diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -3672,7 +3672,7 @@ def perfloadmarkers(ui, repo):
     Result is the number of markers in the repo."""
     timer, fm = gettimer(ui)
     svfs = getsvfs(repo)
-    timer(lambda: len(obsolete.obsstore(svfs)))
+    timer(lambda: len(obsolete.obsstore(repo, svfs)))
     fm.end()
 
 
diff --git a/hgext/absorb.py b/hgext/absorb.py
--- a/hgext/absorb.py
+++ b/hgext/absorb.py
@@ -102,6 +102,9 @@ class nullui(object):
 class emptyfilecontext(object):
     """minimal filecontext representing an empty file"""
 
+    def __init__(self, repo):
+        self._repo = repo
+
     def data(self):
         return b''
 
@@ -212,7 +215,7 @@ def getfilestack(stack, path, seenfctxs=
         if path in pctx:
             fctxs.append(pctx[path])
         else:
-            fctxs.append(emptyfilecontext())
+            fctxs.append(emptyfilecontext(pctx.repo()))
 
     fctxs.reverse()
     # note: we rely on a property of hg: filerev is not reused for linear
diff --git a/hgext/git/gitlog.py b/hgext/git/gitlog.py
--- a/hgext/git/gitlog.py
+++ b/hgext/git/gitlog.py
@@ -8,6 +8,7 @@ from mercurial.node import (
     nullhex,
     nullid,
     nullrev,
+    sha1nodeconstants,
     wdirhex,
 )
 from mercurial import (
@@ -422,6 +423,8 @@ class changelog(baselog):
 
 
 class manifestlog(baselog):
+    nodeconstants = sha1nodeconstants
+
     def __getitem__(self, node):
         return self.get(b'', node)
 
diff --git a/hgext/largefiles/lfutil.py b/hgext/largefiles/lfutil.py
--- a/hgext/largefiles/lfutil.py
+++ b/hgext/largefiles/lfutil.py
@@ -206,6 +206,7 @@ def openlfdirstate(ui, repo, create=True
         repo.root,
         repo.dirstate._validate,
         lambda: sparse.matcher(repo),
+        repo.nodeconstants,
     )
 
     # If the largefiles dirstate does not exist, populate and create
diff --git a/hgext/sqlitestore.py b/hgext/sqlitestore.py
--- a/hgext/sqlitestore.py
+++ b/hgext/sqlitestore.py
@@ -54,6 +54,7 @@ from mercurial.i18n import _
 from mercurial.node import (
     nullid,
     nullrev,
+    sha1nodeconstants,
     short,
 )
 from mercurial.thirdparty import attr
@@ -305,6 +306,7 @@ class sqlitefilestore(object):
     """Implements storage for an individual tracked path."""
 
     def __init__(self, db, path, compression):
+        self.nullid = sha1nodeconstants.nullid
         self._db = db
         self._path = path
 
diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -623,7 +623,7 @@ def unhexlifybookmarks(marks):
 _binaryentry = struct.Struct(b'>20sH')
 
 
-def binaryencode(bookmarks):
+def binaryencode(repo, bookmarks):
     """encode a '(bookmark, node)' iterable into a binary stream
 
     the binary format is:
@@ -645,7 +645,7 @@ def binaryencode(bookmarks):
     return b''.join(binarydata)
 
 
-def binarydecode(stream):
+def binarydecode(repo, stream):
     """decode a binary stream into an '(bookmark, node)' iterable
 
     the binary format is:
diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py
--- a/mercurial/branchmap.py
+++ b/mercurial/branchmap.py
@@ -97,7 +97,7 @@ class BranchMapCache(object):
                 revs.extend(r for r in extrarevs if r <= bcache.tiprev)
             else:
                 # nothing to fall back on, start empty.
-                bcache = branchcache()
+                bcache = branchcache(repo)
 
         revs.extend(cl.revs(start=bcache.tiprev + 1))
         if revs:
@@ -129,6 +129,7 @@ class BranchMapCache(object):
         if rbheads:
             rtiprev = max((int(clrev(node)) for node in rbheads))
             cache = branchcache(
+                repo,
                 remotebranchmap,
                 repo[rtiprev].node(),
                 rtiprev,
@@ -184,6 +185,7 @@ class branchcache(object):
 
