cpython/Modules/xreadlinesmodule.c

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#include "Python.h"
static char xreadlines_doc [] =
"xreadlines(f)\n\
\n\
Return an xreadlines object for the file f.";
typedef struct {
PyObject_HEAD
PyObject *file;
PyObject *lines;
int lineslen;
int lineno;
int abslineno;
} PyXReadlinesObject;
staticforward PyTypeObject XReadlinesObject_Type;
static void
xreadlines_dealloc(PyXReadlinesObject *op)
{
Py_XDECREF(op->file);
Py_XDECREF(op->lines);
PyObject_DEL(op);
}
/* A larger chunk size doesn't seem to make a difference */
#define CHUNKSIZE 8192
static PyXReadlinesObject *
newreadlinesobject(PyObject *file)
{
PyXReadlinesObject *op;
op = PyObject_NEW(PyXReadlinesObject, &XReadlinesObject_Type);
if (op == NULL)
return NULL;
Py_XINCREF(file);
op->file = file;
op->lines = NULL;
op->abslineno = op->lineno = op->lineslen = 0;
return op;
}
static PyObject *
xreadlines(PyObject *self, PyObject *args)
{
PyObject *file;
PyXReadlinesObject *ret;
if (!PyArg_ParseTuple(args, "O:xreadlines", &file))
return NULL;
ret = newreadlinesobject(file);
return (PyObject*)ret;
}
static PyObject *
xreadlines_common(PyXReadlinesObject *a)
{
if (a->lineno >= a->lineslen) {
Py_XDECREF(a->lines);
a->lines = PyObject_CallMethod(a->file, "readlines", "(i)",
CHUNKSIZE);
if (a->lines == NULL)
return NULL;
a->lineno = 0;
if ((a->lineslen = PySequence_Size(a->lines)) < 0)
return NULL;
}
a->abslineno++;
return PySequence_GetItem(a->lines, a->lineno++);
}
static PyObject *
xreadlines_item(PyXReadlinesObject *a, int i)
{
if (i != a->abslineno) {
PyErr_SetString(PyExc_RuntimeError,
"xreadlines object accessed out of order");
return NULL;
}
return xreadlines_common(a);
}
static PyObject *
xreadlines_getiter(PyXReadlinesObject *a)
{
Py_INCREF(a);
return (PyObject *)a;
}
static PyObject *
xreadlines_iternext(PyXReadlinesObject *a)
{
PyObject *res;
res = xreadlines_common(a);
if (res == NULL && PyErr_ExceptionMatches(PyExc_IndexError))
PyErr_Clear();
return res;
}
static PyObject *
xreadlines_next(PyXReadlinesObject *a, PyObject *args)
{
PyObject *res;
if (!PyArg_ParseTuple(args, ""))
return NULL;
res = xreadlines_common(a);
if (res == NULL && PyErr_ExceptionMatches(PyExc_IndexError))
PyErr_SetObject(PyExc_StopIteration, Py_None);
return res;
}
static char next_doc[] = "x.next() -> the next line or raise StopIteration";
static PyMethodDef xreadlines_methods[] = {
{"next", (PyCFunction)xreadlines_next, METH_VARARGS, next_doc},
{NULL, NULL}
};
static PyObject *
xreadlines_getattr(PyObject *a, char *name)
{
return Py_FindMethod(xreadlines_methods, a, name);
}
static PySequenceMethods xreadlines_as_sequence = {
0, /*sq_length*/
0, /*sq_concat*/
0, /*sq_repeat*/
(intargfunc)xreadlines_item, /*sq_item*/
};
static PyTypeObject XReadlinesObject_Type = {
PyObject_HEAD_INIT(NULL)
0,
"xreadlines",
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sizeof(PyXReadlinesObject),
0,
(destructor)xreadlines_dealloc, /* tp_dealloc */
0, /* tp_print */
xreadlines_getattr, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
0, /* tp_as_number */
&xreadlines_as_sequence, /* 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 */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
(getiterfunc)xreadlines_getiter, /* tp_iter */
(iternextfunc)xreadlines_iternext, /* tp_iternext */
};
static PyMethodDef xreadlines_functions[] = {
{"xreadlines", xreadlines, METH_VARARGS, xreadlines_doc},
{NULL, NULL}
};
DL_EXPORT(void)
initxreadlines(void)
{
XReadlinesObject_Type.ob_type = &PyType_Type;
Py_InitModule("xreadlines", xreadlines_functions);
}