requirements: also add a generaldelta constant

Continue the cleanup to the remaining requirements

Differential Revision: https://phab.mercurial-scm.org/D10106

mercurial/bundlecaches.py

@@ -1,424 +1,425 b''
 # bundlecaches.py - utility to deal with pre-computed bundle for servers
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from .i18n import _
 
 from .thirdparty import attr
 
 from . import (
     error,
+    requirements as requirementsmod,
     sslutil,
     util,
 )
 from .utils import stringutil
 
 urlreq = util.urlreq
 
 CB_MANIFEST_FILE = b'clonebundles.manifest'
 
 
 @attr.s
 class bundlespec(object):
     compression = attr.ib()
     wirecompression = attr.ib()
     version = attr.ib()
     wireversion = attr.ib()
     params = attr.ib()
     contentopts = attr.ib()
 
 
 # Maps bundle version human names to changegroup versions.
 _bundlespeccgversions = {
     b'v1': b'01',
     b'v2': b'02',
     b'packed1': b's1',
     b'bundle2': b'02',  # legacy
 }
 
 # Maps bundle version with content opts to choose which part to bundle
 _bundlespeccontentopts = {
     b'v1': {
         b'changegroup': True,
         b'cg.version': b'01',
         b'obsolescence': False,
         b'phases': False,
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
     b'v2': {
         b'changegroup': True,
         b'cg.version': b'02',
         b'obsolescence': False,
         b'phases': False,
         b'tagsfnodescache': True,
         b'revbranchcache': True,
     },
     b'packed1': {b'cg.version': b's1'},
 }
 _bundlespeccontentopts[b'bundle2'] = _bundlespeccontentopts[b'v2']
 
 _bundlespecvariants = {
     b"streamv2": {
         b"changegroup": False,
         b"streamv2": True,
         b"tagsfnodescache": False,
         b"revbranchcache": False,
     }
 }
 
 # Compression engines allowed in version 1. THIS SHOULD NEVER CHANGE.
 _bundlespecv1compengines = {b'gzip', b'bzip2', b'none'}
 
 
 def parsebundlespec(repo, spec, strict=True):
     """Parse a bundle string specification into parts.
 
     Bundle specifications denote a well-defined bundle/exchange format.
     The content of a given specification should not change over time in
     order to ensure that bundles produced by a newer version of Mercurial are
     readable from an older version.
 
     The string currently has the form:
 
        <compression>-<type>[;<parameter0>[;<parameter1>]]
 
     Where <compression> is one of the supported compression formats
     and <type> is (currently) a version string. A ";" can follow the type and
     all text afterwards is interpreted as URI encoded, ";" delimited key=value
     pairs.
 
     If ``strict`` is True (the default) <compression> is required. Otherwise,
     it is optional.
 
     Returns a bundlespec object of (compression, version, parameters).
     Compression will be ``None`` if not in strict mode and a compression isn't
     defined.
 
     An ``InvalidBundleSpecification`` is raised when the specification is
     not syntactically well formed.
 
     An ``UnsupportedBundleSpecification`` is raised when the compression or
     bundle type/version is not recognized.
 
     Note: this function will likely eventually return a more complex data
     structure, including bundle2 part information.
     """
 
     def parseparams(s):
         if b';' not in s:
             return s, {}
 
         params = {}
         version, paramstr = s.split(b';', 1)
 
         for p in paramstr.split(b';'):
             if b'=' not in p:
                 raise error.InvalidBundleSpecification(
                     _(
                         b'invalid bundle specification: '
                         b'missing "=" in parameter: %s'
                     )
                     % p
                 )
 
             key, value = p.split(b'=', 1)
             key = urlreq.unquote(key)
             value = urlreq.unquote(value)
             params[key] = value
 
         return version, params
 
     if strict and b'-' not in spec:
         raise error.InvalidBundleSpecification(
             _(
                 b'invalid bundle specification; '
                 b'must be prefixed with compression: %s'
             )
             % spec
         )
 
     if b'-' in spec:
         compression, version = spec.split(b'-', 1)
 
         if compression not in util.compengines.supportedbundlenames:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s compression is not supported') % compression
             )
 
         version, params = parseparams(version)
 
         if version not in _bundlespeccgversions:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s is not a recognized bundle version') % version
             )
     else:
         # Value could be just the compression or just the version, in which
         # case some defaults are assumed (but only when not in strict mode).
         assert not strict
 
         spec, params = parseparams(spec)
 
         if spec in util.compengines.supportedbundlenames:
             compression = spec
             version = b'v1'
             # Generaldelta repos require v2.
-            if b'generaldelta' in repo.requirements:
+            if requirementsmod.GENERALDELTA_REQUIREMENT in repo.requirements:
                 version = b'v2'
             # Modern compression engines require v2.
             if compression not in _bundlespecv1compengines:
                 version = b'v2'
         elif spec in _bundlespeccgversions:
             if spec == b'packed1':
                 compression = b'none'
             else:
                 compression = b'bzip2'
             version = spec
         else:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s is not a recognized bundle specification') % spec
             )
 
     # Bundle version 1 only supports a known set of compression engines.
     if version == b'v1' and compression not in _bundlespecv1compengines:
         raise error.UnsupportedBundleSpecification(
             _(b'compression engine %s is not supported on v1 bundles')
             % compression
         )
 
     # The specification for packed1 can optionally declare the data formats
     # required to apply it. If we see this metadata, compare against what the
     # repo supports and error if the bundle isn't compatible.
     if version == b'packed1' and b'requirements' in params:
         requirements = set(params[b'requirements'].split(b','))
         missingreqs = requirements - repo.supportedformats
         if missingreqs:
             raise error.UnsupportedBundleSpecification(
                 _(b'missing support for repository features: %s')
                 % b', '.join(sorted(missingreqs))
             )
 
     # Compute contentopts based on the version
     contentopts = _bundlespeccontentopts.get(version, {}).copy()
 
     # Process the variants
     if b"stream" in params and params[b"stream"] == b"v2":
         variant = _bundlespecvariants[b"streamv2"]
         contentopts.update(variant)
 
     engine = util.compengines.forbundlename(compression)
     compression, wirecompression = engine.bundletype()
     wireversion = _bundlespeccgversions[version]
 
     return bundlespec(
         compression, wirecompression, version, wireversion, params, contentopts
     )
 
 
 def parseclonebundlesmanifest(repo, s):
     """Parses the raw text of a clone bundles manifest.
 
     Returns a list of dicts. The dicts have a ``URL`` key corresponding
     to the URL and other keys are the attributes for the entry.
     """
     m = []
     for line in s.splitlines():
         fields = line.split()
         if not fields:
             continue
         attrs = {b'URL': fields[0]}
         for rawattr in fields[1:]:
             key, value = rawattr.split(b'=', 1)
             key = util.urlreq.unquote(key)
             value = util.urlreq.unquote(value)
             attrs[key] = value
 
             # Parse BUNDLESPEC into components. This makes client-side
             # preferences easier to specify since you can prefer a single
             # component of the BUNDLESPEC.
             if key == b'BUNDLESPEC':
                 try:
                     bundlespec = parsebundlespec(repo, value)
                     attrs[b'COMPRESSION'] = bundlespec.compression
                     attrs[b'VERSION'] = bundlespec.version
                 except error.InvalidBundleSpecification:
                     pass
                 except error.UnsupportedBundleSpecification:
                     pass
 
         m.append(attrs)
 
     return m
 
 
 def isstreamclonespec(bundlespec):
     # Stream clone v1
     if bundlespec.wirecompression == b'UN' and bundlespec.wireversion == b's1':
         return True
 
     # Stream clone v2
     if (
         bundlespec.wirecompression == b'UN'
         and bundlespec.wireversion == b'02'
         and bundlespec.contentopts.get(b'streamv2')
     ):
         return True
 
     return False
 
 
 def filterclonebundleentries(repo, entries, streamclonerequested=False):
     """Remove incompatible clone bundle manifest entries.
 
     Accepts a list of entries parsed with ``parseclonebundlesmanifest``
     and returns a new list consisting of only the entries that this client
     should be able to apply.
 
     There is no guarantee we'll be able to apply all returned entries because
     the metadata we use to filter on may be missing or wrong.
     """
     newentries = []
     for entry in entries:
         spec = entry.get(b'BUNDLESPEC')
         if spec:
             try:
                 bundlespec = parsebundlespec(repo, spec, strict=True)
 
                 # If a stream clone was requested, filter out non-streamclone
                 # entries.
                 if streamclonerequested and not isstreamclonespec(bundlespec):
                     repo.ui.debug(
                         b'filtering %s because not a stream clone\n'
                         % entry[b'URL']
                     )
                     continue
 
             except error.InvalidBundleSpecification as e:
                 repo.ui.debug(stringutil.forcebytestr(e) + b'\n')
                 continue
             except error.UnsupportedBundleSpecification as e:
                 repo.ui.debug(
                     b'filtering %s because unsupported bundle '
                     b'spec: %s\n' % (entry[b'URL'], stringutil.forcebytestr(e))
                 )
                 continue
         # If we don't have a spec and requested a stream clone, we don't know
         # what the entry is so don't attempt to apply it.
         elif streamclonerequested:
             repo.ui.debug(
                 b'filtering %s because cannot determine if a stream '
                 b'clone bundle\n' % entry[b'URL']
             )
             continue
 
         if b'REQUIRESNI' in entry and not sslutil.hassni:
             repo.ui.debug(
                 b'filtering %s because SNI not supported\n' % entry[b'URL']
             )
             continue
 
         if b'REQUIREDRAM' in entry:
             try:
                 requiredram = util.sizetoint(entry[b'REQUIREDRAM'])
             except error.ParseError:
                 repo.ui.debug(
                     b'filtering %s due to a bad REQUIREDRAM attribute\n'
                     % entry[b'URL']
                 )
                 continue
             actualram = repo.ui.estimatememory()
             if actualram is not None and actualram * 0.66 < requiredram:
                 repo.ui.debug(
                     b'filtering %s as it needs more than 2/3 of system memory\n'
                     % entry[b'URL']
                 )
                 continue
 
         newentries.append(entry)
 
     return newentries
 
 
 class clonebundleentry(object):
     """Represents an item in a clone bundles manifest.
 
     This rich class is needed to support sorting since sorted() in Python 3
     doesn't support ``cmp`` and our comparison is complex enough that ``key=``
     won't work.
     """
 
     def __init__(self, value, prefers):
         self.value = value
         self.prefers = prefers
 
     def _cmp(self, other):
         for prefkey, prefvalue in self.prefers:
             avalue = self.value.get(prefkey)
             bvalue = other.value.get(prefkey)
 
             # Special case for b missing attribute and a matches exactly.
             if avalue is not None and bvalue is None and avalue == prefvalue:
                 return -1
 
             # Special case for a missing attribute and b matches exactly.
             if bvalue is not None and avalue is None and bvalue == prefvalue:
                 return 1
 
             # We can't compare unless attribute present on both.
             if avalue is None or bvalue is None:
                 continue
 
             # Same values should fall back to next attribute.
             if avalue == bvalue:
                 continue
 
             # Exact matches come first.
             if avalue == prefvalue:
                 return -1
             if bvalue == prefvalue:
                 return 1
 
             # Fall back to next attribute.
             continue
 
         # If we got here we couldn't sort by attributes and prefers. Fall
         # back to index order.
         return 0
 
     def __lt__(self, other):
         return self._cmp(other) < 0
 
     def __gt__(self, other):
         return self._cmp(other) > 0
 
     def __eq__(self, other):
         return self._cmp(other) == 0
 
     def __le__(self, other):
         return self._cmp(other) <= 0
 
     def __ge__(self, other):
         return self._cmp(other) >= 0
 
     def __ne__(self, other):
         return self._cmp(other) != 0
 
 
 def sortclonebundleentries(ui, entries):
     prefers = ui.configlist(b'ui', b'clonebundleprefers')
     if not prefers:
         return list(entries)
 
     def _split(p):
         if b'=' not in p:
             hint = _(b"each comma separated item should be key=value pairs")
             raise error.Abort(
                 _(b"invalid ui.clonebundleprefers item: %s") % p, hint=hint
             )
         return p.split(b'=', 1)
 
     prefers = [_split(p) for p in prefers]
 
     items = sorted(clonebundleentry(v, prefers) for v in entries)
     return [i.value for i in items]

mercurial/changegroup.py

@@ -1,1710 +1,1710 b''
 # changegroup.py - Mercurial changegroup manipulation functions
 #
 #  Copyright 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import os
 import struct
 import weakref
 
 from .i18n import _
 from .node import (
     hex,
     nullid,
     nullrev,
     short,
 )
 from .pycompat import open
 
 from . import (
     error,
     match as matchmod,
     mdiff,
     phases,
     pycompat,
     requirements,
     scmutil,
     util,
 )
 
 from .interfaces import repository
 
 _CHANGEGROUPV1_DELTA_HEADER = struct.Struct(b"20s20s20s20s")
 _CHANGEGROUPV2_DELTA_HEADER = struct.Struct(b"20s20s20s20s20s")
 _CHANGEGROUPV3_DELTA_HEADER = struct.Struct(b">20s20s20s20s20sH")
 
 LFS_REQUIREMENT = b'lfs'
 
 readexactly = util.readexactly
 
 
 def getchunk(stream):
     """return the next chunk from stream as a string"""
     d = readexactly(stream, 4)
     l = struct.unpack(b">l", d)[0]
     if l <= 4:
         if l:
             raise error.Abort(_(b"invalid chunk length %d") % l)
         return b""
     return readexactly(stream, l - 4)
 
 
 def chunkheader(length):
     """return a changegroup chunk header (string)"""
     return struct.pack(b">l", length + 4)
 
 
 def closechunk():
     """return a changegroup chunk header (string) for a zero-length chunk"""
     return struct.pack(b">l", 0)
 
 
 def _fileheader(path):
     """Obtain a changegroup chunk header for a named path."""
     return chunkheader(len(path)) + path
 
 
 def writechunks(ui, chunks, filename, vfs=None):
     """Write chunks to a file and return its filename.
 
     The stream is assumed to be a bundle file.
     Existing files will not be overwritten.
     If no filename is specified, a temporary file is created.
     """
     fh = None
     cleanup = None
     try:
         if filename:
             if vfs:
                 fh = vfs.open(filename, b"wb")
             else:
                 # Increase default buffer size because default is usually
                 # small (4k is common on Linux).
                 fh = open(filename, b"wb", 131072)
         else:
             fd, filename = pycompat.mkstemp(prefix=b"hg-bundle-", suffix=b".hg")
             fh = os.fdopen(fd, "wb")
         cleanup = filename
         for c in chunks:
             fh.write(c)
         cleanup = None
         return filename
     finally:
         if fh is not None:
             fh.close()
         if cleanup is not None:
             if filename and vfs:
                 vfs.unlink(cleanup)
             else:
                 os.unlink(cleanup)
 
 
 class cg1unpacker(object):
     """Unpacker for cg1 changegroup streams.
 
     A changegroup unpacker handles the framing of the revision data in
     the wire format. Most consumers will want to use the apply()
     method to add the changes from the changegroup to a repository.
 
     If you're forwarding a changegroup unmodified to another consumer,
     use getchunks(), which returns an iterator of changegroup
     chunks. This is mostly useful for cases where you need to know the
     data stream has ended by observing the end of the changegroup.
 
     deltachunk() is useful only if you're applying delta data. Most
     consumers should prefer apply() instead.
 