     def __init__(
         self,
+        repo,
         entries=(),
         tipnode=nullid,
         tiprev=nullrev,
@@ -195,6 +197,7 @@ class branchcache(object):
         """hasnode is a function which can be used to verify whether changelog
         has a given node or not. If it's not provided, we assume that every node
         we have exists in changelog"""
+        self._repo = repo
         self.tipnode = tipnode
         self.tiprev = tiprev
         self.filteredhash = filteredhash
@@ -280,6 +283,7 @@ class branchcache(object):
             if len(cachekey) > 2:
                 filteredhash = bin(cachekey[2])
             bcache = cls(
+                repo,
                 tipnode=last,
                 tiprev=lrev,
                 filteredhash=filteredhash,
@@ -388,6 +392,7 @@ class branchcache(object):
     def copy(self):
         """return an deep copy of the branchcache object"""
         return type(self)(
+            self._repo,
             self._entries,
             self.tipnode,
             self.tiprev,
diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -2146,7 +2146,7 @@ def handlecheckbookmarks(op, inpart):
     contains binary encoded (bookmark, node) tuple. If the local state does
     not marks the one in the part, a PushRaced exception is raised
     """
-    bookdata = bookmarks.binarydecode(inpart)
+    bookdata = bookmarks.binarydecode(op.repo, inpart)
 
     msgstandard = (
         b'remote repository changed while pushing - please try again '
@@ -2376,7 +2376,7 @@ def handlebookmark(op, inpart):
     When mode is 'records', the information is recorded into the 'bookmarks'
     records of the bundle operation. This behavior is suitable for pulling.
     """
-    changes = bookmarks.binarydecode(inpart)
+    changes = bookmarks.binarydecode(op.repo, inpart)
 
     pushkeycompat = op.repo.ui.configbool(
         b'server', b'bookmarks-pushkey-compat'
diff --git a/mercurial/bundlerepo.py b/mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py
+++ b/mercurial/bundlerepo.py
@@ -175,9 +175,15 @@ class bundlechangelog(bundlerevlog, chan
 
 class bundlemanifest(bundlerevlog, manifest.manifestrevlog):
     def __init__(
-        self, opener, cgunpacker, linkmapper, dirlogstarts=None, dir=b''
+        self,
+        nodeconstants,
+        opener,
+        cgunpacker,
+        linkmapper,
+        dirlogstarts=None,
+        dir=b'',
     ):
-        manifest.manifestrevlog.__init__(self, opener, tree=dir)
+        manifest.manifestrevlog.__init__(self, nodeconstants, opener, tree=dir)
         bundlerevlog.__init__(
             self, opener, self.indexfile, cgunpacker, linkmapper
         )
@@ -192,6 +198,7 @@ class bundlemanifest(bundlerevlog, manif
         if d in self._dirlogstarts:
             self.bundle.seek(self._dirlogstarts[d])
             return bundlemanifest(
+                self.nodeconstants,
                 self.opener,
                 self.bundle,
                 self._linkmapper,
@@ -368,7 +375,9 @@ class bundlerepository(object):
         # consume the header if it exists
         self._cgunpacker.manifestheader()
         linkmapper = self.unfiltered().changelog.rev
-        rootstore = bundlemanifest(self.svfs, self._cgunpacker, linkmapper)
+        rootstore = bundlemanifest(
+            self.nodeconstants, self.svfs, self._cgunpacker, linkmapper
+        )
         self.filestart = self._cgunpacker.tell()
 
         return manifest.manifestlog(
diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -662,7 +662,7 @@ class headerlessfixup(object):
         return readexactly(self._fh, n)
 
 
-def _revisiondeltatochunks(delta, headerfn):
+def _revisiondeltatochunks(repo, delta, headerfn):
     """Serialize a revisiondelta to changegroup chunks."""
 
     # The captured revision delta may be encoded as a delta against
@@ -1065,7 +1065,9 @@ class cgpacker(object):
             sidedata_helpers=sidedata_helpers,
         )
         for delta in deltas:
-            for chunk in _revisiondeltatochunks(delta, self._builddeltaheader):
+            for chunk in _revisiondeltatochunks(
+                self._repo, delta, self._builddeltaheader
+            ):
                 size += len(chunk)
                 yield chunk
 
@@ -1121,7 +1123,9 @@ class cgpacker(object):
                 yield chunk
 
             for delta in deltas:
-                chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
+                chunks = _revisiondeltatochunks(
+                    self._repo, delta, self._builddeltaheader
+                )
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
@@ -1160,7 +1164,9 @@ class cgpacker(object):
             yield h
 
             for delta in deltas:
-                chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
+                chunks = _revisiondeltatochunks(
+                    self._repo, delta, self._builddeltaheader
+                )
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -191,7 +191,7 @@ class _changelogrevision(object):
     # Extensions might modify _defaultextra, so let the constructor below pass
     # it in
     extra = attr.ib()
-    manifest = attr.ib(default=nullid)
+    manifest = attr.ib()
     user = attr.ib(default=b'')
     date = attr.ib(default=(0, 0))
     files = attr.ib(default=attr.Factory(list))
@@ -219,9 +219,9 @@ class changelogrevision(object):
         '_changes',
     )
 
