mirror of
https://github.com/python/cpython.git
synced 2024-12-06 00:05:32 +08:00
586 lines
16 KiB
C
586 lines
16 KiB
C
/* Implementation helper: a struct that looks like a tuple.
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See timemodule and posixmodule for example uses.
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The structseq helper is considered an internal CPython implementation
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detail. Docs for modules using structseqs should call them
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"named tuples" (be sure to include a space between the two
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words and add a link back to the term in Docs/glossary.rst).
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*/
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#include "Python.h"
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#include "pycore_tuple.h" // _PyTuple_FromArray()
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#include "pycore_object.h" // _PyObject_GC_TRACK()
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#include "structmember.h" // PyMemberDef
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static const char visible_length_key[] = "n_sequence_fields";
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static const char real_length_key[] = "n_fields";
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static const char unnamed_fields_key[] = "n_unnamed_fields";
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static const char match_args_key[] = "__match_args__";
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/* Fields with this name have only a field index, not a field name.
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They are only allowed for indices < n_visible_fields. */
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const char * const PyStructSequence_UnnamedField = "unnamed field";
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_Py_IDENTIFIER(n_sequence_fields);
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_Py_IDENTIFIER(n_fields);
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_Py_IDENTIFIER(n_unnamed_fields);
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static Py_ssize_t
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get_type_attr_as_size(PyTypeObject *tp, _Py_Identifier *id)
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{
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PyObject *name = _PyUnicode_FromId(id);
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if (name == NULL) {
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return -1;
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}
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PyObject *v = PyDict_GetItemWithError(tp->tp_dict, name);
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if (v == NULL && !PyErr_Occurred()) {
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PyErr_Format(PyExc_TypeError,
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"Missed attribute '%U' of type %s",
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name, tp->tp_name);
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}
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return PyLong_AsSsize_t(v);
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}
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#define VISIBLE_SIZE(op) Py_SIZE(op)
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#define VISIBLE_SIZE_TP(tp) get_type_attr_as_size(tp, &PyId_n_sequence_fields)
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#define REAL_SIZE_TP(tp) get_type_attr_as_size(tp, &PyId_n_fields)
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#define REAL_SIZE(op) REAL_SIZE_TP(Py_TYPE(op))
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#define UNNAMED_FIELDS_TP(tp) get_type_attr_as_size(tp, &PyId_n_unnamed_fields)
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#define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_TYPE(op))
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PyObject *
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PyStructSequence_New(PyTypeObject *type)
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{
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PyStructSequence *obj;
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Py_ssize_t size = REAL_SIZE_TP(type), i;
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if (size < 0) {
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return NULL;
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}
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Py_ssize_t vsize = VISIBLE_SIZE_TP(type);
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if (vsize < 0) {
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return NULL;
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}
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obj = PyObject_GC_NewVar(PyStructSequence, type, size);
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if (obj == NULL)
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return NULL;
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/* Hack the size of the variable object, so invisible fields don't appear
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to Python code. */
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Py_SET_SIZE(obj, vsize);
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for (i = 0; i < size; i++)
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obj->ob_item[i] = NULL;
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return (PyObject*)obj;
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}
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void
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PyStructSequence_SetItem(PyObject* op, Py_ssize_t i, PyObject* v)
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{
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PyStructSequence_SET_ITEM(op, i, v);
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}
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PyObject*
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PyStructSequence_GetItem(PyObject* op, Py_ssize_t i)
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{
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return PyStructSequence_GET_ITEM(op, i);
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}
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static int
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structseq_traverse(PyStructSequence *obj, visitproc visit, void *arg)
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{
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if (Py_TYPE(obj)->tp_flags & Py_TPFLAGS_HEAPTYPE) {
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Py_VISIT(Py_TYPE(obj));
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}
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Py_ssize_t i, size;
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size = REAL_SIZE(obj);
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for (i = 0; i < size; ++i) {
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Py_VISIT(obj->ob_item[i]);
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}
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return 0;
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}
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static void
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structseq_dealloc(PyStructSequence *obj)
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{
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Py_ssize_t i, size;
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PyTypeObject *tp;
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PyObject_GC_UnTrack(obj);
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tp = (PyTypeObject *) Py_TYPE(obj);
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size = REAL_SIZE(obj);
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for (i = 0; i < size; ++i) {
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Py_XDECREF(obj->ob_item[i]);
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}
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PyObject_GC_Del(obj);
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if (_PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE)) {
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Py_DECREF(tp);
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}
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}
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/*[clinic input]
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class structseq "PyStructSequence *" "NULL"
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[clinic start generated code]*/
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/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9d781c6922c77752]*/
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#include "clinic/structseq.c.h"
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/*[clinic input]
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@classmethod
