A spot of refactoring

src/calibre/gui2/languages.py

@@ -9,20 +9,9 @@ __docformat__ = 'restructuredtext en'
 
 from calibre.gui2 import gui_prefs
 from calibre.gui2.complete2 import EditWithComplete
-from calibre.utils.localization import lang_map
+from calibre.utils.localization import lang_map_for_ui
 from calibre.utils.icu import sort_key, lower
 
-_lang_map = None
-
-
-def get_lang_map():
-    global _lang_map
-    if _lang_map is None:
-        _lang_map = lang_map().copy()
-        for x in ('zxx', 'mis', 'mul'):
-            _lang_map.pop(x, None)
-    return _lang_map
-
 
 class LanguagesEdit(EditWithComplete):
 
@@ -33,7 +22,7 @@ class LanguagesEdit(EditWithComplete):
 
         self.setSizeAdjustPolicy(self.AdjustToMinimumContentsLengthWithIcon)
         self.setMinimumContentsLength(20)
-        self._lang_map = get_lang_map()
+        self._lang_map = lang_map_for_ui()
         self.names_with_commas = [x for x in self._lang_map.itervalues() if ',' in x]
         self.comma_map = {k:k.replace(',', '|') for k in self.names_with_commas}
         self.comma_rmap = {v:k for k, v in self.comma_map.iteritems()}
@@ -114,4 +103,3 @@ class LanguagesEdit(EditWithComplete):
                 if code is None:
                     bad.append(name)
         return bad
-

src/calibre/utils/localization.py

@@ -426,6 +426,16 @@ def lang_map():
     return _lang_map
 
 
+def lang_map_for_ui():
+    ans = getattr(lang_map_for_ui, 'ans', None)
+    if ans is None:
+        ans = lang_map().copy()
+        for x in ('zxx', 'mis', 'mul'):
+            ans.pop(x, None)
+        lang_map_for_ui.ans = ans
+    return ans
+
+
 def langnames_to_langcodes(names):
     '''
     Given a list of localized language names return a mapping of the names to 3