修复BUG (#570)

一、修复模型历史记录仅一条问题，修改了模型加载代码，已修复。 
二、修复模型历史记录仅一条问题，修改了webui有一个地方有问题，已修复。
三、知识库单条数据入库因知识库名称缓存问题导致的BUG，也已修复。

chains/local_doc_qa.py

@@ -278,7 +278,7 @@ class LocalDocQA:
             if not one_content_segmentation:
                 text_splitter = ChineseTextSplitter(pdf=False, sentence_size=sentence_size)
                 docs = text_splitter.split_documents(docs)
-            if os.path.isdir(vs_path):
+            if os.path.isdir(vs_path) and os.path.isfile(vs_path+"/index.faiss"):
                 vector_store = load_vector_store(vs_path, self.embeddings)
                 vector_store.add_documents(docs)
             else:
@@ -298,7 +298,10 @@ class LocalDocQA:
         vector_store.score_threshold = self.score_threshold
         related_docs_with_score = vector_store.similarity_search_with_score(query, k=self.top_k)
         torch_gc()
+        if len(related_docs_with_score)>0:
             prompt = generate_prompt(related_docs_with_score, query)
+        else:
+            prompt = query
 
         for answer_result in self.llm.generatorAnswer(prompt=prompt, history=chat_history,
                                                       streaming=streaming):

models/chatglm_llm.py

@@ -52,7 +52,7 @@ class ChatGLM(BaseAnswer, LLM, ABC):
             for inum, (stream_resp, _) in enumerate(self.checkPoint.model.stream_chat(
                     self.checkPoint.tokenizer,
                     prompt,
-                    history=history[-self.history_len:-1] if self.history_len > 0 else [],
+                    history=history[-self.history_len:] if self.history_len > 0 else [],
                     max_length=self.max_token,
                     temperature=self.temperature
             )):

models/moss_llm.py

@@ -55,7 +55,7 @@ class MOSSLLM(BaseAnswer, LLM, ABC):
                          history: List[List[str]] = [],
                          streaming: bool = False):
         if len(history) > 0:
-            history = history[-self.history_len:-1] if self.history_len > 0 else []
+            history = history[-self.history_len:] if self.history_len > 0 else []
             prompt_w_history = str(history)
             prompt_w_history += '<|Human|>: ' + prompt + '<eoh>'
         else:

webui.py

@@ -87,7 +87,7 @@ def get_answer(query, vs_path, history, mode, score_threshold=VECTOR_SEARCH_SCOR
             yield history + [[query,
                               "请选择知识库后进行测试，当前未选择知识库。"]], ""
     else:
-        for answer_result in local_doc_qa.llm.generatorAnswer(prompt=query, history=history[:-1],
+        for answer_result in local_doc_qa.llm.generatorAnswer(prompt=query, history=history,
                                                               streaming=streaming):
             resp = answer_result.llm_output["answer"]
             history = answer_result.history