load vectorstore once

src/legisqa_local/app.py

@@ -3,6 +3,7 @@
 import logging
 import streamlit as st
 from legisqa_local.config.settings import STREAMLIT_CONFIG, setup_environment, setup_chromadb
+from legisqa_local.core.vectorstore import initialize_vectorstore
 from legisqa_local.components.sidebar import render_sidebar
 from legisqa_local.tabs.rag_tab import RAGTab
 from legisqa_local.tabs.rag_sbs_tab import RAGSideBySideTab
@@ -35,6 +36,11 @@ def main():
     setup_chromadb()
     logger.info("✅ ChromaDB setup complete")
     
+    # Initialize vectorstore (load once and cache)
+    logger.info("🔄 Initializing vectorstore...")
+    initialize_vectorstore()
+    logger.info("✅ Vectorstore initialization complete")
+    
     # Main content
     st.title(":classical_building: LegisQA :classical_building:")
     st.header("Query Congressional Bills")

src/legisqa_local/core/vectorstore.py

@@ -1,12 +1,22 @@
 """Vector store operations for LegisQA"""
 
+import logging
+import streamlit as st
 from langchain_chroma import Chroma
 from legisqa_local.core.embeddings import load_embeddings
 from legisqa_local.config.settings import get_chroma_config
 
+logger = logging.getLogger(__name__)
+
 
 def load_vectorstore():
-    """Load and return the ChromaDB vectorstore"""
+    """Load and return the ChromaDB vectorstore (cached in session state)"""
+    # Check if vectorstore is already loaded in session state
+    if hasattr(st, 'session_state') and hasattr(st.session_state, 'vectorstore'):
+        logger.debug("Using cached vectorstore from session state")
+        return st.session_state.vectorstore
+    
+    logger.info("🔄 Loading ChromaDB vectorstore...")
     config = get_chroma_config()
     emb_fn = load_embeddings()
     
@@ -15,9 +25,34 @@ def load_vectorstore():
         collection_name=config["collection_name"],
         embedding_function=emb_fn,
     )
+    
+    # Cache in session state for future use
+    if hasattr(st, 'session_state'):
+        st.session_state.vectorstore = vectorstore
+        logger.info("✅ Vectorstore loaded and cached in session state")
+    else:
+        logger.info("✅ Vectorstore loaded (session state not available)")
+    
     return vectorstore
 
 
+def initialize_vectorstore():
+    """Initialize the vectorstore at application startup"""
+    logger.info("🚀 Initializing vectorstore at startup...")
+    vectorstore = load_vectorstore()
+    
+    # Test the vectorstore with a simple query to ensure it's working
+    try:
+        # Get collection info for verification
+        collection = vectorstore._collection
+        count = collection.count()
+        logger.info(f"✅ Vectorstore initialized successfully - {count} documents available")
+        return vectorstore
+    except Exception as e:
+        logger.error(f"❌ Error testing vectorstore: {e}")
+        raise
+
+
 def get_vectorstore_filter(ret_config: dict) -> dict:
     """Get filter dict for ChromaDB queries"""
     where_clause = {}