traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
cpython/Objects/structseq.c

433 lines
13 KiB
C
Raw Blame History

/* Implementation helper: a struct that looks like a tuple. See timemodule
and posixmodule for example uses. */
#include "Python.h"
#include "structmember.h"
static const char visible_length_key[] = "n_sequence_fields";
static const char real_length_key[] = "n_fields";
static const char unnamed_fields_key[] = "n_unnamed_fields";
/* Fields with this name have only a field index, not a field name.
They are only allowed for indices < n_visible_fields. */
char *PyStructSequence_UnnamedField = "unnamed field";
_Py_IDENTIFIER(n_sequence_fields);
_Py_IDENTIFIER(n_fields);
_Py_IDENTIFIER(n_unnamed_fields);
#define VISIBLE_SIZE(op) Py_SIZE(op)
#define VISIBLE_SIZE_TP(tp) PyLong_AsSsize_t( \
_PyDict_GetItemId((tp)->tp_dict, &PyId_n_sequence_fields))
#define REAL_SIZE_TP(tp) PyLong_AsSsize_t( \
_PyDict_GetItemId((tp)->tp_dict, &PyId_n_fields))
#define REAL_SIZE(op) REAL_SIZE_TP(Py_TYPE(op))
#define UNNAMED_FIELDS_TP(tp) PyLong_AsSsize_t( \
_PyDict_GetItemId((tp)->tp_dict, &PyId_n_unnamed_fields))
#define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_TYPE(op))
PyObject *
PyStructSequence_New(PyTypeObject *type)
{
PyStructSequence *obj;
Py_ssize_t size = REAL_SIZE_TP(type), i;
obj = PyObject_GC_NewVar(PyStructSequence, type, size);
if (obj == NULL)
return NULL;
/* Hack the size of the variable object, so invisible fields don't appear
to Python code. */
Py_SIZE(obj) = VISIBLE_SIZE_TP(type);
for (i = 0; i < size; i++)
obj->ob_item[i] = NULL;
return (PyObject*)obj;
}
void
PyStructSequence_SetItem(PyObject* op, Py_ssize_t i, PyObject* v)
{
PyStructSequence_SET_ITEM(op, i, v);
}
PyObject*
PyStructSequence_GetItem(PyObject* op, Py_ssize_t i)
{
return PyStructSequence_GET_ITEM(op, i);
}
static void
structseq_dealloc(PyStructSequence *obj)
{
Py_ssize_t i, size;
size = REAL_SIZE(obj);
for (i = 0; i < size; ++i) {
Py_XDECREF(obj->ob_item[i]);
}
PyObject_GC_Del(obj);
}
/*[clinic input]
class structseq "PyStructSequence *" "NULL"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9d781c6922c77752]*/
#include "clinic/structseq.c.h"
/*[clinic input]
@classmethod
structseq.__new__ as structseq_new
sequence as arg: object
dict: object = NULL
[clinic start generated code]*/
static PyObject *
structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
/*[clinic end generated code: output=baa082e788b171da input=9b44810243907377]*/
{
PyObject *ob;
PyStructSequence *res = NULL;
Py_ssize_t len, min_len, max_len, i, n_unnamed_fields;
arg = PySequence_Fast(arg, "constructor requires a sequence");
if (!arg) {
return NULL;
}
if (dict && !PyDict_Check(dict)) {
PyErr_Format(PyExc_TypeError,
"%.500s() takes a dict as second arg, if any",
type->tp_name);
Py_DECREF(arg);
return NULL;
}
len = PySequence_Fast_GET_SIZE(arg);
min_len = VISIBLE_SIZE_TP(type);
max_len = REAL_SIZE_TP(type);
n_unnamed_fields = UNNAMED_FIELDS_TP(type);
if (min_len != max_len) {
if (len < min_len) {
PyErr_Format(PyExc_TypeError,
"%.500s() takes an at least %zd-sequence (%zd-sequence given)",
type->tp_name, min_len, len);
