utils: Export NiceSortKey function

The ability to split a string into a list of strings and integers can be
handy elsewhere and is necessary for sorting query results by names.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/utils/algo.py

@@ -26,7 +26,8 @@ import re
 import time
 
 
-_SORTER_RE = re.compile("^%s(.*)$" % (8 * "(\D+|\d+)?"))
+_SORTER_GROUPS = 8
+_SORTER_RE = re.compile("^%s(.*)$" % (_SORTER_GROUPS * "(\D+|\d+)?"))
 _SORTER_DIGIT = re.compile("^\d+$")
 
 
@@ -78,7 +79,7 @@ def _NiceSortTryInt(val):
     return val
 
 
-def _NiceSortKey(value):
+def NiceSortKey(value):
   """Extract key for sorting.
 
   """
@@ -107,9 +108,9 @@ def NiceSort(values, key=None):
 
   """
   if key is None:
-    keyfunc = _NiceSortKey
+    keyfunc = NiceSortKey
   else:
-    keyfunc = lambda value: _NiceSortKey(key(value))
+    keyfunc = lambda value: NiceSortKey(key(value))
 
   return sorted(values, key=keyfunc)
 

test/ganeti.utils.algo_unittest.py

@@ -218,6 +218,16 @@ class TestNiceSort(unittest.TestCase):
     self.assertEqual(keyfn.count, len(data),
                      msg="Key function was not called once per value")
 
+  def testNiceSortKey(self):
+    self.assertEqual(algo.NiceSortKey(""),
+                     ([None] * algo._SORTER_GROUPS) + [""])
+    self.assertEqual(algo.NiceSortKey("Hello World"),
+                     ["Hello World"] +
+                     ([None] * int(algo._SORTER_GROUPS - 1)) + [""])
+    self.assertEqual(algo.NiceSortKey("node1.net75.bld3.example.com"),
+                     ["node", 1, ".net", 75, ".bld", 3, ".example.com",
+                      None, ""])
+
 
 class TimeMock:
   def __init__(self, values):