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structseq.__new__ as structseq_new
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sequence as arg: object
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dict: object(c_default="NULL") = {}
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[clinic start generated code]*/
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static PyObject *
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structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
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/*[clinic end generated code: output=baa082e788b171da input=90532511101aa3fb]*/
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{
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PyObject *ob;
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PyStructSequence *res = NULL;
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Py_ssize_t len, min_len, max_len, i, n_unnamed_fields;
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min_len = VISIBLE_SIZE_TP(type);
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if (min_len < 0) {
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return NULL;
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}
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max_len = REAL_SIZE_TP(type);
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if (max_len < 0) {
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return NULL;
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}
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n_unnamed_fields = UNNAMED_FIELDS_TP(type);
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if (n_unnamed_fields < 0) {
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return NULL;
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}
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arg = PySequence_Fast(arg, "constructor requires a sequence");
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if (!arg) {
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return NULL;
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}
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if (dict && !PyDict_Check(dict)) {
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PyErr_Format(PyExc_TypeError,
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"%.500s() takes a dict as second arg, if any",
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type->tp_name);
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Py_DECREF(arg);
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return NULL;
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}
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len = PySequence_Fast_GET_SIZE(arg);
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if (min_len != max_len) {
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if (len < min_len) {
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PyErr_Format(PyExc_TypeError,
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"%.500s() takes an at least %zd-sequence (%zd-sequence given)",
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type->tp_name, min_len, len);
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Py_DECREF(arg);
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return NULL;
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}
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if (len > max_len) {
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PyErr_Format(PyExc_TypeError,
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"%.500s() takes an at most %zd-sequence (%zd-sequence given)",
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type->tp_name, max_len, len);
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Py_DECREF(arg);
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return NULL;
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}
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}
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else {
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if (len != min_len) {
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PyErr_Format(PyExc_TypeError,
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"%.500s() takes a %zd-sequence (%zd-sequence given)",
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type->tp_name, min_len, len);
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Py_DECREF(arg);
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return NULL;
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}
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}
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res = (PyStructSequence*) PyStructSequence_New(type);
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if (res == NULL) {
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Py_DECREF(arg);
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return NULL;
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}
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for (i = 0; i < len; ++i) {
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PyObject *v = PySequence_Fast_GET_ITEM(arg, i);
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Py_INCREF(v);
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res->ob_item[i] = v;
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}
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Py_DECREF(arg);
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for (; i < max_len; ++i) {
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if (dict == NULL) {
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ob = Py_None;
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}
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else {
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ob = _PyDict_GetItemStringWithError(dict,
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type->tp_members[i-n_unnamed_fields].name);
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if (ob == NULL) {
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if (PyErr_Occurred()) {
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Py_DECREF(res);
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return NULL;
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}
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ob = Py_None;
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}
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}
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Py_INCREF(ob);
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res->ob_item[i] = ob;
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}
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_PyObject_GC_TRACK(res);
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return (PyObject*) res;
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}
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static PyObject *
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structseq_repr(PyStructSequence *obj)
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{
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PyTypeObject *typ = Py_TYPE(obj);
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_PyUnicodeWriter writer;
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/* Write "typename(" */
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PyObject *type_name = PyUnicode_DecodeUTF8(typ->tp_name,
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strlen(typ->tp_name),
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NULL);
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if (type_name == NULL) {
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return NULL;
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}
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_PyUnicodeWriter_Init(&writer);
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writer.overallocate = 1;
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/* count 5 characters per item: "x=1, " */
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writer.min_length = (PyUnicode_GET_LENGTH(type_name) + 1
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+ VISIBLE_SIZE(obj) * 5 + 1);
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if (_PyUnicodeWriter_WriteStr(&writer, type_name) < 0) {
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Py_DECREF(type_name);
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goto error;
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}
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Py_DECREF(type_name);
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if (_PyUnicodeWriter_WriteChar(&writer, '(') < 0) {
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goto error;
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}
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for (Py_ssize_t i=0; i < VISIBLE_SIZE(obj); i++) {
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if (i > 0) {
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/* Write ", " */
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if (_PyUnicodeWriter_WriteASCIIString(&writer, ", ", 2) < 0) {
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goto error;
