/**
* \ingroup python_interface_filehandle
* \brief Constructs a new file handle object from a Python object.
*
* \return 0 if everything was OK, 1 otherwise. An appropriate Python
* exception is raised in this case.
*/
int igraphmodule_filehandle_init(igraphmodule_filehandle_t* handle,
PyObject* object, char* mode) {
#ifdef IGRAPH_PYTHON3
int fp;
if (object == 0 || PyLong_Check(object)) {
PyErr_SetString(PyExc_TypeError, "string or file-like object expected");
return 1;
}
#else
if (object == 0 ||
(!PyBaseString_Check(object) && !PyFile_Check(object))) {
PyErr_SetString(PyExc_TypeError, "string or file handle expected");
return 1;
}
#endif
if (PyBaseString_Check(object)) {
#ifdef IGRAPH_PYTHON3
handle->object = PyFile_FromObject(object, mode);
#else
handle->object = PyFile_FromString(PyString_AsString(object), mode);
#endif
if (handle->object == 0)
return 1;
} else {
handle->object = object;
Py_INCREF(handle->object);
}
/* At this stage, handle->object is something we can handle.
* In Python 2, we get here only if object is a file object. In
* Python 3, object can be anything, and PyFile_FromObject will
* complain if the object cannot be converted to a file handle.
*/
#ifdef IGRAPH_PYTHON3
fp = PyObject_AsFileDescriptor(handle->object);
if (fp == -1) {
Py_DECREF(handle->object);
return 1;
}
handle->fp = fdopen(fp, mode);
if (handle->fp == 0) {
Py_DECREF(handle->object);
PyErr_SetString(PyExc_RuntimeError, "fdopen() failed unexpectedly");
return 1;
}
#else
handle->fp = PyFile_AsFile(handle->object);
if (handle->fp == 0) {
Py_DECREF(handle->object);
PyErr_SetString(PyExc_RuntimeError, "PyFile_AsFile() failed unexpectedly");
return 1;
}
#endif
return 0;
}
static int igraphmodule_i_filehandle_init_cpython_3(igraphmodule_filehandle_t* handle,
PyObject* object, char* mode) {
int fp;
if (object == 0 || PyLong_Check(object)) {
PyErr_SetString(PyExc_TypeError, "string or file-like object expected");
return 1;
}
handle->need_close = 0;
handle->object = 0;
if (PyBaseString_Check(object)) {
/* We have received a string; we need to open the file denoted by this
* string now and mark that we opened the file ourselves (so we need
* to close it when igraphmodule_filehandle_destroy is invoked). */
handle->object = PyFile_FromObject(object, mode);
if (handle->object == 0) {
/* Could not open the file; just return an error code because an
* exception was raised already */
return 1;
}
/* Remember that we need to close the file ourselves */
handle->need_close = 1;
} else {
/* This is probably a file-like object; store a reference for it and
* we will handle it later */
handle->object = object;
Py_INCREF(handle->object);
}
/* At this stage, handle->object is something we can handle.
* We have to call PyObject_AsFileDescriptor instead
* and then fdopen() it to get the corresponding FILE* object.
*/
fp = PyObject_AsFileDescriptor(handle->object);
if (fp == -1) {
igraphmodule_filehandle_destroy(handle);
/* This already called Py_DECREF(handle->object), no need to call it */
return 1;
}
handle->fp = fdopen(fp, mode);
if (handle->fp == 0) {
igraphmodule_filehandle_destroy(handle);
/* This already called Py_DECREF(handle->object), no need to call it */
PyErr_SetString(PyExc_RuntimeError, "fdopen() failed unexpectedly");
return 1;
}
return 0;
}
