Basic python server working including hot-reload

yacv_server/__init__.py

@@ -0,0 +1,29 @@
+import os
+import time
+
+from OCP.TopoDS import TopoDS_Shape
+
+from server import Server
+
+server = Server()
+
+if 'YACV_DISABLE_SERVER' not in os.environ:
+    # Start a new server ASAP to let the polling client connect while still building CAD objects
+    # This is a bit of a hack, but it is seamless to the user. This behavior can be disabled by setting
+    # the environment variable YACV_DISABLE_SERVER to a non-empty value
+    server.start()
+
+
+def show_object(obj: TopoDS_Shape):
+    """Show a CAD object in the default server"""
+    server.show_object(obj)
+
+
+if __name__ == '__main__':
+    # Publish the logo to the server
+    from logo.logo import build_logo
+
+    assert server is not None
+    server.show_object(build_logo())
+
+    time.sleep(60)

yacv_server/events.py

@@ -1,4 +1,5 @@
-from typing import TypeVar, Generic, List, Callable
+import asyncio
+from typing import TypeVar, Generic, List, Callable, Tuple
 
 T = TypeVar('T')
 
@@ -8,20 +9,32 @@ class EventPublisher(Generic[T]):
 
     _listeners: List[Callable[[T], None]]
     _buffer: List[T]
+    _lock: asyncio.Lock
 
     def __init__(self):
         self._listeners = []
         self._buffer = []
+        self._lock = asyncio.Lock()
 
-    def subscribe(self, listener: Callable[[T], None]):
+    async def subscribe(self, listener: Callable[[T], None]):
-        self._listeners.append(listener)
+        async with self._lock:
-        for data in self._buffer:
+            self._listeners.append(listener)
-            listener(data)
+            for data in self._buffer:
+                listener(data)
 
     def unsubscribe(self, listener: Callable[[T], None]):
-        self._listeners.remove(listener)
+        async with self._lock:
+            self._listeners.remove(listener)
 
     def emit(self, data: T):
-        self._buffer.append(data)
+        async with self._lock:
-        for listener in self._listeners:
+            self._buffer.append(data)
-            listener(data)
+            for listener in self._listeners:
+                listener(data)
+
+    def buffer(self) -> Tuple[List[T], asyncio.Lock]:
+        return self._buffer, self._lock
+
+    def clear(self):
+        async with self._lock:
+            self._buffer.clear()

yacv_server/logo/logo.py

@@ -1,18 +1,19 @@
+from OCP.TopoDS import TopoDS_Shape
 from build123d import *
 from tqdm import tqdm
 
 from tessellate import tessellate, tessellate_count
 
 
-def logo() -> Compound:
+def build_logo() -> TopoDS_Shape:
     """Builds the CAD part of the logo"""
     with BuildPart() as logo_obj:
         Box(1, 2, 3)
-    return logo_obj.part
+    return logo_obj.part.wrapped
 
 
 if __name__ == "__main__":
-    obj = logo()
+    obj = build_logo()
 
     for update in tqdm(tessellate(obj.wrapped), total=tessellate_count(obj.wrapped)):
         # print(update.gltf)

yacv_server/main.py

@@ -0,0 +1,6 @@
+from os import system
+
+if __name__ == '__main__':
+    # Just a reminder that a hot-reloading server can be started with the following command:
+    # Need to disable auto-start to avoid conflicts with the hot-reloading server
+    system('YACV_DISABLE_SERVER=true aiohttp-devtools runserver server.py --port 32323')

yacv_server/server.py

@@ -0,0 +1,69 @@
+import asyncio
+import atexit
+import os
+import signal
+from threading import Thread
+from typing import Optional
+
+from OCP.TopoDS import TopoDS_Shape
+from aiohttp import web
+
+FRONTEND_BASE_PATH = os.getenv('FRONTEND_BASE_PATH', '../dist')
+
+
+# noinspection PyUnusedLocal
+async def _index_handler(request: web.Request) -> web.Response:
+    return web.HTTPTemporaryRedirect(location='index.html')
+
+
+class Server:
+    app = web.Application()
+    runner: web.AppRunner
+    thread: Optional[Thread] = None
+
+    def __init__(self, *args, **kwargs):
+        # --- Routes ---
+        # - API
+        # self.app.router.add_route({'POST','GET'}, '/api/{collection}', api_handler)
+        # - Static files from the frontend
+        self.app.router.add_get('/{path:(.*/|)}', _index_handler)  # Any folder -> index.html
+        self.app.router.add_static('/', path=FRONTEND_BASE_PATH, name='static_frontend')
+        # --- Misc ---
+        self.runner = web.AppRunner(self.app)
+
+    def start(self):
+        """Starts the web server in the background"""
+        assert self.thread is None, "Server already started"
+        self.thread = Thread(target=self.run_server, name='yacv_server', daemon=True)
+        signal.signal(signal.SIGINT | signal.SIGTERM, self.stop)
+        atexit.register(self.stop)
+        self.thread.start()
+
+    # noinspection PyUnusedLocal
+    def stop(self, *args):
+        """Stops the web server"""
+        print('Stopping server...')
+        if self.thread is None:
+            print('Cannot stop server because it is not running')
+            return
+        asyncio.run(self.runner.shutdown())
+        asyncio.run(self.app.cleanup())
+        self.thread = None  # FIXME: Not properly cleaned up (join blocks forever)
+        print('Cleanup done')
+
+    def run_server(self):
+        """Runs the web server"""
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        loop.run_until_complete(self.runner.setup())
+        site = web.TCPSite(self.runner, os.getenv('YACV_HOST', 'localhost'), int(os.getenv('YACV_PORT', 32323)))
+        loop.run_until_complete(site.start())
+        loop.run_forever()
+
+    def show_object(self, obj: TopoDS_Shape):
+        pass
+
+
+def get_app() -> web.Application:
+    """Required by aiohttp-devtools"""
+    return Server().app