--- a/mercurial/streamclone.py	Mon Jan 13 00:29:11 2025 -0500
+++ b/mercurial/streamclone.py	Mon Jan 13 00:36:25 2025 -0500
@@ -12,7 +12,7 @@
 import os
 import struct
 
-from typing import Iterator, Optional
+from typing import Iterable, Iterator, Optional, Set
 
 from .i18n import _
 from .interfaces import repository
@@ -35,7 +35,10 @@
 )
 
 
-def new_stream_clone_requirements(default_requirements, streamed_requirements):
+def new_stream_clone_requirements(
+    default_requirements: Iterable[bytes],
+    streamed_requirements: Iterable[bytes],
+) -> Set[bytes]:
     """determine the final set of requirement for a new stream clone
 
     this method combine the "default" requirements that a new repository would
@@ -48,7 +51,7 @@
     return requirements
 
 
-def streamed_requirements(repo):
+def streamed_requirements(repo) -> Set[bytes]:
     """the set of requirement the new clone will have to support
 
     This is used for advertising the stream options and to generate the actual
@@ -59,7 +62,7 @@
     return requiredformats
 
 
-def canperformstreamclone(pullop, bundle2=False):
+def canperformstreamclone(pullop, bundle2: bool = False):
     """Whether it is possible to perform a streaming clone as part of pull.
 
     ``bundle2`` will cause the function to consider stream clone through
@@ -153,7 +156,7 @@
     return True, requirements
 
 
-def maybeperformlegacystreamclone(pullop):
+def maybeperformlegacystreamclone(pullop) -> None:
     """Possibly perform a legacy stream clone operation.
 
     Legacy stream clones are performed as part of pull but before all other
@@ -228,7 +231,7 @@
         repo.invalidate()
 
 
-def allowservergeneration(repo):
+def allowservergeneration(repo) -> bool:
     """Whether streaming clones are allowed from the server."""
     if repository.REPO_FEATURE_STREAM_CLONE not in repo.features:
         return False
@@ -246,11 +249,13 @@
 
 
 # This is it's own function so extensions can override it.
-def _walkstreamfiles(repo, matcher=None, phase=False, obsolescence=False):
+def _walkstreamfiles(
+    repo, matcher=None, phase: bool = False, obsolescence: bool = False
+):
     return repo.store.walk(matcher, phase=phase, obsolescence=obsolescence)
 
 
-def generatev1(repo):
+def generatev1(repo) -> tuple[int, int, Iterator[bytes]]:
     """Emit content for version 1 of a streaming clone.
 
     This returns a 3-tuple of (file count, byte size, data iterator).
@@ -291,7 +296,7 @@
     svfs = repo.svfs
     debugflag = repo.ui.debugflag
 
-    def emitrevlogdata():
+    def emitrevlogdata() -> Iterator[bytes]:
         for name, size in entries:
             if debugflag:
                 repo.ui.debug(b'sending %s (%d bytes)\n' % (name, size))
@@ -335,7 +340,9 @@
     yield from it
 
 
-def generatebundlev1(repo, compression=b'UN'):
+def generatebundlev1(
+    repo, compression: bytes = b'UN'
+) -> tuple[Set[bytes], Iterator[bytes]]:
     """Emit content for version 1 of a stream clone bundle.
 
     The first 4 bytes of the output ("HGS1") denote this as stream clone
@@ -363,7 +370,7 @@
     requirements = streamed_requirements(repo)
     requires = b','.join(sorted(requirements))
 
-    def gen():
+    def gen() -> Iterator[bytes]:
         yield b'HGS1'
         yield compression
 
@@ -393,7 +400,7 @@
     return requirements, gen()
 
 
-def consumev1(repo, fp, filecount, bytecount):
+def consumev1(repo, fp, filecount: int, bytecount: int) -> None:
     """Apply the contents from version 1 of a streaming clone file handle.
 
     This takes the output from "stream_out" and applies it to the specified
@@ -477,7 +484,7 @@
         )
 
 
-def readbundle1header(fp):
+def readbundle1header(fp) -> tuple[int, int, Set[bytes]]:
     compression = fp.read(2)
     if compression != b'UN':
         raise error.Abort(
@@ -505,7 +512,7 @@
     return filecount, bytecount, requirements
 
 
-def applybundlev1(repo, fp):
+def applybundlev1(repo, fp) -> None:
     """Apply the content from a stream clone bundle version 1.
 
     We assume the 4 byte header has been read and validated and the file handle
@@ -535,10 +542,10 @@
     readers to perform bundle type-specific functionality.
     """
 
-    def __init__(self, fh):
+    def __init__(self, fh) -> None:
         self._fh = fh
 
-    def apply(self, repo):
+    def apply(self, repo) -> None:
         return applybundlev1(repo, self._fh)
 
 
@@ -552,7 +559,7 @@
 
 
 # This is it's own function so extensions can override it.
-def _walkstreamfullstorefiles(repo):
+def _walkstreamfullstorefiles(repo) -> list[bytes]:
     """list snapshot file from the store"""
     fnames = []
     if not repo.publishing():
@@ -589,7 +596,7 @@
     # for flushing to disk in __call__().
     MAX_OPEN = 2 if pycompat.iswindows else 100
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._counter = 0
         self._volatile_fps = None
         self._copies = None
@@ -619,7 +626,7 @@
             assert self._copies is None
             assert self._dst_dir is None
 
-    def _init_tmp_copies(self):
+    def _init_tmp_copies(self) -> None:
         """prepare a temporary directory to save volatile files
 