     A few other public methods exist. Those are used only for
     bundlerepo and some debug commands - their use is discouraged.
     """
 
     deltaheader = _CHANGEGROUPV1_DELTA_HEADER
     deltaheadersize = deltaheader.size
     version = b'01'
     _grouplistcount = 1  # One list of files after the manifests
 
     def __init__(self, fh, alg, extras=None):
         if alg is None:
             alg = b'UN'
         if alg not in util.compengines.supportedbundletypes:
             raise error.Abort(_(b'unknown stream compression type: %s') % alg)
         if alg == b'BZ':
             alg = b'_truncatedBZ'
 
         compengine = util.compengines.forbundletype(alg)
         self._stream = compengine.decompressorreader(fh)
         self._type = alg
         self.extras = extras or {}
         self.callback = None
 
     # These methods (compressed, read, seek, tell) all appear to only
     # be used by bundlerepo, but it's a little hard to tell.
     def compressed(self):
         return self._type is not None and self._type != b'UN'
 
     def read(self, l):
         return self._stream.read(l)
 
     def seek(self, pos):
         return self._stream.seek(pos)
 
     def tell(self):
         return self._stream.tell()
 
     def close(self):
         return self._stream.close()
 
     def _chunklength(self):
         d = readexactly(self._stream, 4)
         l = struct.unpack(b">l", d)[0]
         if l <= 4:
             if l:
                 raise error.Abort(_(b"invalid chunk length %d") % l)
             return 0
         if self.callback:
             self.callback()
         return l - 4
 
     def changelogheader(self):
         """v10 does not have a changelog header chunk"""
         return {}
 
     def manifestheader(self):
         """v10 does not have a manifest header chunk"""
         return {}
 
     def filelogheader(self):
         """return the header of the filelogs chunk, v10 only has the filename"""
         l = self._chunklength()
         if not l:
             return {}
         fname = readexactly(self._stream, l)
         return {b'filename': fname}
 
     def _deltaheader(self, headertuple, prevnode):
         node, p1, p2, cs = headertuple
         if prevnode is None:
             deltabase = p1
         else:
             deltabase = prevnode
         flags = 0
         return node, p1, p2, deltabase, cs, flags
 
     def deltachunk(self, prevnode):
         l = self._chunklength()
         if not l:
             return {}
         headerdata = readexactly(self._stream, self.deltaheadersize)
         header = self.deltaheader.unpack(headerdata)
         delta = readexactly(self._stream, l - self.deltaheadersize)
         node, p1, p2, deltabase, cs, flags = self._deltaheader(header, prevnode)
         return (node, p1, p2, cs, deltabase, delta, flags)
 
     def getchunks(self):
         """returns all the chunks contains in the bundle
 
         Used when you need to forward the binary stream to a file or another
         network API. To do so, it parse the changegroup data, otherwise it will
         block in case of sshrepo because it don't know the end of the stream.
         """
         # For changegroup 1 and 2, we expect 3 parts: changelog, manifestlog,
         # and a list of filelogs. For changegroup 3, we expect 4 parts:
         # changelog, manifestlog, a list of tree manifestlogs, and a list of
         # filelogs.
         #
         # Changelog and manifestlog parts are terminated with empty chunks. The
         # tree and file parts are a list of entry sections. Each entry section
         # is a series of chunks terminating in an empty chunk. The list of these
         # entry sections is terminated in yet another empty chunk, so we know
         # we've reached the end of the tree/file list when we reach an empty
         # chunk that was proceeded by no non-empty chunks.
 
         parts = 0
         while parts < 2 + self._grouplistcount:
             noentries = True
             while True:
                 chunk = getchunk(self)
                 if not chunk:
                     # The first two empty chunks represent the end of the
                     # changelog and the manifestlog portions. The remaining
                     # empty chunks represent either A) the end of individual
                     # tree or file entries in the file list, or B) the end of
                     # the entire list. It's the end of the entire list if there
                     # were no entries (i.e. noentries is True).
                     if parts < 2:
                         parts += 1
                     elif noentries:
                         parts += 1
                     break
                 noentries = False
                 yield chunkheader(len(chunk))
                 pos = 0
                 while pos < len(chunk):
                     next = pos + 2 ** 20
                     yield chunk[pos:next]
                     pos = next
             yield closechunk()
 
     def _unpackmanifests(self, repo, revmap, trp, prog):
         self.callback = prog.increment
         # no need to check for empty manifest group here:
         # if the result of the merge of 1 and 2 is the same in 3 and 4,
         # no new manifest will be created and the manifest group will
         # be empty during the pull
         self.manifestheader()
         deltas = self.deltaiter()
         repo.manifestlog.getstorage(b'').addgroup(deltas, revmap, trp)
         prog.complete()
         self.callback = None
 
     def apply(
         self,
         repo,
         tr,
         srctype,
         url,
         targetphase=phases.draft,
         expectedtotal=None,
     ):
         """Add the changegroup returned by source.read() to this repo.
         srctype is a string like 'push', 'pull', or 'unbundle'.  url is
         the URL of the repo where this changegroup is coming from.
 
         Return an integer summarizing the change to this repo:
         - nothing changed or no source: 0
         - more heads than before: 1+added heads (2..n)
         - fewer heads than before: -1-removed heads (-2..-n)
         - number of heads stays the same: 1
         """
         repo = repo.unfiltered()
 
         def csmap(x):
             repo.ui.debug(b"add changeset %s\n" % short(x))
             return len(cl)
 
         def revmap(x):
             return cl.rev(x)
 
         try:
             # The transaction may already carry source information. In this
             # case we use the top level data. We overwrite the argument
             # because we need to use the top level value (if they exist)
             # in this function.
             srctype = tr.hookargs.setdefault(b'source', srctype)
             tr.hookargs.setdefault(b'url', url)
             repo.hook(
                 b'prechangegroup', throw=True, **pycompat.strkwargs(tr.hookargs)
             )
 
             # write changelog data to temp files so concurrent readers
             # will not see an inconsistent view
             cl = repo.changelog
             cl.delayupdate(tr)
             oldheads = set(cl.heads())
 
             trp = weakref.proxy(tr)
             # pull off the changeset group
             repo.ui.status(_(b"adding changesets\n"))
             clstart = len(cl)
             progress = repo.ui.makeprogress(
                 _(b'changesets'), unit=_(b'chunks'), total=expectedtotal
             )
             self.callback = progress.increment
 
             efilesset = set()
             duprevs = []
 
             def ondupchangelog(cl, rev):
                 if rev < clstart:
                     duprevs.append(rev)
 
             def onchangelog(cl, rev):
                 ctx = cl.changelogrevision(rev)
                 efilesset.update(ctx.files)
                 repo.register_changeset(rev, ctx)
 
             self.changelogheader()
             deltas = self.deltaiter()
             if not cl.addgroup(
                 deltas,
                 csmap,
                 trp,
                 alwayscache=True,
                 addrevisioncb=onchangelog,
                 duplicaterevisioncb=ondupchangelog,
             ):
                 repo.ui.develwarn(
                     b'applied empty changelog from changegroup',
                     config=b'warn-empty-changegroup',
                 )
             efiles = len(efilesset)
             clend = len(cl)
             changesets = clend - clstart
             progress.complete()
             del deltas
             # TODO Python 2.7 removal
             # del efilesset
             efilesset = None
             self.callback = None
 
             # pull off the manifest group
             repo.ui.status(_(b"adding manifests\n"))
             # We know that we'll never have more manifests than we had
             # changesets.
             progress = repo.ui.makeprogress(
                 _(b'manifests'), unit=_(b'chunks'), total=changesets
             )
             self._unpackmanifests(repo, revmap, trp, progress)
 
             needfiles = {}
             if repo.ui.configbool(b'server', b'validate'):
                 cl = repo.changelog
                 ml = repo.manifestlog
                 # validate incoming csets have their manifests
                 for cset in pycompat.xrange(clstart, clend):
                     mfnode = cl.changelogrevision(cset).manifest
                     mfest = ml[mfnode].readdelta()
                     # store file nodes we must see
                     for f, n in pycompat.iteritems(mfest):
                         needfiles.setdefault(f, set()).add(n)
 
             # process the files
             repo.ui.status(_(b"adding file changes\n"))
             newrevs, newfiles = _addchangegroupfiles(
                 repo, self, revmap, trp, efiles, needfiles
             )
 
             # making sure the value exists
             tr.changes.setdefault(b'changegroup-count-changesets', 0)
             tr.changes.setdefault(b'changegroup-count-revisions', 0)
             tr.changes.setdefault(b'changegroup-count-files', 0)
             tr.changes.setdefault(b'changegroup-count-heads', 0)
 
             # some code use bundle operation for internal purpose. They usually
             # set `ui.quiet` to do this outside of user sight. Size the report
             # of such operation now happens at the end of the transaction, that
             # ui.quiet has not direct effect on the output.
             #
             # To preserve this intend use an inelegant hack, we fail to report
             # the change if `quiet` is set. We should probably move to
             # something better, but this is a good first step to allow the "end
             # of transaction report" to pass tests.
             if not repo.ui.quiet:
                 tr.changes[b'changegroup-count-changesets'] += changesets
                 tr.changes[b'changegroup-count-revisions'] += newrevs
                 tr.changes[b'changegroup-count-files'] += newfiles
 
             deltaheads = 0
             if oldheads:
                 heads = cl.heads()
                 deltaheads += len(heads) - len(oldheads)
                 for h in heads:
                     if h not in oldheads and repo[h].closesbranch():
                         deltaheads -= 1
 
             # see previous comment about checking ui.quiet
             if not repo.ui.quiet:
                 tr.changes[b'changegroup-count-heads'] += deltaheads
             repo.invalidatevolatilesets()
 
             if changesets > 0:
                 if b'node' not in tr.hookargs:
                     tr.hookargs[b'node'] = hex(cl.node(clstart))
                     tr.hookargs[b'node_last'] = hex(cl.node(clend - 1))
                     hookargs = dict(tr.hookargs)
                 else:
                     hookargs = dict(tr.hookargs)
                     hookargs[b'node'] = hex(cl.node(clstart))
                     hookargs[b'node_last'] = hex(cl.node(clend - 1))
                 repo.hook(
                     b'pretxnchangegroup',
                     throw=True,
                     **pycompat.strkwargs(hookargs)
                 )
 
             added = pycompat.xrange(clstart, clend)
             phaseall = None
             if srctype in (b'push', b'serve'):
                 # Old servers can not push the boundary themselves.
                 # New servers won't push the boundary if changeset already
                 # exists locally as secret
                 #
                 # We should not use added here but the list of all change in
                 # the bundle
                 if repo.publishing():
                     targetphase = phaseall = phases.public
                 else:
                     # closer target phase computation
 
                     # Those changesets have been pushed from the
                     # outside, their phases are going to be pushed
                     # alongside. Therefor `targetphase` is
                     # ignored.
                     targetphase = phaseall = phases.draft
             if added:
                 phases.registernew(repo, tr, targetphase, added)
             if phaseall is not None:
                 if duprevs:
                     duprevs.extend(added)
                 else:
                     duprevs = added
                 phases.advanceboundary(repo, tr, phaseall, [], revs=duprevs)
                 duprevs = []
 
             if changesets > 0:
 
                 def runhooks(unused_success):
                     # These hooks run when the lock releases, not when the
                     # transaction closes. So it's possible for the changelog
                     # to have changed since we last saw it.
                     if clstart >= len(repo):
                         return
 
                     repo.hook(b"changegroup", **pycompat.strkwargs(hookargs))
 
                     for rev in added:
                         args = hookargs.copy()
                         args[b'node'] = hex(cl.node(rev))
                         del args[b'node_last']
                         repo.hook(b"incoming", **pycompat.strkwargs(args))
 
                     newheads = [h for h in repo.heads() if h not in oldheads]
                     repo.ui.log(
                         b"incoming",
                         b"%d incoming changes - new heads: %s\n",
                         len(added),
                         b', '.join([hex(c[:6]) for c in newheads]),
                     )
 
                 tr.addpostclose(
                     b'changegroup-runhooks-%020i' % clstart,
                     lambda tr: repo._afterlock(runhooks),
                 )
         finally:
             repo.ui.flush()
         # never return 0 here:
         if deltaheads < 0:
             ret = deltaheads - 1
         else:
             ret = deltaheads + 1
         return ret
 
     def deltaiter(self):
         """
         returns an iterator of the deltas in this changegroup
 
         Useful for passing to the underlying storage system to be stored.
         """
         chain = None
         for chunkdata in iter(lambda: self.deltachunk(chain), {}):
             # Chunkdata: (node, p1, p2, cs, deltabase, delta, flags)
             yield chunkdata
             chain = chunkdata[0]
 
 
 class cg2unpacker(cg1unpacker):
     """Unpacker for cg2 streams.
 
     cg2 streams add support for generaldelta, so the delta header
     format is slightly different. All other features about the data
     remain the same.
     """
 
     deltaheader = _CHANGEGROUPV2_DELTA_HEADER
     deltaheadersize = deltaheader.size
     version = b'02'
 
     def _deltaheader(self, headertuple, prevnode):
         node, p1, p2, deltabase, cs = headertuple
         flags = 0
         return node, p1, p2, deltabase, cs, flags
 
 
 class cg3unpacker(cg2unpacker):
     """Unpacker for cg3 streams.
 
     cg3 streams add support for exchanging treemanifests and revlog
     flags. It adds the revlog flags to the delta header and an empty chunk
     separating manifests and files.
     """
 
     deltaheader = _CHANGEGROUPV3_DELTA_HEADER
     deltaheadersize = deltaheader.size
     version = b'03'
     _grouplistcount = 2  # One list of manifests and one list of files
 
     def _deltaheader(self, headertuple, prevnode):
         node, p1, p2, deltabase, cs, flags = headertuple
         return node, p1, p2, deltabase, cs, flags
 
     def _unpackmanifests(self, repo, revmap, trp, prog):
         super(cg3unpacker, self)._unpackmanifests(repo, revmap, trp, prog)
         for chunkdata in iter(self.filelogheader, {}):
             # If we get here, there are directory manifests in the changegroup
             d = chunkdata[b"filename"]
             repo.ui.debug(b"adding %s revisions\n" % d)
             deltas = self.deltaiter()
             if not repo.manifestlog.getstorage(d).addgroup(deltas, revmap, trp):
                 raise error.Abort(_(b"received dir revlog group is empty"))
 
 
 class headerlessfixup(object):
     def __init__(self, fh, h):
         self._h = h
         self._fh = fh
 
     def read(self, n):
         if self._h:
             d, self._h = self._h[:n], self._h[n:]
             if len(d) < n:
                 d += readexactly(self._fh, n - len(d))
             return d
         return readexactly(self._fh, n)
 
 
 def _revisiondeltatochunks(delta, headerfn):
     """Serialize a revisiondelta to changegroup chunks."""
 
     # The captured revision delta may be encoded as a delta against
     # a base revision or as a full revision. The changegroup format
     # requires that everything on the wire be deltas. So for full
     # revisions, we need to invent a header that says to rewrite
     # data.
 
     if delta.delta is not None:
         prefix, data = b'', delta.delta
     elif delta.basenode == nullid:
         data = delta.revision
         prefix = mdiff.trivialdiffheader(len(data))
     else:
         data = delta.revision
         prefix = mdiff.replacediffheader(delta.baserevisionsize, len(data))
 
     meta = headerfn(delta)
 
     yield chunkheader(len(meta) + len(prefix) + len(data))
     yield meta
     if prefix:
         yield prefix
     yield data
 
 
 def _sortnodesellipsis(store, nodes, cl, lookup):
     """Sort nodes for changegroup generation."""
     # Ellipses serving mode.
     #
     # In a perfect world, we'd generate better ellipsis-ified graphs
     # for non-changelog revlogs. In practice, we haven't started doing
     # that yet, so the resulting DAGs for the manifestlog and filelogs
     # are actually full of bogus parentage on all the ellipsis
     # nodes. This has the side effect that, while the contents are
     # correct, the individual DAGs might be completely out of whack in
     # a case like 882681bc3166 and its ancestors (back about 10
     # revisions or so) in the main hg repo.
     #
     # The one invariant we *know* holds is that the new (potentially
     # bogus) DAG shape will be valid if we order the nodes in the
     # order that they're introduced in dramatis personae by the
     # changelog, so what we do is we sort the non-changelog histories
     # by the order in which they are used by the changelog.
     key = lambda n: cl.rev(lookup(n))
     return sorted(nodes, key=key)
 
 
 def _resolvenarrowrevisioninfo(
     cl,
     store,
     ischangelog,
     rev,
     linkrev,
     linknode,
     clrevtolocalrev,
     fullclnodes,
     precomputedellipsis,
 ):
     linkparents = precomputedellipsis[linkrev]
 
     def local(clrev):
         """Turn a changelog revnum into a local revnum.
 
