diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -12,7 +12,17 @@ import struct
 import weakref
 
 from typing import (
+    ByteString,
+    Callable,
+    Dict,
     Iterable,
+    Iterator,
+    List,
+    Optional,
+    Set,
+    Tuple,
+    Union,
+    cast,
 )
 
 from .i18n import _
@@ -47,7 +57,7 @@ propertycache = util.propertycache
 FASTDELTA_TEXTDIFF_THRESHOLD = 1000
 
 
-def _parse(nodelen, data):
+def _parse(nodelen, data: bytes):
     # This method does a little bit of excessive-looking
     # precondition checking. This is so that the behavior of this
     # class exactly matches its C counterpart to try and help
@@ -88,21 +98,23 @@ def _text(it):
 
 
 class lazymanifestiter:
-    def __init__(self, lm):
+    def __init__(self, lm: '_LazyManifest') -> None:
         self.pos = 0
         self.lm = lm
 
-    def __iter__(self):
+    def __iter__(self) -> 'lazymanifestiter':
         return self
 
-    def next(self):
+    def next(self) -> bytes:
         try:
             data, pos = self.lm._get(self.pos)
         except IndexError:
             raise StopIteration
         if pos == -1:
+            assert isinstance(data, tuple)
             self.pos += 1
             return data[0]
+        assert isinstance(data, bytes)
         self.pos += 1
         zeropos = data.find(b'\x00', pos)
         return data[pos:zeropos]
@@ -111,21 +123,23 @@ class lazymanifestiter:
 
 
 class lazymanifestiterentries:
-    def __init__(self, lm):
+    def __init__(self, lm: '_LazyManifest') -> None:
         self.lm = lm
         self.pos = 0
 
-    def __iter__(self):
+    def __iter__(self) -> 'lazymanifestiterentries':
         return self
 
-    def next(self):
+    def next(self) -> Tuple[bytes, bytes, bytes]:
         try:
             data, pos = self.lm._get(self.pos)
         except IndexError:
             raise StopIteration
         if pos == -1:
+            assert isinstance(data, tuple)
             self.pos += 1
             return data
+        assert isinstance(data, bytes)
         zeropos = data.find(b'\x00', pos)
         nlpos = data.find(b'\n', pos)
         if zeropos == -1 or nlpos == -1 or nlpos < zeropos:
@@ -181,12 +195,12 @@ class _LazyManifest:
 
     def __init__(
         self,
-        nodelen,
-        data,
+        nodelen: int,
+        data: bytes,
         positions=None,
         extrainfo=None,
         extradata=None,
-        hasremovals=False,
+        hasremovals: bool = False,
     ):
         self._nodelen = nodelen
         if positions is None:
@@ -202,7 +216,7 @@ class _LazyManifest:
             self.data = data
             self.hasremovals = hasremovals
 
-    def findlines(self, data):
+    def findlines(self, data: bytes) -> List[int]:
         if not data:
             return []
         pos = data.find(b"\n")
@@ -219,7 +233,9 @@ class _LazyManifest:
             pos = data.find(b"\n", pos + 1)
         return positions
 
-    def _get(self, index):
+    def _get(
+        self, index: int
+    ) -> Tuple[Union[bytes, Tuple[bytes, bytes, bytes]], int]:
         # get the position encoded in pos:
         #   positive number is an index in 'data'
         #   negative number is in extrapieces
@@ -228,12 +244,12 @@ class _LazyManifest:
             return self.data, pos
         return self.extradata[-pos - 1], -1
 
-    def _getkey(self, pos):
+    def _getkey(self, pos) -> bytes:
         if pos >= 0:
             return self.data[pos : self.data.find(b'\x00', pos + 1)]
         return self.extradata[-pos - 1][0]
 
-    def bsearch(self, key):
+    def bsearch(self, key: bytes) -> int:
         first = 0
         last = len(self.positions) - 1
 
@@ -251,7 +267,7 @@ class _LazyManifest:
                     first = midpoint + 1
         return -1
 
-    def bsearch2(self, key):
+    def bsearch2(self, key: bytes) -> Tuple[int, bool]:
         # same as the above, but will always return the position
         # done for performance reasons
         first = 0
@@ -271,10 +287,10 @@ class _LazyManifest:
                     first = midpoint + 1
         return (first, False)
 
-    def __contains__(self, key):
+    def __contains__(self, key: bytes) -> bool:
         return self.bsearch(key) != -1
 
