Tidy up connection logic (#90)

* Add code:

* code

* code

---------

Co-authored-by: Freddy Boulton <freddyboulton@hf-freddy.local>

backend/fastrtc/webrtc_connection_mixin.py

@@ -70,7 +70,7 @@ class WebRTCConnectionMixin:
     data_channels: dict[str, DataChannel] = {}
     additional_outputs: dict[str, OutputQueue] = defaultdict(OutputQueue)
     handlers: dict[str, HandlerType | Callable] = {}
-
+    connection_timeouts: dict[str, asyncio.Event] = defaultdict(asyncio.Event)
     concurrency_limit: int | float
     event_handler: HandlerType
     time_limit: float | int | None
@@ -82,8 +82,24 @@ class WebRTCConnectionMixin:
         await asyncio.sleep(time_limit)
         await pc.close()
 
+    async def connection_timeout(
+        self,
+        pc: RTCPeerConnection,
+        webrtc_id: str,
+        time_limit: float,
+    ):
+        try:
+            await asyncio.wait_for(
+                self.connection_timeouts[webrtc_id].wait(), time_limit
+            )
+        except (asyncio.TimeoutError, TimeoutError):
+            await pc.close()
+            self.connection_timeouts[webrtc_id].clear()
+            self.clean_up(webrtc_id)
+
     def clean_up(self, webrtc_id: str):
         self.handlers.pop(webrtc_id, None)
+        self.connection_timeouts.pop(webrtc_id, None)
         connection = self.connections.pop(webrtc_id, [])
         for conn in connection:
             if isinstance(conn, AudioCallback):
@@ -132,7 +148,7 @@ class WebRTCConnectionMixin:
         logger.debug("Offer body %s", body)
         if len(self.connections) >= cast(int, self.concurrency_limit):
             return JSONResponse(
-                status_code=429,
+                status_code=200,
                 content={
                     "status": "failed",
                     "meta": {
@@ -181,6 +197,7 @@ class WebRTCConnectionMixin:
                         conn.stop()
                 self.pcs.discard(pc)
             if pc.connectionState == "connected":
+                self.connection_timeouts[body["webrtc_id"]].set()
                 if self.time_limit is not None:
                     asyncio.create_task(self.wait_for_time_limit(pc, self.time_limit))
 
@@ -269,7 +286,7 @@ class WebRTCConnectionMixin:
 
         # handle offer
         await pc.setRemoteDescription(offer)
-
+        asyncio.create_task(self.connection_timeout(pc, body["webrtc_id"], 30))
         # send answer
         answer = await pc.createAnswer()
         await pc.setLocalDescription(answer)  # type: ignore

demo/moonshine_live/app.py

@@ -1,16 +1,17 @@
+from functools import lru_cache
+from typing import Generator, Literal
+
+import gradio as gr
+import numpy as np
 from fastrtc import (
-    Stream,
     AdditionalOutputs,
-    audio_to_float32,
     ReplyOnPause,
+    Stream,
+    audio_to_float32,
     get_twilio_turn_credentials,
 )
-from functools import lru_cache
-import gradio as gr
-from typing import Generator, Literal
-from numpy.typing import NDArray
-import numpy as np
 from moonshine_onnx import MoonshineOnnxModel, load_tokenizer
+from numpy.typing import NDArray
 
 
 @lru_cache(maxsize=None)

docs/userguide/api.md

@@ -109,7 +109,7 @@ async def stream_updates(webrtc_id: str):
 
 ### Handling Errors
 
-When connecting via `WebRTC`, the server will respond to the `/webrtc/offer` route with a JSON response. If there are too many connections, the server will respond with a 429 error.
+When connecting via `WebRTC`, the server will respond to the `/webrtc/offer` route with a JSON response. If there are too many connections, the server will respond with a 200 error.
 
 ```json
 {
@@ -122,6 +122,8 @@ When connecting via `WebRTC`, the server will respond to the `/webrtc/offer` rou
 
 Over `WebSocket`, the server will send the same message before closing the connection.
 
+!!! tip
+    The server will sends a 200 status code because otherwise the gradio client will not be able to process the json response and display the error.
 
 <style>
 .config-selector {

frontend/shared/InteractiveAudio.svelte

@@ -154,6 +154,13 @@
                     _time_limit = null;
                     stop(pc);
                     break;
+                case "failed":
+                    console.info("failed");
+                    stream_state = "closed";
+                    _time_limit = null;
+                    dispatch("error", "Connection failed!");
+                    stop(pc);
+                    break;
                 default:
                     break;
             }
@@ -209,6 +216,7 @@
             })
             .catch(() => {
                 console.info("catching");
+                clearTimeout(timeoutId);
                 stream_state = "closed";
             });
     }

frontend/shared/StaticAudio.svelte

@@ -60,6 +60,11 @@
                         console.info("closed");
                         stop(pc);
                         break;
+                    case "failed":
+                        stream_state = "closed";
+                        dispatch("error", "Connection failed!");
+                        stop(pc);
+                        break;
                     default:
                         break;
                 }

frontend/shared/StaticVideo.svelte

@@ -47,6 +47,11 @@
 				case "disconnected":
 					stop(pc);
 					break;
+				case "failed":
+					stream_state = "closed";
+					dispatch("error", "Connection failed!");
+					stop(pc);
+					break;
 				default:
 					break;
 			}

frontend/shared/Webcam.svelte

@@ -155,6 +155,12 @@
 						stop(pc);
 						await access_webcam();
 						break;
+					case "failed":
+						stream_state = "closed";
+						_time_limit = null;
+						dispatch("error", "Connection failed!");
+						stop(pc);
+						break;
 					default:
 						break;
 				}

pyproject.toml

@@ -8,7 +8,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "fastrtc"
-version = "0.0.6"
+version = "0.0.8post1"
 description = "The realtime communication library for Python"
 readme = "README.md"
 license = "apache-2.0"