         The ellipsis dag is stored as revnums on the changelog,
         but when we're producing ellipsis entries for
         non-changelog revlogs, we need to turn those numbers into
         something local. This does that for us, and during the
         changelog sending phase will also expand the stored
         mappings as needed.
         """
         if clrev == nullrev:
             return nullrev
 
         if ischangelog:
             return clrev
 
         # Walk the ellipsis-ized changelog breadth-first looking for a
         # change that has been linked from the current revlog.
         #
         # For a flat manifest revlog only a single step should be necessary
         # as all relevant changelog entries are relevant to the flat
         # manifest.
         #
         # For a filelog or tree manifest dirlog however not every changelog
         # entry will have been relevant, so we need to skip some changelog
         # nodes even after ellipsis-izing.
         walk = [clrev]
         while walk:
             p = walk[0]
             walk = walk[1:]
             if p in clrevtolocalrev:
                 return clrevtolocalrev[p]
             elif p in fullclnodes:
                 walk.extend([pp for pp in cl.parentrevs(p) if pp != nullrev])
             elif p in precomputedellipsis:
                 walk.extend(
                     [pp for pp in precomputedellipsis[p] if pp != nullrev]
                 )
             else:
                 # In this case, we've got an ellipsis with parents
                 # outside the current bundle (likely an
                 # incremental pull). We "know" that we can use the
                 # value of this same revlog at whatever revision
                 # is pointed to by linknode. "Know" is in scare
                 # quotes because I haven't done enough examination
                 # of edge cases to convince myself this is really
                 # a fact - it works for all the (admittedly
                 # thorough) cases in our testsuite, but I would be
                 # somewhat unsurprised to find a case in the wild
                 # where this breaks down a bit. That said, I don't
                 # know if it would hurt anything.
                 for i in pycompat.xrange(rev, 0, -1):
                     if store.linkrev(i) == clrev:
                         return i
                 # We failed to resolve a parent for this node, so
                 # we crash the changegroup construction.
                 raise error.Abort(
                     b"unable to resolve parent while packing '%s' %r"
                     b' for changeset %r' % (store.indexfile, rev, clrev)
                 )
 
         return nullrev
 
     if not linkparents or (store.parentrevs(rev) == (nullrev, nullrev)):
         p1, p2 = nullrev, nullrev
     elif len(linkparents) == 1:
         (p1,) = sorted(local(p) for p in linkparents)
         p2 = nullrev
     else:
         p1, p2 = sorted(local(p) for p in linkparents)
 
     p1node, p2node = store.node(p1), store.node(p2)
 
     return p1node, p2node, linknode
 
 
 def deltagroup(
     repo,
     store,
     nodes,
     ischangelog,
     lookup,
     forcedeltaparentprev,
     topic=None,
     ellipses=False,
     clrevtolocalrev=None,
     fullclnodes=None,
     precomputedellipsis=None,
 ):
     """Calculate deltas for a set of revisions.
 
     Is a generator of ``revisiondelta`` instances.
 
     If topic is not None, progress detail will be generated using this
     topic name (e.g. changesets, manifests, etc).
     """
     if not nodes:
         return
 
     cl = repo.changelog
 
     if ischangelog:
         # `hg log` shows changesets in storage order. To preserve order
         # across clones, send out changesets in storage order.
         nodesorder = b'storage'
     elif ellipses:
         nodes = _sortnodesellipsis(store, nodes, cl, lookup)
         nodesorder = b'nodes'
     else:
         nodesorder = None
 
     # Perform ellipses filtering and revision massaging. We do this before
     # emitrevisions() because a) filtering out revisions creates less work
     # for emitrevisions() b) dropping revisions would break emitrevisions()'s
     # assumptions about delta choices and we would possibly send a delta
     # referencing a missing base revision.
     #
     # Also, calling lookup() has side-effects with regards to populating
     # data structures. If we don't call lookup() for each node or if we call
     # lookup() after the first pass through each node, things can break -
     # possibly intermittently depending on the python hash seed! For that
     # reason, we store a mapping of all linknodes during the initial node
     # pass rather than use lookup() on the output side.
     if ellipses:
         filtered = []
         adjustedparents = {}
         linknodes = {}
 
         for node in nodes:
             rev = store.rev(node)
             linknode = lookup(node)
             linkrev = cl.rev(linknode)
             clrevtolocalrev[linkrev] = rev
 
             # If linknode is in fullclnodes, it means the corresponding
             # changeset was a full changeset and is being sent unaltered.
             if linknode in fullclnodes:
                 linknodes[node] = linknode
 
             # If the corresponding changeset wasn't in the set computed
             # as relevant to us, it should be dropped outright.
             elif linkrev not in precomputedellipsis:
                 continue
 
             else:
                 # We could probably do this later and avoid the dict
                 # holding state. But it likely doesn't matter.
                 p1node, p2node, linknode = _resolvenarrowrevisioninfo(
                     cl,
                     store,
                     ischangelog,
                     rev,
                     linkrev,
                     linknode,
                     clrevtolocalrev,
                     fullclnodes,
                     precomputedellipsis,
                 )
 
                 adjustedparents[node] = (p1node, p2node)
                 linknodes[node] = linknode
 
             filtered.append(node)
 
         nodes = filtered
 
     # We expect the first pass to be fast, so we only engage the progress
     # meter for constructing the revision deltas.
     progress = None
     if topic is not None:
         progress = repo.ui.makeprogress(
             topic, unit=_(b'chunks'), total=len(nodes)
         )
 
     configtarget = repo.ui.config(b'devel', b'bundle.delta')
     if configtarget not in (b'', b'p1', b'full'):
         msg = _("""config "devel.bundle.delta" as unknown value: %s""")
         repo.ui.warn(msg % configtarget)
 
     deltamode = repository.CG_DELTAMODE_STD
     if forcedeltaparentprev:
         deltamode = repository.CG_DELTAMODE_PREV
     elif configtarget == b'p1':
         deltamode = repository.CG_DELTAMODE_P1
     elif configtarget == b'full':
         deltamode = repository.CG_DELTAMODE_FULL
 
     revisions = store.emitrevisions(
         nodes,
         nodesorder=nodesorder,
         revisiondata=True,
         assumehaveparentrevisions=not ellipses,
         deltamode=deltamode,
     )
 
     for i, revision in enumerate(revisions):
         if progress:
             progress.update(i + 1)
 
         if ellipses:
             linknode = linknodes[revision.node]
 
             if revision.node in adjustedparents:
                 p1node, p2node = adjustedparents[revision.node]
                 revision.p1node = p1node
                 revision.p2node = p2node
                 revision.flags |= repository.REVISION_FLAG_ELLIPSIS
 
         else:
             linknode = lookup(revision.node)
 
         revision.linknode = linknode
         yield revision
 
     if progress:
         progress.complete()
 
 
 class cgpacker(object):
     def __init__(
         self,
         repo,
         oldmatcher,
         matcher,
         version,
         builddeltaheader,
         manifestsend,
         forcedeltaparentprev=False,
         bundlecaps=None,
         ellipses=False,
         shallow=False,
         ellipsisroots=None,
         fullnodes=None,
     ):
         """Given a source repo, construct a bundler.
 
         oldmatcher is a matcher that matches on files the client already has.
         These will not be included in the changegroup.
 
         matcher is a matcher that matches on files to include in the
         changegroup. Used to facilitate sparse changegroups.
 
         forcedeltaparentprev indicates whether delta parents must be against
         the previous revision in a delta group. This should only be used for
         compatibility with changegroup version 1.
 
         builddeltaheader is a callable that constructs the header for a group
         delta.
 
         manifestsend is a chunk to send after manifests have been fully emitted.
 
         ellipses indicates whether ellipsis serving mode is enabled.
 
         bundlecaps is optional and can be used to specify the set of
         capabilities which can be used to build the bundle. While bundlecaps is
         unused in core Mercurial, extensions rely on this feature to communicate
         capabilities to customize the changegroup packer.
 
         shallow indicates whether shallow data might be sent. The packer may
         need to pack file contents not introduced by the changes being packed.
 
         fullnodes is the set of changelog nodes which should not be ellipsis
         nodes. We store this rather than the set of nodes that should be
         ellipsis because for very large histories we expect this to be
         significantly smaller.
         """
         assert oldmatcher
         assert matcher
         self._oldmatcher = oldmatcher
         self._matcher = matcher
 
         self.version = version
         self._forcedeltaparentprev = forcedeltaparentprev
         self._builddeltaheader = builddeltaheader
         self._manifestsend = manifestsend
         self._ellipses = ellipses
 
         # Set of capabilities we can use to build the bundle.
         if bundlecaps is None:
             bundlecaps = set()
         self._bundlecaps = bundlecaps
         self._isshallow = shallow
         self._fullclnodes = fullnodes
 
         # Maps ellipsis revs to their roots at the changelog level.
         self._precomputedellipsis = ellipsisroots
 
         self._repo = repo
 
         if self._repo.ui.verbose and not self._repo.ui.debugflag:
             self._verbosenote = self._repo.ui.note
         else:
             self._verbosenote = lambda s: None
 
     def generate(
         self, commonrevs, clnodes, fastpathlinkrev, source, changelog=True
     ):
         """Yield a sequence of changegroup byte chunks.
         If changelog is False, changelog data won't be added to changegroup
         """
 
         repo = self._repo
         cl = repo.changelog
 
         self._verbosenote(_(b'uncompressed size of bundle content:\n'))
         size = 0
 
         clstate, deltas = self._generatechangelog(
             cl, clnodes, generate=changelog
         )
         for delta in deltas:
             for chunk in _revisiondeltatochunks(delta, self._builddeltaheader):
                 size += len(chunk)
                 yield chunk
 
         close = closechunk()
         size += len(close)
         yield closechunk()
 
         self._verbosenote(_(b'%8.i (changelog)\n') % size)
 
         clrevorder = clstate[b'clrevorder']
         manifests = clstate[b'manifests']
         changedfiles = clstate[b'changedfiles']
 
         # We need to make sure that the linkrev in the changegroup refers to
         # the first changeset that introduced the manifest or file revision.
         # The fastpath is usually safer than the slowpath, because the filelogs
         # are walked in revlog order.
         #
         # When taking the slowpath when the manifest revlog uses generaldelta,
         # the manifest may be walked in the "wrong" order. Without 'clrevorder',
         # we would get an incorrect linkrev (see fix in cc0ff93d0c0c).
         #
         # When taking the fastpath, we are only vulnerable to reordering
         # of the changelog itself. The changelog never uses generaldelta and is
         # never reordered. To handle this case, we simply take the slowpath,
         # which already has the 'clrevorder' logic. This was also fixed in
         # cc0ff93d0c0c.
 
         # Treemanifests don't work correctly with fastpathlinkrev
         # either, because we don't discover which directory nodes to
         # send along with files. This could probably be fixed.
         fastpathlinkrev = fastpathlinkrev and not scmutil.istreemanifest(repo)
 
         fnodes = {}  # needed file nodes
 
         size = 0
         it = self.generatemanifests(
             commonrevs,
             clrevorder,
             fastpathlinkrev,
             manifests,
             fnodes,
             source,
             clstate[b'clrevtomanifestrev'],
         )
 
         for tree, deltas in it:
             if tree:
                 assert self.version == b'03'
                 chunk = _fileheader(tree)
                 size += len(chunk)
                 yield chunk
 
             for delta in deltas:
                 chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
 
             close = closechunk()
             size += len(close)
             yield close
 
         self._verbosenote(_(b'%8.i (manifests)\n') % size)
         yield self._manifestsend
 
         mfdicts = None
         if self._ellipses and self._isshallow:
             mfdicts = [
                 (repo.manifestlog[n].read(), lr)
                 for (n, lr) in pycompat.iteritems(manifests)
             ]
 
         manifests.clear()
         clrevs = {cl.rev(x) for x in clnodes}
 
         it = self.generatefiles(
             changedfiles,
             commonrevs,
             source,
             mfdicts,
             fastpathlinkrev,
             fnodes,
             clrevs,
         )
 
         for path, deltas in it:
             h = _fileheader(path)
             size = len(h)
             yield h
 
             for delta in deltas:
                 chunks = _revisiondeltatochunks(delta, self._builddeltaheader)
                 for chunk in chunks:
                     size += len(chunk)
                     yield chunk
 
             close = closechunk()
             size += len(close)
             yield close
 
             self._verbosenote(_(b'%8.i  %s\n') % (size, path))
 
         yield closechunk()
 
         if clnodes:
             repo.hook(b'outgoing', node=hex(clnodes[0]), source=source)
 
     def _generatechangelog(self, cl, nodes, generate=True):
         """Generate data for changelog chunks.
 
         Returns a 2-tuple of a dict containing state and an iterable of
         byte chunks. The state will not be fully populated until the
         chunk stream has been fully consumed.
 
         if generate is False, the state will be fully populated and no chunk
         stream will be yielded
         """
         clrevorder = {}
         manifests = {}
         mfl = self._repo.manifestlog
         changedfiles = set()
         clrevtomanifestrev = {}
 
         state = {
             b'clrevorder': clrevorder,
             b'manifests': manifests,
             b'changedfiles': changedfiles,
             b'clrevtomanifestrev': clrevtomanifestrev,
         }
 
         if not (generate or self._ellipses):
             # sort the nodes in storage order
             nodes = sorted(nodes, key=cl.rev)
             for node in nodes:
                 c = cl.changelogrevision(node)
                 clrevorder[node] = len(clrevorder)
                 # record the first changeset introducing this manifest version
                 manifests.setdefault(c.manifest, node)
                 # Record a complete list of potentially-changed files in
                 # this manifest.
                 changedfiles.update(c.files)
 
             return state, ()
 
         # Callback for the changelog, used to collect changed files and
         # manifest nodes.
         # Returns the linkrev node (identity in the changelog case).
         def lookupcl(x):
             c = cl.changelogrevision(x)
             clrevorder[x] = len(clrevorder)
 
             if self._ellipses:
                 # Only update manifests if x is going to be sent. Otherwise we
                 # end up with bogus linkrevs specified for manifests and
                 # we skip some manifest nodes that we should otherwise
                 # have sent.
                 if (
                     x in self._fullclnodes
                     or cl.rev(x) in self._precomputedellipsis
                 ):
 
                     manifestnode = c.manifest
                     # Record the first changeset introducing this manifest
                     # version.
                     manifests.setdefault(manifestnode, x)
                     # Set this narrow-specific dict so we have the lowest
                     # manifest revnum to look up for this cl revnum. (Part of
                     # mapping changelog ellipsis parents to manifest ellipsis
                     # parents)
                     clrevtomanifestrev.setdefault(
                         cl.rev(x), mfl.rev(manifestnode)
                     )
                 # We can't trust the changed files list in the changeset if the
                 # client requested a shallow clone.
                 if self._isshallow:
                     changedfiles.update(mfl[c.manifest].read().keys())
                 else:
                     changedfiles.update(c.files)
             else:
                 # record the first changeset introducing this manifest version
                 manifests.setdefault(c.manifest, x)
                 # Record a complete list of potentially-changed files in
                 # this manifest.
                 changedfiles.update(c.files)
 
             return x
 
         gen = deltagroup(
             self._repo,
             cl,
             nodes,
             True,
             lookupcl,
             self._forcedeltaparentprev,
             ellipses=self._ellipses,
             topic=_(b'changesets'),
             clrevtolocalrev={},
             fullclnodes=self._fullclnodes,
             precomputedellipsis=self._precomputedellipsis,
         )
 
         return state, gen
 
     def generatemanifests(
         self,
         commonrevs,
         clrevorder,
         fastpathlinkrev,
         manifests,
         fnodes,
         source,
         clrevtolocalrev,
     ):
         """Returns an iterator of changegroup chunks containing manifests.
 
         `source` is unused here, but is used by extensions like remotefilelog to
         change what is sent based in pulls vs pushes, etc.
         """
         repo = self._repo
         mfl = repo.manifestlog
         tmfnodes = {b'': manifests}
 
         # Callback for the manifest, used to collect linkrevs for filelog
         # revisions.
         # Returns the linkrev node (collected in lookupcl).
         def makelookupmflinknode(tree, nodes):
             if fastpathlinkrev:
                 assert not tree
                 return (
                     manifests.__getitem__
                 )  # pytype: disable=unsupported-operands
 
             def lookupmflinknode(x):
                 """Callback for looking up the linknode for manifests.
 
                 Returns the linkrev node for the specified manifest.
 