-    def __getitem__(self, key):
+    def __getitem__(self, key: bytes) -> Tuple[bytes, bytes]:
         if not isinstance(key, bytes):
             raise TypeError(b"getitem: manifest keys must be a bytes.")
         needle = self.bsearch(key)
@@ -282,7 +298,10 @@ class _LazyManifest:
             raise KeyError
         data, pos = self._get(needle)
         if pos == -1:
+            assert isinstance(data, tuple)
             return (data[1], data[2])
+
+        assert isinstance(data, bytes)
         zeropos = data.find(b'\x00', pos)
         nlpos = data.find(b'\n', zeropos)
         assert 0 <= needle <= len(self.positions)
@@ -300,7 +319,7 @@ class _LazyManifest:
         hashval = unhexlify(data, self.extrainfo[needle], zeropos + 1, hlen)
         return (hashval, flags)
 
-    def __delitem__(self, key):
+    def __delitem__(self, key: bytes) -> None:
         needle, found = self.bsearch2(key)
         if not found:
             raise KeyError
@@ -313,7 +332,7 @@ class _LazyManifest:
             self.data = self.data[:cur] + b'\x00' + self.data[cur + 1 :]
             self.hasremovals = True
 
-    def __setitem__(self, key, value):
+    def __setitem__(self, key: bytes, value: Tuple[bytes, bytes]):
         if not isinstance(key, bytes):
             raise TypeError(b"setitem: manifest keys must be a byte string.")
         if not isinstance(value, tuple) or len(value) != 2:
@@ -348,7 +367,7 @@ class _LazyManifest:
                 self.extrainfo[:needle] + [0] + self.extrainfo[needle:]
             )
 
-    def copy(self):
+    def copy(self) -> '_LazyManifest':
         # XXX call _compact like in C?
         return _lazymanifest(
             self._nodelen,
@@ -359,7 +378,7 @@ class _LazyManifest:
             self.hasremovals,
         )
 
-    def _compact(self):
+    def _compact(self) -> None:
         # hopefully not called TOO often
         if len(self.extradata) == 0 and not self.hasremovals:
             return
@@ -418,16 +437,23 @@ class _LazyManifest:
         self.hasremovals = False
         self.extradata = []
 
-    def _pack(self, d):
+    def _pack(self, d: Tuple[bytes, bytes, bytes]) -> bytes:
         n = d[1]
         assert len(n) in (20, 32)
         return d[0] + b'\x00' + hex(n) + d[2] + b'\n'
 
-    def text(self):
+    def text(self) -> ByteString:
         self._compact()
         return self.data
 
-    def diff(self, m2, clean=False):
+    def diff(
+        self, m2: '_LazyManifest', clean: bool = False
+    ) -> Dict[
+        bytes,
+        Optional[
+            Tuple[Tuple[Optional[bytes], bytes], Tuple[Optional[bytes], bytes]]
+        ],
+    ]:
         '''Finds changes between the current manifest and m2.'''
         # XXX think whether efficiency matters here
         diff = {}
@@ -448,19 +474,19 @@ class _LazyManifest:
 
         return diff
 
-    def iterentries(self):
+    def iterentries(self) -> lazymanifestiterentries:
         return lazymanifestiterentries(self)
 
-    def iterkeys(self):
+    def iterkeys(self) -> lazymanifestiter:
         return lazymanifestiter(self)
 
-    def __iter__(self):
+    def __iter__(self) -> lazymanifestiter:
         return lazymanifestiter(self)
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self.positions)
 
-    def filtercopy(self, filterfn):
+    def filtercopy(self, filterfn: Callable[[bytes], bool]) -> '_LazyManifest':
         # XXX should be optimized
         c = _lazymanifest(self._nodelen, b'')
         for f, n, fl in self.iterentries():
@@ -476,50 +502,50 @@ except AttributeError:
 
 
 class ManifestDict:
-    def __init__(self, nodelen, data=b''):
+    def __init__(self, nodelen: int, data: ByteString = b''):
         self._nodelen = nodelen
         self._lm = _lazymanifest(nodelen, data)
 
-    def __getitem__(self, key):
+    def __getitem__(self, key: bytes) -> bytes:
         return self._lm[key][0]
 
-    def find(self, key):
+    def find(self, key: bytes) -> Tuple[bytes, bytes]:
         return self._lm[key]
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self._lm)
 
-    def __nonzero__(self):
+    def __nonzero__(self) -> bool:
         # nonzero is covered by the __len__ function, but implementing it here
         # makes it easier for extensions to override.
         return len(self._lm) != 0
 
     __bool__ = __nonzero__
 
-    def set(self, key, node, flags):
+    def set(self, key: bytes, node: bytes, flags: bytes) -> None:
         self._lm[key] = node, flags
 
-    def __setitem__(self, key, node):
+    def __setitem__(self, key: bytes, node: bytes) -> None:
         self._lm[key] = node, self.flags(key)
 
-    def __contains__(self, key):
+    def __contains__(self, key: bytes) -> bool:
         if key is None:
             return False
         return key in self._lm
 
