cpython/Objects/structseq.c

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/* Implementation helper: a struct that looks like a tuple. See timemodule
and posixmodule for example uses. */
#include "Python.h"
#include "structmember.h"
#include "structseq.h"
static char visible_length_key[] = "n_sequence_fields";
static char real_length_key[] = "n_fields";
#define VISIBLE_SIZE(op) ((op)->ob_size)
#define VISIBLE_SIZE_TP(tp) PyInt_AsLong( \
PyDict_GetItemString((tp)->tp_dict, visible_length_key))
#define REAL_SIZE_TP(tp) PyInt_AsLong( \
PyDict_GetItemString((tp)->tp_dict, real_length_key))
#define REAL_SIZE(op) REAL_SIZE_TP((op)->ob_type)
PyObject *
PyStructSequence_New(PyTypeObject *type)
{
PyStructSequence *obj;
obj = PyObject_New(PyStructSequence, type);
obj->ob_size = VISIBLE_SIZE_TP(type);
return (PyObject*) obj;
}
static void
structseq_dealloc(PyStructSequence *obj)
{
int i, size;
size = REAL_SIZE(obj);
for (i = 0; i < size; ++i) {
Py_XDECREF(obj->ob_item[i]);
}
PyObject_FREE(obj);
}
static int
structseq_length(PyStructSequence *obj)
{
return VISIBLE_SIZE(obj);
}
static PyObject*
structseq_item(PyStructSequence *obj, int i)
{
if (i < 0 || i >= VISIBLE_SIZE(obj)) {
PyErr_SetString(PyExc_IndexError, "tuple index out of range");
return NULL;
}
Py_INCREF(obj->ob_item[i]);
return obj->ob_item[i];
}
static PyObject*
structseq_slice(PyStructSequence *obj, int low, int high)
{
PyTupleObject *np;
int i;
if (low < 0)
low = 0;
if (high > VISIBLE_SIZE(obj))
high = VISIBLE_SIZE(obj);
if (high < low)
high = low;
np = (PyTupleObject *)PyTuple_New(high-low);
if (np == NULL)
return NULL;
for(i = low; i < high; ++i) {
PyObject *v = obj->ob_item[i];
Py_INCREF(v);
PyTuple_SET_ITEM(np, i-low, v);
}
return (PyObject *) np;
}
static PyObject *
structseq_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
PyObject *arg = NULL;
PyStructSequence *res = NULL;
int len, required_len, i;
static char *kwlist[] = {"sequence", 0};
static char msgbuf[128];
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:structseq",
kwlist, &arg))
return NULL;
if (!PySequence_Check(arg)) {
PyErr_SetString(PyExc_TypeError,
"constructor requires a sequence");
return NULL;
}
len = PySequence_Length(arg);
required_len = REAL_SIZE_TP(type);
if (len != required_len) {
sprintf(msgbuf,
"constructor takes exactly %d arguments (%d given)",
required_len,
len);
PyErr_SetString(PyExc_TypeError, msgbuf);
return NULL;
}
res = (PyStructSequence*) PyStructSequence_New(type);
for (i = 0; i < len; ++i) {
/* INCREF???? XXXX */
res->ob_item[i] = PySequence_GetItem(arg, i);
}
return (PyObject*) res;
}
static PyObject *
make_tuple(PyStructSequence *obj)
{
return structseq_slice(obj, 0, VISIBLE_SIZE(obj));
}
static PyObject *
structseq_repr(PyStructSequence *obj)
{
PyObject *tup, *str;
tup = make_tuple(obj);
str = PyObject_Repr(tup);
Py_DECREF(tup);
return str;
}
static PyObject *
structseq_concat(PyStructSequence *obj, PyObject *b)
{
PyObject *tup, *result;
tup = make_tuple(obj);
result = PySequence_Concat(tup, b);
Py_DECREF(tup);
return result;
}
static PyObject *
structseq_repeat(PyStructSequence *obj, int n)
{
PyObject *tup, *result;
tup = make_tuple(obj);
result = PySequence_Repeat(tup, n);
Py_DECREF(tup);
return result;
}
static int
structseq_contains(PyStructSequence *obj, PyObject *o)
{
PyObject *tup;
int result;
tup = make_tuple(obj);
result = PySequence_Contains(tup, o);
Py_DECREF(tup);
return result;
}
static long
structseq_hash(PyObject *obj)
{
PyObject *tup;
long result;
tup = make_tuple((PyStructSequence*) obj);
result = PyObject_Hash(tup);
Py_DECREF(tup);
return result;
}
static PyObject *
structseq_richcompare(PyObject *obj, PyObject *o2, int op)
{
PyObject *tup, *result;
tup = make_tuple((PyStructSequence*) obj);
result = PyObject_RichCompare(tup, o2, op);
Py_DECREF(tup);
return result;
}
static PySequenceMethods structseq_as_sequence = {
(inquiry)structseq_length,
(binaryfunc)structseq_concat, /* sq_concat */
(intargfunc)structseq_repeat, /* sq_repeat */
(intargfunc)structseq_item, /* sq_item */
(intintargfunc)structseq_slice, /* sq_slice */
0, /* sq_ass_item */
0, /* sq_ass_slice */
(objobjproc)structseq_contains, /* sq_contains */
};
static PyTypeObject _struct_sequence_template = {
PyObject_HEAD_INIT(&PyType_Type)
0, /* ob_size */
NULL, /* tp_name */
0, /* tp_basicsize */
0, /* tp_itemsize */
(destructor)structseq_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
(reprfunc)structseq_repr, /* tp_repr */
0, /* tp_as_number */
&structseq_as_sequence, /* tp_as_sequence */
0, /* tp_as_mapping */
(hashfunc)structseq_hash, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
NULL, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
structseq_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
NULL, /* tp_members */
0, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
structseq_new, /* tp_new */
};
void
PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
{
PyObject *dict;
PyMemberDef* members;
int n_members, i;
for (i = 0; desc->fields[i].name != NULL; ++i)
;
n_members = i;
memcpy(type, &_struct_sequence_template, sizeof(PyTypeObject));
type->tp_name = desc->name;
type->tp_doc = desc->doc;
type->tp_basicsize = sizeof(PyStructSequence)+
sizeof(PyObject*)*(n_members-1);
type->tp_itemsize = 0;
members = PyMem_NEW(PyMemberDef, n_members+1);
for (i = 0; i < n_members; ++i) {
members[i].name = desc->fields[i].name;
members[i].type = T_OBJECT;
members[i].offset = offsetof(PyStructSequence, ob_item)
+ i * sizeof(PyObject*);
members[i].flags = READONLY;
members[i].doc = desc->fields[i].doc;
}
members[n_members].name = NULL;
type->tp_members = members;
if (PyType_Ready(type) < 0)
return;
Py_INCREF(type);
dict = type->tp_dict;
PyDict_SetItemString(dict, visible_length_key,
PyInt_FromLong((long) desc->n_in_sequence));
PyDict_SetItemString(dict, real_length_key,
PyInt_FromLong((long) n_members));
}