                 SIDE EFFECT:
 
                 1) fclnodes gets populated with the list of relevant
                    file nodes if we're not using fastpathlinkrev
                 2) When treemanifests are in use, collects treemanifest nodes
                    to send
 
                 Note that this means manifests must be completely sent to
                 the client before you can trust the list of files and
                 treemanifests to send.
                 """
                 clnode = nodes[x]
                 mdata = mfl.get(tree, x).readfast(shallow=True)
                 for p, n, fl in mdata.iterentries():
                     if fl == b't':  # subdirectory manifest
                         subtree = tree + p + b'/'
                         tmfclnodes = tmfnodes.setdefault(subtree, {})
                         tmfclnode = tmfclnodes.setdefault(n, clnode)
                         if clrevorder[clnode] < clrevorder[tmfclnode]:
                             tmfclnodes[n] = clnode
                     else:
                         f = tree + p
                         fclnodes = fnodes.setdefault(f, {})
                         fclnode = fclnodes.setdefault(n, clnode)
                         if clrevorder[clnode] < clrevorder[fclnode]:
                             fclnodes[n] = clnode
                 return clnode
 
             return lookupmflinknode
 
         while tmfnodes:
             tree, nodes = tmfnodes.popitem()
 
             should_visit = self._matcher.visitdir(tree[:-1])
             if tree and not should_visit:
                 continue
 
             store = mfl.getstorage(tree)
 
             if not should_visit:
                 # No nodes to send because this directory is out of
                 # the client's view of the repository (probably
                 # because of narrow clones). Do this even for the root
                 # directory (tree=='')
                 prunednodes = []
             else:
                 # Avoid sending any manifest nodes we can prove the
                 # client already has by checking linkrevs. See the
                 # related comment in generatefiles().
                 prunednodes = self._prunemanifests(store, nodes, commonrevs)
 
             if tree and not prunednodes:
                 continue
 
             lookupfn = makelookupmflinknode(tree, nodes)
 
             deltas = deltagroup(
                 self._repo,
                 store,
                 prunednodes,
                 False,
                 lookupfn,
                 self._forcedeltaparentprev,
                 ellipses=self._ellipses,
                 topic=_(b'manifests'),
                 clrevtolocalrev=clrevtolocalrev,
                 fullclnodes=self._fullclnodes,
                 precomputedellipsis=self._precomputedellipsis,
             )
 
             if not self._oldmatcher.visitdir(store.tree[:-1]):
                 yield tree, deltas
             else:
                 # 'deltas' is a generator and we need to consume it even if
                 # we are not going to send it because a side-effect is that
                 # it updates tmdnodes (via lookupfn)
                 for d in deltas:
                     pass
                 if not tree:
                     yield tree, []
 
     def _prunemanifests(self, store, nodes, commonrevs):
         if not self._ellipses:
             # In non-ellipses case and large repositories, it is better to
             # prevent calling of store.rev and store.linkrev on a lot of
             # nodes as compared to sending some extra data
             return nodes.copy()
         # This is split out as a separate method to allow filtering
         # commonrevs in extension code.
         #
         # TODO(augie): this shouldn't be required, instead we should
         # make filtering of revisions to send delegated to the store
         # layer.
         frev, flr = store.rev, store.linkrev
         return [n for n in nodes if flr(frev(n)) not in commonrevs]
 
     # The 'source' parameter is useful for extensions
     def generatefiles(
         self,
         changedfiles,
         commonrevs,
         source,
         mfdicts,
         fastpathlinkrev,
         fnodes,
         clrevs,
     ):
         changedfiles = [
             f
             for f in changedfiles
             if self._matcher(f) and not self._oldmatcher(f)
         ]
 
         if not fastpathlinkrev:
 
             def normallinknodes(unused, fname):
                 return fnodes.get(fname, {})
 
         else:
             cln = self._repo.changelog.node
 
             def normallinknodes(store, fname):
                 flinkrev = store.linkrev
                 fnode = store.node
                 revs = ((r, flinkrev(r)) for r in store)
                 return {fnode(r): cln(lr) for r, lr in revs if lr in clrevs}
 
         clrevtolocalrev = {}
 
         if self._isshallow:
             # In a shallow clone, the linknodes callback needs to also include
             # those file nodes that are in the manifests we sent but weren't
             # introduced by those manifests.
             commonctxs = [self._repo[c] for c in commonrevs]
             clrev = self._repo.changelog.rev
 
             def linknodes(flog, fname):
                 for c in commonctxs:
                     try:
                         fnode = c.filenode(fname)
                         clrevtolocalrev[c.rev()] = flog.rev(fnode)
                     except error.ManifestLookupError:
                         pass
                 links = normallinknodes(flog, fname)
                 if len(links) != len(mfdicts):
                     for mf, lr in mfdicts:
                         fnode = mf.get(fname, None)
                         if fnode in links:
                             links[fnode] = min(links[fnode], lr, key=clrev)
                         elif fnode:
                             links[fnode] = lr
                 return links
 
         else:
             linknodes = normallinknodes
 
         repo = self._repo
         progress = repo.ui.makeprogress(
             _(b'files'), unit=_(b'files'), total=len(changedfiles)
         )
         for i, fname in enumerate(sorted(changedfiles)):
             filerevlog = repo.file(fname)
             if not filerevlog:
                 raise error.Abort(
                     _(b"empty or missing file data for %s") % fname
                 )
 
             clrevtolocalrev.clear()
 
             linkrevnodes = linknodes(filerevlog, fname)
             # Lookup for filenodes, we collected the linkrev nodes above in the
             # fastpath case and with lookupmf in the slowpath case.
             def lookupfilelog(x):
                 return linkrevnodes[x]
 
             frev, flr = filerevlog.rev, filerevlog.linkrev
             # Skip sending any filenode we know the client already
             # has. This avoids over-sending files relatively
             # inexpensively, so it's not a problem if we under-filter
             # here.
             filenodes = [
                 n for n in linkrevnodes if flr(frev(n)) not in commonrevs
             ]
 
             if not filenodes:
                 continue
 
             progress.update(i + 1, item=fname)
 
             deltas = deltagroup(
                 self._repo,
                 filerevlog,
                 filenodes,
                 False,
                 lookupfilelog,
                 self._forcedeltaparentprev,
                 ellipses=self._ellipses,
                 clrevtolocalrev=clrevtolocalrev,
                 fullclnodes=self._fullclnodes,
                 precomputedellipsis=self._precomputedellipsis,
             )
 
             yield fname, deltas
 
         progress.complete()
 
 
 def _makecg1packer(
     repo,
     oldmatcher,
     matcher,
     bundlecaps,
     ellipses=False,
     shallow=False,
     ellipsisroots=None,
     fullnodes=None,
 ):
     builddeltaheader = lambda d: _CHANGEGROUPV1_DELTA_HEADER.pack(
         d.node, d.p1node, d.p2node, d.linknode
     )
 
     return cgpacker(
         repo,
         oldmatcher,
         matcher,
         b'01',
         builddeltaheader=builddeltaheader,
         manifestsend=b'',
         forcedeltaparentprev=True,
         bundlecaps=bundlecaps,
         ellipses=ellipses,
         shallow=shallow,
         ellipsisroots=ellipsisroots,
         fullnodes=fullnodes,
     )
 
 
 def _makecg2packer(
     repo,
     oldmatcher,
     matcher,
     bundlecaps,
     ellipses=False,
     shallow=False,
     ellipsisroots=None,
     fullnodes=None,
 ):
     builddeltaheader = lambda d: _CHANGEGROUPV2_DELTA_HEADER.pack(
         d.node, d.p1node, d.p2node, d.basenode, d.linknode
     )
 
     return cgpacker(
         repo,
         oldmatcher,
         matcher,
         b'02',
         builddeltaheader=builddeltaheader,
         manifestsend=b'',
         bundlecaps=bundlecaps,
         ellipses=ellipses,
         shallow=shallow,
         ellipsisroots=ellipsisroots,
         fullnodes=fullnodes,
     )
 
 
 def _makecg3packer(
     repo,
     oldmatcher,
     matcher,
     bundlecaps,
     ellipses=False,
     shallow=False,
     ellipsisroots=None,
     fullnodes=None,
 ):
     builddeltaheader = lambda d: _CHANGEGROUPV3_DELTA_HEADER.pack(
         d.node, d.p1node, d.p2node, d.basenode, d.linknode, d.flags
     )
 
     return cgpacker(
         repo,
         oldmatcher,
         matcher,
         b'03',
         builddeltaheader=builddeltaheader,
         manifestsend=closechunk(),
         bundlecaps=bundlecaps,
         ellipses=ellipses,
         shallow=shallow,
         ellipsisroots=ellipsisroots,
         fullnodes=fullnodes,
     )
 
 
 _packermap = {
     b'01': (_makecg1packer, cg1unpacker),
     # cg2 adds support for exchanging generaldelta
     b'02': (_makecg2packer, cg2unpacker),
     # cg3 adds support for exchanging revlog flags and treemanifests
     b'03': (_makecg3packer, cg3unpacker),
 }
 
 
 def allsupportedversions(repo):
     versions = set(_packermap.keys())
     needv03 = False
     if (
         repo.ui.configbool(b'experimental', b'changegroup3')
         or repo.ui.configbool(b'experimental', b'treemanifest')
         or scmutil.istreemanifest(repo)
     ):
         # we keep version 03 because we need to to exchange treemanifest data
         #
         # we also keep vresion 01 and 02, because it is possible for repo to
         # contains both normal and tree manifest at the same time. so using
         # older version to pull data is viable
         #
         # (or even to push subset of history)
         needv03 = True
     if b'exp-sidedata-flag' in repo.requirements:
         needv03 = True
         # don't attempt to use 01/02 until we do sidedata cleaning
         versions.discard(b'01')
         versions.discard(b'02')
     if not needv03:
         versions.discard(b'03')
     return versions
 
 
 # Changegroup versions that can be applied to the repo
 def supportedincomingversions(repo):
     return allsupportedversions(repo)
 
 
 # Changegroup versions that can be created from the repo
 def supportedoutgoingversions(repo):
     versions = allsupportedversions(repo)
     if scmutil.istreemanifest(repo):
         # Versions 01 and 02 support only flat manifests and it's just too
         # expensive to convert between the flat manifest and tree manifest on
         # the fly. Since tree manifests are hashed differently, all of history
         # would have to be converted. Instead, we simply don't even pretend to
         # support versions 01 and 02.
         versions.discard(b'01')
         versions.discard(b'02')
     if requirements.NARROW_REQUIREMENT in repo.requirements:
         # Versions 01 and 02 don't support revlog flags, and we need to
         # support that for stripping and unbundling to work.
         versions.discard(b'01')
         versions.discard(b'02')
     if LFS_REQUIREMENT in repo.requirements:
         # Versions 01 and 02 don't support revlog flags, and we need to
         # mark LFS entries with REVIDX_EXTSTORED.
         versions.discard(b'01')
         versions.discard(b'02')
 
     return versions
 
 
 def localversion(repo):
     # Finds the best version to use for bundles that are meant to be used
     # locally, such as those from strip and shelve, and temporary bundles.
     return max(supportedoutgoingversions(repo))
 
 
 def safeversion(repo):
     # Finds the smallest version that it's safe to assume clients of the repo
     # will support. For example, all hg versions that support generaldelta also
     # support changegroup 02.
     versions = supportedoutgoingversions(repo)
-    if b'generaldelta' in repo.requirements:
+    if requirements.GENERALDELTA_REQUIREMENT in repo.requirements:
         versions.discard(b'01')
     assert versions
     return min(versions)
 
 
 def getbundler(
     version,
     repo,
     bundlecaps=None,
     oldmatcher=None,
     matcher=None,
     ellipses=False,
     shallow=False,
     ellipsisroots=None,
     fullnodes=None,
 ):
     assert version in supportedoutgoingversions(repo)
 
     if matcher is None:
         matcher = matchmod.always()
     if oldmatcher is None:
         oldmatcher = matchmod.never()
 
     if version == b'01' and not matcher.always():
         raise error.ProgrammingError(
             b'version 01 changegroups do not support sparse file matchers'
         )
 
     if ellipses and version in (b'01', b'02'):
         raise error.Abort(
             _(
                 b'ellipsis nodes require at least cg3 on client and server, '
                 b'but negotiated version %s'
             )
             % version
         )
 
     # Requested files could include files not in the local store. So
     # filter those out.
     matcher = repo.narrowmatch(matcher)
 
     fn = _packermap[version][0]
     return fn(
         repo,
         oldmatcher,
         matcher,
         bundlecaps,
         ellipses=ellipses,
         shallow=shallow,
         ellipsisroots=ellipsisroots,
         fullnodes=fullnodes,
     )
 
 
 def getunbundler(version, fh, alg, extras=None):
     return _packermap[version][1](fh, alg, extras=extras)
 
 
 def _changegroupinfo(repo, nodes, source):
     if repo.ui.verbose or source == b'bundle':
         repo.ui.status(_(b"%d changesets found\n") % len(nodes))
     if repo.ui.debugflag:
         repo.ui.debug(b"list of changesets:\n")
         for node in nodes:
             repo.ui.debug(b"%s\n" % hex(node))
 
 
 def makechangegroup(
     repo, outgoing, version, source, fastpath=False, bundlecaps=None
 ):
     cgstream = makestream(
         repo,
         outgoing,
         version,
         source,
         fastpath=fastpath,
         bundlecaps=bundlecaps,
     )
     return getunbundler(
         version,
         util.chunkbuffer(cgstream),
         None,
         {b'clcount': len(outgoing.missing)},
     )
 
 
 def makestream(
     repo,
     outgoing,
     version,
     source,
     fastpath=False,
     bundlecaps=None,
     matcher=None,
 ):
     bundler = getbundler(version, repo, bundlecaps=bundlecaps, matcher=matcher)
 
     repo = repo.unfiltered()
     commonrevs = outgoing.common
     csets = outgoing.missing
     heads = outgoing.ancestorsof
     # We go through the fast path if we get told to, or if all (unfiltered
     # heads have been requested (since we then know there all linkrevs will
     # be pulled by the client).
     heads.sort()
     fastpathlinkrev = fastpath or (
         repo.filtername is None and heads == sorted(repo.heads())
     )
 
     repo.hook(b'preoutgoing', throw=True, source=source)
     _changegroupinfo(repo, csets, source)
     return bundler.generate(commonrevs, csets, fastpathlinkrev, source)
 
 
 def _addchangegroupfiles(repo, source, revmap, trp, expectedfiles, needfiles):
     revisions = 0
     files = 0
     progress = repo.ui.makeprogress(
         _(b'files'), unit=_(b'files'), total=expectedfiles
     )
     for chunkdata in iter(source.filelogheader, {}):
         files += 1
         f = chunkdata[b"filename"]
         repo.ui.debug(b"adding %s revisions\n" % f)
         progress.increment()
         fl = repo.file(f)
         o = len(fl)
         try:
             deltas = source.deltaiter()
             if not fl.addgroup(deltas, revmap, trp):
                 raise error.Abort(_(b"received file revlog group is empty"))
         except error.CensoredBaseError as e:
             raise error.Abort(_(b"received delta base is censored: %s") % e)
         revisions += len(fl) - o
         if f in needfiles:
             needs = needfiles[f]
             for new in pycompat.xrange(o, len(fl)):
                 n = fl.node(new)
                 if n in needs:
                     needs.remove(n)
                 else:
                     raise error.Abort(_(b"received spurious file revlog entry"))
             if not needs:
                 del needfiles[f]
     progress.complete()
 
     for f, needs in pycompat.iteritems(needfiles):
         fl = repo.file(f)
         for n in needs:
             try:
                 fl.rev(n)
             except error.LookupError:
                 raise error.Abort(
                     _(b'missing file data for %s:%s - run hg verify')
                     % (f, hex(n))
                 )
 
     return revisions, files

mercurial/localrepo.py

@@ -1,3698 +1,3698 b''
 # localrepo.py - read/write repository class for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 import functools
 import os
 import random
 import sys
 import time
 import weakref
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     nullid,
     nullrev,
     short,
 )
 from .pycompat import (
     delattr,
     getattr,
 )
 from . import (
     bookmarks,
     branchmap,
     bundle2,
     bundlecaches,
     changegroup,
     color,
     commit,
     context,
     dirstate,
     dirstateguard,
     discovery,
     encoding,
     error,
     exchange,
     extensions,
     filelog,
     hook,
     lock as lockmod,
     match as matchmod,
     mergestate as mergestatemod,
     mergeutil,
     namespaces,
     narrowspec,
     obsolete,
     pathutil,
     phases,
     pushkey,
     pycompat,
     rcutil,
     repoview,
     requirements as requirementsmod,
     revlog,
     revset,
     revsetlang,
     scmutil,
     sparse,
     store as storemod,
     subrepoutil,
     tags as tagsmod,
     transaction,
     txnutil,
     util,
     vfs as vfsmod,
 )
 