Py_DECREF(arg);
return NULL;
}
if (len > max_len) {
PyErr_Format(PyExc_TypeError,
"%.500s() takes an at most %zd-sequence (%zd-sequence given)",
type->tp_name, max_len, len);
Py_DECREF(arg);
return NULL;
}
}
else {
if (len != min_len) {
PyErr_Format(PyExc_TypeError,
"%.500s() takes a %zd-sequence (%zd-sequence given)",
type->tp_name, min_len, len);
Py_DECREF(arg);
return NULL;
}
}
res = (PyStructSequence*) PyStructSequence_New(type);
if (res == NULL) {
Py_DECREF(arg);
return NULL;
}
for (i = 0; i < len; ++i) {
PyObject *v = PySequence_Fast_GET_ITEM(arg, i);
Py_INCREF(v);
res->ob_item[i] = v;
}
for (; i < max_len; ++i) {
if (dict && (ob = PyDict_GetItemString(
dict, type->tp_members[i-n_unnamed_fields].name))) {
}
else {
ob = Py_None;
}
Py_INCREF(ob);
res->ob_item[i] = ob;
}
Py_DECREF(arg);
return (PyObject*) res;
}
static PyObject *
structseq_repr(PyStructSequence *obj)
{
/* buffer and type size were chosen well considered. */
#define REPR_BUFFER_SIZE 512
#define TYPE_MAXSIZE 100
PyTypeObject *typ = Py_TYPE(obj);
Py_ssize_t i;
int removelast = 0;
Py_ssize_t len;
char buf[REPR_BUFFER_SIZE];
char *endofbuf, *pbuf = buf;
/* pointer to end of writeable buffer; safes space for "...)\0" */
endofbuf= &buf[REPR_BUFFER_SIZE-5];
/* "typename(", limited to TYPE_MAXSIZE */
len = strlen(typ->tp_name) > TYPE_MAXSIZE ? TYPE_MAXSIZE :
strlen(typ->tp_name);
strncpy(pbuf, typ->tp_name, len);
pbuf += len;
*pbuf++ = '(';
for (i=0; i < VISIBLE_SIZE(obj); i++) {
PyObject *val, *repr;
const char *cname, *crepr;
cname = typ->tp_members[i].name;
if (cname == NULL) {
PyErr_Format(PyExc_SystemError, "In structseq_repr(), member %d name is NULL"
" for type %.500s", i, typ->tp_name);
return NULL;
}
val = PyStructSequence_GET_ITEM(obj, i);
repr = PyObject_Repr(val);
if (repr == NULL)
return NULL;
crepr = PyUnicode_AsUTF8(repr);
if (crepr == NULL) {
Py_DECREF(repr);
return NULL;
}
/* + 3: keep space for "=" and ", " */
len = strlen(cname) + strlen(crepr) + 3;
if ((pbuf+len) <= endofbuf) {
strcpy(pbuf, cname);
pbuf += strlen(cname);
*pbuf++ = '=';
strcpy(pbuf, crepr);
pbuf += strlen(crepr);
*pbuf++ = ',';
*pbuf++ = ' ';
removelast = 1;
Py_DECREF(repr);
}
else {
strcpy(pbuf, "...");
pbuf += 3;
removelast = 0;
Py_DECREF(repr);
break;
}
}
if (removelast) {
/* overwrite last ", " */
pbuf-=2;
}
*pbuf++ = ')';
*pbuf = '\0';
return PyUnicode_FromString(buf);
}
static PyObject *
structseq_reduce(PyStructSequence* self, PyObject *Py_UNUSED(ignored))
{
PyObject* tup = NULL;
PyObject* dict = NULL;
PyObject* result;
Py_ssize_t n_fields, n_visible_fields, n_unnamed_fields, i;
n_fields = REAL_SIZE(self);
n_visible_fields = VISIBLE_SIZE(self);
n_unnamed_fields = UNNAMED_FIELDS(self);
tup = PyTuple_New(n_visible_fields);
if (!tup)
goto error;
dict = PyDict_New();
if (!dict)
goto error;
for (i = 0; i < n_visible_fields; i++) {
Py_INCREF(self->ob_item[i]);
PyTuple_SET_ITEM(tup, i, self->ob_item[i]);
}
for (; i < n_fields; i++) {
const char *n = Py_TYPE(self)->tp_members[i-n_unnamed_fields].name;
if (PyDict_SetItemString(dict, n, self->ob_item[i]) < 0)
goto error;
}
result = Py_BuildValue("(O(OO))", Py_TYPE(self), tup, dict);
