetRestricted()) {
		PyErr_SetString(PyExc_RuntimeError, "restricted attribute");
		return NULL;
	}
	addr += l->offset;
	switch (l->type) {
	case T_BYTE:
		v = PyInt_FromLong(
			(long) (((*(char*)addr & 0xff) ^ 0x80) - 0x80));
		break;
	case T_UBYTE:
		v = PyInt_FromLong((long) *(char*)addr & 0xff);
		break;
	case T_SHORT:
		v = PyInt_FromLong((long) *(short*)addr);
		break;
	case T_USHORT:
		v = PyInt_FromLong((long) *(unsigned short*)addr);
		break;
	case T_INT:
		v = PyInt_FromLong((long) *(int*)addr);
		break;
	case T_UINT:
		v = PyInt_FromLong((long) *(unsigned int*)addr);
		break;
	case T_LONG:
		v = PyInt_FromLong(*(long*)addr);
		break;
	case T_ULONG:
		v = PyLong_FromDouble((double) *(unsigned long*)addr);
		break;
	case T_FLOAT:
		v = PyFloat_FromDouble((double)*(float*)addr);
		break;
	case T_DOUBLE:
		v = PyFloat_FromDouble(*(double*)addr);
		break;
	case T_STRING:
		if (*(char**)addr == NULL) {
			Py_INCREF(Py_None);
			v = Py_None;
		}
		else
			v = PyString_FromString(*(char**)addr);
		break;
	case T_STRING_INPLACE:
		v = PyString_FromString((char*)addr);
		break;
	case T_CHAR:
		v = PyString_FromStringAndSize((char*)addr, 1);
		break;
	case T_OBJECT:
		v = *(PyObject **)addr;
		if (v == NULL)
			v = Py_None;
		Py_INCREF(v);
		break;
	case T_OBJECT_EX:
		v = *(PyObject **)addr;
		if (v == NULL)
			PyErr_SetString(PyExc_AttributeError, l->name);
		Py_XINCREF(v);
		break;
#ifdef HAVE_LONG_LONG
	case T_LONGLONG:
		v = PyLong_FromLongLong(*(PY_LONG_LONG *)addr);
		break;
	case T_ULONGLONG:
		v = PyLong_FromUnsignedLongLong(*(unsigned PY_LONG_LONG *)addr);
		break;
#endif /* HAVE_LONG_LONG */
	default:
		PyErr_SetString(PyExc_SystemError, "bad memberdescr type");
		v = NULL;
	}
	return v;
}

int
PyMember_Set(char *addr, struct memberlist *mlist, const char *name, PyObject *v)
{
	struct memberlist *l;

	for (l = mlist; l->name != NULL; l++) {
		if (strcmp(l->name, name) == 0) {
			PyMemberDef copy;
			copy.name = l->name;
			copy.type = l->type;
			copy.offset = l->offset;
			copy.flags = l->flags;
			copy.doc = NULL;
			return PyMember_SetOne(addr, &copy, v);
		}
	}

	PyErr_SetString(PyExc_AttributeError, name);
	return -1;
}

int
PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
{
	PyObject *oldv;

	if ((l->flags & READONLY) || l->type == T_STRING)
	{
		PyErr_SetString(PyExc_TypeError, "readonly attribute");
		return -1;
	}
	if ((l->flags & WRITE_RESTRICTED) && PyEval_GetRestricted()) {
		PyErr_SetString(PyExc_RuntimeError, "restricted attribute");
		return -1;
	}
	if (v == NULL && l->type != T_OBJECT_EX && l->type != T_OBJECT) {
		PyErr_SetString(PyExc_TypeError,
				"can't delete numeric/char attribute");
		return -1;
	}
	addr += l->offset;
	switch (l->type) {
	case T_BYTE:
	case T_UBYTE:
		if (!PyInt_Check(v)) {
			PyErr_BadArgument();
			return -1;
		}
		*(char*)addr = (char) PyInt_AsLong(v);
		break;
	case T_SHORT:
	case T_USHORT:
		if (!PyInt_Check(v)) {
			PyErr_BadArgument();
			return -1;
		}
		*(short*)addr = (short) PyInt_AsLong(v);
		break;
	case T_UINT:
	case T_INT:
		if (!PyInt_Check(v)) {
			PyErr_BadArgument();
			return -1;
		}
		*(int*)addr = (int) PyInt_AsLong(v);
		break;
	case T_LONG:
		if (!PyInt_Check(v)) {
			PyErr_BadArgument();
			return -1;
		}
		*(long*)addr = PyInt_AsLong(v);
		break;
	case T_ULONG:
		if (PyInt_Check(v))
			*(long*)addr = PyInt_AsLong(v);
		else if (PyLong_Check(v))
			*(long*)addr = PyLong_AsLong(v);
		else {
			PyErr_BadArgument();
			return -1;
		}
		break;
	case T_FLOAT:
		if (PyInt_Check(v))
			*(float*)addr =
				(float) PyInt_AsLong(v);
		else if (PyFloat_Check(v))
			*(float*)addr =
				(float) PyFloat_AsDouble(v);
		else {
			PyErr_BadArgument();
			return -1;
		}
		break;
	case T_DOUBLE:
		if (PyInt_Check(v))
			*(double*)addr = (double) PyInt_AsLong(v);
		else if (PyFloat_Check(v))
			*(double*)addr = PyFloat_AsDouble(v);
		else {
			PyErr_BadArgument();
			return -1;
		}
		break;
	case T_OBJECT:
	case T_OBJECT_EX:
		Py_XINCREF(v);
		oldv = *(PyObject **)addr;
		*(PyObject **)addr = v;
		Py_XDECREF(oldv);
		break;
	case T_CHAR:
		if (PyString_Check(v) && PyString_Size(v) == 1) {
			*(char*)addr = PyString_AsString(v)[0];
		}
		else {
			PyErr_BadArgument();
			return -1;
		}
		break;
#ifdef HAVE_LONG_LONG
	case T_LONGLONG:
		if (!PyLong_Check(v)) {
			PyErr_BadArgument();
			return -1;
		} else {
                        *(PY_LONG_LONG*)addr = PyLong_AsLongLong(v);
                        if ((*addr == -1) && PyErr_Occurred()) {
                                return -1;
                        }
                }
                break;
	case T_ULONGLONG:
                if (!PyLong_Check(v)) {
                        PyErr_BadArgument();
                        return -1;
                } else {
                        *(unsigned PY_LONG_LONG*)addr = PyLong_AsUnsignedLongLong(v);
                        if ((*addr == -1) && PyErr_Occurred()) {
                                return -1;
                        }
                }
                break;
#endif /* HAVE_LONG_LONG */
	default:
		PyErr_Format(PyExc_SystemError,
			     "bad memberdescr type for %s", l->name);
		return -1;
	}
	return 0;
}