-    def __new__(cls, text, sidedata, cpsd):
+    def __new__(cls, cl, text, sidedata, cpsd):
         if not text:
-            return _changelogrevision(extra=_defaultextra)
+            return _changelogrevision(extra=_defaultextra, manifest=nullid)
 
         self = super(changelogrevision, cls).__new__(cls)
         # We could return here and implement the following as an __init__.
@@ -526,7 +526,7 @@ class changelog(revlog.revlog):
         """
         d, s = self._revisiondata(nodeorrev)
         c = changelogrevision(
-            d, s, self._copiesstorage == b'changeset-sidedata'
+            self, d, s, self._copiesstorage == b'changeset-sidedata'
         )
         return (c.manifest, c.user, c.date, c.files, c.description, c.extra)
 
@@ -534,7 +534,7 @@ class changelog(revlog.revlog):
         """Obtain a ``changelogrevision`` for a node or revision."""
         text, sidedata = self._revisiondata(nodeorrev)
         return changelogrevision(
-            text, sidedata, self._copiesstorage == b'changeset-sidedata'
+            self, text, sidedata, self._copiesstorage == b'changeset-sidedata'
         )
 
     def readfiles(self, nodeorrev):
diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -73,13 +73,16 @@ def _getfsnow(vfs):
 
 @interfaceutil.implementer(intdirstate.idirstate)
 class dirstate(object):
-    def __init__(self, opener, ui, root, validate, sparsematchfn):
+    def __init__(
+        self, opener, ui, root, validate, sparsematchfn, nodeconstants
+    ):
         """Create a new dirstate object.
 
         opener is an open()-like callable that can be used to open the
         dirstate file; root is the root of the directory tracked by
         the dirstate.
         """
+        self._nodeconstants = nodeconstants
         self._opener = opener
         self._validate = validate
         self._root = root
@@ -136,7 +139,9 @@ class dirstate(object):
     @propertycache
     def _map(self):
         """Return the dirstate contents (see documentation for dirstatemap)."""
-        self._map = self._mapcls(self._ui, self._opener, self._root)
+        self._map = self._mapcls(
+            self._ui, self._opener, self._root, self._nodeconstants
+        )
         return self._map
 
     @property
@@ -1420,12 +1425,13 @@ class dirstatemap(object):
       denormalized form that they appear as in the dirstate.
     """
 
-    def __init__(self, ui, opener, root):
+    def __init__(self, ui, opener, root, nodeconstants):
         self._ui = ui
         self._opener = opener
         self._root = root
         self._filename = b'dirstate'
         self._nodelen = 20
+        self._nodeconstants = nodeconstants
 
         self._parents = None
         self._dirtyparents = False
@@ -1724,7 +1730,8 @@ class dirstatemap(object):
 if rustmod is not None:
 
     class dirstatemap(object):
-        def __init__(self, ui, opener, root):
+        def __init__(self, ui, opener, root, nodeconstants):
+            self._nodeconstants = nodeconstants
             self._ui = ui
             self._opener = opener
             self._root = root
diff --git a/mercurial/discovery.py b/mercurial/discovery.py
--- a/mercurial/discovery.py
+++ b/mercurial/discovery.py
@@ -270,9 +270,12 @@ def _headssummary(pushop):
     # C. Update newmap with outgoing changes.
     # This will possibly add new heads and remove existing ones.
     newmap = branchmap.remotebranchcache(
-        (branch, heads[1])
-        for branch, heads in pycompat.iteritems(headssum)
-        if heads[0] is not None
+        repo,
+        (
+            (branch, heads[1])
+            for branch, heads in pycompat.iteritems(headssum)
+            if heads[0] is not None
+        ),
     )
     newmap.update(repo, (ctx.rev() for ctx in missingctx))
     for branch, newheads in pycompat.iteritems(newmap):
diff --git a/mercurial/exchange.py b/mercurial/exchange.py
--- a/mercurial/exchange.py
+++ b/mercurial/exchange.py
@@ -827,7 +827,7 @@ def _pushb2checkbookmarks(pushop, bundle
     data = []
     for book, old, new in pushop.outbookmarks:
         data.append((book, old))
-    checkdata = bookmod.binaryencode(data)
+    checkdata = bookmod.binaryencode(pushop.repo, data)
     bundler.newpart(b'check:bookmarks', data=checkdata)
 