-    def __delitem__(self, key):
+    def __delitem__(self, key: bytes) -> bool:
         del self._lm[key]
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[bytes]:
         return self._lm.__iter__()
 
-    def iterkeys(self):
+    def iterkeys(self) -> Iterator[bytes]:
         return self._lm.iterkeys()
 
-    def keys(self):
+    def keys(self) -> List[bytes]:
         return list(self.iterkeys())
 
-    def filesnotin(self, m2, match=None):
+    def filesnotin(self, m2, match=None) -> Set[bytes]:
         '''Set of files in this manifest that are not in the other'''
         if match is not None:
             match = matchmod.badmatch(match, lambda path, msg: None)
@@ -528,16 +554,16 @@ class ManifestDict:
         return {f for f in self if f not in m2}
 
     @propertycache
-    def _dirs(self):
+    def _dirs(self) -> pathutil.dirs:
         return pathutil.dirs(self)
 
-    def dirs(self):
+    def dirs(self) -> pathutil.dirs:
         return self._dirs
 
-    def hasdir(self, dir):
+    def hasdir(self, dir: bytes) -> bool:
         return dir in self._dirs
 
-    def _filesfastpath(self, match):
+    def _filesfastpath(self, match: matchmod.basematcher) -> bool:
         """Checks whether we can correctly and quickly iterate over matcher
         files instead of over manifest files."""
         files = match.files()
@@ -546,7 +572,7 @@ class ManifestDict:
             or (match.prefix() and all(fn in self for fn in files))
         )
 
-    def walk(self, match):
+    def walk(self, match: matchmod.basematcher) -> Iterator[bytes]:
         """Generates matching file names.
 
         Equivalent to manifest.matches(match).iterkeys(), but without creating
@@ -583,7 +609,7 @@ class ManifestDict:
             if not self.hasdir(fn):
                 match.bad(fn, None)
 
-    def _matches(self, match):
+    def _matches(self, match: matchmod.basematcher) -> 'ManifestDict':
         '''generate a new manifest filtered by the match argument'''
         if match.always():
             return self.copy()
@@ -600,7 +626,17 @@ class ManifestDict:
         m._lm = self._lm.filtercopy(match)
         return m
 
-    def diff(self, m2, match=None, clean=False):
+    def diff(
+        self,
+        m2: 'ManifestDict',
+        match: Optional[matchmod.basematcher] = None,
+        clean: bool = False,
+    ) -> Dict[
+        bytes,
+        Optional[
+            Tuple[Tuple[Optional[bytes], bytes], Tuple[Optional[bytes], bytes]]
+        ],
+    ]:
         """Finds changes between the current manifest and m2.
 
         Args:
@@ -621,42 +657,44 @@ class ManifestDict:
             return m1.diff(m2, clean=clean)
         return self._lm.diff(m2._lm, clean)
 
-    def setflag(self, key, flag):
+    def setflag(self, key: bytes, flag: bytes) -> None:
         if flag not in _manifestflags:
             raise TypeError(b"Invalid manifest flag set.")
         self._lm[key] = self[key], flag
 
-    def get(self, key, default=None):
+    def get(self, key: bytes, default=None) -> Optional[bytes]:
         try:
             return self._lm[key][0]
         except KeyError:
             return default
 
-    def flags(self, key):
+    def flags(self, key: bytes) -> bytes:
         try:
             return self._lm[key][1]
         except KeyError:
             return b''
 
-    def copy(self):
+    def copy(self) -> 'ManifestDict':
         c = manifestdict(self._nodelen)
         c._lm = self._lm.copy()
         return c
 
-    def items(self):
+    def items(self) -> Iterator[Tuple[bytes, bytes]]:
         return (x[:2] for x in self._lm.iterentries())
 
-    def iteritems(self):
+    def iteritems(self) -> Iterator[Tuple[bytes, bytes]]:
         return (x[:2] for x in self._lm.iterentries())
 
-    def iterentries(self):
+    def iterentries(self) -> Iterator[Tuple[bytes, bytes, bytes]]:
         return self._lm.iterentries()
 
-    def text(self):
+    def text(self) -> ByteString:
         # most likely uses native version
         return self._lm.text()
 
-    def fastdelta(self, base, changes):
+    def fastdelta(
+        self, base: ByteString, changes: Iterable[Tuple[bytes, bool]]
+    ) -> Tuple[ByteString, ByteString]:
         """Given a base manifest text as a bytearray and a list of changes
         relative to that text, compute a delta that can be used by revlog.
         """
@@ -715,17 +753,17 @@ class ManifestDict:
 manifestdict = interfaceutil.implementer(repository.imanifestdict)(ManifestDict)
 
 
-def _msearch(m, s, lo=0, hi=None):
+def _msearch(
+    m: ByteString, s: bytes, lo: int = 0, hi: Optional[int] = None
+) -> Tuple[int, int]:
     """return a tuple (start, end) that says where to find s within m.
 
