Add snapshot to read table responses

PR:3060713

Author: rekby

ydb/_session_impl.py

@@ -407,7 +407,8 @@ def bulk_upsert_request_factory(table, rows, column_types):
 
 def wrap_read_table_response(response):
     issues._process_response(response)
-    return convert.ResultSet.from_message(response.result.result_set)
+    snapshot = response.snapshot if response.HasField("snapshot") else None
+    return convert.ResultSet.from_message(response.result.result_set, snapshot=snapshot)
 
 
 class SessionState(object):

ydb/convert.py

@@ -313,15 +313,15 @@ def _unwrap_optionality(column):
 
 
 class _ResultSet(object):
-    __slots__ = ("columns", "rows", "truncated")
+    __slots__ = ("columns", "rows", "truncated", "snapshot")
 
-    def __init__(self, columns, rows, truncated):
+    def __init__(self, columns, rows, truncated, snapshot=None):
         self.columns = columns
         self.rows = rows
         self.truncated = truncated
 
     @classmethod
-    def from_message(cls, message, table_client_settings=None):
+    def from_message(cls, message, table_client_settings=None, snapshot=None):
         rows = []
         # prepare columnn parsers before actuall parsing
         column_parsers = []
@@ -348,12 +348,12 @@ def from_message(cls, message, table_client_settings=None):
                     unwrapped_type, value, table_client_settings
                 )
             rows.append(row)
-        return cls(message.columns, rows, message.truncated)
+        return cls(message.columns, rows, message.truncated, snapshot)
 
     @classmethod
-    def lazy_from_message(cls, message, table_client_settings=None):
+    def lazy_from_message(cls, message, table_client_settings=None, snapshot=None):
         rows = _LazyRows(message.rows, table_client_settings, message.columns)
-        return cls(message.columns, rows, message.truncated)
+        return cls(message.columns, rows, message.truncated, snapshot)
 
 
 ResultSet = _ResultSet