 from .interfaces import (
     repository,
     util as interfaceutil,
 )
 
 from .utils import (
     hashutil,
     procutil,
     stringutil,
 )
 
 from .revlogutils import (
     concurrency_checker as revlogchecker,
     constants as revlogconst,
 )
 
 release = lockmod.release
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 # set of (path, vfs-location) tuples. vfs-location is:
 # - 'plain for vfs relative paths
 # - '' for svfs relative paths
 _cachedfiles = set()
 
 
 class _basefilecache(scmutil.filecache):
     """All filecache usage on repo are done for logic that should be unfiltered"""
 
     def __get__(self, repo, type=None):
         if repo is None:
             return self
         # proxy to unfiltered __dict__ since filtered repo has no entry
         unfi = repo.unfiltered()
         try:
             return unfi.__dict__[self.sname]
         except KeyError:
             pass
         return super(_basefilecache, self).__get__(unfi, type)
 
     def set(self, repo, value):
         return super(_basefilecache, self).set(repo.unfiltered(), value)
 
 
 class repofilecache(_basefilecache):
     """filecache for files in .hg but outside of .hg/store"""
 
     def __init__(self, *paths):
         super(repofilecache, self).__init__(*paths)
         for path in paths:
             _cachedfiles.add((path, b'plain'))
 
     def join(self, obj, fname):
         return obj.vfs.join(fname)
 
 
 class storecache(_basefilecache):
     """filecache for files in the store"""
 
     def __init__(self, *paths):
         super(storecache, self).__init__(*paths)
         for path in paths:
             _cachedfiles.add((path, b''))
 
     def join(self, obj, fname):
         return obj.sjoin(fname)
 
 
 class mixedrepostorecache(_basefilecache):
     """filecache for a mix files in .hg/store and outside"""
 
     def __init__(self, *pathsandlocations):
         # scmutil.filecache only uses the path for passing back into our
         # join(), so we can safely pass a list of paths and locations
         super(mixedrepostorecache, self).__init__(*pathsandlocations)
         _cachedfiles.update(pathsandlocations)
 
     def join(self, obj, fnameandlocation):
         fname, location = fnameandlocation
         if location == b'plain':
             return obj.vfs.join(fname)
         else:
             if location != b'':
                 raise error.ProgrammingError(
                     b'unexpected location: %s' % location
                 )
             return obj.sjoin(fname)
 
 
 def isfilecached(repo, name):
     """check if a repo has already cached "name" filecache-ed property
 
     This returns (cachedobj-or-None, iscached) tuple.
     """
     cacheentry = repo.unfiltered()._filecache.get(name, None)
     if not cacheentry:
         return None, False
     return cacheentry.obj, True
 
 
 class unfilteredpropertycache(util.propertycache):
     """propertycache that apply to unfiltered repo only"""
 
     def __get__(self, repo, type=None):
         unfi = repo.unfiltered()
         if unfi is repo:
             return super(unfilteredpropertycache, self).__get__(unfi)
         return getattr(unfi, self.name)
 
 
 class filteredpropertycache(util.propertycache):
     """propertycache that must take filtering in account"""
 
     def cachevalue(self, obj, value):
         object.__setattr__(obj, self.name, value)
 
 
 def hasunfilteredcache(repo, name):
     """check if a repo has an unfilteredpropertycache value for <name>"""
     return name in vars(repo.unfiltered())
 
 
 def unfilteredmethod(orig):
     """decorate method that always need to be run on unfiltered version"""
 
     @functools.wraps(orig)
     def wrapper(repo, *args, **kwargs):
         return orig(repo.unfiltered(), *args, **kwargs)
 
     return wrapper
 
 
 moderncaps = {
     b'lookup',
     b'branchmap',
     b'pushkey',
     b'known',
     b'getbundle',
     b'unbundle',
 }
 legacycaps = moderncaps.union({b'changegroupsubset'})
 
 
 @interfaceutil.implementer(repository.ipeercommandexecutor)
 class localcommandexecutor(object):
     def __init__(self, peer):
         self._peer = peer
         self._sent = False
         self._closed = False
 
     def __enter__(self):
         return self
 
     def __exit__(self, exctype, excvalue, exctb):
         self.close()
 
     def callcommand(self, command, args):
         if self._sent:
             raise error.ProgrammingError(
                 b'callcommand() cannot be used after sendcommands()'
             )
 
         if self._closed:
             raise error.ProgrammingError(
                 b'callcommand() cannot be used after close()'
             )
 
         # We don't need to support anything fancy. Just call the named
         # method on the peer and return a resolved future.
         fn = getattr(self._peer, pycompat.sysstr(command))
 
         f = pycompat.futures.Future()
 
         try:
             result = fn(**pycompat.strkwargs(args))
         except Exception:
             pycompat.future_set_exception_info(f, sys.exc_info()[1:])
         else:
             f.set_result(result)
 
         return f
 
     def sendcommands(self):
         self._sent = True
 
     def close(self):
         self._closed = True
 
 
 @interfaceutil.implementer(repository.ipeercommands)
 class localpeer(repository.peer):
     '''peer for a local repo; reflects only the most recent API'''
 
     def __init__(self, repo, caps=None):
         super(localpeer, self).__init__()
 
         if caps is None:
             caps = moderncaps.copy()
         self._repo = repo.filtered(b'served')
         self.ui = repo.ui
         self._caps = repo._restrictcapabilities(caps)
 
     # Begin of _basepeer interface.
 
     def url(self):
         return self._repo.url()
 
     def local(self):
         return self._repo
 
     def peer(self):
         return self
 
     def canpush(self):
         return True
 
     def close(self):
         self._repo.close()
 
     # End of _basepeer interface.
 
     # Begin of _basewirecommands interface.
 
     def branchmap(self):
         return self._repo.branchmap()
 
     def capabilities(self):
         return self._caps
 
     def clonebundles(self):
         return self._repo.tryread(bundlecaches.CB_MANIFEST_FILE)
 
     def debugwireargs(self, one, two, three=None, four=None, five=None):
         """Used to test argument passing over the wire"""
         return b"%s %s %s %s %s" % (
             one,
             two,
             pycompat.bytestr(three),
             pycompat.bytestr(four),
             pycompat.bytestr(five),
         )
 
     def getbundle(
         self, source, heads=None, common=None, bundlecaps=None, **kwargs
     ):
         chunks = exchange.getbundlechunks(
             self._repo,
             source,
             heads=heads,
             common=common,
             bundlecaps=bundlecaps,
             **kwargs
         )[1]
         cb = util.chunkbuffer(chunks)
 
         if exchange.bundle2requested(bundlecaps):
             # When requesting a bundle2, getbundle returns a stream to make the
             # wire level function happier. We need to build a proper object
             # from it in local peer.
             return bundle2.getunbundler(self.ui, cb)
         else:
             return changegroup.getunbundler(b'01', cb, None)
 
     def heads(self):
         return self._repo.heads()
 
     def known(self, nodes):
         return self._repo.known(nodes)
 
     def listkeys(self, namespace):
         return self._repo.listkeys(namespace)
 
     def lookup(self, key):
         return self._repo.lookup(key)
 
     def pushkey(self, namespace, key, old, new):
         return self._repo.pushkey(namespace, key, old, new)
 
     def stream_out(self):
         raise error.Abort(_(b'cannot perform stream clone against local peer'))
 
     def unbundle(self, bundle, heads, url):
         """apply a bundle on a repo
 
         This function handles the repo locking itself."""
         try:
             try:
                 bundle = exchange.readbundle(self.ui, bundle, None)
                 ret = exchange.unbundle(self._repo, bundle, heads, b'push', url)
                 if util.safehasattr(ret, b'getchunks'):
                     # This is a bundle20 object, turn it into an unbundler.
                     # This little dance should be dropped eventually when the
                     # API is finally improved.
                     stream = util.chunkbuffer(ret.getchunks())
                     ret = bundle2.getunbundler(self.ui, stream)
                 return ret
             except Exception as exc:
                 # If the exception contains output salvaged from a bundle2
                 # reply, we need to make sure it is printed before continuing
                 # to fail. So we build a bundle2 with such output and consume
                 # it directly.
                 #
                 # This is not very elegant but allows a "simple" solution for
                 # issue4594
                 output = getattr(exc, '_bundle2salvagedoutput', ())
                 if output:
                     bundler = bundle2.bundle20(self._repo.ui)
                     for out in output:
                         bundler.addpart(out)
                     stream = util.chunkbuffer(bundler.getchunks())
                     b = bundle2.getunbundler(self.ui, stream)
                     bundle2.processbundle(self._repo, b)
                 raise
         except error.PushRaced as exc:
             raise error.ResponseError(
                 _(b'push failed:'), stringutil.forcebytestr(exc)
             )
 
     # End of _basewirecommands interface.
 
     # Begin of peer interface.
 
     def commandexecutor(self):
         return localcommandexecutor(self)
 
     # End of peer interface.
 
 
 @interfaceutil.implementer(repository.ipeerlegacycommands)
 class locallegacypeer(localpeer):
     """peer extension which implements legacy methods too; used for tests with
     restricted capabilities"""
 
     def __init__(self, repo):
         super(locallegacypeer, self).__init__(repo, caps=legacycaps)
 
     # Begin of baselegacywirecommands interface.
 
     def between(self, pairs):
         return self._repo.between(pairs)
 
     def branches(self, nodes):
         return self._repo.branches(nodes)
 
     def changegroup(self, nodes, source):
         outgoing = discovery.outgoing(
             self._repo, missingroots=nodes, ancestorsof=self._repo.heads()
         )
         return changegroup.makechangegroup(self._repo, outgoing, b'01', source)
 
     def changegroupsubset(self, bases, heads, source):
         outgoing = discovery.outgoing(
             self._repo, missingroots=bases, ancestorsof=heads
         )
         return changegroup.makechangegroup(self._repo, outgoing, b'01', source)
 
     # End of baselegacywirecommands interface.
 
 
 # Functions receiving (ui, features) that extensions can register to impact
 # the ability to load repositories with custom requirements. Only
 # functions defined in loaded extensions are called.
 #
 # The function receives a set of requirement strings that the repository
 # is capable of opening. Functions will typically add elements to the
 # set to reflect that the extension knows how to handle that requirements.
 featuresetupfuncs = set()
 
 
 def _getsharedvfs(hgvfs, requirements):
     """returns the vfs object pointing to root of shared source
     repo for a shared repository
 
     hgvfs is vfs pointing at .hg/ of current repo (shared one)
     requirements is a set of requirements of current repo (shared one)
     """
     # The ``shared`` or ``relshared`` requirements indicate the
     # store lives in the path contained in the ``.hg/sharedpath`` file.
     # This is an absolute path for ``shared`` and relative to
     # ``.hg/`` for ``relshared``.
     sharedpath = hgvfs.read(b'sharedpath').rstrip(b'\n')
     if requirementsmod.RELATIVE_SHARED_REQUIREMENT in requirements:
         sharedpath = hgvfs.join(sharedpath)
 
     sharedvfs = vfsmod.vfs(sharedpath, realpath=True)
 
     if not sharedvfs.exists():
         raise error.RepoError(
             _(b'.hg/sharedpath points to nonexistent directory %s')
             % sharedvfs.base
         )
     return sharedvfs
 
 
 def _readrequires(vfs, allowmissing):
     """reads the require file present at root of this vfs
     and return a set of requirements
 
     If allowmissing is True, we suppress ENOENT if raised"""
     # requires file contains a newline-delimited list of
     # features/capabilities the opener (us) must have in order to use
     # the repository. This file was introduced in Mercurial 0.9.2,
     # which means very old repositories may not have one. We assume
     # a missing file translates to no requirements.
     try:
         requirements = set(vfs.read(b'requires').splitlines())
     except IOError as e:
         if not (allowmissing and e.errno == errno.ENOENT):
             raise
         requirements = set()
     return requirements
 
 
 def makelocalrepository(baseui, path, intents=None):
     """Create a local repository object.
 
     Given arguments needed to construct a local repository, this function
     performs various early repository loading functionality (such as
     reading the ``.hg/requires`` and ``.hg/hgrc`` files), validates that
     the repository can be opened, derives a type suitable for representing
     that repository, and returns an instance of it.
 
     The returned object conforms to the ``repository.completelocalrepository``
     interface.
 
     The repository type is derived by calling a series of factory functions
     for each aspect/interface of the final repository. These are defined by
     ``REPO_INTERFACES``.
 
     Each factory function is called to produce a type implementing a specific
     interface. The cumulative list of returned types will be combined into a
     new type and that type will be instantiated to represent the local
     repository.
 
     The factory functions each receive various state that may be consulted
     as part of deriving a type.
 
     Extensions should wrap these factory functions to customize repository type
     creation. Note that an extension's wrapped function may be called even if
     that extension is not loaded for the repo being constructed. Extensions
     should check if their ``__name__`` appears in the
     ``extensionmodulenames`` set passed to the factory function and no-op if
     not.
     """
     ui = baseui.copy()
     # Prevent copying repo configuration.
     ui.copy = baseui.copy
 
     # Working directory VFS rooted at repository root.
     wdirvfs = vfsmod.vfs(path, expandpath=True, realpath=True)
 
     # Main VFS for .hg/ directory.
     hgpath = wdirvfs.join(b'.hg')
     hgvfs = vfsmod.vfs(hgpath, cacheaudited=True)
     # Whether this repository is shared one or not
     shared = False
     # If this repository is shared, vfs pointing to shared repo
     sharedvfs = None
 
     # The .hg/ path should exist and should be a directory. All other
     # cases are errors.
     if not hgvfs.isdir():
         try:
             hgvfs.stat()
         except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
         except ValueError as e:
             # Can be raised on Python 3.8 when path is invalid.
             raise error.Abort(
                 _(b'invalid path %s: %s') % (path, pycompat.bytestr(e))
             )
 
         raise error.RepoError(_(b'repository %s not found') % path)
 
     requirements = _readrequires(hgvfs, True)
     shared = (
         requirementsmod.SHARED_REQUIREMENT in requirements
         or requirementsmod.RELATIVE_SHARED_REQUIREMENT in requirements
     )
     storevfs = None
     if shared:
         # This is a shared repo
         sharedvfs = _getsharedvfs(hgvfs, requirements)
         storevfs = vfsmod.vfs(sharedvfs.join(b'store'))
     else:
         storevfs = vfsmod.vfs(hgvfs.join(b'store'))
 
     # if .hg/requires contains the sharesafe requirement, it means
     # there exists a `.hg/store/requires` too and we should read it
     # NOTE: presence of SHARESAFE_REQUIREMENT imply that store requirement
     # is present. We never write SHARESAFE_REQUIREMENT for a repo if store
     # is not present, refer checkrequirementscompat() for that
     #
     # However, if SHARESAFE_REQUIREMENT is not present, it means that the
     # repository was shared the old way. We check the share source .hg/requires
     # for SHARESAFE_REQUIREMENT to detect whether the current repository needs
     # to be reshared
     hint = _("see `hg help config.format.use-share-safe` for more information")
     if requirementsmod.SHARESAFE_REQUIREMENT in requirements:
 
         if (
             shared
             and requirementsmod.SHARESAFE_REQUIREMENT
             not in _readrequires(sharedvfs, True)
         ):
             mismatch_warn = ui.configbool(
                 b'share', b'safe-mismatch.source-not-safe.warn'
             )
             mismatch_config = ui.config(
                 b'share', b'safe-mismatch.source-not-safe'
             )
             if mismatch_config in (
                 b'downgrade-allow',
                 b'allow',
                 b'downgrade-abort',
             ):
                 # prevent cyclic import localrepo -> upgrade -> localrepo
                 from . import upgrade
 
                 upgrade.downgrade_share_to_non_safe(
                     ui,
                     hgvfs,
                     sharedvfs,
                     requirements,
                     mismatch_config,
                     mismatch_warn,
                 )
             elif mismatch_config == b'abort':
                 raise error.Abort(
                     _(b"share source does not support share-safe requirement"),
                     hint=hint,
                 )
             else:
                 raise error.Abort(
                     _(
                         b"share-safe mismatch with source.\nUnrecognized"
                         b" value '%s' of `share.safe-mismatch.source-not-safe`"
                         b" set."
                     )
                     % mismatch_config,
                     hint=hint,
                 )
         else:
             requirements |= _readrequires(storevfs, False)
     elif shared:
         sourcerequires = _readrequires(sharedvfs, False)
         if requirementsmod.SHARESAFE_REQUIREMENT in sourcerequires:
             mismatch_config = ui.config(b'share', b'safe-mismatch.source-safe')
             mismatch_warn = ui.configbool(
                 b'share', b'safe-mismatch.source-safe.warn'
             )
             if mismatch_config in (
                 b'upgrade-allow',
                 b'allow',
                 b'upgrade-abort',
             ):
                 # prevent cyclic import localrepo -> upgrade -> localrepo
                 from . import upgrade
 
                 upgrade.upgrade_share_to_safe(
                     ui,
                     hgvfs,
                     storevfs,
                     requirements,
                     mismatch_config,
                     mismatch_warn,
                 )
             elif mismatch_config == b'abort':
                 raise error.Abort(
                     _(
                         b'version mismatch: source uses share-safe'
                         b' functionality while the current share does not'
                     ),
                     hint=hint,
                 )
             else:
                 raise error.Abort(
                     _(
                         b"share-safe mismatch with source.\nUnrecognized"
                         b" value '%s' of `share.safe-mismatch.source-safe` set."
                     )
                     % mismatch_config,
                     hint=hint,
                 )
 