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}
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}
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/* Write "name=repr" */
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const char *name_utf8 = typ->tp_members[i].name;
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if (name_utf8 == NULL) {
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PyErr_Format(PyExc_SystemError, "In structseq_repr(), member %zd name is NULL"
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" for type %.500s", i, typ->tp_name);
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goto error;
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}
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PyObject *name = PyUnicode_DecodeUTF8(name_utf8, strlen(name_utf8), NULL);
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if (name == NULL) {
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goto error;
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}
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if (_PyUnicodeWriter_WriteStr(&writer, name) < 0) {
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Py_DECREF(name);
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goto error;
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}
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Py_DECREF(name);
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if (_PyUnicodeWriter_WriteChar(&writer, '=') < 0) {
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goto error;
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}
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PyObject *value = PyStructSequence_GET_ITEM(obj, i);
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assert(value != NULL);
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PyObject *repr = PyObject_Repr(value);
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if (repr == NULL) {
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goto error;
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}
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if (_PyUnicodeWriter_WriteStr(&writer, repr) < 0) {
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Py_DECREF(repr);
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goto error;
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}
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Py_DECREF(repr);
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}
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if (_PyUnicodeWriter_WriteChar(&writer, ')') < 0) {
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goto error;
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}
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return _PyUnicodeWriter_Finish(&writer);
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error:
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_PyUnicodeWriter_Dealloc(&writer);
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return NULL;
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}
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static PyObject *
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structseq_reduce(PyStructSequence* self, PyObject *Py_UNUSED(ignored))
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{
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PyObject* tup = NULL;
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PyObject* dict = NULL;
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PyObject* result;
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Py_ssize_t n_fields, n_visible_fields, n_unnamed_fields, i;
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n_fields = REAL_SIZE(self);
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if (n_fields < 0) {
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return NULL;
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}
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n_visible_fields = VISIBLE_SIZE(self);
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n_unnamed_fields = UNNAMED_FIELDS(self);
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if (n_unnamed_fields < 0) {
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return NULL;
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}
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tup = _PyTuple_FromArray(self->ob_item, n_visible_fields);
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if (!tup)
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goto error;
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dict = PyDict_New();
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if (!dict)
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goto error;
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for (i = n_visible_fields; i < n_fields; i++) {
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const char *n = Py_TYPE(self)->tp_members[i-n_unnamed_fields].name;
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if (PyDict_SetItemString(dict, n, self->ob_item[i]) < 0)
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goto error;
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}
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result = Py_BuildValue("(O(OO))", Py_TYPE(self), tup, dict);
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Py_DECREF(tup);
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Py_DECREF(dict);
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return result;
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error:
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Py_XDECREF(tup);
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Py_XDECREF(dict);
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return NULL;
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}
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static PyMethodDef structseq_methods[] = {
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{"__reduce__", (PyCFunction)structseq_reduce, METH_NOARGS, NULL},
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{NULL, NULL}
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};
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static Py_ssize_t
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count_members(PyStructSequence_Desc *desc, Py_ssize_t *n_unnamed_members) {
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Py_ssize_t i;
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*n_unnamed_members = 0;
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for (i = 0; desc->fields[i].name != NULL; ++i) {
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if (desc->fields[i].name == PyStructSequence_UnnamedField) {
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(*n_unnamed_members)++;
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}
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}
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return i;
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}
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static int
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initialize_structseq_dict(PyStructSequence_Desc *desc, PyObject* dict,
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Py_ssize_t n_members, Py_ssize_t n_unnamed_members) {
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PyObject *v;
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#define SET_DICT_FROM_SIZE(key, value) \
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do { \
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v = PyLong_FromSsize_t(value); \
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if (v == NULL) { \
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return -1; \
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} \
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if (PyDict_SetItemString(dict, key, v) < 0) { \
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Py_DECREF(v); \
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return -1; \
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} \
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Py_DECREF(v); \
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} while (0)
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SET_DICT_FROM_SIZE(visible_length_key, desc->n_in_sequence);
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SET_DICT_FROM_SIZE(real_length_key, n_members);
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SET_DICT_FROM_SIZE(unnamed_fields_key, n_unnamed_members);
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// Prepare and set __match_args__
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Py_ssize_t i, k;
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PyObject* keys = PyTuple_New(desc->n_in_sequence);
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if (keys == NULL) {
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return -1;
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}
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for (i = k = 0; i < desc->n_in_sequence; ++i) {
