# HG changeset patch
# User Wojciech Lopata <lopek@fb.com>
# Date 1376935598 25200
# Node ID 55749cb14d248eb8c231767be0709d7ed4d7801c
# Parent  d0dbe5330177fbc01fed2f23a06604d3d6768225
revlog: extract 'checkhash' method

Extract method that decides whether nodeid is correct for paricular revision
text and parent nodes. Having this method extracted will allow revlog
subclasses to implement custom way of computing nodes. In particular this
change is necessary to implement manifest compression.

diff -r d0dbe5330177 -r 55749cb14d24 mercurial/revlog.py
--- a/mercurial/revlog.py	Mon Aug 26 16:11:21 2013 +0900
+++ b/mercurial/revlog.py	Mon Aug 19 11:06:38 2013 -0700
@@ -14,7 +14,7 @@
 # import stuff from node for others to import from revlog
 from node import bin, hex, nullid, nullrev
 from i18n import _
-import ancestor, mdiff, parsers, error, util
+import ancestor, mdiff, parsers, error, util, templatefilters
 import struct, zlib, errno
 
 _pack = struct.pack
@@ -943,10 +943,16 @@
 
     def _checkhash(self, text, node, rev):
         p1, p2 = self.parents(node)
+        self.checkhash(text, p1, p2, node, rev)
+        return text
+
+    def checkhash(self, text, p1, p2, node, rev=None):
         if node != hash(text, p1, p2):
-            raise RevlogError(_("integrity check failed on %s:%d")
-                              % (self.indexfile, rev))
-        return text
+            revornode = rev
+            if revornode is None:
+                revornode = templatefilters.short(hex(node))
+            raise RevlogError(_("integrity check failed on %s:%s")
+                % (self.indexfile, revornode))
 
     def checkinlinesize(self, tr, fp=None):
         if not self._inline or (self.start(-2) + self.length(-2)) < _maxinline:
@@ -1063,9 +1069,7 @@
             ifh.flush()
             basetext = self.revision(self.node(cachedelta[0]))
             btext[0] = mdiff.patch(basetext, cachedelta[1])
-            chk = hash(btext[0], p1, p2)
-            if chk != node:
-                raise RevlogError(_("consistency error in delta"))
+            self.checkhash(btext[0], p1, p2, node)
             return btext[0]
 
         def builddelta(rev):