 
@@ -1027,7 +1027,7 @@ def _pushb2bookmarkspart(pushop, bundler
         _abortonsecretctx(pushop, new, book)
         data.append((book, new))
         allactions.append((book, _bmaction(old, new)))
-    checkdata = bookmod.binaryencode(data)
+    checkdata = bookmod.binaryencode(pushop.repo, data)
     bundler.newpart(b'bookmarks', data=checkdata)
 
     def handlereply(op):
@@ -2455,7 +2455,7 @@ def _getbundlebookmarkpart(
     if not b2caps or b'bookmarks' not in b2caps:
         raise error.Abort(_(b'no common bookmarks exchange method'))
     books = bookmod.listbinbookmarks(repo)
-    data = bookmod.binaryencode(books)
+    data = bookmod.binaryencode(repo, books)
     if data:
         bundler.newpart(b'bookmarks', data=data)
 
diff --git a/mercurial/filelog.py b/mercurial/filelog.py
--- a/mercurial/filelog.py
+++ b/mercurial/filelog.py
@@ -33,6 +33,7 @@ class filelog(object):
         # Used by LFS.
         self._revlog.filename = path
         self._revlog.revlog_kind = b'filelog'
+        self.nullid = self._revlog.nullid
 
     def __len__(self):
         return len(self._revlog)
diff --git a/mercurial/interfaces/dirstate.py b/mercurial/interfaces/dirstate.py
--- a/mercurial/interfaces/dirstate.py
+++ b/mercurial/interfaces/dirstate.py
@@ -8,7 +8,7 @@ from . import util as interfaceutil
 
 
 class idirstate(interfaceutil.Interface):
-    def __init__(opener, ui, root, validate, sparsematchfn):
+    def __init__(opener, ui, root, validate, sparsematchfn, nodeconstants):
         """Create a new dirstate object.
 
         opener is an open()-like callable that can be used to open the
diff --git a/mercurial/interfaces/repository.py b/mercurial/interfaces/repository.py
--- a/mercurial/interfaces/repository.py
+++ b/mercurial/interfaces/repository.py
@@ -523,6 +523,10 @@ class ifileindex(interfaceutil.Interface
     * Metadata to facilitate storage.
     """
 
+    nullid = interfaceutil.Attribute(
+        """node for the null revision for use as delta base."""
+    )
+
     def __len__():
         """Obtain the number of revisions stored for this file."""
 
@@ -1143,6 +1147,10 @@ class imanifestrevisionwritable(imanifes
 class imanifeststorage(interfaceutil.Interface):
     """Storage interface for manifest data."""
 
+    nodeconstants = interfaceutil.Attribute(
+        """nodeconstants used by the current repository."""
+    )
+
     tree = interfaceutil.Attribute(
         """The path to the directory this manifest tracks.
 
@@ -1366,6 +1374,10 @@ class imanifestlog(interfaceutil.Interfa
     tree manifests.
     """
 
+    nodeconstants = interfaceutil.Attribute(
+        """nodeconstants used by the current repository."""
+    )
+
     def __getitem__(node):
         """Obtain a manifest instance for a given binary node.
 
@@ -1434,6 +1446,13 @@ class ilocalrepositorymain(interfaceutil
     This currently captures the reality of things - not how things should be.
     """
 
+    nodeconstants = interfaceutil.Attribute(
+        """Constant nodes matching the hash function used by the repository."""
+    )
+    nullid = interfaceutil.Attribute(
+        """null revision for the hash function used by the repository."""
+    )
+
     supportedformats = interfaceutil.Attribute(
         """Set of requirements that apply to stream clone.
 
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -21,6 +21,7 @@ from .node import (
     hex,
     nullid,
     nullrev,
+    sha1nodeconstants,
     short,
 )
 from .pycompat import (
@@ -1330,6 +1331,8 @@ class localrepository(object):
         self.vfs = hgvfs
         self.path = hgvfs.base
         self.requirements = requirements
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
         self.supported = supportedrequirements
         self.sharedpath = sharedpath
         self.store = store
@@ -1676,7 +1679,12 @@ class localrepository(object):
         sparsematchfn = lambda: sparse.matcher(self)
 
         return dirstate.dirstate(
-            self.vfs, self.ui, self.root, self._dirstatevalidate, sparsematchfn
+            self.vfs,
+            self.ui,
+            self.root,
+            self._dirstatevalidate,
+            sparsematchfn,
+            self.nodeconstants,
         )
 
     def _dirstatevalidate(self, node):
diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -792,8 +792,9 @@ def _splittopdir(f):
 
