nodemap: keep track of the docket for loaded data

To perform incremental update of the on disk data, we need to keep tracks of
some aspect of that data.

Differential Revision: https://phab.mercurial-scm.org/D7885

mercurial/debugcommands.py

@@ -2113,13 +2113,17 b' def debugnodemap(ui, repo, **opts):'
     elif opts['dump_disk']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
-        data = nodemap.persisted_data(cl)
-        ui.write(data)
+        nm_data = nodemap.persisted_data(cl)
+        if nm_data is not None:
+            docket, data = nm_data
+            ui.write(data)
     elif opts['check']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
-        data = nodemap.persisted_data(cl)
-        return nodemap.check_data(ui, cl.index, data)
+        nm_data = nodemap.persisted_data(cl)
+        if nm_data is not None:
+            docket, data = nm_data
+            return nodemap.check_data(ui, cl.index, data)
 
 
 @command(

mercurial/revlog.py

@@ -455,6 +455,7 b' class revlog(object):'
         self._maxchainlen = None
         self._deltabothparents = True
         self.index = None
+        self._nodemap_docket = None
         # Mapping of partial identifiers to full nodes.
         self._pcache = {}
         # Mapping of revision integer to full node.
@@ -544,6 +545,9 b' class revlog(object):'
         indexdata = b''
         self._initempty = True
         try:
+            nodemap_data = nodemaputil.persisted_data(self)
+            if nodemap_data is not None:
+                self._nodemap_docket = nodemap_data[0]
             with self._indexfp() as f:
                 if (
                     mmapindexthreshold is not None
@@ -635,7 +639,7 b' class revlog(object):'
             if use_nodemap:
                 nodemap_data = nodemaputil.persisted_data(self)
                 if nodemap_data is not None:
-                    index.update_nodemap_data(nodemap_data)
+                    index.update_nodemap_data(nodemap_data[1])
         except (ValueError, IndexError):
             raise error.RevlogError(
                 _(b"index %s is corrupted") % self.indexfile

mercurial/revlogutils/nodemap.py

@@ -41,7 +41,7 b' def persisted_data(revlog):'
     docket = NodeMapDocket(pdata[offset : offset + uid_size])
 
     filename = _rawdata_filepath(revlog, docket)
-    return revlog.opener.tryread(filename)
+    return docket, revlog.opener.tryread(filename)
 
 
 def setup_persistent_nodemap(tr, revlog):
@@ -93,6 +93,7 b' def _persist_nodemap(tr, revlog):'
     # store vfs
     with revlog.opener(revlog.nodemap_file, b'w', atomictemp=True) as fp:
         fp.write(target_docket.serialize())
+    revlog._nodemap_docket = target_docket
     # EXP-TODO: if the transaction abort, we should remove the new data and
     # reinstall the old one.