Track whether loading is underway

In preparation for safeguards preventing alteration of elements from
read-only backing files, we need a way to identify that loading
updated files is in progress; that's the only time elements from
read-only files should ever change.

diff --git a/mudpy/misc.py b/mudpy/misc.py
index af5427a..4e32ccc 100644 (file)
--- a/mudpy/misc.py
+++ b/mudpy/misc.py
@@ -347,6 +347,7 @@ class Universe:
         self.contents = {}
         self.default_origins = {}
         self.directions = set()
+        self.loading = False
         self.loglines = []
         self.private_files = []
         self.reload_flag = False
@@ -375,6 +376,9 @@ class Universe:
     def load(self):
         """Load universe data from persistent storage."""
 
+        # while loading, it's safe to update elements from read-only files
+        self.loading = True
+
         # it's possible for this to enter before logging configuration is read
         pending_loglines = []
 
@@ -425,6 +429,10 @@ class Universe:
         for element in self.contents.values():
             element.update_location()
             element.clean_contents()
+
+        # done loading, so disallow updating elements from read-only files
+        self.loading = False
+
         return pending_loglines
 
     def new(self):