backend/app/engine/__init__.py

@@ -11,6 +11,7 @@ from sqlalchemy import create_engine, Engine
 from app.engine.loaders.db import makeDescriptionByEngine
 from app.engine.tools import ToolFactory
 from app.engine.index import get_index
+from app.engine.retriever.CHBM25Retriever import CHBM25Retriever
 from app.settings import get_node_postprocessors
 
 from llama_index.core.retrievers import BaseRetriever
@@ -29,9 +30,6 @@ class HybridRetriever(BaseRetriever):
         filters = None,
         **kwargs: Any,
     ) -> None:
-        from llama_index.retrievers.bm25 import BM25Retriever
-        from nltk.corpus import stopwords
-
         super().__init__(**kwargs)
         self._vector_index = vector_index
         self._embed_model = vector_index._embed_model
@@ -39,9 +37,13 @@ class HybridRetriever(BaseRetriever):
         self._vecRetriever = vector_index.as_retriever(
             similarity_top_k=similarity_top_k,filters = filters
         )
-        self._bm25Retriever = BM25Retriever.from_defaults(similarity_top_k=similarity_top_k,
-                                             nodes=self._vector_index.vector_store.get_nodes(None),
-                                             language=stopwords.words('chinese'))
+
+        STORAGE_DIR = os.getenv("BM_RETRIEVER_PATH", "storage_bm")
+        if os.path.exists(STORAGE_DIR) and len(os.listdir(STORAGE_DIR)) > 0:
+            self._bm25Retriever = CHBM25Retriever.from_persist_dir(STORAGE_DIR)
+        else:
+            bmRetriver = CHBM25Retriever.from_defaults(similarity_top_k=similarity_top_k,nodes=self._vector_index.vector_store.get_nodes(None))
+            bmRetriver.persist(STORAGE_DIR)
         self._alpha = alpha
 
     def _retrieve(self, query_bundle: QueryBundle) -> List[NodeWithScore]:

backend/app/engine/generate.py

@@ -8,6 +8,7 @@ import os
 from app.engine.loaders import get_documents
 from app.engine.vectordb import get_vector_store
 from app.settings import init_settings
+from app.engine.retriever.CHBM25Retriever import CHBM25Retriever
 from llama_index.core.ingestion import IngestionPipeline
 from llama_index.core.node_parser import SentenceSplitter
 from llama_index.core.settings import Settings
@@ -58,6 +59,13 @@ def persist_storage(docstore, vector_store):
     storage_context.persist(STORAGE_DIR)
 
 
+def persist_BMRetriever(vector_store):
+    STORAGE_DIR = os.getenv("BM_RETRIEVER_PATH", "storage_bm")
+    top_k = int(os.getenv("TOP_K", "3"))
+    bmRetriver = CHBM25Retriever.from_defaults(similarity_top_k=top_k,nodes=vector_store.get_nodes([]))
+    bmRetriver.persist(STORAGE_DIR)
+
+
 def generate_datasource():
     init_settings()
     logger.info("Generate index for the provided data")
@@ -75,6 +83,7 @@ def generate_datasource():
 
     # Build the index and persist storage
     persist_storage(docstore, vector_store)
+    persist_BMRetriever(vector_store)
 
     logger.info("Finished generating the index")