     If the string is found m[start:end] are the line containing
     that string.  If start == end the string was not found and
     they indicate the proper sorted insertion point.
-
-    m should be a buffer, a memoryview or a byte string.
-    s is a byte string"""
-
-    def advance(i, c):
+    """
+
+    def advance(i: int, c: bytes):
         while i < lenm and m[i : i + 1] != c:
             i += 1
         return i
@@ -758,7 +796,7 @@ def _msearch(m, s, lo=0, hi=None):
         return (lo, lo)
 
 
-def _checkforbidden(l):
+def _checkforbidden(l: Iterable[bytes]) -> None:
     """Check filenames for illegal characters."""
     for f in l:
         if b'\n' in f or b'\r' in f:
@@ -770,7 +808,10 @@ def _checkforbidden(l):
 
 # apply the changes collected during the bisect loop to our addlist
 # return a delta suitable for addrevision
-def _addlistdelta(addlist, x):
+def _addlistdelta(
+    addlist: ByteString,
+    x: Iterable[Tuple[int, int, bytes]],
+) -> Tuple[bytes, ByteString]:
     # for large addlist arrays, building a new array is cheaper
     # than repeatedly modifying the existing one
     currentposition = 0
@@ -792,7 +833,7 @@ def _addlistdelta(addlist, x):
     return deltatext, newaddlist
 
 
-def _splittopdir(f):
+def _splittopdir(f: bytes) -> Tuple[bytes, bytes]:
     if b'/' in f:
         dir, subpath = f.split(b'/', 1)
         return dir + b'/', subpath
@@ -804,7 +845,7 @@ def _splittopdir(f):
 
 
 class TreeManifest:
-    def __init__(self, nodeconstants, dir=b'', text=b''):
+    def __init__(self, nodeconstants, dir: bytes = b'', text: bytes = b''):
         self._dir = dir
         self.nodeconstants = nodeconstants
         self._node = self.nodeconstants.nullid
@@ -812,10 +853,13 @@ class TreeManifest:
         self._loadfunc = _noop
         self._copyfunc = _noop
         self._dirty = False
-        self._dirs = {}
-        self._lazydirs = {}
+        self._dirs: Dict[bytes, 'TreeManifest'] = {}
+        self._lazydirs: Dict[
+            bytes,
+            Tuple[bytes, Callable[[bytes, bytes], 'TreeManifest'], bool],
+        ] = {}
         # Using _lazymanifest here is a little slower than plain old dicts
-        self._files = {}
+        self._files: Dict[bytes, bytes] = {}
         self._flags = {}
         if text:
 
@@ -827,10 +871,10 @@ class TreeManifest:
             self.parse(text, readsubtree)
             self._dirty = True  # Mark flat manifest dirty after parsing
 
-    def _subpath(self, path):
+    def _subpath(self, path: bytes) -> bytes:
         return self._dir + path
 
-    def _loadalllazy(self):
+    def _loadalllazy(self) -> None:
         selfdirs = self._dirs
         subpath = self._subpath
         for d, (node, readsubtree, docopy) in self._lazydirs.items():
@@ -840,7 +884,7 @@ class TreeManifest:
                 selfdirs[d] = readsubtree(subpath(d), node)
         self._lazydirs.clear()
 
-    def _loadlazy(self, d):
+    def _loadlazy(self, d: bytes) -> None:
         v = self._lazydirs.get(d)
         if v is not None:
             node, readsubtree, docopy = v
@@ -850,19 +894,23 @@ class TreeManifest:
                 self._dirs[d] = readsubtree(self._subpath(d), node)
             del self._lazydirs[d]
 
-    def _loadchildrensetlazy(self, visit):
+    def _loadchildrensetlazy(
+        self, visit: Union[Set[bytes], bytes]
+    ) -> Optional[Set[bytes]]:
         if not visit:
             return None
         if visit == b'all' or visit == b'this':
             self._loadalllazy()
             return None
 
+        visit = cast(Set[bytes], visit)
+
         loadlazy = self._loadlazy
         for k in visit:
             loadlazy(k + b'/')
         return visit
 
-    def _loaddifflazy(self, t1, t2):
+    def _loaddifflazy(self, t1: 'TreeManifest', t2: 'TreeManifest'):
         """load items in t1 and t2 if they're needed for diffing.
 
