[PATCH 2 of 2] obsstore: issue debug message when adding duplicate markers

[Eric Sumner]

# HG changeset patch
# User Eric Sumner <ericsumner at fb.com>
# Date 1429037944 14400
#      Tue Apr 14 14:59:04 2015 -0400
# Node ID c8fd0a4978ea764b321faa1a98f29c4eec510300
# Parent  b30cb32ea6821e165aab65051767aa810fdb8464
obsstore: issue debug message when adding duplicate markers

One of the performance issues with evolve right now is the sending of redundant
obsolete information; this patch tracks and reports this via a debug message

diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -583,11 +583,19 @@
             raise util.Abort('creating obsolete markers is not enabled on this '
                              'repo')
         known = set(self._all)
+        duplicate = set()
+        count = 0
         new = []
         for m in markers:
+            count += 1
             if m not in known:
                 known.add(m)
                 new.append(m)
+            else:
+                duplicate.add(m)
+        if duplicate:
+            self.ui.debug(_('obsolete: %i/%i added markers are duplicates\n')
+                          % (len(duplicate), count))
         if new:
             f = self.sopener('obsstore', 'ab')
             try: