Start work on rsync support for file transfers

kittens/transfer/rsync.c

@@ -0,0 +1,35 @@
+/*
+ * rsync.c
+ * Copyright (C) 2021 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include "data-types.h"
+#include <librsync.h>
+
+static PyMethodDef module_methods[] = {
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+static int
+exec_module(PyObject *m UNUSED) {
+    return 0;
+}
+
+IGNORE_PEDANTIC_WARNINGS
+static PyModuleDef_Slot slots[] = { {Py_mod_exec, (void*)exec_module}, {0, NULL} };
+END_IGNORE_PEDANTIC_WARNINGS
+
+static struct PyModuleDef module = {
+   .m_base = PyModuleDef_HEAD_INIT,
+   .m_name = "rsync",   /* name of module */
+   .m_doc = NULL,
+   .m_slots = slots,
+   .m_methods = module_methods
+};
+
+EXPORTED PyMODINIT_FUNC
+PyInit_rsync(void) {
+	return PyModuleDef_Init(&module);
+}