diff mercurial/pure/parsers.py @ 43525:845e5b313783

revlog: move the nodemap into the index object (for pure)

This make the pure code closer to the C extension one. The ultimate goal is to
merge the two into a single object and offer a unified API. This changeset
focus on gathering the data on the same object.

For now the code for `revlogoldindex` and `BaseIndexObject` index object are
quite similar. However, there will be larger divergence later on, so I don't
think is worth doing a base case.

This work is part of a refactoring to unify the revlog index and the nodemap.
This unification prepare the use of a persistent nodemap.

Differential Revision: https://phab.mercurial-scm.org/D7313

--- a/mercurial/pure/parsers.py	Wed Nov 06 14:13:19 2019 +0100
+++ b/mercurial/pure/parsers.py	Wed Nov 06 14:13:19 2019 +0100
@@ -10,8 +10,12 @@
 import struct
 import zlib
 
-from ..node import nullid
-from .. import pycompat
+from ..node import nullid, nullrev
+from .. import (
+    pycompat,
+    revlogutils,
+    util,
+)
 
 stringio = pycompat.bytesio
 
@@ -43,6 +47,17 @@
 
 
 class BaseIndexObject(object):
+    @util.propertycache
+    def nodemap(self):
+        nodemap = revlogutils.NodeMap({nullid: nullrev})
+        for r in range(0, len(self)):
+            n = self[r][7]
+            nodemap[n] = r
+        return nodemap
+
+    def clearcaches(self):
+        self.__dict__.pop('nodemap', None)
+
     def __len__(self):
         return self._lgt + len(self._extra)