 @interfaceutil.implementer(repository.imanifestdict)
 class treemanifest(object):
-    def __init__(self, dir=b'', text=b''):
+    def __init__(self, nodeconstants, dir=b'', text=b''):
         self._dir = dir
+        self.nodeconstants = nodeconstants
         self._node = nullid
         self._loadfunc = _noop
         self._copyfunc = _noop
@@ -1051,7 +1052,9 @@ class treemanifest(object):
         if dir:
             self._loadlazy(dir)
             if dir not in self._dirs:
-                self._dirs[dir] = treemanifest(self._subpath(dir))
+                self._dirs[dir] = treemanifest(
+                    self.nodeconstants, self._subpath(dir)
+                )
             self._dirs[dir].__setitem__(subpath, n)
         else:
             # manifest nodes are either 20 bytes or 32 bytes,
@@ -1078,14 +1081,16 @@ class treemanifest(object):
         if dir:
             self._loadlazy(dir)
             if dir not in self._dirs:
-                self._dirs[dir] = treemanifest(self._subpath(dir))
+                self._dirs[dir] = treemanifest(
+                    self.nodeconstants, self._subpath(dir)
+                )
             self._dirs[dir].setflag(subpath, flags)
         else:
             self._flags[f] = flags
         self._dirty = True
 
     def copy(self):
-        copy = treemanifest(self._dir)
+        copy = treemanifest(self.nodeconstants, self._dir)
         copy._node = self._node
         copy._dirty = self._dirty
         if self._copyfunc is _noop:
@@ -1215,7 +1220,7 @@ class treemanifest(object):
         visit = match.visitchildrenset(self._dir[:-1])
         if visit == b'all':
             return self.copy()
-        ret = treemanifest(self._dir)
+        ret = treemanifest(self.nodeconstants, self._dir)
         if not visit:
             return ret
 
@@ -1272,7 +1277,7 @@ class treemanifest(object):
             m2 = m2._matches(match)
             return m1.diff(m2, clean=clean)
         result = {}
-        emptytree = treemanifest()
+        emptytree = treemanifest(self.nodeconstants)
 
         def _iterativediff(t1, t2, stack):
             """compares two tree manifests and append new tree-manifests which
@@ -1368,7 +1373,7 @@ class treemanifest(object):
         self._load()  # for consistency; should never have any effect here
         m1._load()
         m2._load()
-        emptytree = treemanifest()
+        emptytree = treemanifest(self.nodeconstants)
 
         def getnode(m, d):
             ld = m._lazydirs.get(d)
@@ -1551,6 +1556,7 @@ class manifestrevlog(object):
 
     def __init__(
         self,
+        nodeconstants,
         opener,
         tree=b'',
         dirlogcache=None,
@@ -1567,6 +1573,7 @@ class manifestrevlog(object):
         option takes precedence, so if it is set to True, we ignore whatever
         value is passed in to the constructor.
         """
+        self.nodeconstants = nodeconstants
         # During normal operations, we expect to deal with not more than four
         # revs at a time (such as during commit --amend). When rebasing large
         # stacks of commits, the number can go up, hence the config knob below.
@@ -1654,7 +1661,11 @@ class manifestrevlog(object):
             assert self._treeondisk
         if d not in self._dirlogcache:
             mfrevlog = manifestrevlog(
-                self.opener, d, self._dirlogcache, treemanifest=self._treeondisk
+                self.nodeconstants,
+                self.opener,
+                d,
+                self._dirlogcache,
+                treemanifest=self._treeondisk,
             )
             self._dirlogcache[d] = mfrevlog
         return self._dirlogcache[d]
@@ -1917,6 +1928,7 @@ class manifestlog(object):
     they receive (i.e. tree or flat or lazily loaded, etc)."""
 
     def __init__(self, opener, repo, rootstore, narrowmatch):
+        self.nodeconstants = repo.nodeconstants
         usetreemanifest = False
         cachesize = 4
 
@@ -1955,7 +1967,7 @@ class manifestlog(object):
 
         if not self._narrowmatch.always():
             if not self._narrowmatch.visitdir(tree[:-1]):
-                return excludeddirmanifestctx(tree, node)
+                return excludeddirmanifestctx(self.nodeconstants, tree, node)
         if tree:
             if self._rootstore._treeondisk:
                 if verify:
@@ -2118,7 +2130,7 @@ class memtreemanifestctx(object):
     def __init__(self, manifestlog, dir=b''):
         self._manifestlog = manifestlog
         self._dir = dir
-        self._treemanifest = treemanifest()
+        self._treemanifest = treemanifest(manifestlog.nodeconstants)
 
     def _storage(self):
         return self._manifestlog.getstorage(b'')
@@ -2168,17 +2180,19 @@ class treemanifestctx(object):
         narrowmatch = self._manifestlog._narrowmatch
         if not narrowmatch.always():
             if not narrowmatch.visitdir(self._dir[:-1]):
-                return excludedmanifestrevlog(self._dir)
+                return excludedmanifestrevlog(
+                    self._manifestlog.nodeconstants, self._dir
+                )
         return self._manifestlog.getstorage(self._dir)
 
