server: refactor to separate websocket management + start pipeline runner

server/reflector/views/rtc_offer.py

@@ -2,6 +2,7 @@ import asyncio
 from enum import StrEnum
 from json import dumps, loads
 from pathlib import Path
+from typing import Callable
 
 import av
 from aiortc import MediaStreamTrack, RTCPeerConnection, RTCSessionDescription
@@ -38,7 +39,7 @@ m_rtc_sessions = Gauge("rtc_sessions", "Number of active RTC sessions")
 class TranscriptionContext(object):
     def __init__(self, logger):
         self.logger = logger
-        self.pipeline = None
+        self.pipeline_runner = None
         self.data_channel = None
         self.status = "idle"
         self.topics = []
@@ -60,7 +61,7 @@ class AudioStreamTrack(MediaStreamTrack):
         ctx = self.ctx
         frame = await self.track.recv()
         try:
-            await ctx.pipeline.push(frame)
+            await ctx.pipeline_runner.push(frame)
         except Exception as e:
             ctx.logger.error("Pipeline error", error=e)
         return frame
@@ -84,6 +85,113 @@ class PipelineEvent(StrEnum):
     FINAL_TITLE = "FINAL_TITLE"
 
 
+class PipelineOptions(BaseModel):
+    audio_filename: Path | None = None
+    source_language: str = "en"
+    target_language: str = "en"
+
+    on_transcript: Callable | None = None
+    on_topic: Callable | None = None
+    on_final_title: Callable | None = None
+    on_final_short_summary: Callable | None = None
+    on_final_long_summary: Callable | None = None
+
+
+class PipelineRunner(object):
+    """
+    Pipeline runner designed to be executed in a asyncio task
+    """
+
+    def __init__(self, pipeline: Pipeline, status_callback: Callable | None = None):
+        self.pipeline = pipeline
+        self.q_cmd = asyncio.Queue()
+        self.ev_done = asyncio.Event()
+        self.status = "idle"
+        self.status_callback = status_callback
+
+    async def update_status(self, status):
+        print("update_status", status)
+        self.status = status
+        if self.status_callback:
+            try:
+                await self.status_callback(status)
+            except Exception as e:
+                logger.error("PipelineRunner status_callback error", error=e)
+
+    async def add_cmd(self, cmd: str, data):
+        await self.q_cmd.put([cmd, data])
+
+    async def push(self, data):
+        await self.add_cmd("PUSH", data)
+
+    async def flush(self):
+        await self.add_cmd("FLUSH", None)
+
+    async def run(self):
+        try:
+            await self.update_status("running")
+            while not self.ev_done.is_set():
+                cmd, data = await self.q_cmd.get()
+                func = getattr(self, f"cmd_{cmd.lower()}")
+                if func:
+                    await func(data)
+                else:
+                    raise Exception(f"Unknown command {cmd}")
+        except Exception as e:
+            await self.update_status("error")
+            logger.error("PipelineRunner error", error=e)
+
+    async def cmd_push(self, data):
+        if self.status == "idle":
+            await self.update_status("recording")
+        await self.pipeline.push(data)
+
+    async def cmd_flush(self, data):
+        await self.update_status("processing")
+        await self.pipeline.flush()
+        await self.update_status("ended")
+        self.ev_done.set()
+
+    def start(self):
+        print("start task")
+        asyncio.get_event_loop().create_task(self.run())
+
+
+async def pipeline_live_create(options: PipelineOptions):
+    # create a context for the whole rtc transaction
+    # add a customised logger to the context
+    processors = []
+    if options.audio_filename is not None:
+        processors += [AudioFileWriterProcessor(path=options.audio_filename)]
+    processors += [
+        AudioChunkerProcessor(),
+        AudioMergeProcessor(),
+        AudioTranscriptAutoProcessor.as_threaded(),
+        TranscriptLinerProcessor(),
+        TranscriptTranslatorProcessor.as_threaded(callback=options.on_transcript),
+        TranscriptTopicDetectorProcessor.as_threaded(callback=options.on_topic),
+        BroadcastProcessor(
+            processors=[
+                TranscriptFinalTitleProcessor.as_threaded(
+                    callback=options.on_final_title
+                ),
+                TranscriptFinalLongSummaryProcessor.as_threaded(
+                    callback=options.on_final_long_summary
+                ),
+                TranscriptFinalShortSummaryProcessor.as_threaded(
+                    callback=options.on_final_short_summary
+                ),
+            ]
+        ),
+    ]
+    pipeline = Pipeline(*processors)
+    pipeline.options = options
+    pipeline.set_pref("audio:source_language", options.source_language)
+    pipeline.set_pref("audio:target_language", options.target_language)
+
+    return pipeline
+
+
 async def rtc_offer_base(
     params: RtcOffer,
     request: Request,
@@ -211,37 +319,24 @@ async def rtc_offer_base(
                 data=title,
             )
 
-    # create a context for the whole rtc transaction
-    # add a customised logger to the context
-    processors = []
-    if audio_filename is not None:
-        processors += [AudioFileWriterProcessor(path=audio_filename)]
-    processors += [
-        AudioChunkerProcessor(),
-        AudioMergeProcessor(),
-        AudioTranscriptAutoProcessor.as_threaded(),
-        TranscriptLinerProcessor(),
-        TranscriptTranslatorProcessor.as_threaded(callback=on_transcript),
-        TranscriptTopicDetectorProcessor.as_threaded(callback=on_topic),
-        BroadcastProcessor(
-            processors=[
-                TranscriptFinalTitleProcessor.as_threaded(callback=on_final_title),
-                TranscriptFinalLongSummaryProcessor.as_threaded(
-                    callback=on_final_long_summary
-                ),
-                TranscriptFinalShortSummaryProcessor.as_threaded(
-                    callback=on_final_short_summary
-                ),
-            ]
-        ),
-    ]
-    ctx.pipeline = Pipeline(*processors)
-    ctx.pipeline.set_pref("audio:source_language", source_language)
-    ctx.pipeline.set_pref("audio:target_language", target_language)
-
     # handle RTC peer connection
     pc = RTCPeerConnection()
 
+    # create pipeline
+    options = PipelineOptions(
+        audio_filename=audio_filename,
+        source_language=source_language,
+        target_language=target_language,
+        on_transcript=on_transcript,
+        on_topic=on_topic,
+        on_final_short_summary=on_final_short_summary,
+        on_final_long_summary=on_final_long_summary,
+        on_final_title=on_final_title,
+    )
+    pipeline = await pipeline_live_create(options)
+    ctx.pipeline_runner = PipelineRunner(pipeline, update_status)
+    ctx.pipeline_runner.start()
+
     async def flush_pipeline_and_quit(close=True):
         # may be called twice
         # 1. either the client ask to sotp the meeting
@@ -249,12 +344,10 @@ async def rtc_offer_base(
         #    - when we receive the close event, we do nothing.
         # 2. or the client close the connection
         #    and there is nothing to do because it is already closed
-        await update_status("processing")
-        await ctx.pipeline.flush()
+        await ctx.pipeline_runner.flush()
         if close:
             ctx.logger.debug("Closing peer connection")
             await pc.close()
-            await update_status("ended")
             if pc in sessions:
                 sessions.remove(pc)
                 m_rtc_sessions.dec()
@@ -287,7 +380,6 @@ async def rtc_offer_base(
     def on_track(track):
         ctx.logger.info(f"Track {track.kind} received")
         pc.addTrack(AudioStreamTrack(ctx, track))
-        asyncio.get_event_loop().create_task(update_status("recording"))
 
     await pc.setRemoteDescription(offer)
 

server/reflector/views/transcripts.py

@@ -483,16 +483,16 @@ async def transcript_get_topics(
     ]
 
 
-@router.get("/transcripts/{transcript_id}/events")
-async def transcript_get_websocket_events(transcript_id: str):
-    pass
-
-
 # ==============================================================
 # Websocket
 # ==============================================================
 
 
+@router.get("/transcripts/{transcript_id}/events")
+async def transcript_get_websocket_events(transcript_id: str):
+    pass
+
+
 @router.websocket("/transcripts/{transcript_id}/events")
 async def transcript_events_websocket(
     transcript_id: str,
@@ -512,6 +512,13 @@ async def transcript_events_websocket(
     try:
         # on first connection, send all events only to the current user
         for event in transcript.events:
+            # for now, do not send TRANSCRIPT or STATUS options - theses are live event
+            # not necessary to be sent to the client; but keep the rest
+            name = event.event
+            if name == PipelineEvent.TRANSCRIPT:
+                continue
+            if name == PipelineEvent.STATUS:
+                continue
             await websocket.send_json(event.model_dump(mode="json"))
 
         # XXX if transcript is final (locked=True and status=ended)

server/reflector/ws_manager.py

@@ -33,6 +33,8 @@ class RedisPubSubManager:
         )
 
     async def connect(self) -> None:
+        if self.redis_connection is not None:
+            return
         self.redis_connection = await self.get_redis_connection()
         self.pubsub = self.redis_connection.pubsub()
 
@@ -43,6 +45,8 @@ class RedisPubSubManager:
         self.redis_connection = None
 
     async def send_json(self, room_id: str, message: str) -> None:
+        if not self.redis_connection:
+            await self.connect()
         message = json.dumps(message)
         await self.redis_connection.publish(room_id, message)
 
@@ -94,18 +98,6 @@ class WebsocketManager:
                     await socket.send_json(data)
 
 
-def get_pubsub_client() -> RedisPubSubManager:
-    """
-    Returns the RedisPubSubManager instance for managing Redis pubsub.
-    """
-    from reflector.settings import settings
-
-    return RedisPubSubManager(
-        host=settings.REDIS_HOST,
-        port=settings.REDIS_PORT,
-    )
-
-
 def get_ws_manager() -> WebsocketManager:
     """
     Returns the WebsocketManager instance for managing websockets.
@@ -122,6 +114,11 @@ def get_ws_manager() -> WebsocketManager:
         RedisConnectionError: If there is an error connecting to the Redis server.
     """
     global ws_manager
-    pubsub_client = get_pubsub_client()
+    from reflector.settings import settings
+
+    pubsub_client = RedisPubSubManager(
+        host=settings.REDIS_HOST,
+        port=settings.REDIS_PORT,
+    )
     ws_manager = WebsocketManager(pubsub_client=pubsub_client)
     return ws_manager