         The criteria currently is:
@@ -884,7 +932,7 @@ class TreeManifest:
             t1._loadlazy(d)
             t2._loadlazy(d)
 
-    def __len__(self):
+    def __len__(self) -> int:
         self._load()
         size = len(self._files)
         self._loadalllazy()
@@ -892,13 +940,13 @@ class TreeManifest:
             size += m.__len__()
         return size
 
-    def __nonzero__(self):
-        # Faster than "__len() != 0" since it avoids loading sub-manifests
+    def __nonzero__(self) -> bool:
+        # Faster than "__len__() != 0" since it avoids loading sub-manifests
         return not self._isempty()
 
     __bool__ = __nonzero__
 
-    def _isempty(self):
+    def _isempty(self) -> bool:
         self._load()  # for consistency; already loaded by all callers
         # See if we can skip loading everything.
         if self._files or (
@@ -909,7 +957,7 @@ class TreeManifest:
         return not self._dirs or all(m._isempty() for m in self._dirs.values())
 
     @encoding.strmethod
-    def __repr__(self):
+    def __repr__(self) -> bytes:
         return (
             b'<treemanifest dir=%s, node=%s, loaded=%r, dirty=%r at 0x%x>'
             % (
@@ -921,23 +969,25 @@ class TreeManifest:
             )
         )
 
-    def dir(self):
+    def dir(self) -> bytes:
         """The directory that this tree manifest represents, including a
         trailing '/'. Empty string for the repo root directory."""
         return self._dir
 
-    def node(self):
+    def node(self) -> bytes:
         """This node of this instance. nullid for unsaved instances. Should
         be updated when the instance is read or written from a revlog.
         """
         assert not self._dirty
         return self._node
 
-    def setnode(self, node):
+    def setnode(self, node: bytes) -> None:
         self._node = node
         self._dirty = False
 
-    def iterentries(self):
+    def iterentries(
+        self,
+    ) -> Iterator[Tuple[bytes, Union[bytes, 'TreeManifest'], bytes]]:
         self._load()
         self._loadalllazy()
         for p, n in sorted(
@@ -949,7 +999,7 @@ class TreeManifest:
                 for x in n.iterentries():
                     yield x
 
-    def items(self):
+    def items(self) -> Iterator[Tuple[bytes, Union[bytes, 'TreeManifest']]]:
         self._load()
         self._loadalllazy()
         for p, n in sorted(
@@ -963,7 +1013,7 @@ class TreeManifest:
 
     iteritems = items
 
-    def iterkeys(self):
+    def iterkeys(self) -> Iterator[bytes]:
         self._load()
         self._loadalllazy()
         for p in sorted(itertools.chain(self._dirs, self._files)):
@@ -973,13 +1023,13 @@ class TreeManifest:
                 for f in self._dirs[p]:
                     yield f
 
-    def keys(self):
+    def keys(self) -> List[bytes]:
         return list(self.iterkeys())
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[bytes]:
         return self.iterkeys()
 
-    def __contains__(self, f):
+    def __contains__(self, f: bytes) -> bool:
         if f is None:
             return False
         self._load()
@@ -994,7 +1044,7 @@ class TreeManifest:
         else:
             return f in self._files
 
-    def get(self, f, default=None):
+    def get(self, f: bytes, default: Optional[bytes] = None) -> Optional[bytes]:
         self._load()
         dir, subpath = _splittopdir(f)
         if dir:
@@ -1006,7 +1056,7 @@ class TreeManifest:
         else:
             return self._files.get(f, default)
 
-    def __getitem__(self, f):
+    def __getitem__(self, f: bytes) -> bytes:
         self._load()
         dir, subpath = _splittopdir(f)
         if dir:
@@ -1016,7 +1066,7 @@ class TreeManifest:
         else:
             return self._files[f]
 
-    def flags(self, f):
+    def flags(self, f: bytes) -> bytes:
         self._load()
         dir, subpath = _splittopdir(f)
         if dir:
@@ -1030,7 +1080,7 @@ class TreeManifest:
                 return b''
             return self._flags.get(f, b'')
 
-    def find(self, f):
+    def find(self, f: bytes) -> Tuple[bytes, bytes]:
         self._load()
         dir, subpath = _splittopdir(f)
         if dir:
@@ -1040,7 +1090,7 @@ class TreeManifest:
         else:
             return self._files[f], self._flags.get(f, b'')
 
-    def __delitem__(self, f):
+    def __delitem__(self, f: bytes) -> None:
         self._load()
         dir, subpath = _splittopdir(f)
         if dir:
@@ -1056,7 +1106,7 @@ class TreeManifest:
                 del self._flags[f]
         self._dirty = True
 
-    def set(self, f, node, flags):
+    def set(self, f: bytes, node: bytes, flags: bytes) -> None:
         """Set both the node and the flags for path f."""
         assert node is not None
         if flags not in _manifestflags:
@@ -1076,7 +1126,7 @@ class TreeManifest:
             self._flags[f] = flags
         self._dirty = True
 