Py_DECREF(tup);
Py_DECREF(dict);
return result;
error:
Py_XDECREF(tup);
Py_XDECREF(dict);
return NULL;
}
static PyMethodDef structseq_methods[] = {
{"__reduce__", (PyCFunction)structseq_reduce, METH_NOARGS, NULL},
{NULL, NULL}
};
static PyTypeObject _struct_sequence_template = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
NULL, /* tp_name */
sizeof(PyStructSequence) - sizeof(PyObject *), /* tp_basicsize */
sizeof(PyObject *), /* tp_itemsize */
(destructor)structseq_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
(reprfunc)structseq_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* 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 */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
structseq_methods, /* 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 */
};
int
PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
{
PyObject *dict;
PyMemberDef* members;
Py_ssize_t n_members, n_unnamed_members, i, k;
PyObject *v;
#ifdef Py_TRACE_REFS
/* if the type object was chained, unchain it first
before overwriting its storage */
if (type->ob_base.ob_base._ob_next) {
_Py_ForgetReference((PyObject*)type);
}
#endif
n_unnamed_members = 0;
for (i = 0; desc->fields[i].name != NULL; ++i)
if (desc->fields[i].name == PyStructSequence_UnnamedField)
n_unnamed_members++;
n_members = i;
memcpy(type, &_struct_sequence_template, sizeof(PyTypeObject));
type->tp_base = &PyTuple_Type;
type->tp_name = desc->name;
type->tp_doc = desc->doc;
members = PyMem_NEW(PyMemberDef, n_members-n_unnamed_members+1);
if (members == NULL) {
PyErr_NoMemory();
return -1;
}
for (i = k = 0; i < n_members; ++i) {
if (desc->fields[i].name == PyStructSequence_UnnamedField)
continue;
members[k].name = desc->fields[i].name;
members[k].type = T_OBJECT;
members[k].offset = offsetof(PyStructSequence, ob_item)
+ i * sizeof(PyObject*);
members[k].flags = READONLY;
members[k].doc = desc->fields[i].doc;
k++;
}
members[k].name = NULL;
type->tp_members = members;
if (PyType_Ready(type) < 0)
return -1;
Py_INCREF(type);
dict = type->tp_dict;
#define SET_DICT_FROM_SIZE(key, value) \
do { \
v = PyLong_FromSsize_t(value); \
if (v == NULL) \
return -1; \
if (PyDict_SetItemString(dict, key, v) < 0) { \
Py_DECREF(v); \
return -1; \
} \
Py_DECREF(v); \
} while (0)
SET_DICT_FROM_SIZE(visible_length_key, desc->n_in_sequence);
SET_DICT_FROM_SIZE(real_length_key, n_members);
SET_DICT_FROM_SIZE(unnamed_fields_key, n_unnamed_members);
return 0;
}
void
PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
{
(void)PyStructSequence_InitType2(type, desc);
}
PyTypeObject*
PyStructSequence_NewType(PyStructSequence_Desc *desc)
{
PyTypeObject *result;
result = (PyTypeObject*)PyType_GenericAlloc(&PyType_Type, 0);
if (result == NULL)
return NULL;
if (PyStructSequence_InitType2(result, desc) < 0) {
Py_DECREF(result);
return NULL;
}
return result;
}
int _PyStructSequence_Init(void)
{
if (_PyUnicode_FromId(&PyId_n_sequence_fields) == NULL
|| _PyUnicode_FromId(&PyId_n_fields) == NULL
|| _PyUnicode_FromId(&PyId_n_unnamed_fields) == NULL)
return -1;
return 0;
}
Reference in New Issue View Git Blame Copy Permalink