Use TodoListBase for archive files.

No dependency tracking is needed and gives a huge performance
improvement for huge done.txt files.

topydo/cli/Main.py

@@ -82,6 +82,7 @@ from topydo.lib.SortCommand import SortCommand
 from topydo.lib.TagCommand import TagCommand
 from topydo.lib import TodoFile
 from topydo.lib import TodoList
+from topydo.lib import TodoListBase
 from topydo.lib.Utils import escape_ansi
 
 class CLIApplication(object):
@@ -96,7 +97,7 @@ class CLIApplication(object):
         (defaults to done.txt).
         """
         archive_file = TodoFile.TodoFile(config().archive())
-        archive = TodoList.TodoList(archive_file.read())
+        archive = TodoListBase.TodoListBase(archive_file.read())
 
         if archive:
             command = ArchiveCommand(self.todolist, archive)

topydo/lib/ArchiveCommand.py

@@ -18,6 +18,14 @@ import Command
 
 class ArchiveCommand(Command.Command):
     def __init__(self, p_todolist, p_archive_list):
+        """
+        Constructor.
+
+        p_todolist where all completed items will be moved from.
+        p_archive_list is the list where the items go to. This can be a
+        TodoListBase class which does no dependency checking, so a better
+        choice for huge done.txt files.
+        """
         super(ArchiveCommand, self).__init__([], p_todolist)
         self.archive = p_archive_list