     # The .hg/hgrc file may load extensions or contain config options
     # that influence repository construction. Attempt to load it and
     # process any new extensions that it may have pulled in.
     if loadhgrc(ui, wdirvfs, hgvfs, requirements, sharedvfs):
         afterhgrcload(ui, wdirvfs, hgvfs, requirements)
         extensions.loadall(ui)
         extensions.populateui(ui)
 
     # Set of module names of extensions loaded for this repository.
     extensionmodulenames = {m.__name__ for n, m in extensions.extensions(ui)}
 
     supportedrequirements = gathersupportedrequirements(ui)
 
     # We first validate the requirements are known.
     ensurerequirementsrecognized(requirements, supportedrequirements)
 
     # Then we validate that the known set is reasonable to use together.
     ensurerequirementscompatible(ui, requirements)
 
     # TODO there are unhandled edge cases related to opening repositories with
     # shared storage. If storage is shared, we should also test for requirements
     # compatibility in the pointed-to repo. This entails loading the .hg/hgrc in
     # that repo, as that repo may load extensions needed to open it. This is a
     # bit complicated because we don't want the other hgrc to overwrite settings
     # in this hgrc.
     #
     # This bug is somewhat mitigated by the fact that we copy the .hg/requires
     # file when sharing repos. But if a requirement is added after the share is
     # performed, thereby introducing a new requirement for the opener, we may
     # will not see that and could encounter a run-time error interacting with
     # that shared store since it has an unknown-to-us requirement.
 
     # At this point, we know we should be capable of opening the repository.
     # Now get on with doing that.
 
     features = set()
 
     # The "store" part of the repository holds versioned data. How it is
     # accessed is determined by various requirements. If `shared` or
     # `relshared` requirements are present, this indicates current repository
     # is a share and store exists in path mentioned in `.hg/sharedpath`
     if shared:
         storebasepath = sharedvfs.base
         cachepath = sharedvfs.join(b'cache')
         features.add(repository.REPO_FEATURE_SHARED_STORAGE)
     else:
         storebasepath = hgvfs.base
         cachepath = hgvfs.join(b'cache')
     wcachepath = hgvfs.join(b'wcache')
 
     # The store has changed over time and the exact layout is dictated by
     # requirements. The store interface abstracts differences across all
     # of them.
     store = makestore(
         requirements,
         storebasepath,
         lambda base: vfsmod.vfs(base, cacheaudited=True),
     )
     hgvfs.createmode = store.createmode
 
     storevfs = store.vfs
     storevfs.options = resolvestorevfsoptions(ui, requirements, features)
 
     # The cache vfs is used to manage cache files.
     cachevfs = vfsmod.vfs(cachepath, cacheaudited=True)
     cachevfs.createmode = store.createmode
     # The cache vfs is used to manage cache files related to the working copy
     wcachevfs = vfsmod.vfs(wcachepath, cacheaudited=True)
     wcachevfs.createmode = store.createmode
 
     # Now resolve the type for the repository object. We do this by repeatedly
     # calling a factory function to produces types for specific aspects of the
     # repo's operation. The aggregate returned types are used as base classes
     # for a dynamically-derived type, which will represent our new repository.
 
     bases = []
     extrastate = {}
 
     for iface, fn in REPO_INTERFACES:
         # We pass all potentially useful state to give extensions tons of
         # flexibility.
         typ = fn()(
             ui=ui,
             intents=intents,
             requirements=requirements,
             features=features,
             wdirvfs=wdirvfs,
             hgvfs=hgvfs,
             store=store,
             storevfs=storevfs,
             storeoptions=storevfs.options,
             cachevfs=cachevfs,
             wcachevfs=wcachevfs,
             extensionmodulenames=extensionmodulenames,
             extrastate=extrastate,
             baseclasses=bases,
         )
 
         if not isinstance(typ, type):
             raise error.ProgrammingError(
                 b'unable to construct type for %s' % iface
             )
 
         bases.append(typ)
 
     # type() allows you to use characters in type names that wouldn't be
     # recognized as Python symbols in source code. We abuse that to add
     # rich information about our constructed repo.
     name = pycompat.sysstr(
         b'derivedrepo:%s<%s>' % (wdirvfs.base, b','.join(sorted(requirements)))
     )
 
     cls = type(name, tuple(bases), {})
 
     return cls(
         baseui=baseui,
         ui=ui,
         origroot=path,
         wdirvfs=wdirvfs,
         hgvfs=hgvfs,
         requirements=requirements,
         supportedrequirements=supportedrequirements,
         sharedpath=storebasepath,
         store=store,
         cachevfs=cachevfs,
         wcachevfs=wcachevfs,
         features=features,
         intents=intents,
     )
 
 
 def loadhgrc(ui, wdirvfs, hgvfs, requirements, sharedvfs=None):
     """Load hgrc files/content into a ui instance.
 
     This is called during repository opening to load any additional
     config files or settings relevant to the current repository.
 
     Returns a bool indicating whether any additional configs were loaded.
 
     Extensions should monkeypatch this function to modify how per-repo
     configs are loaded. For example, an extension may wish to pull in
     configs from alternate files or sources.
 
     sharedvfs is vfs object pointing to source repo if the current one is a
     shared one
     """
     if not rcutil.use_repo_hgrc():
         return False
 
     ret = False
     # first load config from shared source if we has to
     if requirementsmod.SHARESAFE_REQUIREMENT in requirements and sharedvfs:
         try:
             ui.readconfig(sharedvfs.join(b'hgrc'), root=sharedvfs.base)
             ret = True
         except IOError:
             pass
 
     try:
         ui.readconfig(hgvfs.join(b'hgrc'), root=wdirvfs.base)
         ret = True
     except IOError:
         pass
 
     try:
         ui.readconfig(hgvfs.join(b'hgrc-not-shared'), root=wdirvfs.base)
         ret = True
     except IOError:
         pass
 
     return ret
 
 
 def afterhgrcload(ui, wdirvfs, hgvfs, requirements):
     """Perform additional actions after .hg/hgrc is loaded.
 
     This function is called during repository loading immediately after
     the .hg/hgrc file is loaded and before per-repo extensions are loaded.
 
     The function can be used to validate configs, automatically add
     options (including extensions) based on requirements, etc.
     """
 
     # Map of requirements to list of extensions to load automatically when
     # requirement is present.
     autoextensions = {
         b'git': [b'git'],
         b'largefiles': [b'largefiles'],
         b'lfs': [b'lfs'],
     }
 
     for requirement, names in sorted(autoextensions.items()):
         if requirement not in requirements:
             continue
 
         for name in names:
             if not ui.hasconfig(b'extensions', name):
                 ui.setconfig(b'extensions', name, b'', source=b'autoload')
 
 
 def gathersupportedrequirements(ui):
     """Determine the complete set of recognized requirements."""
     # Start with all requirements supported by this file.
     supported = set(localrepository._basesupported)
 
     # Execute ``featuresetupfuncs`` entries if they belong to an extension
     # relevant to this ui instance.
     modules = {m.__name__ for n, m in extensions.extensions(ui)}
 
     for fn in featuresetupfuncs:
         if fn.__module__ in modules:
             fn(ui, supported)
 
     # Add derived requirements from registered compression engines.
     for name in util.compengines:
         engine = util.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
 
     return supported
 
 
 def ensurerequirementsrecognized(requirements, supported):
     """Validate that a set of local requirements is recognized.
 
     Receives a set of requirements. Raises an ``error.RepoError`` if there
     exists any requirement in that set that currently loaded code doesn't
     recognize.
 
     Returns a set of supported requirements.
     """
     missing = set()
 
     for requirement in requirements:
         if requirement in supported:
             continue
 
         if not requirement or not requirement[0:1].isalnum():
             raise error.RequirementError(_(b'.hg/requires file is corrupt'))
 
         missing.add(requirement)
 
     if missing:
         raise error.RequirementError(
             _(b'repository requires features unknown to this Mercurial: %s')
             % b' '.join(sorted(missing)),
             hint=_(
                 b'see https://mercurial-scm.org/wiki/MissingRequirement '
                 b'for more information'
             ),
         )
 
 
 def ensurerequirementscompatible(ui, requirements):
     """Validates that a set of recognized requirements is mutually compatible.
 
     Some requirements may not be compatible with others or require
     config options that aren't enabled. This function is called during
     repository opening to ensure that the set of requirements needed
     to open a repository is sane and compatible with config options.
 
     Extensions can monkeypatch this function to perform additional
     checking.
 
     ``error.RepoError`` should be raised on failure.
     """
     if (
         requirementsmod.SPARSE_REQUIREMENT in requirements
         and not sparse.enabled
     ):
         raise error.RepoError(
             _(
                 b'repository is using sparse feature but '
                 b'sparse is not enabled; enable the '
                 b'"sparse" extensions to access'
             )
         )
 
 
 def makestore(requirements, path, vfstype):
     """Construct a storage object for a repository."""
     if b'store' in requirements:
         if b'fncache' in requirements:
             return storemod.fncachestore(
                 path, vfstype, b'dotencode' in requirements
             )
 
         return storemod.encodedstore(path, vfstype)
 
     return storemod.basicstore(path, vfstype)
 
 
 def resolvestorevfsoptions(ui, requirements, features):
     """Resolve the options to pass to the store vfs opener.
 
     The returned dict is used to influence behavior of the storage layer.
     """
     options = {}
 
     if requirementsmod.TREEMANIFEST_REQUIREMENT in requirements:
         options[b'treemanifest'] = True
 
     # experimental config: format.manifestcachesize
     manifestcachesize = ui.configint(b'format', b'manifestcachesize')
     if manifestcachesize is not None:
         options[b'manifestcachesize'] = manifestcachesize
 
     # In the absence of another requirement superseding a revlog-related
     # requirement, we have to assume the repo is using revlog version 0.
     # This revlog format is super old and we don't bother trying to parse
     # opener options for it because those options wouldn't do anything
     # meaningful on such old repos.
     if (
         requirementsmod.REVLOGV1_REQUIREMENT in requirements
         or requirementsmod.REVLOGV2_REQUIREMENT in requirements
     ):
         options.update(resolverevlogstorevfsoptions(ui, requirements, features))
     else:  # explicitly mark repo as using revlogv0
         options[b'revlogv0'] = True
 
     if requirementsmod.COPIESSDC_REQUIREMENT in requirements:
         options[b'copies-storage'] = b'changeset-sidedata'
     else:
         writecopiesto = ui.config(b'experimental', b'copies.write-to')
         copiesextramode = (b'changeset-only', b'compatibility')
         if writecopiesto in copiesextramode:
             options[b'copies-storage'] = b'extra'
 
     return options
 
 
 def resolverevlogstorevfsoptions(ui, requirements, features):
     """Resolve opener options specific to revlogs."""
 
     options = {}
     options[b'flagprocessors'] = {}
 
     if requirementsmod.REVLOGV1_REQUIREMENT in requirements:
         options[b'revlogv1'] = True
     if requirementsmod.REVLOGV2_REQUIREMENT in requirements:
         options[b'revlogv2'] = True
 
-    if b'generaldelta' in requirements:
+    if requirementsmod.GENERALDELTA_REQUIREMENT in requirements:
         options[b'generaldelta'] = True
 
     # experimental config: format.chunkcachesize
     chunkcachesize = ui.configint(b'format', b'chunkcachesize')
     if chunkcachesize is not None:
         options[b'chunkcachesize'] = chunkcachesize
 
     deltabothparents = ui.configbool(
         b'storage', b'revlog.optimize-delta-parent-choice'
     )
     options[b'deltabothparents'] = deltabothparents
 
     lazydelta = ui.configbool(b'storage', b'revlog.reuse-external-delta')
     lazydeltabase = False
     if lazydelta:
         lazydeltabase = ui.configbool(
             b'storage', b'revlog.reuse-external-delta-parent'
         )
     if lazydeltabase is None:
         lazydeltabase = not scmutil.gddeltaconfig(ui)
     options[b'lazydelta'] = lazydelta
     options[b'lazydeltabase'] = lazydeltabase
 
     chainspan = ui.configbytes(b'experimental', b'maxdeltachainspan')
     if 0 <= chainspan:
         options[b'maxdeltachainspan'] = chainspan
 
     mmapindexthreshold = ui.configbytes(b'experimental', b'mmapindexthreshold')
     if mmapindexthreshold is not None:
         options[b'mmapindexthreshold'] = mmapindexthreshold
 
     withsparseread = ui.configbool(b'experimental', b'sparse-read')
     srdensitythres = float(
         ui.config(b'experimental', b'sparse-read.density-threshold')
     )
     srmingapsize = ui.configbytes(b'experimental', b'sparse-read.min-gap-size')
     options[b'with-sparse-read'] = withsparseread
     options[b'sparse-read-density-threshold'] = srdensitythres
     options[b'sparse-read-min-gap-size'] = srmingapsize
 
     sparserevlog = requirementsmod.SPARSEREVLOG_REQUIREMENT in requirements
     options[b'sparse-revlog'] = sparserevlog
     if sparserevlog:
         options[b'generaldelta'] = True
 
     sidedata = requirementsmod.SIDEDATA_REQUIREMENT in requirements
     options[b'side-data'] = sidedata
 
     maxchainlen = None
     if sparserevlog:
         maxchainlen = revlogconst.SPARSE_REVLOG_MAX_CHAIN_LENGTH
     # experimental config: format.maxchainlen
     maxchainlen = ui.configint(b'format', b'maxchainlen', maxchainlen)
     if maxchainlen is not None:
         options[b'maxchainlen'] = maxchainlen
 
     for r in requirements:
         # we allow multiple compression engine requirement to co-exist because
         # strickly speaking, revlog seems to support mixed compression style.
         #
         # The compression used for new entries will be "the last one"
         prefix = r.startswith
         if prefix(b'revlog-compression-') or prefix(b'exp-compression-'):
             options[b'compengine'] = r.split(b'-', 2)[2]
 
     options[b'zlib.level'] = ui.configint(b'storage', b'revlog.zlib.level')
     if options[b'zlib.level'] is not None:
         if not (0 <= options[b'zlib.level'] <= 9):
             msg = _(b'invalid value for `storage.revlog.zlib.level` config: %d')
             raise error.Abort(msg % options[b'zlib.level'])
     options[b'zstd.level'] = ui.configint(b'storage', b'revlog.zstd.level')
     if options[b'zstd.level'] is not None:
         if not (0 <= options[b'zstd.level'] <= 22):
             msg = _(b'invalid value for `storage.revlog.zstd.level` config: %d')
             raise error.Abort(msg % options[b'zstd.level'])
 
     if requirementsmod.NARROW_REQUIREMENT in requirements:
         options[b'enableellipsis'] = True
 
     if ui.configbool(b'experimental', b'rust.index'):
         options[b'rust.index'] = True
     if requirementsmod.NODEMAP_REQUIREMENT in requirements:
         slow_path = ui.config(
             b'storage', b'revlog.persistent-nodemap.slow-path'
         )
         if slow_path not in (b'allow', b'warn', b'abort'):
             default = ui.config_default(
                 b'storage', b'revlog.persistent-nodemap.slow-path'
             )
             msg = _(
                 b'unknown value for config '
                 b'"storage.revlog.persistent-nodemap.slow-path": "%s"\n'
             )
             ui.warn(msg % slow_path)
             if not ui.quiet:
                 ui.warn(_(b'falling back to default value: %s\n') % default)
             slow_path = default
 
         msg = _(
             b"accessing `persistent-nodemap` repository without associated "
             b"fast implementation."
         )
         hint = _(
             b"check `hg help config.format.use-persistent-nodemap` "
             b"for details"
         )
         if not revlog.HAS_FAST_PERSISTENT_NODEMAP:
             if slow_path == b'warn':
                 msg = b"warning: " + msg + b'\n'
                 ui.warn(msg)
                 if not ui.quiet:
                     hint = b'(' + hint + b')\n'
                     ui.warn(hint)
             if slow_path == b'abort':
                 raise error.Abort(msg, hint=hint)
         options[b'persistent-nodemap'] = True
     if ui.configbool(b'storage', b'revlog.persistent-nodemap.mmap'):
         options[b'persistent-nodemap.mmap'] = True
     if ui.configbool(b'devel', b'persistent-nodemap'):
         options[b'devel-force-nodemap'] = True
 
     return options
 
 
 def makemain(**kwargs):
     """Produce a type conforming to ``ilocalrepositorymain``."""
     return localrepository
 
