implement a detach() method for BufferedIOBase and TextIOBase #5883
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 26fc68d..f201ba7 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -28,6 +28,19 @@
return NULL;
}
+PyDoc_STRVAR(TextIOBase_detach_doc,
+ "Separate the underlying buffer from the TextIOBase and return it.\n"
+ "\n"
+ "After the underlying buffer has been detached, the TextIO is in an\n"
+ "unusable state.\n"
+ );
+
+static PyObject *
+TextIOBase_detach(PyObject *self)
+{
+ return _unsupported("detach");
+}
+
PyDoc_STRVAR(TextIOBase_read_doc,
"Read at most n characters from stream.\n"
"\n"
@@ -93,6 +106,7 @@
static PyMethodDef TextIOBase_methods[] = {
+ {"detach", (PyCFunction)TextIOBase_detach, METH_NOARGS, TextIOBase_detach_doc},
{"read", TextIOBase_read, METH_VARARGS, TextIOBase_read_doc},
{"readline", TextIOBase_readline, METH_VARARGS, TextIOBase_readline_doc},
{"write", TextIOBase_write, METH_VARARGS, TextIOBase_write_doc},
@@ -616,6 +630,7 @@
{
PyObject_HEAD
int ok; /* initialized? */
+ int detached;
Py_ssize_t chunk_size;
PyObject *buffer;
PyObject *encoding;
@@ -759,6 +774,7 @@
int r;
self->ok = 0;
+ self->detached = 0;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|zzzi:fileio",
kwlist, &buffer, &encoding, &errors,
&newline, &line_buffering))
@@ -1059,19 +1075,45 @@
#define CHECK_INITIALIZED(self) \
if (self->ok <= 0) { \
- PyErr_SetString(PyExc_ValueError, \
- "I/O operation on uninitialized object"); \
+ if (self->detached) { \
+ PyErr_SetString(PyExc_ValueError, \
+ "underlying buffer has been detached"); \
+ } else { \
+ PyErr_SetString(PyExc_ValueError, \
+ "I/O operation on uninitialized object"); \
+ } \
return NULL; \
}
#define CHECK_INITIALIZED_INT(self) \
if (self->ok <= 0) { \
- PyErr_SetString(PyExc_ValueError, \
- "I/O operation on uninitialized object"); \
+ if (self->detached) { \
+ PyErr_SetString(PyExc_ValueError, \
+ "underlying buffer has been detached"); \
+ } else { \
+ PyErr_SetString(PyExc_ValueError, \
+ "I/O operation on uninitialized object"); \
+ } \
return -1; \
}
+static PyObject *
+TextIOWrapper_detach(PyTextIOWrapperObject *self)
+{
+ PyObject *buffer, *res;
+ CHECK_INITIALIZED(self);
+ res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
+ if (res == NULL)
+ return NULL;
+ Py_DECREF(res);
+ buffer = self->buffer;
+ self->buffer = NULL;
+ self->detached = 1;
+ self->ok = 0;
+ return buffer;
+}
+
Py_LOCAL_INLINE(const Py_UNICODE *)
findchar(const Py_UNICODE *s, Py_ssize_t size, Py_UNICODE ch)
{
@@ -2341,6 +2383,7 @@
}
static PyMethodDef TextIOWrapper_methods[] = {
+ {"detach", (PyCFunction)TextIOWrapper_detach, METH_NOARGS},
{"write", (PyCFunction)TextIOWrapper_write, METH_VARARGS},
{"read", (PyCFunction)TextIOWrapper_read, METH_VARARGS},
{"readline", (PyCFunction)TextIOWrapper_readline, METH_VARARGS},