optimize the '_add_routes' function

semantic_router/layer.py

@@ -482,28 +482,44 @@ class RouteLayer:
             self.routes.append(route)
 
     def _add_routes(self, routes: List[Route]):
-        if routes:
-            for route in routes:
-                logger.info(f"Adding `{route.name}` route")
-                embeddings = self.encoder(route.utterances)
-                if route.score_threshold is None:
-                    route.score_threshold = self.score_threshold
-                try:
-                    self.index.add(
-                        embeddings=embeddings,
-                        routes=[route.name] * len(route.utterances),
-                        utterances=route.utterances,
-                        function_schemas=(
-                            route.function_schemas * len(route.utterances)
-                            if route.function_schemas
-                            else [{}] * len(route.utterances)
-                        ),
-                    )
-                except Exception as e:
-                    logger.error(
-                        f"Failed to add route `{route.name}` to the index: {e}"
-                    )
-                    raise Exception(f"Indexing error for route `{route.name}`") from e
+        if not routes:
+            logger.warning("No routes provided to add.")
+            return
+
+        route_names = []
+        all_embeddings = []
+        all_utterances = []
+        all_function_schemas = []
+
+        for route in routes:
+            logger.info(f"Adding `{route.name}` route")
+            route_embeddings = self.encoder(route.utterances)
+            
+            # Set score_threshold if not already set
+            route.score_threshold = route.score_threshold or self.score_threshold
+            
+            # Prepare data for batch insertion
+            route_names.extend([route.name] * len(route.utterances))
+            all_embeddings.extend(route_embeddings)
+            all_utterances.extend(route.utterances)
+            all_function_schemas.extend(
+                route.function_schemas * len(route.utterances)
+                if route.function_schemas
+                else [{}] * len(route.utterances)
+            )
+
+        try:
+            # Batch insertion into the index
+            self.index.add(
+                embeddings=all_embeddings,
+                routes=route_names,
+                utterances=all_utterances,
+                function_schemas=all_function_schemas,
+            )
+        except Exception as e:
+            logger.error(f"Failed to add routes to the index: {e}")
+            raise Exception("Indexing error occurred") from e
+
 
     def _add_and_sync_routes(self, routes: List[Route]):
         # create embeddings for all routes and sync at startup with remote ones based on sync setting