static void s_ws_handshake_transform()

in source/mqtt_client_connection.c [360:454]

• 69 lines of code
• 11 McCabe index (conditional complexity)

static void s_ws_handshake_transform(
    struct aws_http_message *request,
    void *user_data,
    aws_mqtt_transform_websocket_handshake_complete_fn *complete_fn,
    void *complete_ctx) {

    struct mqtt_connection_binding *connection_binding = user_data;

    bool success = false;

    /* We'll create a ws_handshake_transform_data object, place it in a capsule, and pass it to callback */
    struct ws_handshake_transform_data *ws_transform_data = NULL;
    PyObject *ws_transform_capsule = NULL;

    /*************** GIL ACQUIRE ***************
     * If error occurs, ensure an aws error is raised and goto done */
    PyGILState_STATE state;
    if (aws_py_gilstate_ensure(&state)) {
        return; /* Python has shut down. Nothing matters anymore, but don't crash */
    }

    /* Ensure python mqtt connection object is still alive */
    PyObject *connection_py = PyWeakref_GetObject(connection_binding->self_proxy); /* borrowed reference */
    if (connection_py == Py_None) {
        aws_raise_error(AWS_ERROR_INVALID_STATE);
        goto done;
    }

    ws_transform_data = aws_mem_calloc(aws_py_get_allocator(), 1, sizeof(struct ws_handshake_transform_data));
    if (!ws_transform_data) {
        goto done;
    }

    ws_transform_capsule = PyCapsule_New(
        ws_transform_data, s_capsule_name_ws_handshake_transform_data, s_ws_handshake_transform_data_destructor);
    if (!ws_transform_capsule) {
        aws_py_raise_error();
        goto done;
    }

    /* From hereon, capsule destructor will clean up anything stored within it */

    ws_transform_data->request = request;
    ws_transform_data->complete_fn = complete_fn;
    ws_transform_data->complete_ctx = complete_ctx;

    ws_transform_data->connection_py = connection_py;
    Py_INCREF(ws_transform_data->connection_py);

    ws_transform_data->request_binding_py = aws_py_http_message_new_request_from_native(request);
    if (!ws_transform_data->request_binding_py) {
        aws_py_raise_error();
        goto done;
    }

    ws_transform_data->headers_binding_py = aws_py_http_headers_new_from_native(aws_http_message_get_headers(request));
    if (!ws_transform_data->headers_binding_py) {
        aws_py_raise_error();
        goto done;
    }

    PyObject *result = PyObject_CallMethod(
        connection_py,
        "_ws_handshake_transform",
        "(OOO)",
        ws_transform_data->request_binding_py,
        ws_transform_data->headers_binding_py,
        ws_transform_capsule);

    if (result) {
        Py_DECREF(result);
    } else {
        aws_py_raise_error();
        goto done;
    }

    success = true;
done:;
    /* Save off error code, so it doesn't got stomped before we pass it to callback*/
    int error_code = aws_last_error();

    if (ws_transform_capsule) {
        Py_DECREF(ws_transform_capsule);
    } else if (ws_transform_data) {
        aws_mem_release(aws_py_get_allocator(), ws_transform_data);
    }

    PyGILState_Release(state);
    /*************** GIL RELEASE ***************/

    /* Invoke completion cb if we failed to pass data to user. */
    if (!success) {
        complete_fn(request, error_code, complete_ctx);
    }
}