-    def __setitem__(self, f, n):
+    def __setitem__(self, f: bytes, n: bytes) -> None:
         assert n is not None
         self._load()
         dir, subpath = _splittopdir(f)
@@ -1095,7 +1145,7 @@ class TreeManifest:
             self._files[f] = n
         self._dirty = True
 
-    def _load(self):
+    def _load(self) -> None:
         if self._loadfunc is not _noop:
             lf, self._loadfunc = self._loadfunc, _noop
             lf(self)
@@ -1103,7 +1153,7 @@ class TreeManifest:
             cf, self._copyfunc = self._copyfunc, _noop
             cf(self)
 
-    def setflag(self, f, flags):
+    def setflag(self, f: bytes, flags: bytes) -> None:
         """Set the flags (symlink, executable) for path f."""
         if flags not in _manifestflags:
             raise TypeError(b"Invalid manifest flag set.")
@@ -1120,7 +1170,7 @@ class TreeManifest:
             self._flags[f] = flags
         self._dirty = True
 
-    def copy(self):
+    def copy(self) -> 'TreeManifest':
         copy = treemanifest(self.nodeconstants, self._dir)
         copy._node = self._node
         copy._dirty = self._dirty
@@ -1145,7 +1195,9 @@ class TreeManifest:
             copy._copyfunc = self._copyfunc
         return copy
 
-    def filesnotin(self, m2, match=None):
+    def filesnotin(
+        self, m2: 'TreeManifest', match: Optional[matchmod.basematcher] = None
+    ) -> Set[bytes]:
         '''Set of files in this manifest that are not in the other'''
         if match and not match.always():
             m1 = self._matches(match)
@@ -1175,13 +1227,13 @@ class TreeManifest:
         return files
 
     @propertycache
-    def _alldirs(self):
+    def _alldirs(self) -> pathutil.dirs:
         return pathutil.dirs(self)
 
-    def dirs(self):
+    def dirs(self) -> pathutil.dirs:
         return self._alldirs
 
-    def hasdir(self, dir):
+    def hasdir(self, dir: bytes) -> bool:
         self._load()
         topdir, subdir = _splittopdir(dir)
         if topdir:
@@ -1192,7 +1244,7 @@ class TreeManifest:
         dirslash = dir + b'/'
         return dirslash in self._dirs or dirslash in self._lazydirs
 
-    def walk(self, match):
+    def walk(self, match: matchmod.basematcher) -> Iterator[bytes]:
         """Generates matching file names.
 
         It also reports nonexistent files by marking them bad with match.bad().
@@ -1218,7 +1270,7 @@ class TreeManifest:
             if not self.hasdir(fn):
                 match.bad(fn, None)
 
-    def _walk(self, match):
+    def _walk(self, match: matchmod.basematcher) -> Iterator[bytes]:
         '''Recursively generates matching file names for walk().'''
         visit = match.visitchildrenset(self._dir[:-1])
         if not visit:
@@ -1237,13 +1289,13 @@ class TreeManifest:
                     for f in self._dirs[p]._walk(match):
                         yield f
 
-    def _matches(self, match):
+    def _matches(self, match: matchmod.basematcher) -> 'TreeManifest':
         """recursively generate a new manifest filtered by the match argument."""
         if match.always():
             return self.copy()
         return self._matches_inner(match)
 
-    def _matches_inner(self, match):
+    def _matches_inner(self, match: matchmod.basematcher) -> 'TreeManifest':
         if match.always():
             return self.copy()
 
@@ -1284,10 +1336,22 @@ class TreeManifest:
             ret._dirty = True
         return ret
 
-    def fastdelta(self, base, changes):
+    def fastdelta(
+        self, base: ByteString, changes: Iterable[Tuple[bytes, bool]]
+    ) -> ByteString:
         raise FastdeltaUnavailable()
 
-    def diff(self, m2, match=None, clean=False):
+    def diff(
+        self,
+        m2: 'TreeManifest',
+        match: Optional[matchmod.basematcher] = None,
+        clean: bool = False,
+    ) -> Dict[
+        bytes,
+        Optional[
+            Tuple[Tuple[Optional[bytes], bytes], Tuple[Optional[bytes], bytes]]
+        ],
+    ]:
         """Finds changes between the current manifest and m2.
 