         This will be used as backup if we have too many files open"""
@@ -629,7 +636,7 @@
         self._copies = {}
         self._dst_dir = pycompat.mkdtemp(prefix=b'hg-clone-')
 
-    def _flush_some_on_disk(self):
+    def _flush_some_on_disk(self) -> None:
         """move some of the open files to tempory files on disk"""
         if self._copies is None:
             self._init_tmp_copies()
@@ -648,7 +655,7 @@
             del self._volatile_fps[src]
             fp.close()
 
-    def _keep_one(self, src):
+    def _keep_one(self, src: bytes) -> int:
         """preserve an open file handle for a given path"""
         # store the file quickly to ensure we close it if any error happens
         _, fp = self._volatile_fps[src] = (None, open(src, 'rb'))
@@ -657,14 +664,14 @@
         self._volatile_fps[src] = (size, fp)
         return size
 
-    def __call__(self, src):
+    def __call__(self, src: bytes) -> None:
         """preserve the volatile file at src"""
         assert 0 < self._counter
         if len(self._volatile_fps) >= (self.MAX_OPEN - 1):
             self._flush_some_on_disk()
         self._keep_one(src)
 
-    def try_keep(self, src) -> Optional[int]:
+    def try_keep(self, src: bytes) -> Optional[int]:
         """record a volatile file and returns it size
 
         return None if the file does not exists.
@@ -778,7 +785,7 @@
                         raise error.Abort(msg % (bytecount, name, size))
 
 
-def _emit3(repo, entries):
+def _emit3(repo, entries) -> Iterator[bytes | None]:
     """actually emit the stream bundle (v3)"""
     vfsmap = _makemap(repo)
     # we keep repo.vfs out of the map on purpose, ther are too many dangers
@@ -880,14 +887,14 @@
     BaseEntry base class, bbut the store one would be identical)
     """
 
-    def __init__(self, entry_path):
+    def __init__(self, entry_path) -> None:
         super().__init__(
             entry_path,
             # we will directly deal with that in `setup_cache_file`
             is_volatile=True,
         )
 
-    def preserve_volatiles(self, vfs, volatiles):
+    def preserve_volatiles(self, vfs, volatiles) -> None:
         self._file_size = volatiles.try_keep(vfs.join(self._entry_path))
         if self._file_size is None:
             self._files = []
@@ -901,7 +908,7 @@
                 )
             ]
 
-    def files(self):
+    def files(self) -> list[store.StoreFile]:
         if self._files is None:
             self._files = [
                 CacheFile(
@@ -915,10 +922,10 @@
 class CacheFile(store.StoreFile):
     # inform the "copy/hardlink" version that this file might be missing
     # without consequences.
-    optional = True
+    optional: bool = True
 
 
-def _entries_walk(repo, includes, excludes, includeobsmarkers):
+def _entries_walk(repo, includes, excludes, includeobsmarkers: bool):
     """emit a seris of files information useful to clone a repo
 
     return (vfs-key, entry) iterator
@@ -950,7 +957,7 @@
                 yield (_srccache, CacheEntry(entry_path=name))
 
 
-def generatev2(repo, includes, excludes, includeobsmarkers):
+def generatev2(repo, includes, excludes, includeobsmarkers: bool):
     """Emit content for version 2 of a streaming clone.
 
     the data stream consists the following entries:
@@ -981,7 +988,9 @@
     return file_count, total_file_size, chunks
 
 
-def generatev3(repo, includes, excludes, includeobsmarkers):
+def generatev3(
+    repo, includes, excludes, includeobsmarkers: bool
+) -> Iterator[bytes | None]:
     """Emit content for version 3 of a streaming clone.
 
     the data stream consists the following:
@@ -1039,7 +1048,7 @@
             yield
 
 
-def consumev2(repo, fp, filecount, filesize):
+def consumev2(repo, fp, filecount: int, filesize: int) -> None:
     """Apply the contents from a version 2 streaming clone.
 
     Data is read from an object that only needs to provide a ``read(size)``
@@ -1108,7 +1117,7 @@
         progress.complete()
 
 
-def consumev3(repo, fp):
+def consumev3(repo, fp) -> None:
     """Apply the contents from a version 3 streaming clone.
 
     Data is read from an object that only needs to provide a ``read(size)``
@@ -1181,7 +1190,9 @@
         progress.complete()
 
 
-def applybundlev2(repo, fp, filecount, filesize, requirements):
+def applybundlev2(
+    repo, fp, filecount: int, filesize: int, requirements: Iterable[bytes]
+) -> None:
     from . import localrepo
 
     missingreqs = [r for r in requirements if r not in repo.supported]
@@ -1204,7 +1215,7 @@
     nodemap.post_stream_cleanup(repo)
 
 
-def applybundlev3(repo, fp, requirements):
+def applybundlev3(repo, fp, requirements: Iterable[bytes]) -> None:
     from . import localrepo
 
     missingreqs = [r for r in requirements if r not in repo.supported]
@@ -1226,7 +1237,7 @@
     nodemap.post_stream_cleanup(repo)
 
 
-def _copy_files(src_vfs_map, dst_vfs_map, entries, progress):
+def _copy_files(src_vfs_map, dst_vfs_map, entries, progress) -> bool:
     hardlink = [True]
 
     def copy_used():
@@ -1260,7 +1271,7 @@
     return hardlink[0]
 
 
-def local_copy(src_repo, dest_repo):
+def local_copy(src_repo, dest_repo) -> None:
     """copy all content from one local repository to another
 
     This is useful for local clone"""