Fix Doc-Sum stream output format

Keep Doc-Sum stream output aligned with v1.1 format

Fix issue:
opea-project/GenAIInfra#753

Signed-off-by: Wang, Xigui <[email protected]>

comps/llms/src/doc-summarization/integrations/common.py

@@ -191,11 +191,19 @@ async def generate(self, input: DocSumChatCompletionRequest, client):
         if input.stream:
 
             async def stream_generator():
+                import json
                 from langserve.serialization import WellKnownLCSerializer
 
                 _serializer = WellKnownLCSerializer()
                 async for chunk in llm_chain.astream_log(docs):
-                    data = _serializer.dumps({"ops": chunk.ops}).decode("utf-8")
+                    chunk_data = _serializer.dumps({"ops": chunk.ops}).decode("utf-8")
+                    parsed_data = json.loads(chunk_data)
+
+                    # Extract the 'value' items
+                    data = [op['value'] for op in parsed_data['ops'] if 'value' in op]
+                    if isinstance(data, list) and len(data) > 1:
+                        data = data[0]
+
                     if logflag:
                         logger.info(data)
                     yield f"data: {data}\n\n"