         Args:
@@ -1348,10 +1412,14 @@ class TreeManifest:
             _iterativediff(t1, t2, stackls)
         return result
 
-    def unmodifiedsince(self, m2):
+    def unmodifiedsince(self, m2: 'TreeManifest') -> bool:
         return not self._dirty and not m2._dirty and self._node == m2._node
 
-    def parse(self, text, readsubtree):
+    def parse(
+        self,
+        text: bytes,
+        readsubtree: Callable[[bytes, bytes], 'TreeManifest'],
+    ) -> None:
         selflazy = self._lazydirs
         for f, n, fl in _parse(self._nodelen, text):
             if fl == b't':
@@ -1374,12 +1442,12 @@ class TreeManifest:
                 if fl:
                     self._flags[f] = fl
 
-    def text(self):
+    def text(self) -> ByteString:
         """Get the full data of this manifest as a bytestring."""
         self._load()
         return _text(self.iterentries())
 
-    def dirtext(self):
+    def dirtext(self) -> ByteString:
         """Get the full data of this directory as a bytestring. Make sure that
         any submanifests have been written first, so their nodeids are correct.
         """
@@ -1390,14 +1458,32 @@ class TreeManifest:
         files = [(f, self._files[f], flags(f)) for f in self._files]
         return _text(sorted(dirs + files + lazydirs))
 
-    def read(self, gettext, readsubtree):
+    def read(
+        self,
+        gettext: Callable[[], ByteString],
+        readsubtree: Callable[[bytes, bytes], 'TreeManifest'],
+    ) -> None:
         def _load_for_read(s):
             s.parse(gettext(), readsubtree)
             s._dirty = False
 
         self._loadfunc = _load_for_read
 
-    def writesubtrees(self, m1, m2, writesubtree, match):
+    def writesubtrees(
+        self,
+        m1: 'TreeManifest',
+        m2: 'TreeManifest',
+        writesubtree: Callable[
+            [
+                Callable[['TreeManifest'], None],
+                bytes,
+                bytes,
+                matchmod.basematcher,
+            ],
+            None,
+        ],
+        match: matchmod.basematcher,
+    ) -> None:
         self._load()  # for consistency; should never have any effect here
         m1._load()
         m2._load()
@@ -1425,7 +1511,9 @@ class TreeManifest:
                 subp1, subp2 = subp2, subp1
             writesubtree(subm, subp1, subp2, match)
 
-    def walksubtrees(self, matcher=None):
+    def walksubtrees(
+        self, matcher: Optional[matchmod.basematcher] = None
+    ) -> Iterator['TreeManifest']:
         """Returns an iterator of the subtrees of this manifest, including this
         manifest itself.
 
@@ -1716,8 +1804,8 @@ class ManifestRevlog:
         link,
         p1,
         p2,
-        added: Iterable[Iterable],
-        removed: Iterable[Iterable],
+        added: Iterable[bytes],
+        removed: Iterable[bytes],
         readtree=None,
         match=None,
     ):
@@ -1959,6 +2047,10 @@ manifestrevlog = interfaceutil.implement
 )
 
 
+AnyManifestCtx = Union['ManifestCtx', 'TreeManifestCtx']
+AnyManifestDict = Union[ManifestDict, TreeManifest]
+
+
 @interfaceutil.implementer(repository.imanifestlog)
 class manifestlog:
     """A collection class representing the collection of manifest snapshots
@@ -1997,7 +2089,9 @@ class manifestlog:
         """
         return self.get(b'', node)
 
-    def get(self, tree, node, verify=True):
+    def get(
+        self, tree: bytes, node: bytes, verify: bool = True
+    ) -> AnyManifestCtx:
         """Retrieves the manifest instance for the given node. Throws a
         LookupError if not found.
 
@@ -2047,14 +2141,14 @@ class manifestlog:
     def getstorage(self, tree):
         return self._rootstore.dirlog(tree)
 
-    def clearcaches(self, clear_persisted_data=False):
+    def clearcaches(self, clear_persisted_data: bool = False) -> None:
         self._dirmancache.clear()
         self._rootstore.clearcaches(clear_persisted_data=clear_persisted_data)
 
-    def rev(self, node):
+    def rev(self, node) -> int:
         return self._rootstore.rev(node)
 
-    def update_caches(self, transaction):
+    def update_caches(self, transaction) -> None:
         return self._rootstore._revlog.update_caches(transaction=transaction)
 
 
@@ -2063,15 +2157,15 @@ class MemManifestCtx:
         self._manifestlog = manifestlog
         self._manifestdict = manifestdict(manifestlog.nodeconstants.nodelen)
 
-    def _storage(self):
+    def _storage(self) -> ManifestRevlog:
         return self._manifestlog.getstorage(b'')
 
-    def copy(self):
+    def copy(self) -> 'MemManifestCtx':
         memmf = memmanifestctx(self._manifestlog)
         memmf._manifestdict = self.read().copy()
         return memmf
 
-    def read(self):
+    def read(self) -> 'ManifestDict':
         return self._manifestdict
 
     def write(self, transaction, link, p1, p2, added, removed, match=None):
@@ -2110,22 +2204,22 @@ class ManifestCtx:
         # rev = store.rev(node)
         # self.linkrev = store.linkrev(rev)
 
-    def _storage(self):
+    def _storage(self) -> 'ManifestRevlog':
         return self._manifestlog.getstorage(b'')
 
-    def node(self):
+    def node(self) -> bytes:
         return self._node
 
-    def copy(self):
+    def copy(self) -> MemManifestCtx:
         memmf = memmanifestctx(self._manifestlog)
         memmf._manifestdict = self.read().copy()
         return memmf
 
     @propertycache
-    def parents(self):
+    def parents(self) -> Tuple[bytes, bytes]:
         return self._storage().parents(self._node)
 
-    def read(self):
+    def read(self) -> 'ManifestDict':
         if self._data is None:
             nc = self._manifestlog.nodeconstants
             if self._node == nc.nullid:
@@ -2141,7 +2235,7 @@ class ManifestCtx:
                 self._data = manifestdict(nc.nodelen, text)
         return self._data
 
-    def readfast(self, shallow=False):
+    def readfast(self, shallow: bool = False) -> 'ManifestDict':
         """Calls either readdelta or read, based on which would be less work.
         readdelta is called if the delta is against the p1, and therefore can be
         read quickly.
@@ -2155,7 +2249,7 @@ class ManifestCtx:
             return self.readdelta()
         return self.read()
 
-    def readdelta(self, shallow=False):
+    def readdelta(self, shallow: bool = False) -> 'ManifestDict':
         """Returns a manifest containing just the entries that are present
         in this manifest, but not in its p1 manifest. This is efficient to read
         if the revlog delta is already p1.
@@ -2167,7 +2261,7 @@ class ManifestCtx:
         d = mdiff.patchtext(store.revdiff(store.deltaparent(r), r))
         return manifestdict(store.nodeconstants.nodelen, d)
 
-    def find(self, key):
+    def find(self, key: bytes) -> Tuple[bytes, bytes]:
         return self.read().find(key)
 
 
@@ -2182,15 +2276,15 @@ class MemTreeManifestCtx:
         self._dir = dir
         self._treemanifest = treemanifest(manifestlog.nodeconstants)
 
-    def _storage(self):
+    def _storage(self) -> ManifestRevlog:
         return self._manifestlog.getstorage(b'')
 
-    def copy(self):
+    def copy(self) -> 'MemTreeManifestCtx':
         memmf = memtreemanifestctx(self._manifestlog, dir=self._dir)
         memmf._treemanifest = self._treemanifest.copy()
         return memmf
 
-    def read(self):
+    def read(self) -> 'TreeManifest':
         return self._treemanifest
 
     def write(self, transaction, link, p1, p2, added, removed, match=None):
@@ -2230,7 +2324,7 @@ class TreeManifestCtx:
         # rev = store.rev(node)
         # self.linkrev = store.linkrev(rev)
 
-    def _storage(self):
+    def _storage(self) -> ManifestRevlog:
         narrowmatch = self._manifestlog._narrowmatch
         if not narrowmatch.always():
             if not narrowmatch.visitdir(self._dir[:-1]):
@@ -2239,7 +2333,7 @@ class TreeManifestCtx:
                 )
         return self._manifestlog.getstorage(self._dir)
 
-    def read(self):
+    def read(self) -> 'TreeManifest':
         if self._data is None:
             store = self._storage()
             if self._node == self._manifestlog.nodeconstants.nullid:
@@ -2272,19 +2366,19 @@ class TreeManifestCtx:
 
         return self._data
 
-    def node(self):
+    def node(self) -> bytes:
         return self._node
 
-    def copy(self):
+    def copy(self) -> 'MemTreeManifestCtx':
         memmf = memtreemanifestctx(self._manifestlog, dir=self._dir)
         memmf._treemanifest = self.read().copy()
         return memmf
 
     @propertycache
-    def parents(self):
+    def parents(self) -> Tuple[bytes, bytes]:
         return self._storage().parents(self._node)
 
-    def readdelta(self, shallow=False):
+    def readdelta(self, shallow: bool = False) -> AnyManifestDict:
         """Returns a manifest containing just the entries that are present
         in this manifest, but not in its p1 manifest. This is efficient to read
         if the revlog delta is already p1.
@@ -2313,7 +2407,7 @@ class TreeManifestCtx:
                         md.setflag(f, fl1)
             return md
 
-    def readfast(self, shallow=False):
+    def readfast(self, shallow=False) -> AnyManifestDict:
         """Calls either readdelta or read, based on which would be less work.
         readdelta is called if the delta is against the p1, and therefore can be
         read quickly.
@@ -2334,7 +2428,7 @@ class TreeManifestCtx:
         else:
             return self.read()
 
-    def find(self, key):
+    def find(self, key: bytes) -> Tuple[bytes, bytes]:
         return self.read().find(key)