 
 @interfaceutil.implementer(repository.ilocalrepositoryfilestorage)
 class revlogfilestorage(object):
     """File storage when using revlogs."""
 
     def file(self, path):
         if path[0] == b'/':
             path = path[1:]
 
         return filelog.filelog(self.svfs, path)
 
 
 @interfaceutil.implementer(repository.ilocalrepositoryfilestorage)
 class revlognarrowfilestorage(object):
     """File storage when using revlogs and narrow files."""
 
     def file(self, path):
         if path[0] == b'/':
             path = path[1:]
 
         return filelog.narrowfilelog(self.svfs, path, self._storenarrowmatch)
 
 
 def makefilestorage(requirements, features, **kwargs):
     """Produce a type conforming to ``ilocalrepositoryfilestorage``."""
     features.add(repository.REPO_FEATURE_REVLOG_FILE_STORAGE)
     features.add(repository.REPO_FEATURE_STREAM_CLONE)
 
     if requirementsmod.NARROW_REQUIREMENT in requirements:
         return revlognarrowfilestorage
     else:
         return revlogfilestorage
 
 
 # List of repository interfaces and factory functions for them. Each
 # will be called in order during ``makelocalrepository()`` to iteratively
 # derive the final type for a local repository instance. We capture the
 # function as a lambda so we don't hold a reference and the module-level
 # functions can be wrapped.
 REPO_INTERFACES = [
     (repository.ilocalrepositorymain, lambda: makemain),
     (repository.ilocalrepositoryfilestorage, lambda: makefilestorage),
 ]
 
 
 @interfaceutil.implementer(repository.ilocalrepositorymain)
 class localrepository(object):
     """Main class for representing local repositories.
 
     All local repositories are instances of this class.
 
     Constructed on its own, instances of this class are not usable as
     repository objects. To obtain a usable repository object, call
     ``hg.repository()``, ``localrepo.instance()``, or
     ``localrepo.makelocalrepository()``. The latter is the lowest-level.
     ``instance()`` adds support for creating new repositories.
     ``hg.repository()`` adds more extension integration, including calling
     ``reposetup()``. Generally speaking, ``hg.repository()`` should be
     used.
     """
 
     # obsolete experimental requirements:
     #  - manifestv2: An experimental new manifest format that allowed
     #    for stem compression of long paths. Experiment ended up not
     #    being successful (repository sizes went up due to worse delta
     #    chains), and the code was deleted in 4.6.
     supportedformats = {
         requirementsmod.REVLOGV1_REQUIREMENT,
-        b'generaldelta',
+        requirementsmod.GENERALDELTA_REQUIREMENT,
         requirementsmod.TREEMANIFEST_REQUIREMENT,
         requirementsmod.COPIESSDC_REQUIREMENT,
         requirementsmod.REVLOGV2_REQUIREMENT,
         requirementsmod.SIDEDATA_REQUIREMENT,
         requirementsmod.SPARSEREVLOG_REQUIREMENT,
         requirementsmod.NODEMAP_REQUIREMENT,
         bookmarks.BOOKMARKS_IN_STORE_REQUIREMENT,
         requirementsmod.SHARESAFE_REQUIREMENT,
     }
     _basesupported = supportedformats | {
         b'store',
         b'fncache',
         requirementsmod.SHARED_REQUIREMENT,
         requirementsmod.RELATIVE_SHARED_REQUIREMENT,
         b'dotencode',
         requirementsmod.SPARSE_REQUIREMENT,
         requirementsmod.INTERNAL_PHASE_REQUIREMENT,
     }
 
     # list of prefix for file which can be written without 'wlock'
     # Extensions should extend this list when needed
     _wlockfreeprefix = {
         # We migh consider requiring 'wlock' for the next
         # two, but pretty much all the existing code assume
         # wlock is not needed so we keep them excluded for
         # now.
         b'hgrc',
         b'requires',
         # XXX cache is a complicatged business someone
         # should investigate this in depth at some point
         b'cache/',
         # XXX shouldn't be dirstate covered by the wlock?
         b'dirstate',
         # XXX bisect was still a bit too messy at the time
         # this changeset was introduced. Someone should fix
         # the remainig bit and drop this line
         b'bisect.state',
     }
 
     def __init__(
         self,
         baseui,
         ui,
         origroot,
         wdirvfs,
         hgvfs,
         requirements,
         supportedrequirements,
         sharedpath,
         store,
         cachevfs,
         wcachevfs,
         features,
         intents=None,
     ):
         """Create a new local repository instance.
 
         Most callers should use ``hg.repository()``, ``localrepo.instance()``,
         or ``localrepo.makelocalrepository()`` for obtaining a new repository
         object.
 
         Arguments:
 
         baseui
            ``ui.ui`` instance that ``ui`` argument was based off of.
 
         ui
            ``ui.ui`` instance for use by the repository.
 
         origroot
            ``bytes`` path to working directory root of this repository.
 
         wdirvfs
            ``vfs.vfs`` rooted at the working directory.
 
         hgvfs
            ``vfs.vfs`` rooted at .hg/
 
         requirements
            ``set`` of bytestrings representing repository opening requirements.
 
         supportedrequirements
            ``set`` of bytestrings representing repository requirements that we
            know how to open. May be a supetset of ``requirements``.
 
         sharedpath
            ``bytes`` Defining path to storage base directory. Points to a
            ``.hg/`` directory somewhere.
 
         store
            ``store.basicstore`` (or derived) instance providing access to
            versioned storage.
 
         cachevfs
            ``vfs.vfs`` used for cache files.
 
         wcachevfs
            ``vfs.vfs`` used for cache files related to the working copy.
 
         features
            ``set`` of bytestrings defining features/capabilities of this
            instance.
 
         intents
            ``set`` of system strings indicating what this repo will be used
            for.
         """
         self.baseui = baseui
         self.ui = ui
         self.origroot = origroot
         # vfs rooted at working directory.
         self.wvfs = wdirvfs
         self.root = wdirvfs.base
         # vfs rooted at .hg/. Used to access most non-store paths.
         self.vfs = hgvfs
         self.path = hgvfs.base
         self.requirements = requirements
         self.supported = supportedrequirements
         self.sharedpath = sharedpath
         self.store = store
         self.cachevfs = cachevfs
         self.wcachevfs = wcachevfs
         self.features = features
 
         self.filtername = None
 
         if self.ui.configbool(b'devel', b'all-warnings') or self.ui.configbool(
             b'devel', b'check-locks'
         ):
             self.vfs.audit = self._getvfsward(self.vfs.audit)
         # A list of callback to shape the phase if no data were found.
         # Callback are in the form: func(repo, roots) --> processed root.
         # This list it to be filled by extension during repo setup
         self._phasedefaults = []
 
         color.setup(self.ui)
 
         self.spath = self.store.path
         self.svfs = self.store.vfs
         self.sjoin = self.store.join
         if self.ui.configbool(b'devel', b'all-warnings') or self.ui.configbool(
             b'devel', b'check-locks'
         ):
             if util.safehasattr(self.svfs, b'vfs'):  # this is filtervfs
                 self.svfs.vfs.audit = self._getsvfsward(self.svfs.vfs.audit)
             else:  # standard vfs
                 self.svfs.audit = self._getsvfsward(self.svfs.audit)
 
         self._dirstatevalidatewarned = False
 
         self._branchcaches = branchmap.BranchMapCache()
         self._revbranchcache = None
         self._filterpats = {}
         self._datafilters = {}
         self._transref = self._lockref = self._wlockref = None
 
         # A cache for various files under .hg/ that tracks file changes,
         # (used by the filecache decorator)
         #
         # Maps a property name to its util.filecacheentry
         self._filecache = {}
 
         # hold sets of revision to be filtered
         # should be cleared when something might have changed the filter value:
         # - new changesets,
         # - phase change,
         # - new obsolescence marker,
         # - working directory parent change,
         # - bookmark changes
         self.filteredrevcache = {}
 
         # post-dirstate-status hooks
         self._postdsstatus = []
 
         # generic mapping between names and nodes
         self.names = namespaces.namespaces()
 
         # Key to signature value.
         self._sparsesignaturecache = {}
         # Signature to cached matcher instance.
         self._sparsematchercache = {}
 
         self._extrafilterid = repoview.extrafilter(ui)
 
         self.filecopiesmode = None
         if requirementsmod.COPIESSDC_REQUIREMENT in self.requirements:
             self.filecopiesmode = b'changeset-sidedata'
 
     def _getvfsward(self, origfunc):
         """build a ward for self.vfs"""
         rref = weakref.ref(self)
 
         def checkvfs(path, mode=None):
             ret = origfunc(path, mode=mode)
             repo = rref()
             if (
                 repo is None
                 or not util.safehasattr(repo, b'_wlockref')
                 or not util.safehasattr(repo, b'_lockref')
             ):
                 return
             if mode in (None, b'r', b'rb'):
                 return
             if path.startswith(repo.path):
                 # truncate name relative to the repository (.hg)
                 path = path[len(repo.path) + 1 :]
             if path.startswith(b'cache/'):
                 msg = b'accessing cache with vfs instead of cachevfs: "%s"'
                 repo.ui.develwarn(msg % path, stacklevel=3, config=b"cache-vfs")
             # path prefixes covered by 'lock'
             vfs_path_prefixes = (
                 b'journal.',
                 b'undo.',
                 b'strip-backup/',
                 b'cache/',
             )
             if any(path.startswith(prefix) for prefix in vfs_path_prefixes):
                 if repo._currentlock(repo._lockref) is None:
                     repo.ui.develwarn(
                         b'write with no lock: "%s"' % path,
                         stacklevel=3,
                         config=b'check-locks',
                     )
             elif repo._currentlock(repo._wlockref) is None:
                 # rest of vfs files are covered by 'wlock'
                 #
                 # exclude special files
                 for prefix in self._wlockfreeprefix:
                     if path.startswith(prefix):
                         return
                 repo.ui.develwarn(
                     b'write with no wlock: "%s"' % path,
                     stacklevel=3,
                     config=b'check-locks',
                 )
             return ret
 
         return checkvfs
 
     def _getsvfsward(self, origfunc):
         """build a ward for self.svfs"""
         rref = weakref.ref(self)
 
         def checksvfs(path, mode=None):
             ret = origfunc(path, mode=mode)
             repo = rref()
             if repo is None or not util.safehasattr(repo, b'_lockref'):
                 return
             if mode in (None, b'r', b'rb'):
                 return
             if path.startswith(repo.sharedpath):
                 # truncate name relative to the repository (.hg)
                 path = path[len(repo.sharedpath) + 1 :]
             if repo._currentlock(repo._lockref) is None:
                 repo.ui.develwarn(
                     b'write with no lock: "%s"' % path, stacklevel=4
                 )
             return ret
 
         return checksvfs
 
     def close(self):
         self._writecaches()
 
     def _writecaches(self):
         if self._revbranchcache:
             self._revbranchcache.write()
 
     def _restrictcapabilities(self, caps):
         if self.ui.configbool(b'experimental', b'bundle2-advertise'):
             caps = set(caps)
             capsblob = bundle2.encodecaps(
                 bundle2.getrepocaps(self, role=b'client')
             )
             caps.add(b'bundle2=' + urlreq.quote(capsblob))
         return caps
 
     # Don't cache auditor/nofsauditor, or you'll end up with reference cycle:
     # self -> auditor -> self._checknested -> self
 
     @property
     def auditor(self):
         # This is only used by context.workingctx.match in order to
         # detect files in subrepos.
         return pathutil.pathauditor(self.root, callback=self._checknested)
 
     @property
     def nofsauditor(self):
         # This is only used by context.basectx.match in order to detect
         # files in subrepos.
         return pathutil.pathauditor(
             self.root, callback=self._checknested, realfs=False, cached=True
         )
 
     def _checknested(self, path):
         """Determine if path is a legal nested repository."""
         if not path.startswith(self.root):
             return False
         subpath = path[len(self.root) + 1 :]
         normsubpath = util.pconvert(subpath)
 
         # XXX: Checking against the current working copy is wrong in
         # the sense that it can reject things like
         #
         #   $ hg cat -r 10 sub/x.txt
         #
         # if sub/ is no longer a subrepository in the working copy
         # parent revision.
         #
         # However, it can of course also allow things that would have
         # been rejected before, such as the above cat command if sub/
         # is a subrepository now, but was a normal directory before.
         # The old path auditor would have rejected by mistake since it
         # panics when it sees sub/.hg/.
         #
         # All in all, checking against the working copy seems sensible
         # since we want to prevent access to nested repositories on
         # the filesystem *now*.
         ctx = self[None]
         parts = util.splitpath(subpath)
         while parts:
             prefix = b'/'.join(parts)
             if prefix in ctx.substate:
                 if prefix == normsubpath:
                     return True
                 else:
                     sub = ctx.sub(prefix)
                     return sub.checknested(subpath[len(prefix) + 1 :])
             else:
                 parts.pop()
         return False
 
     def peer(self):
         return localpeer(self)  # not cached to avoid reference cycle
 
     def unfiltered(self):
         """Return unfiltered version of the repository
 
         Intended to be overwritten by filtered repo."""
         return self
 
     def filtered(self, name, visibilityexceptions=None):
         """Return a filtered version of a repository
 
         The `name` parameter is the identifier of the requested view. This
         will return a repoview object set "exactly" to the specified view.
 
         This function does not apply recursive filtering to a repository. For
         example calling `repo.filtered("served")` will return a repoview using
         the "served" view, regardless of the initial view used by `repo`.
 
