增加回显1

app.py

@@ -45,24 +45,33 @@ async def websocket_endpoint(websocket: WebSocket):
             # binary frame handling
             if "bytes" in msg:
                 data = msg.get("bytes") or b""
-                # Expecting length-prefixed: 4-byte BE length + payload
-                if len(data) < 4:
-                    # ignore or notify client
+                # Support two possible binary formats:
+                # New multiplex format: 1-byte type + 4-byte BE length + payload
+                # Legacy format: 4-byte BE length + payload
+                if len(data) >= 5 and data[0:1] in (b'D', b'O'):
+                    frame_type = data[0:1]
+                    length = int.from_bytes(data[1:5], "big")
+                    payload = data[5:5+length]
+                elif len(data) >= 4:
+                    # legacy
+                    frame_type = b'D'
+                    length = int.from_bytes(data[:4], "big")
+                    payload = data[4:4+length]
+                else:
                     await websocket.send_text("error: frame too short")
                     continue
-                length = int.from_bytes(data[:4], "big")
-                payload = data[4:4+length]
 
                 # Log frame summary (length and first up to 32 bytes as hex)
                 try:
                     sample = payload[:32]
                     sample_hex = sample.hex()
-                    print(f"Received binary frame length={length} sample={sample_hex}")
+                    print(f"Received binary frame type={frame_type.decode(errors='ignore')} length={length} sample={sample_hex}")
                 except Exception:
                     print(f"Received binary frame length={length} (sample unavailable)")
 
-                # For demo, echo payload back in same frame format
-                resp = len(payload).to_bytes(4, "big") + payload
+                # For demo, echo payload back in same frame format (preserve frame_type)
+                resp_header = frame_type + len(payload).to_bytes(4, "big")
+                resp = resp_header + payload
                 try:
                     await websocket.send_bytes(resp)
                 except Exception: