# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1464042988 -3600
# Node ID 2e4145e452cd69d0a07f1e13b8ccfc2d8fee6afb
# Parent  c161586a6b771b2ae6d61f0cc0152fae75b356f0
maps: add "lasthash" property to RevMap

This is a part of the bigger plan to get rid of reading or writing rev_map
directly without going through the RevMap class.

The "lasthash" property will be used in updatemeta.

diff --git a/hgsubversion/maps.py b/hgsubversion/maps.py
--- a/hgsubversion/maps.py
+++ b/hgsubversion/maps.py
@@ -355,6 +355,13 @@ class RevMap(dict):
         check = lambda x: x[0][1] == branch and x[0][0] < rev.revnum
         return sorted(filter(check, self.iteritems()), reverse=True)
 
+    @property
+    def lasthash(self):
+        lines = list(self.readmapfile(self.meta.revmap_file))
+        if not lines:
+            return None
+        return bin(lines[-1].split(' ', 2)[1])
+
     def revhashes(self, revnum):
         for key, value in self.iteritems():
             if key[0] == revnum: