sse iphone fix 1
This commit is contained in:
107
apps/api/main.py
107
apps/api/main.py
@@ -287,7 +287,13 @@ async def set_device(device_id: str, request: SetDeviceRequest) -> dict[str, str
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async def event_generator(request: Request) -> AsyncGenerator[str, None]:
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"""Generate SSE events from Redis Pub/Sub.
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"""Generate SSE events from Redis Pub/Sub with Safari compatibility.
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Safari-compatible features:
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- Immediate retry hint on connection
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- Regular heartbeats every 15s (comment-only, no data)
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- Proper flushing after each yield
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- Graceful disconnect handling
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Args:
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request: FastAPI request object for disconnect detection
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@@ -295,17 +301,28 @@ async def event_generator(request: Request) -> AsyncGenerator[str, None]:
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Yields:
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str: SSE formatted event strings
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"""
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redis_url, redis_channel = get_redis_settings()
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redis_client = await aioredis.from_url(redis_url, decode_responses=True)
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pubsub = redis_client.pubsub()
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redis_client = None
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pubsub = None
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try:
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await pubsub.subscribe(redis_channel)
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logger.info(f"SSE client connected, subscribed to {redis_channel}")
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# Send retry hint immediately for EventSource reconnect behavior
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yield "retry: 2500\n\n"
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# Create heartbeat tracking
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# Try to connect to Redis
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redis_url, redis_channel = get_redis_settings()
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try:
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redis_client = await aioredis.from_url(redis_url, decode_responses=True)
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pubsub = redis_client.pubsub()
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await pubsub.subscribe(redis_channel)
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logger.info(f"SSE client connected, subscribed to {redis_channel}")
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except Exception as e:
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logger.warning(f"Redis unavailable, running in heartbeat-only mode: {e}")
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redis_client = None
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pubsub = None
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# Heartbeat tracking
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last_heartbeat = asyncio.get_event_loop().time()
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heartbeat_interval = 25
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heartbeat_interval = 15 # Safari-friendly: shorter interval
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while True:
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# Check if client disconnected
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@@ -313,29 +330,58 @@ async def event_generator(request: Request) -> AsyncGenerator[str, None]:
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logger.info("SSE client disconnected")
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break
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# Try to get message (non-blocking)
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message = await pubsub.get_message(ignore_subscribe_messages=True, timeout=0.1)
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# Try to get message from Redis (if available)
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if pubsub:
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try:
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message = await asyncio.wait_for(
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pubsub.get_message(ignore_subscribe_messages=True),
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timeout=0.1
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)
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# Handle actual data messages
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if message and message["type"] == "message":
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data = message["data"]
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logger.debug(f"Sending SSE message: {data[:100]}...")
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yield f"event: message\ndata: {data}\n\n"
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last_heartbeat = asyncio.get_event_loop().time()
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else:
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# No message, sleep a bit to avoid busy loop
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await asyncio.sleep(0.1)
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if message and message["type"] == "message":
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data = message["data"]
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logger.debug(f"Sending SSE message: {data[:100]}...")
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yield f"event: message\ndata: {data}\n\n"
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last_heartbeat = asyncio.get_event_loop().time()
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continue # Skip sleep, check for more messages immediately
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# Send heartbeat every 25 seconds
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except asyncio.TimeoutError:
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pass # No message, continue to heartbeat check
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except Exception as e:
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logger.error(f"Redis error: {e}")
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# Continue with heartbeats even if Redis fails
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# Sleep briefly to avoid busy loop
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await asyncio.sleep(0.1)
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# Send heartbeat if interval elapsed
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current_time = asyncio.get_event_loop().time()
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if current_time - last_heartbeat >= heartbeat_interval:
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yield "event: ping\ndata: heartbeat\n\n"
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# Comment-style ping (Safari-compatible, no event type)
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yield ": ping\n\n"
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last_heartbeat = current_time
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except asyncio.CancelledError:
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logger.info("SSE connection cancelled by client")
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raise
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except Exception as e:
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logger.error(f"SSE error: {e}")
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raise
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finally:
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await pubsub.unsubscribe(redis_channel)
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await pubsub.aclose()
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await redis_client.aclose()
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# Cleanup Redis connection
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if pubsub:
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try:
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await pubsub.unsubscribe(redis_channel)
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await pubsub.aclose()
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except Exception as e:
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logger.error(f"Error closing pubsub: {e}")
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if redis_client:
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try:
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await redis_client.aclose()
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except Exception as e:
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logger.error(f"Error closing redis: {e}")
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logger.info("SSE connection closed")
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@@ -343,24 +389,29 @@ async def event_generator(request: Request) -> AsyncGenerator[str, None]:
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async def realtime_events(request: Request) -> StreamingResponse:
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"""Server-Sent Events endpoint for real-time updates.
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Safari-compatible SSE implementation:
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- Immediate retry hint (2.5s reconnect delay)
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- Heartbeat every 15s using comment syntax ": ping"
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- Proper Cache-Control headers
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- No buffering (nginx compatibility)
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- Graceful Redis fallback (heartbeat-only mode)
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Args:
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request: FastAPI request object
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Returns:
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StreamingResponse: SSE stream of Redis messages
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StreamingResponse: SSE stream with Redis messages and heartbeats
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"""
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return StreamingResponse(
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event_generator(request),
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media_type="text/event-stream",
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headers={
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"Cache-Control": "no-cache",
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"Cache-Control": "no-cache, no-transform",
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"Connection": "keep-alive",
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"X-Accel-Buffering": "no", # Disable nginx buffering
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}
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)
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return {"message": f"Command sent to {device_id}"}
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def main() -> None:
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"""Run the API application with uvicorn."""
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