[PATCH 1 of 7] revlog: parentdelta flags for revlog index

[in3xes at gmail.com]

# HG changeset patch
# User Pradeepkumar Gayam <in3xes at gmail.com>
# Date 1281076770 -19800
# Node ID ea75c464fe41b33161561c131946a47fb94612dc
# Parent  b8b4a2417fbd51067524f0a9bb4dd698f60a31b3
revlog: parentdelta flags for revlog index

diff -r b8b4a2417fbd -r ea75c464fe41 mercurial/revlog.py
--- a/mercurial/revlog.py	Wed Aug 04 13:21:11 2010 -0500
+++ b/mercurial/revlog.py	Fri Aug 06 12:09:30 2010 +0530
@@ -34,8 +34,9 @@
 REVLOGNG_FLAGS = REVLOGNGINLINEDATA | REVLOGSHALLOW
 
 # revlog index flags
+REVIDX_PARENTDELTA  = 1
 REVIDX_PUNCHED_FLAG = 2
-REVIDX_KNOWN_FLAGS = REVIDX_PUNCHED_FLAG
+REVIDX_KNOWN_FLAGS = REVIDX_PUNCHED_FLAG | REVIDX_PARENTDELTA
 
 # amount of data read unconditionally, should be >= 4
 # when not inline: threshold for using lazy index
@@ -441,12 +442,14 @@
         self.nodemap = {nullid: nullrev}
         self.index = []
         self._shallowroot = shallowroot
+        self._parentdelta = 0
 
         v = REVLOG_DEFAULT_VERSION
         if hasattr(opener, 'options') and 'defversion' in opener.options:
             v = opener.options['defversion']
             if v & REVLOGNG:
                 v |= REVLOGNGINLINEDATA
+            self._parentdelta = v & REVLOGNG and 'parentdelta' in opener.options
         if shallowroot:
             v |= REVLOGSHALLOW