     def read(self):
         if self._data is None:
             store = self._storage()
             if self._node == nullid:
-                self._data = treemanifest()
+                self._data = treemanifest(self._manifestlog.nodeconstants)
             # TODO accessing non-public API
             elif store._treeondisk:
-                m = treemanifest(dir=self._dir)
+                m = treemanifest(self._manifestlog.nodeconstants, dir=self._dir)
 
                 def gettext():
                     return store.revision(self._node)
@@ -2198,7 +2212,9 @@ class treemanifestctx(object):
                     text = store.revision(self._node)
                     arraytext = bytearray(text)
                     store.fulltextcache[self._node] = arraytext
-                self._data = treemanifest(dir=self._dir, text=text)
+                self._data = treemanifest(
+                    self._manifestlog.nodeconstants, dir=self._dir, text=text
+                )
 
         return self._data
 
@@ -2235,7 +2251,7 @@ class treemanifestctx(object):
             r0 = store.deltaparent(store.rev(self._node))
             m0 = self._manifestlog.get(self._dir, store.node(r0)).read()
             m1 = self.read()
-            md = treemanifest(dir=self._dir)
+            md = treemanifest(self._manifestlog.nodeconstants, dir=self._dir)
             for f, ((n0, fl0), (n1, fl1)) in pycompat.iteritems(m0.diff(m1)):
                 if n1:
                     md[f] = n1
@@ -2278,8 +2294,8 @@ class excludeddir(treemanifest):
     whose contents are unknown.
     """
 
-    def __init__(self, dir, node):
-        super(excludeddir, self).__init__(dir)
+    def __init__(self, nodeconstants, dir, node):
+        super(excludeddir, self).__init__(nodeconstants, dir)
         self._node = node
         # Add an empty file, which will be included by iterators and such,
         # appearing as the directory itself (i.e. something like "dir/")
@@ -2298,12 +2314,13 @@ class excludeddir(treemanifest):
 class excludeddirmanifestctx(treemanifestctx):
     """context wrapper for excludeddir - see that docstring for rationale"""
 
-    def __init__(self, dir, node):
+    def __init__(self, nodeconstants, dir, node):
+        self.nodeconstants = nodeconstants
         self._dir = dir
         self._node = node
 
     def read(self):
-        return excludeddir(self._dir, self._node)
+        return excludeddir(self.nodeconstants, self._dir, self._node)
 
     def readfast(self, shallow=False):
         # special version of readfast since we don't have underlying storage
@@ -2325,7 +2342,8 @@ class excludedmanifestrevlog(manifestrev
     outside the narrowspec.
     """
 
-    def __init__(self, dir):
+    def __init__(self, nodeconstants, dir):
+        self.nodeconstants = nodeconstants
         self._dir = dir
 
     def __len__(self):
diff --git a/mercurial/node.py b/mercurial/node.py
--- a/mercurial/node.py
+++ b/mercurial/node.py
@@ -21,29 +21,48 @@ def bin(s):
         raise TypeError(e)
 
 
-nullrev = -1
-# In hex, this is '0000000000000000000000000000000000000000'
-nullid = b"\0" * 20
-nullhex = hex(nullid)
+def short(node):
+    return hex(node[:6])
+
 
-# Phony node value to stand-in for new files in some uses of
-# manifests.
-# In hex, this is '2121212121212121212121212121212121212121'
-newnodeid = b'!!!!!!!!!!!!!!!!!!!!'
-# In hex, this is '3030303030303030303030303030306164646564'
-addednodeid = b'000000000000000added'
-# In hex, this is '3030303030303030303030306d6f646966696564'
-modifiednodeid = b'000000000000modified'
+nullrev = -1
 
-wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}
-
-# pseudo identifiers for working directory
-# (they are experimental, so don't add too many dependencies on them)
+# pseudo identifier for working directory
+# (experimental, so don't add too many dependencies on it)
 wdirrev = 0x7FFFFFFF
-# In hex, this is 'ffffffffffffffffffffffffffffffffffffffff'
-wdirid = b"\xff" * 20
-wdirhex = hex(wdirid)
 
