wip(sync): websocket server with ASGI and PostgreSQL LISTEN/NOTIFY

umap/asgi.py

@@ -1,22 +1,20 @@
 import os
 
-from channels.routing import ProtocolTypeRouter, URLRouter
-from channels.security.websocket import AllowedHostsOriginValidator
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "umap.settings")
+
 from django.core.asgi import get_asgi_application
-from django.urls import re_path
 
-from .sync import consumers
+from .sync.app import application as ws_application
 
-os.environ.setdefault("DJANGO_SETTINGS_MODULE", "umap.settings")
 # Initialize Django ASGI application early to ensure the AppRegistry
 # is populated before importing code that may import ORM models.
 django_asgi_app = get_asgi_application()
 
-urlpatterns = (re_path(r"ws/sync/(?P<map_id>\w+)/$", consumers.SyncConsumer.as_asgi()),)
 
-application = ProtocolTypeRouter(
-    {
-        "http": django_asgi_app,
-        "websocket": AllowedHostsOriginValidator(URLRouter(urlpatterns)),
-    }
-)
+async def application(scope, receive, send):
+    if scope["type"] == "http":
+        await django_asgi_app(scope, receive, send)
+    elif scope["type"] == "websocket":
+        await ws_application(scope, receive, send)
+    else:
+        raise NotImplementedError(f"Unknown scope type {scope['type']}")

umap/settings/base.py

@@ -129,6 +129,7 @@
     "django.contrib.gis",
     "django_probes",
     "umap",
+    "umap.sync",
     "social_django",
     # See https://github.com/peopledoc/django-agnocomplete/commit/26eda2dfa4a2f8a805ca2ea19a0c504b9d773a1c
     # Django does not find the app config in the default place, so the app is not loaded
@@ -343,4 +344,3 @@
 WEBSOCKET_BACK_HOST = env("WEBSOCKET_BACK_HOST", default="localhost")
 WEBSOCKET_BACK_PORT = env.int("WEBSOCKET_BACK_PORT", default=8001)
 WEBSOCKET_FRONT_URI = env("WEBSOCKET_FRONT_URI", default="ws://localhost:8001")
-CHANNEL_LAYERS = {"default": {"BACKEND": "channels.layers.InMemoryChannelLayer"}}

umap/static/umap/js/modules/sync/websocket.js

@@ -6,7 +6,7 @@ export class WebSocketTransport {
   constructor(webSocketURI, authToken, messagesReceiver) {
     this.receiver = messagesReceiver
 
-    this.websocket = new WebSocket(`${webSocketURI}`)
+    this.websocket = new WebSocket(webSocketURI)
 
     this.websocket.onopen = () => {
       this.send('JoinRequest', { token: authToken })
@@ -21,6 +21,10 @@ export class WebSocketTransport {
       }
     }
 
+    this.websocket.onerror = (error) => {
+      console.log('WS ERROR', error)
+    }
+
     this.ensureOpen = setInterval(() => {
       if (this.websocket.readyState !== WebSocket.OPEN) {
         this.websocket.close()
@@ -34,6 +38,7 @@ export class WebSocketTransport {
     // See https://making.close.com/posts/reliable-websockets/ for more details.
     this.pingInterval = setInterval(() => {
       if (this.websocket.readyState === WebSocket.OPEN) {
+        console.log('sending ping')
         this.websocket.send('ping')
         this.pongReceived = false
         setTimeout(() => {
@@ -48,7 +53,6 @@ export class WebSocketTransport {
   }
 
   onMessage(wsMessage) {
-    console.log(wsMessage)
     if (wsMessage.data === 'pong') {
       this.pongReceived = true
     } else {
@@ -64,6 +68,7 @@ export class WebSocketTransport {
   }
 
   close() {
+    console.log('Closing')
     this.receiver.closeRequested = true
     this.websocket.close()
   }

umap/sync/app.py

@@ -0,0 +1,45 @@
+import uuid
+
+from django.urls.resolvers import RoutePattern
+
+ws_pattern = RoutePattern("/ws/sync/<str:map_id>")
+
+
+async def application(scope, receive, send):
+    from .models import Peer
+
+    matched = ws_pattern.match(scope["path"])
+    print(matched)
+    if not matched:
+        print("Wrong path")
+        return
+    _, _, kwargs = matched
+
+    map_id = kwargs["map_id"]
+    room_id = f"room{map_id}"
+    peer = await Peer.objects.acreate(uuid=uuid.uuid4(), name="FooBar", room_id=room_id)
+    print(peer)
+    peer._send = send
+    while True:
+        event = await receive()
+        print("EVENT", event)
+
+        if event["type"] == "websocket.connect":
+            try:
+                print("Let's accept")
+                await send({"type": "websocket.accept"})
+                await peer.connect()
+            except ValueError:
+                await send({"type": "websocket.close"})
+
+        if event["type"] == "websocket.disconnect":
+            print("Closing", event)
+            await peer.disconnect()
+            print("Closed")
+            break
+
+        if event["type"] == "websocket.receive":
+            if event["text"] == "ping":
+                await send({"type": "websocket.send", "text": "pong"})
+            else:
+                await peer.receive(event["text"])

umap/sync/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class UmapConfig(AppConfig):
+    name = "umap.sync"
+    verbose_name = "uMap Sync"

umap/sync/migrations/0001_initial.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.1.4 on 2024-12-27 16:14
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    initial = True
+
+    dependencies = []
+
+    operations = [
+        migrations.CreateModel(
+            name="Peer",
+            fields=[
+                (
+                    "uuid",
+                    models.UUIDField(primary_key=True, serialize=False, unique=True),
+                ),
+                ("name", models.CharField(max_length=200)),
+                ("room_id", models.CharField(max_length=200)),
+            ],
+        ),
+    ]