Langchain-Chatchat/server/knowledge_base/utils.py

from typing import Union
import os
from langchain.embeddings.huggingface import HuggingFaceEmbeddings
from configs.model_config import (embedding_model_dict, KB_ROOT_PATH, EMBEDDING_MODEL, kbs_config)
from functools import lru_cache
import langchain.document_loaders
import sys


def validate_kb_name(knowledge_base_id: str) -> bool:
    # 检查是否包含预期外的字符或路径攻击关键字
    if "../" in knowledge_base_id:
        return False
    return True

def get_kb_path(knowledge_base_name: str):
    return os.path.join(KB_ROOT_PATH, knowledge_base_name)

def get_doc_path(knowledge_base_name: str):
    return os.path.join(get_kb_path(knowledge_base_name), "content")

def get_vs_path(knowledge_base_name: str):
    return os.path.join(get_kb_path(knowledge_base_name), "vector_store")

def get_file_path(knowledge_base_name: str, doc_name: str):
    return os.path.join(get_doc_path(knowledge_base_name), doc_name)

def list_kbs_from_folder():
    return [f for f in os.listdir(KB_ROOT_PATH)
            if os.path.isdir(os.path.join(KB_ROOT_PATH, f))]

def list_docs_from_folder(kb_name: str):
    doc_path = get_doc_path(kb_name)
    return [file for file in os.listdir(doc_path)
            if os.path.isfile(os.path.join(doc_path, file))]

@lru_cache(1)
def load_embeddings(model: str, device: str):
    embeddings = HuggingFaceEmbeddings(model_name=embedding_model_dict[model],
                                       model_kwargs={'device': device})
    return embeddings


LOADER_DICT = {"UnstructuredFileLoader": ['.eml', '.html', '.json', '.md', '.msg', '.rst',
                                          '.rtf', '.txt', '.xml',
                                          '.doc', '.docx', '.epub', '.odt', '.pdf',
                                          '.ppt', '.pptx', '.tsv'],  # '.pdf', '.xlsx', '.csv'
               "CSVLoader": [".csv"],
               }
SUPPORTED_EXTS = [ext for sublist in LOADER_DICT.values() for ext in sublist]

def get_LoaderClass(file_extension):
    for LoaderClass, extensions in LOADER_DICT.items():
        if file_extension in extensions:
            return LoaderClass


class KnowledgeFile:
    def __init__(
            self,
            filename: str,
            knowledge_base_name: str
    ):
        self.kb_name = knowledge_base_name
        self.filename = filename
        self.ext = os.path.splitext(filename)[-1]
        if self.ext not in SUPPORTED_EXTS:
            raise ValueError(f"暂未支持的文件格式 {self.ext}")
        self.filepath = get_file_path(knowledge_base_name, filename)
        self.docs = None
        self.document_loader_name = get_LoaderClass(self.ext)

        # TODO: 增加依据文件格式匹配text_splitter
        self.text_splitter_name = "CharacterTextSplitter"

    def file2text(self):
        DocumentLoader = getattr(sys.modules['langchain.document_loaders'], self.document_loader_name)
        loader = DocumentLoader(self.filepath)

        # TODO: 增加依据文件格式匹配text_splitter
        TextSplitter = getattr(sys.modules['langchain.text_splitter'], self.text_splitter_name)
        text_splitter = TextSplitter(chunk_size=500, chunk_overlap=200)
        return loader.load_and_split(text_splitter)