 
-def short(node):
-    return hex(node[:6])
+class sha1nodeconstants(object):
+    nodelen = 20
+
+    # In hex, this is '0000000000000000000000000000000000000000'
+    nullid = b"\0" * nodelen
+    nullhex = hex(nullid)
+
+    # Phony node value to stand-in for new files in some uses of
+    # manifests.
+    # In hex, this is '2121212121212121212121212121212121212121'
+    newnodeid = b'!!!!!!!!!!!!!!!!!!!!'
+    # In hex, this is '3030303030303030303030303030306164646564'
+    addednodeid = b'000000000000000added'
+    # In hex, this is '3030303030303030303030306d6f646966696564'
+    modifiednodeid = b'000000000000modified'
+
+    wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}
+
+    # pseudo identifier for working directory
+    # (experimental, so don't add too many dependencies on it)
+    # In hex, this is 'ffffffffffffffffffffffffffffffffffffffff'
+    wdirid = b"\xff" * nodelen
+    wdirhex = hex(wdirid)
+
+
+# legacy starting point for porting modules
+nullid = sha1nodeconstants.nullid
+nullhex = sha1nodeconstants.nullhex
+newnodeid = sha1nodeconstants.newnodeid
+addednodeid = sha1nodeconstants.addednodeid
+modifiednodeid = sha1nodeconstants.modifiednodeid
+wdirfilenodeids = sha1nodeconstants.wdirfilenodeids
+wdirid = sha1nodeconstants.wdirid
+wdirhex = sha1nodeconstants.wdirhex
diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -560,10 +560,11 @@ class obsstore(object):
     # parents: (tuple of nodeid) or None, parents of predecessors
     #          None is used when no data has been recorded
 
-    def __init__(self, svfs, defaultformat=_fm1version, readonly=False):
+    def __init__(self, repo, svfs, defaultformat=_fm1version, readonly=False):
         # caches for various obsolescence related cache
         self.caches = {}
         self.svfs = svfs
+        self.repo = repo
         self._defaultformat = defaultformat
         self._readonly = readonly
 
@@ -806,7 +807,7 @@ def makestore(ui, repo):
     if defaultformat is not None:
         kwargs['defaultformat'] = defaultformat
     readonly = not isenabled(repo, createmarkersopt)
-    store = obsstore(repo.svfs, readonly=readonly, **kwargs)
+    store = obsstore(repo, repo.svfs, readonly=readonly, **kwargs)
     if store and readonly:
         ui.warn(
             _(b'obsolete feature not enabled but %i markers found!\n')
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -28,6 +28,7 @@ from .node import (
     nullhex,
     nullid,
     nullrev,
+    sha1nodeconstants,
     short,
     wdirfilenodeids,
     wdirhex,
@@ -651,6 +652,10 @@ class revlog(object):
             raise error.RevlogError(
                 _(b'unknown version (%d) in revlog %s') % (fmt, self.indexfile)
             )
+
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
+
         # sparse-revlog can't be on without general-delta (issue6056)
         if not self._generaldelta:
             self._sparserevlog = False
diff --git a/mercurial/statichttprepo.py b/mercurial/statichttprepo.py
--- a/mercurial/statichttprepo.py
+++ b/mercurial/statichttprepo.py
@@ -12,6 +12,7 @@ from __future__ import absolute_import
 import errno
 
 from .i18n import _
+from .node import sha1nodeconstants
 from . import (
     branchmap,
     changelog,
@@ -198,6 +199,8 @@ class statichttprepository(
             requirements, supportedrequirements
         )
         localrepo.ensurerequirementscompatible(ui, requirements)
+        self.nodeconstants = sha1nodeconstants
+        self.nullid = self.nodeconstants.nullid
 
         # setup store
         self.store = localrepo.makestore(requirements, self.path, vfsclass)
@@ -207,7 +210,7 @@ class statichttprepository(
         self._filecache = {}
         self.requirements = requirements
 
-        rootmanifest = manifest.manifestrevlog(self.svfs)
+        rootmanifest = manifest.manifestrevlog(self.nodeconstants, self.svfs)
         self.manifestlog = manifest.manifestlog(
             self.svfs, self, rootmanifest, self.narrowmatch()
         )
diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -441,7 +441,7 @@ class basicstore(object):
         )
 
     def manifestlog(self, repo, storenarrowmatch):
-        rootstore = manifest.manifestrevlog(self.vfs)
+        rootstore = manifest.manifestrevlog(repo.nodeconstants, self.vfs)
         return manifest.manifestlog(self.vfs, repo, rootstore, storenarrowmatch)
 
     def datafiles(self, matcher=None):
diff --git a/mercurial/unionrepo.py b/mercurial/unionrepo.py
--- a/mercurial/unionrepo.py
+++ b/mercurial/unionrepo.py
@@ -153,9 +153,9 @@ class unionchangelog(unionrevlog, change
 
