fix: ark token usage is none (#8351)

api/core/model_runtime/model_providers/volcengine_maas/client.py

@@ -208,11 +208,9 @@ class ArkClientV3:
             presence_penalty=presence_penalty,
             top_p=top_p,
             temperature=temperature,
+            stream_options={"include_usage": True},
         )
-        for chunk in chunks:
-            if not chunk.choices:
-                continue
-            yield chunk
+        yield from chunks
 
     def embeddings(self, texts: list[str]) -> CreateEmbeddingResponse:
         return self.ark.embeddings.create(model=self.endpoint_id, input=texts)

api/core/model_runtime/model_providers/volcengine_maas/llm/llm.py

@@ -239,16 +239,14 @@ class VolcengineMaaSLargeLanguageModel(LargeLanguageModel):
 
         def _handle_stream_chat_response(chunks: Generator[ChatCompletionChunk]) -> Generator:
             for chunk in chunks:
-                if not chunk.choices:
-                    continue
-                choice = chunk.choices[0]
-
                 yield LLMResultChunk(
                     model=model,
                     prompt_messages=prompt_messages,
                     delta=LLMResultChunkDelta(
-                        index=choice.index,
-                        message=AssistantPromptMessage(content=choice.delta.content, tool_calls=[]),
+                        index=0,
+                        message=AssistantPromptMessage(
+                            content=chunk.choices[0].delta.content if chunk.choices else "", tool_calls=[]
+                        ),
                         usage=self._calc_response_usage(
                             model=model,
                             credentials=credentials,
@@ -257,7 +255,7 @@ class VolcengineMaaSLargeLanguageModel(LargeLanguageModel):
                         )
                         if chunk.usage
                         else None,
-                        finish_reason=choice.finish_reason,
+                        finish_reason=chunk.choices[0].finish_reason if chunk.choices else None,
                     ),
                 )