fix sequence2txt error and usage total token issue (#2961)

### What problem does this PR solve?

#1363

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/conversation_app.py

 from api.db.services.knowledgebase_service import KnowledgebaseService
 from api.db.services.llm_service import LLMBundle, TenantService, TenantLLMService
 from api.settings import RetCode, retrievaler
-from api.utils import get_uuid
 from api.utils.api_utils import get_json_result
 from api.utils.api_utils import server_error_response, get_data_error_result, validate_request
 from graphrag.mind_map_extractor import MindMapExtractor
                     yield "data:" + json.dumps({"retcode": 0, "retmsg": "", "data": ans}, ensure_ascii=False) + "\n\n"
                 ConversationService.update_by_id(conv.id, conv.to_dict())
             except Exception as e:
+                traceback.print_exc()
                 yield "data:" + json.dumps({"retcode": 500, "retmsg": str(e),
                                             "data": {"answer": "**ERROR**: " + str(e), "reference": []}},
                                            ensure_ascii=False) + "\n\n"

api/db/services/llm_service.py

             if model_config["llm_factory"] not in Seq2txtModel:
                 return
             return Seq2txtModel[model_config["llm_factory"]](
-                model_config["api_key"], model_config["llm_name"], lang,
+                key=model_config["api_key"], model_name=model_config["llm_name"],
+                lang=lang,
                 base_url=model_config["api_base"]
             )
         if llm_type == LLMType.TTS:

api/utils/file_utils.py

             pass
     return None
 
+
 def thumbnail(filename, blob):
     img = thumbnail_img(filename, blob)
     if img is not None:
     else:
         return ''
 
+
 def traversal_files(base):
     for root, ds, fs in os.walk(base):
         for f in fs:

rag/llm/chat_model.py

                 if not resp.choices[0].delta.content:
                     resp.choices[0].delta.content = ""
                 ans += resp.choices[0].delta.content
-                total_tokens = (
-                    (
-                            total_tokens
-                            + num_tokens_from_string(resp.choices[0].delta.content)
-                    )
-                    if not hasattr(resp, "usage") or not resp.usage
-                    else resp.usage.get("total_tokens", total_tokens)
-                )
+                total_tokens += 1
+                if not hasattr(resp, "usage") or not resp.usage:
+                    total_tokens = (
+                                total_tokens
+                                + num_tokens_from_string(resp.choices[0].delta.content)
+                        )
+                elif isinstance(resp.usage, dict):
+                    total_tokens = resp.usage.get("total_tokens", total_tokens)
+                else: total_tokens = resp.usage.total_tokens
+
                 if resp.choices[0].finish_reason == "length":
                     ans += "...\nFor the content length reason, it stopped, continue?" if is_english(
                         [ans]) else "······\n由于长度的原因，回答被截断了，要继续吗？"

rag/llm/sequence2txt_model.py

 
 
 class XinferenceSeq2txt(Base):
-    def __init__(self,key,model_name="whisper-small",**kwargs):
+    def __init__(self, key, model_name="whisper-small", **kwargs):
         self.base_url = kwargs.get('base_url', None)
         self.model_name = model_name
         self.key = key