Subinterpretor compatible __res module (2nd attempt)

Cython is not yet subinterpreter compatible. There are no ETA when cython is going to support subinterpreters.

This PR removes cython from hermetic python imoprt hooks in order to make them subinterpretr-compatible.
commit_hash:427b6f9db6afa6695659ee147621e1ccb391d3cb

1 files changed, 77 insertions, 0 deletions

diff --git a/library/python/runtime_py3/test/subinterpreter/stdout_interceptor.cpp b/library/python/runtime_py3/test/subinterpreter/stdout_interceptor.cpp
new file mode 100644
index 00000000000..3cd4b69d012
--- /dev/null
+++ b/library/python/runtime_py3/test/subinterpreter/stdout_interceptor.cpp
@@ -0,0 +1,77 @@
+#include "stdout_interceptor.h"
+
+#include <util/stream/output.h>
+
+namespace {
+
+struct TOStreamWrapper {
+    PyObject_HEAD
+    IOutputStream* Stm = nullptr;
+};
+
+PyObject* Write(TOStreamWrapper *self, PyObject *const *args, Py_ssize_t nargs) noexcept {
+    try {
+        Py_buffer view;
+        for (Py_ssize_t i = 0; i < nargs; ++i) {
+            PyObject* buf = args[i];
+            if (PyUnicode_Check(args[i])) {
+                buf = PyUnicode_AsUTF8String(buf);
+                if (!buf) {
+                    return nullptr;
+                }
+            }
+
+            if (PyObject_GetBuffer(buf, &view, PyBUF_SIMPLE | PyBUF_C_CONTIGUOUS) == -1) {
+                return nullptr;
+            }
+            self->Stm->Write(reinterpret_cast<const char*>(view.buf), view.len);
+            PyBuffer_Release(&view);
+        }
+
+        return Py_None;
+    } catch(const std::exception& err) {
+        PyErr_SetString(PyExc_IOError, err.what());
+    } catch (...) {
+        PyErr_SetString(PyExc_RuntimeError, "Unhandled C++ exception of unknown type");
+    }
+    return nullptr;
+}
+
+PyMethodDef TOStreamWrapperMethods[] = {
+    {"write", reinterpret_cast<PyCFunction>(Write), METH_FASTCALL, PyDoc_STR("write buffer to wrapped C++ stream")},
+    {}
+};
+
+PyTypeObject TOStreamWrapperType {
+    .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
+    .tp_name = "testwrap.OStream",
+    .tp_basicsize = sizeof(TOStreamWrapper),
+    .tp_itemsize = 0,
+    .tp_flags = Py_TPFLAGS_DEFAULT,
+    .tp_doc = PyDoc_STR("C++ IOStream wrapper"),
+    .tp_methods = TOStreamWrapperMethods,
+    .tp_new = PyType_GenericNew,
+};
+
+}
+
+TPyStdoutInterceptor::TPyStdoutInterceptor(IOutputStream& redirectionStream) noexcept
+    : RealStdout_{PySys_GetObject("stdout")}
+{
+    Py_INCREF(RealStdout_);
+
+    PyObject* redirect = TOStreamWrapperType.tp_alloc(&TOStreamWrapperType, 0);
+    reinterpret_cast<TOStreamWrapper*>(redirect)->Stm = &redirectionStream;
+
+    PySys_SetObject("stdout", redirect);
+    Py_DECREF(redirect);
+}
+
+TPyStdoutInterceptor::~TPyStdoutInterceptor() noexcept {
+    PySys_SetObject("stdout", RealStdout_);
+    Py_DECREF(RealStdout_);
+}
+
+bool TPyStdoutInterceptor::SetupInterceptionSupport() noexcept {
+    return PyType_Ready(&TOStreamWrapperType) == 0;
+}