Adding optimization rewrite pass to utilize server with information about masked columns

pydough/configs/session.py

@@ -26,6 +26,7 @@
     load_database_context,
 )
 from pydough.errors import PyDoughErrorBuilder
+from pydough.mask_server import MaskServerInfo
 from pydough.metadata import GraphMetadata, parse_json_metadata_from_file
 
 from .pydough_configs import PyDoughConfigs
@@ -50,6 +51,7 @@ def __init__(self) -> None:
             connection=empty_connection, dialect=DatabaseDialect.ANSI
         )
         self._error_builder: PyDoughErrorBuilder = PyDoughErrorBuilder()
+        self._mask_server: MaskServerInfo | None = None
 
     @property
     def metadata(self) -> GraphMetadata | None:
@@ -131,6 +133,26 @@ def error_builder(self, builder: PyDoughErrorBuilder) -> None:
         """
         self._error_builder = builder
 
+    @property
+    def mask_server(self) -> MaskServerInfo | None:
+        """
+        Get the active mask server information.
+
+        Returns:
+            The active mask server information.
+        """
+        return self._mask_server
+
+    @mask_server.setter
+    def mask_server(self, server_info: MaskServerInfo | None) -> None:
+        """
+        Set the active mask server information.
+
+        Args:
+            The mask server information to set.
+        """
+        self._mask_server = server_info
+
     def connect_database(self, database_name: str, **kwargs) -> DatabaseContext:
         """
         Create a new DatabaseContext and register it in the session. This returns