Add async buffered pubsub, websocket updates endpoint and initial fast hashing of objects

yacv_server/server.py

@@ -4,12 +4,17 @@ import os
 import signal
 import sys
 from threading import Thread
-from typing import Optional
+from typing import Optional, Tuple
 
 from OCP.TopoDS import TopoDS_Shape
 from aiohttp import web
 
+from pubsub import BufferedPubSub
+from tessellate import _hashcode
+
 FRONTEND_BASE_PATH = os.getenv('FRONTEND_BASE_PATH', '../dist')
+UPDATES_API_PATH = '/api/updates'
+OBJECTS_API_PATH = '/api/objects'  # /{name}
 
 
 # noinspection PyUnusedLocal
@@ -22,11 +27,13 @@ class Server:
     runner: web.AppRunner
     thread: Optional[Thread] = None
     do_shutdown = asyncio.Event()
+    show_events = BufferedPubSub[Tuple[TopoDS_Shape, str]]()
 
     def __init__(self, *args, **kwargs):
         # --- Routes ---
-        # - API
-        # self.app.router.add_route({'POST','GET'}, '/api/{collection}', api_handler)
+        # - APIs
+        self.app.router.add_route('GET', f'{UPDATES_API_PATH}', self.api_updates)
+        self.app.router.add_route('GET', f'{OBJECTS_API_PATH}/{{name}}', self.api_objects)
         # - 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')
@@ -74,10 +81,37 @@ class Server:
         # print('Shutting down server...')
         await runner.cleanup()
 
-    def show_object(self, obj: TopoDS_Shape):
-        pass
+    async def api_updates(self, request: web.Request) -> web.WebSocketResponse:
+        """Handles a publish-only websocket connection that send show_object events along with their hashes and URLs"""
+        ws = web.WebSocketResponse()
+        await ws.prepare(request)
+
+        print('New client connected')
+        async for (obj, name) in self.show_events.subscribe():
+            hash_code = _hashcode(obj)
+            url = f'{UPDATES_API_PATH}/{name}'
+            print('New object:', name, hash_code, url)
+            await ws.send_json({'name': name, 'hash': hash_code, 'url': url})
+
+        # TODO: Start previous loop in a separate task and detect connection close to stop it
+
+        return ws
+
+    obj_counter = 0
+
+    def show_object(self, obj: TopoDS_Shape, name: Optional[str] = None):
+        """Publishes a CAD object to the server"""
+        name = name or f'object_{self.obj_counter}'
+        self.obj_counter += 1
+        self.show_events.publish_nowait((obj, name))
+
+    async def api_objects(self, request: web.Request) -> web.Response:
+        return web.Response(body='TODO: Serve the object file here')
 
 
 def get_app() -> web.Application:
     """Required by aiohttp-devtools"""
-    return Server().app
+    from logo.logo import build_logo
+    server = Server()
+    server.show_object(build_logo())
+    return server.app