 
 class unionmanifest(unionrevlog, manifest.manifestrevlog):
-    def __init__(self, opener, opener2, linkmapper):
-        manifest.manifestrevlog.__init__(self, opener)
-        manifest2 = manifest.manifestrevlog(opener2)
+    def __init__(self, nodeconstants, opener, opener2, linkmapper):
+        manifest.manifestrevlog.__init__(self, nodeconstants, opener)
+        manifest2 = manifest.manifestrevlog(nodeconstants, opener2)
         unionrevlog.__init__(
             self, opener, self.indexfile, manifest2, linkmapper
         )
@@ -205,7 +205,10 @@ class unionrepository(object):
     @localrepo.unfilteredpropertycache
     def manifestlog(self):
         rootstore = unionmanifest(
-            self.svfs, self.repo2.svfs, self.unfiltered()._clrev
+            self.nodeconstants,
+            self.svfs,
+            self.repo2.svfs,
+            self.unfiltered()._clrev,
         )
         return manifest.manifestlog(
             self.svfs, self, rootstore, self.narrowmatch()
diff --git a/mercurial/upgrade_utils/engine.py b/mercurial/upgrade_utils/engine.py
--- a/mercurial/upgrade_utils/engine.py
+++ b/mercurial/upgrade_utils/engine.py
@@ -36,7 +36,9 @@ def _revlogfrompath(repo, path):
         return changelog.changelog(repo.svfs)
     elif path.endswith(b'00manifest.i'):
         mandir = path[: -len(b'00manifest.i')]
-        return manifest.manifestrevlog(repo.svfs, tree=mandir)
+        return manifest.manifestrevlog(
+            repo.nodeconstants, repo.svfs, tree=mandir
+        )
     else:
         # reverse of "/".join(("data", path + ".i"))
         return filelog.filelog(repo.svfs, path[5:-2])
diff --git a/relnotes/next b/relnotes/next
--- a/relnotes/next
+++ b/relnotes/next
@@ -43,3 +43,7 @@
    now get a revision number as argument instead of a node.
 
  * revlog.addrevision returns the revision number instead of the node.
+
+ * `nodes.nullid` and related constants are being phased out as part of
+   the deprecation of SHA1. Repository instances and related classes
+   provide access via `nodeconstants` and in some cases `nullid` attributes.
diff --git a/tests/simplestorerepo.py b/tests/simplestorerepo.py
--- a/tests/simplestorerepo.py
+++ b/tests/simplestorerepo.py
@@ -106,7 +106,9 @@ class filestorage(object):
 
     _flagserrorclass = simplestoreerror
 
-    def __init__(self, svfs, path):
+    def __init__(self, repo, svfs, path):
+        self.nullid = repo.nullid
+        self._repo = repo
         self._svfs = svfs
         self._path = path
 
@@ -689,7 +691,7 @@ def reposetup(ui, repo):
 
     class simplestorerepo(repo.__class__):
         def file(self, f):
-            return filestorage(self.svfs, f)
+            return filestorage(repo, self.svfs, f)
 
     repo.__class__ = simplestorerepo
 
diff --git a/tests/test-check-interfaces.py b/tests/test-check-interfaces.py
--- a/tests/test-check-interfaces.py
+++ b/tests/test-check-interfaces.py
@@ -248,7 +248,10 @@ def main():
 
     # Conforms to imanifestlog.
     ml = manifest.manifestlog(
-        vfs, repo, manifest.manifestrevlog(repo.svfs), repo.narrowmatch()
+        vfs,
+        repo,
+        manifest.manifestrevlog(repo.nodeconstants, repo.svfs),
+        repo.narrowmatch(),
     )
     checkzobject(ml)
     checkzobject(repo.manifestlog)
@@ -263,7 +266,7 @@ def main():
     # Conforms to imanifestdict.
     checkzobject(mctx.read())
 
-    mrl = manifest.manifestrevlog(vfs)
+    mrl = manifest.manifestrevlog(repo.nodeconstants, vfs)
     checkzobject(mrl)
 
     ziverify.verifyClass(repository.irevisiondelta, revlog.revlogrevisiondelta)
diff --git a/tests/test-manifest.py b/tests/test-manifest.py
--- a/tests/test-manifest.py
+++ b/tests/test-manifest.py
@@ -6,6 +6,8 @@ import silenttestrunner
 import unittest
 import zlib
 
+from mercurial.node import sha1nodeconstants
+
 from mercurial import (
     manifest as manifestmod,
     match as matchmod,
@@ -436,7 +438,7 @@ class testmanifestdict(unittest.TestCase
 
 class testtreemanifest(unittest.TestCase, basemanifesttests):
     def parsemanifest(self, text):
-        return manifestmod.treemanifest(b'', text)
+        return manifestmod.treemanifest(sha1nodeconstants, b'', text)
 
     def testWalkSubtrees(self):
         m = self.parsemanifest(A_DEEPER_MANIFEST)