--- /dev/null
+
+import re
+import os.path
+
+from allmydata.util.assertutil import precondition, _assert
+
+def path2magic(path):
+ return re.sub(ur'[/@]', lambda m: {u'/': u'@_', u'@': u'@@'}[m.group(0)], path)
+
+def magic2path(path):
+ return re.sub(ur'@[_@]', lambda m: {u'@_': u'/', u'@@': u'@'}[m.group(0)], path)
+
+
+IGNORE_SUFFIXES = [u'.backup', u'.tmp', u'.conflicted']
+IGNORE_PREFIXES = [u'.']
+
+def should_ignore_file(path_u):
+ precondition(isinstance(path_u, unicode), path_u=path_u)
+
+ for suffix in IGNORE_SUFFIXES:
+ if path_u.endswith(suffix):
+ return True
+
+ while path_u != u"":
+ oldpath_u = path_u
+ path_u, tail_u = os.path.split(path_u)
+ if tail_u.startswith(u"."):
+ return True
+ if path_u == oldpath_u:
+ return True # the path was absolute
+ _assert(len(path_u) < len(oldpath_u), path_u=path_u, oldpath_u=oldpath_u)
+
+ return False