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if (desc->fields[i].name == PyStructSequence_UnnamedField) {
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continue;
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}
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PyObject* new_member = PyUnicode_FromString(desc->fields[i].name);
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if (new_member == NULL) {
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goto error;
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}
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PyTuple_SET_ITEM(keys, k, new_member);
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k++;
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}
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if (_PyTuple_Resize(&keys, k) == -1) {
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goto error;
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}
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if (PyDict_SetItemString(dict, match_args_key, keys) < 0) {
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goto error;
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}
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Py_DECREF(keys);
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return 0;
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error:
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Py_DECREF(keys);
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return -1;
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}
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static void
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initialize_members(PyStructSequence_Desc *desc, PyMemberDef* members,
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Py_ssize_t n_members) {
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Py_ssize_t i, k;
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for (i = k = 0; i < n_members; ++i) {
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if (desc->fields[i].name == PyStructSequence_UnnamedField) {
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continue;
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}
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/* The names and docstrings in these MemberDefs are statically */
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/* allocated so it is expected that they'll outlive the MemberDef */
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members[k].name = desc->fields[i].name;
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members[k].type = T_OBJECT;
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members[k].offset = offsetof(PyStructSequence, ob_item)
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+ i * sizeof(PyObject*);
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members[k].flags = READONLY;
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members[k].doc = desc->fields[i].doc;
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k++;
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}
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members[k].name = NULL;
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}
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int
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PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc)
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{
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PyMemberDef *members;
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Py_ssize_t n_members, n_unnamed_members;
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#ifdef Py_TRACE_REFS
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/* if the type object was chained, unchain it first
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before overwriting its storage */
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if (type->ob_base.ob_base._ob_next) {
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_Py_ForgetReference((PyObject *)type);
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}
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#endif
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/* PyTypeObject has already been initialized */
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if (Py_REFCNT(type) != 0) {
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PyErr_BadInternalCall();
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return -1;
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}
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type->tp_name = desc->name;
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type->tp_basicsize = sizeof(PyStructSequence) - sizeof(PyObject *);
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type->tp_itemsize = sizeof(PyObject *);
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type->tp_dealloc = (destructor)structseq_dealloc;
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type->tp_repr = (reprfunc)structseq_repr;
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type->tp_doc = desc->doc;
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type->tp_base = &PyTuple_Type;
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type->tp_methods = structseq_methods;
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type->tp_new = structseq_new;
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type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC;
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type->tp_traverse = (traverseproc) structseq_traverse;
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n_members = count_members(desc, &n_unnamed_members);
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members = PyMem_NEW(PyMemberDef, n_members - n_unnamed_members + 1);
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if (members == NULL) {
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PyErr_NoMemory();
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return -1;
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}
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initialize_members(desc, members, n_members);
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type->tp_members = members;
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if (PyType_Ready(type) < 0) {
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PyMem_Free(members);
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return -1;
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}
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Py_INCREF(type);
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if (initialize_structseq_dict(
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desc, type->tp_dict, n_members, n_unnamed_members) < 0) {
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PyMem_Free(members);
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Py_DECREF(type);
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return -1;
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}
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return 0;
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}
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void
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PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
|
|
{
|
|
(void)PyStructSequence_InitType2(type, desc);
|
|
}
|
|
|
|
PyTypeObject *
|
|
PyStructSequence_NewType(PyStructSequence_Desc *desc)
|
|
{
|
|
PyMemberDef *members;
|
|
PyTypeObject *type;
|
|
PyType_Slot slots[8];
|
|
PyType_Spec spec;
|
|
Py_ssize_t n_members, n_unnamed_members;
|
|
|
|
/* Initialize MemberDefs */
|
|
n_members = count_members(desc, &n_unnamed_members);
|
|
members = PyMem_NEW(PyMemberDef, n_members - n_unnamed_members + 1);
|
|
if (members == NULL) {
|
|
PyErr_NoMemory();
|
|
return NULL;
|
|
}
|
|
initialize_members(desc, members, n_members);
|
|
|
|
/* Initialize Slots */
|
|
slots[0] = (PyType_Slot){Py_tp_dealloc, (destructor)structseq_dealloc};
|
|
slots[1] = (PyType_Slot){Py_tp_repr, (reprfunc)structseq_repr};
|
|
slots[2] = (PyType_Slot){Py_tp_doc, (void *)desc->doc};
|
|
slots[3] = (PyType_Slot){Py_tp_methods, structseq_methods};
|
|
slots[4] = (PyType_Slot){Py_tp_new, structseq_new};
|
|
slots[5] = (PyType_Slot){Py_tp_members, members};
|
|
slots[6] = (PyType_Slot){Py_tp_traverse, (traverseproc)structseq_traverse};
|
|
slots[7] = (PyType_Slot){0, 0};
|
|
|
|
/* Initialize Spec */
|
|
/* The name in this PyType_Spec is statically allocated so it is */
|
|
/* expected that it'll outlive the PyType_Spec */
|
|
spec.name = desc->name;
|
|
spec.basicsize = sizeof(PyStructSequence) - sizeof(PyObject *);
|
|
spec.itemsize = sizeof(PyObject *);
|
|
spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC;
|
|
spec.slots = slots;
|
|
|
|
type = (PyTypeObject *)PyType_FromSpecWithBases(&spec, (PyObject *)&PyTuple_Type);
|
|
PyMem_Free(members);
|
|
if (type == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
if (initialize_structseq_dict(
|
|
desc, type->tp_dict, n_members, n_unnamed_members) < 0) {
|
|
Py_DECREF(type);
|
|
return NULL;
|
|
}
|
|
|
|
return type;
|
|
}
|
|
|
|
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;
|
|
}
|