D6808: revlog: introduce a `sidedata` method

[marmoute (Pierre-Yves David)]

marmoute created this revision.
marmoute added reviewers: yuja, durin42.
Herald added a reviewer: indygreg.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  The method give access to extra information related to the revision. Such data
  will not be part of the hash be strongly related to the revision. Having them
  stored at the revlog level helps the storage consistency story and simplify
  various things.
  
  Example of data we could store there:
  
  - copy tracing related informations
  - graph structure related information (useful for discovery)
  - unresolved conflict data
  
  The full implementation will be introduced gradually in the coming changesets.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6808

AFFECTED FILES
  mercurial/revlog.py

CHANGE DETAILS

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -1612,6 +1612,16 @@
         """
         return self._revisiondata(nodeorrev, _df, raw=raw)
 
+    def sidedata(self, nodeorrev, _df=None):
+        """a map of extra data related to the changeset but not part of the hash
+
+        This function currently return a dictionary. However, more advanced
+        mapping object will likely be used in the future for a more
+        efficient/lazy code.
+        """
+        # XXX will actualy return data once storage is implemented.
+        return {}
+
     def _revisiondata(self, nodeorrev, _df=None, raw=False):
         # deal with <nodeorrev> argument type
         if isinstance(nodeorrev, int):



To: marmoute, yuja, durin42, indygreg, #hg-reviewers
Cc: mercurial-devel