Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/engineio/async_drivers/gevent_uwsgi.py

@@ -0,0 +1,168 @@
+import gevent
+from gevent import queue
+from gevent.event import Event
+from gevent import selectors
+import uwsgi
+_websocket_available = hasattr(uwsgi, 'websocket_handshake')
+
+
+class Thread(gevent.Greenlet):  # pragma: no cover
+    """
+    This wrapper class provides gevent Greenlet interface that is compatible
+    with the standard library's Thread class.
+    """
+    def __init__(self, target, args=[], kwargs={}):
+        super().__init__(target, *args, **kwargs)
+
+    def _run(self):
+        return self.run()
+
+
+class uWSGIWebSocket(object):  # pragma: no cover
+    """
+    This wrapper class provides a uWSGI WebSocket interface that is
+    compatible with eventlet's implementation.
+    """
+    def __init__(self, handler, server):
+        self.app = handler
+        self._sock = None
+        self.received_messages = []
+
+    def __call__(self, environ, start_response):
+        self._sock = uwsgi.connection_fd()
+        self.environ = environ
+
+        uwsgi.websocket_handshake()
+
+        self._req_ctx = None
+        if hasattr(uwsgi, 'request_context'):
+            # uWSGI >= 2.1.x with support for api access across-greenlets
+            self._req_ctx = uwsgi.request_context()
+        else:
+            # use event and queue for sending messages
+            self._event = Event()
+            self._send_queue = queue.Queue()
+
+            # spawn a select greenlet
+            def select_greenlet_runner(fd, event):
+                """Sets event when data becomes available to read on fd."""
+                sel = selectors.DefaultSelector()
+                sel.register(fd, selectors.EVENT_READ)
+                try:
+                    while True:
+                        sel.select()
+                        event.set()
+                except gevent.GreenletExit:
+                    sel.unregister(fd)
+            self._select_greenlet = gevent.spawn(
+                select_greenlet_runner,
+                self._sock,
+                self._event)
+
+        self.app(self)
+        uwsgi.disconnect()
+        return ''  # send nothing as response
+
+    def close(self):
+        """Disconnects uWSGI from the client."""
+        if self._req_ctx is None:
+            # better kill it here in case wait() is not called again
+            self._select_greenlet.kill()
+            self._event.set()
+
+    def _send(self, msg):
+        """Transmits message either in binary or UTF-8 text mode,
+        depending on its type."""
+        if isinstance(msg, bytes):
+            method = uwsgi.websocket_send_binary
+        else:
+            method = uwsgi.websocket_send
+        if self._req_ctx is not None:
+            method(msg, request_context=self._req_ctx)
+        else:
+            method(msg)
+
+    def _decode_received(self, msg):
+        """Returns either bytes or str, depending on message type."""
+        if not isinstance(msg, bytes):
+            # already decoded - do nothing
+            return msg
+        # only decode from utf-8 if message is not binary data
+        type = ord(msg[0:1])
+        if type >= 48:  # no binary
+            return msg.decode('utf-8')
+        # binary message, don't try to decode
+        return msg
+
+    def send(self, msg):
+        """Queues a message for sending. Real transmission is done in
+        wait method.
+        Sends directly if uWSGI version is new enough."""
+        if self._req_ctx is not None:
+            self._send(msg)
+        else:
+            self._send_queue.put(msg)
+            self._event.set()
+
+    def wait(self):
+        """Waits and returns received messages.
+        If running in compatibility mode for older uWSGI versions,
+        it also sends messages that have been queued by send().
+        A return value of None means that connection was closed.
+        This must be called repeatedly. For uWSGI < 2.1.x it must
+        be called from the main greenlet."""
+        while True:
+            if self._req_ctx is not None:
+                try:
+                    msg = uwsgi.websocket_recv(request_context=self._req_ctx)
+                except IOError:  # connection closed
+                    self.close()
+                    return None
+                return self._decode_received(msg)
+            else:
+                if self.received_messages:
+                    return self.received_messages.pop(0)
+
+                # we wake up at least every 3 seconds to let uWSGI
+                # do its ping/ponging
+                event_set = self._event.wait(timeout=3)
+                if event_set:
+                    self._event.clear()
+                    # maybe there is something to send
+                    msgs = []
+                    while True:
+                        try:
+                            msgs.append(self._send_queue.get(block=False))
+                        except gevent.queue.Empty:
+                            break
+                    for msg in msgs:
+                        try:
+                            self._send(msg)
+                        except IOError:
+                            self.close()
+                            return None
+                # maybe there is something to receive, if not, at least
+                # ensure uWSGI does its ping/ponging
+                while True:
+                    try:
+                        msg = uwsgi.websocket_recv_nb()
+                    except IOError:  # connection closed
+                        self.close()
+                        return None
+                    if msg:  # message available
+                        self.received_messages.append(
+                            self._decode_received(msg))
+                    else:
+                        break
+                if self.received_messages:
+                    return self.received_messages.pop(0)
+
+
+_async = {
+    'thread': Thread,
+    'queue': queue.JoinableQueue,
+    'queue_empty': queue.Empty,
+    'event': Event,
+    'websocket': uWSGIWebSocket if _websocket_available else None,
+    'sleep': gevent.sleep,
+}