         In other word, there is always only one level of `repoview` "filtering".
         """
         if self._extrafilterid is not None and b'%' not in name:
             name = name + b'%' + self._extrafilterid
 
         cls = repoview.newtype(self.unfiltered().__class__)
         return cls(self, name, visibilityexceptions)
 
     @mixedrepostorecache(
         (b'bookmarks', b'plain'),
         (b'bookmarks.current', b'plain'),
         (b'bookmarks', b''),
         (b'00changelog.i', b''),
     )
     def _bookmarks(self):
         # Since the multiple files involved in the transaction cannot be
         # written atomically (with current repository format), there is a race
         # condition here.
         #
         # 1) changelog content A is read
         # 2) outside transaction update changelog to content B
         # 3) outside transaction update bookmark file referring to content B
         # 4) bookmarks file content is read and filtered against changelog-A
         #
         # When this happens, bookmarks against nodes missing from A are dropped.
         #
         # Having this happening during read is not great, but it become worse
         # when this happen during write because the bookmarks to the "unknown"
         # nodes will be dropped for good. However, writes happen within locks.
         # This locking makes it possible to have a race free consistent read.
         # For this purpose data read from disc before locking  are
         # "invalidated" right after the locks are taken. This invalidations are
         # "light", the `filecache` mechanism keep the data in memory and will
         # reuse them if the underlying files did not changed. Not parsing the
         # same data multiple times helps performances.
         #
         # Unfortunately in the case describe above, the files tracked by the
         # bookmarks file cache might not have changed, but the in-memory
         # content is still "wrong" because we used an older changelog content
         # to process the on-disk data. So after locking, the changelog would be
         # refreshed but `_bookmarks` would be preserved.
         # Adding `00changelog.i` to the list of tracked file is not
         # enough, because at the time we build the content for `_bookmarks` in
         # (4), the changelog file has already diverged from the content used
         # for loading `changelog` in (1)
         #
         # To prevent the issue, we force the changelog to be explicitly
         # reloaded while computing `_bookmarks`. The data race can still happen
         # without the lock (with a narrower window), but it would no longer go
         # undetected during the lock time refresh.
         #
         # The new schedule is as follow
         #
         # 1) filecache logic detect that `_bookmarks` needs to be computed
         # 2) cachestat for `bookmarks` and `changelog` are captured (for book)
         # 3) We force `changelog` filecache to be tested
         # 4) cachestat for `changelog` are captured (for changelog)
         # 5) `_bookmarks` is computed and cached
         #
         # The step in (3) ensure we have a changelog at least as recent as the
         # cache stat computed in (1). As a result at locking time:
         #  * if the changelog did not changed since (1) -> we can reuse the data
         #  * otherwise -> the bookmarks get refreshed.
         self._refreshchangelog()
         return bookmarks.bmstore(self)
 
     def _refreshchangelog(self):
         """make sure the in memory changelog match the on-disk one"""
         if 'changelog' in vars(self) and self.currenttransaction() is None:
             del self.changelog
 
     @property
     def _activebookmark(self):
         return self._bookmarks.active
 
     # _phasesets depend on changelog. what we need is to call
     # _phasecache.invalidate() if '00changelog.i' was changed, but it
     # can't be easily expressed in filecache mechanism.
     @storecache(b'phaseroots', b'00changelog.i')
     def _phasecache(self):
         return phases.phasecache(self, self._phasedefaults)
 
     @storecache(b'obsstore')
     def obsstore(self):
         return obsolete.makestore(self.ui, self)
 
     @storecache(b'00changelog.i')
     def changelog(self):
         # load dirstate before changelog to avoid race see issue6303
         self.dirstate.prefetch_parents()
         return self.store.changelog(
             txnutil.mayhavepending(self.root),
             concurrencychecker=revlogchecker.get_checker(self.ui, b'changelog'),
         )
 
     @storecache(b'00manifest.i')
     def manifestlog(self):
         return self.store.manifestlog(self, self._storenarrowmatch)
 
     @repofilecache(b'dirstate')
     def dirstate(self):
         return self._makedirstate()
 
     def _makedirstate(self):
         """Extension point for wrapping the dirstate per-repo."""
         sparsematchfn = lambda: sparse.matcher(self)
 
         return dirstate.dirstate(
             self.vfs, self.ui, self.root, self._dirstatevalidate, sparsematchfn
         )
 
     def _dirstatevalidate(self, node):
         try:
             self.changelog.rev(node)
             return node
         except error.LookupError:
             if not self._dirstatevalidatewarned:
                 self._dirstatevalidatewarned = True
                 self.ui.warn(
                     _(b"warning: ignoring unknown working parent %s!\n")
                     % short(node)
                 )
             return nullid
 
     @storecache(narrowspec.FILENAME)
     def narrowpats(self):
         """matcher patterns for this repository's narrowspec
 
         A tuple of (includes, excludes).
         """
         return narrowspec.load(self)
 
     @storecache(narrowspec.FILENAME)
     def _storenarrowmatch(self):
         if requirementsmod.NARROW_REQUIREMENT not in self.requirements:
             return matchmod.always()
         include, exclude = self.narrowpats
         return narrowspec.match(self.root, include=include, exclude=exclude)
 
     @storecache(narrowspec.FILENAME)
     def _narrowmatch(self):
         if requirementsmod.NARROW_REQUIREMENT not in self.requirements:
             return matchmod.always()
         narrowspec.checkworkingcopynarrowspec(self)
         include, exclude = self.narrowpats
         return narrowspec.match(self.root, include=include, exclude=exclude)
 
     def narrowmatch(self, match=None, includeexact=False):
         """matcher corresponding the the repo's narrowspec
 
         If `match` is given, then that will be intersected with the narrow
         matcher.
 
         If `includeexact` is True, then any exact matches from `match` will
         be included even if they're outside the narrowspec.
         """
         if match:
             if includeexact and not self._narrowmatch.always():
                 # do not exclude explicitly-specified paths so that they can
                 # be warned later on
                 em = matchmod.exact(match.files())
                 nm = matchmod.unionmatcher([self._narrowmatch, em])
                 return matchmod.intersectmatchers(match, nm)
             return matchmod.intersectmatchers(match, self._narrowmatch)
         return self._narrowmatch
 
     def setnarrowpats(self, newincludes, newexcludes):
         narrowspec.save(self, newincludes, newexcludes)
         self.invalidate(clearfilecache=True)
 
     @unfilteredpropertycache
     def _quick_access_changeid_null(self):
         return {
             b'null': (nullrev, nullid),
             nullrev: (nullrev, nullid),
             nullid: (nullrev, nullid),
         }
 
     @unfilteredpropertycache
     def _quick_access_changeid_wc(self):
         # also fast path access to the working copy parents
         # however, only do it for filter that ensure wc is visible.
         quick = self._quick_access_changeid_null.copy()
         cl = self.unfiltered().changelog
         for node in self.dirstate.parents():
             if node == nullid:
                 continue
             rev = cl.index.get_rev(node)
             if rev is None:
                 # unknown working copy parent case:
                 #
                 #   skip the fast path and let higher code deal with it
                 continue
             pair = (rev, node)
             quick[rev] = pair
             quick[node] = pair
             # also add the parents of the parents
             for r in cl.parentrevs(rev):
                 if r == nullrev:
                     continue
                 n = cl.node(r)
                 pair = (r, n)
                 quick[r] = pair
                 quick[n] = pair
         p1node = self.dirstate.p1()
         if p1node != nullid:
             quick[b'.'] = quick[p1node]
         return quick
 
     @unfilteredmethod
     def _quick_access_changeid_invalidate(self):
         if '_quick_access_changeid_wc' in vars(self):
             del self.__dict__['_quick_access_changeid_wc']
 
     @property
     def _quick_access_changeid(self):
         """an helper dictionnary for __getitem__ calls
 
         This contains a list of symbol we can recognise right away without
         further processing.
         """
         if self.filtername in repoview.filter_has_wc:
             return self._quick_access_changeid_wc
         return self._quick_access_changeid_null
 
     def __getitem__(self, changeid):
         # dealing with special cases
         if changeid is None:
             return context.workingctx(self)
         if isinstance(changeid, context.basectx):
             return changeid
 
         # dealing with multiple revisions
         if isinstance(changeid, slice):
             # wdirrev isn't contiguous so the slice shouldn't include it
             return [
                 self[i]
                 for i in pycompat.xrange(*changeid.indices(len(self)))
                 if i not in self.changelog.filteredrevs
             ]
 
         # dealing with some special values
         quick_access = self._quick_access_changeid.get(changeid)
         if quick_access is not None:
             rev, node = quick_access
             return context.changectx(self, rev, node, maybe_filtered=False)
         if changeid == b'tip':
             node = self.changelog.tip()
             rev = self.changelog.rev(node)
             return context.changectx(self, rev, node)
 
         # dealing with arbitrary values
         try:
             if isinstance(changeid, int):
                 node = self.changelog.node(changeid)
                 rev = changeid
             elif changeid == b'.':
                 # this is a hack to delay/avoid loading obsmarkers
                 # when we know that '.' won't be hidden
                 node = self.dirstate.p1()
                 rev = self.unfiltered().changelog.rev(node)
             elif len(changeid) == 20:
                 try:
                     node = changeid
                     rev = self.changelog.rev(changeid)
                 except error.FilteredLookupError:
                     changeid = hex(changeid)  # for the error message
                     raise
                 except LookupError:
                     # check if it might have come from damaged dirstate
                     #
                     # XXX we could avoid the unfiltered if we had a recognizable
                     # exception for filtered changeset access
                     if (
                         self.local()
                         and changeid in self.unfiltered().dirstate.parents()
                     ):
                         msg = _(b"working directory has unknown parent '%s'!")
                         raise error.Abort(msg % short(changeid))
                     changeid = hex(changeid)  # for the error message
                     raise
 
             elif len(changeid) == 40:
                 node = bin(changeid)
                 rev = self.changelog.rev(node)
             else:
                 raise error.ProgrammingError(
                     b"unsupported changeid '%s' of type %s"
                     % (changeid, pycompat.bytestr(type(changeid)))
                 )
 
             return context.changectx(self, rev, node)
 
         except (error.FilteredIndexError, error.FilteredLookupError):
             raise error.FilteredRepoLookupError(
                 _(b"filtered revision '%s'") % pycompat.bytestr(changeid)
             )
         except (IndexError, LookupError):
             raise error.RepoLookupError(
                 _(b"unknown revision '%s'") % pycompat.bytestr(changeid)
             )
         except error.WdirUnsupported:
             return context.workingctx(self)
 
     def __contains__(self, changeid):
         """True if the given changeid exists"""
         try:
             self[changeid]
             return True
         except error.RepoLookupError:
             return False
 
     def __nonzero__(self):
         return True
 
     __bool__ = __nonzero__
 
     def __len__(self):
         # no need to pay the cost of repoview.changelog
         unfi = self.unfiltered()
         return len(unfi.changelog)
 
     def __iter__(self):
         return iter(self.changelog)
 
     def revs(self, expr, *args):
         """Find revisions matching a revset.
 
         The revset is specified as a string ``expr`` that may contain
         %-formatting to escape certain types. See ``revsetlang.formatspec``.
 
         Revset aliases from the configuration are not expanded. To expand
         user aliases, consider calling ``scmutil.revrange()`` or
         ``repo.anyrevs([expr], user=True)``.
 
         Returns a smartset.abstractsmartset, which is a list-like interface
         that contains integer revisions.
         """
         tree = revsetlang.spectree(expr, *args)
         return revset.makematcher(tree)(self)
 
     def set(self, expr, *args):
         """Find revisions matching a revset and emit changectx instances.
 
         This is a convenience wrapper around ``revs()`` that iterates the
         result and is a generator of changectx instances.
 
         Revset aliases from the configuration are not expanded. To expand
         user aliases, consider calling ``scmutil.revrange()``.
         """
         for r in self.revs(expr, *args):
             yield self[r]
 
     def anyrevs(self, specs, user=False, localalias=None):
         """Find revisions matching one of the given revsets.
 
         Revset aliases from the configuration are not expanded by default. To
         expand user aliases, specify ``user=True``. To provide some local
         definitions overriding user aliases, set ``localalias`` to
         ``{name: definitionstring}``.
         """
         if specs == [b'null']:
             return revset.baseset([nullrev])
         if specs == [b'.']:
             quick_data = self._quick_access_changeid.get(b'.')
             if quick_data is not None:
                 return revset.baseset([quick_data[0]])
         if user:
             m = revset.matchany(
                 self.ui,
                 specs,
                 lookup=revset.lookupfn(self),
                 localalias=localalias,
             )
         else:
             m = revset.matchany(None, specs, localalias=localalias)
         return m(self)
 
     def url(self):
         return b'file:' + self.root
 
     def hook(self, name, throw=False, **args):
         """Call a hook, passing this repo instance.
 
         This a convenience method to aid invoking hooks. Extensions likely
         won't call this unless they have registered a custom hook or are
         replacing code that is expected to call a hook.
         """
         return hook.hook(self.ui, self, name, throw, **args)
 
     @filteredpropertycache
     def _tagscache(self):
         """Returns a tagscache object that contains various tags related
         caches."""
 
         # This simplifies its cache management by having one decorated
         # function (this one) and the rest simply fetch things from it.
         class tagscache(object):
             def __init__(self):
                 # These two define the set of tags for this repository. tags
                 # maps tag name to node; tagtypes maps tag name to 'global' or
                 # 'local'. (Global tags are defined by .hgtags across all
                 # heads, and local tags are defined in .hg/localtags.)
                 # They constitute the in-memory cache of tags.
                 self.tags = self.tagtypes = None
 
                 self.nodetagscache = self.tagslist = None
 
         cache = tagscache()
         cache.tags, cache.tagtypes = self._findtags()
 
         return cache
 
     def tags(self):
         '''return a mapping of tag to node'''
         t = {}
         if self.changelog.filteredrevs:
             tags, tt = self._findtags()
         else:
             tags = self._tagscache.tags
         rev = self.changelog.rev
         for k, v in pycompat.iteritems(tags):
             try:
                 # ignore tags to unknown nodes
                 rev(v)
                 t[k] = v
             except (error.LookupError, ValueError):
                 pass
         return t
 
     def _findtags(self):
         """Do the hard work of finding tags.  Return a pair of dicts
         (tags, tagtypes) where tags maps tag name to node, and tagtypes
         maps tag name to a string like \'global\' or \'local\'.
         Subclasses or extensions are free to add their own tags, but
         should be aware that the returned dicts will be retained for the
         duration of the localrepo object."""
 
         # XXX what tagtype should subclasses/extensions use?  Currently
         # mq and bookmarks add tags, but do not set the tagtype at all.
         # Should each extension invent its own tag type?  Should there
         # be one tagtype for all such "virtual" tags?  Or is the status
         # quo fine?
 
         # map tag name to (node, hist)
         alltags = tagsmod.findglobaltags(self.ui, self)
         # map tag name to tag type
         tagtypes = {tag: b'global' for tag in alltags}
 
         tagsmod.readlocaltags(self.ui, self, alltags, tagtypes)
 
         # Build the return dicts.  Have to re-encode tag names because
         # the tags module always uses UTF-8 (in order not to lose info
         # writing to the cache), but the rest of Mercurial wants them in
         # local encoding.
         tags = {}
         for (name, (node, hist)) in pycompat.iteritems(alltags):
             if node != nullid:
                 tags[encoding.tolocal(name)] = node
         tags[b'tip'] = self.changelog.tip()
         tagtypes = {
             encoding.tolocal(name): value
             for (name, value) in pycompat.iteritems(tagtypes)
         }
         return (tags, tagtypes)
 
     def tagtype(self, tagname):
         """
         return the type of the given tag. result can be:
 
         'local'  : a local tag
         'global' : a global tag
         None     : tag does not exist
         """
 
         return self._tagscache.tagtypes.get(tagname)
 
     def tagslist(self):
         '''return a list of tags ordered by revision'''
         if not self._tagscache.tagslist:
             l = []
             for t, n in pycompat.iteritems(self.tags()):
                 l.append((self.changelog.rev(n), t, n))
             self._tagscache.tagslist = [(t, n) for r, t, n in sorted(l)]
 
         return self._tagscache.tagslist
 
     def nodetags(self, node):
         '''return the tags associated with a node'''
         if not self._tagscache.nodetagscache:
             nodetagscache = {}
             for t, n in pycompat.iteritems(self._tagscache.tags):
                 nodetagscache.setdefault(n, []).append(t)
             for tags in pycompat.itervalues(nodetagscache):
                 tags.sort()
             self._tagscache.nodetagscache = nodetagscache
         return self._tagscache.nodetagscache.get(node, [])
 
     def nodebookmarks(self, node):
         """return the list of bookmarks pointing to the specified node"""
         return self._bookmarks.names(node)
 
     def branchmap(self):
         """returns a dictionary {branch: [branchheads]} with branchheads
         ordered by increasing revision number"""
         return self._branchcaches[self]
 
     @unfilteredmethod
     def revbranchcache(self):
         if not self._revbranchcache:
             self._revbranchcache = branchmap.revbranchcache(self.unfiltered())
         return self._revbranchcache
 
     def register_changeset(self, rev, changelogrevision):
         self.revbranchcache().setdata(rev, changelogrevision)
 
     def branchtip(self, branch, ignoremissing=False):
         """return the tip node for a given branch
 
         If ignoremissing is True, then this method will not raise an error.
         This is helpful for callers that only expect None for a missing branch
         (e.g. namespace).
 
         """
         try:
             return self.branchmap().branchtip(branch)
         except KeyError:
             if not ignoremissing:
                 raise error.RepoLookupError(_(b"unknown branch '%s'") % branch)
             else:
                 pass
 
     def lookup(self, key):
         node = scmutil.revsymbol(self, key).node()
         if node is None:
             raise error.RepoLookupError(_(b"unknown revision '%s'") % key)
         return node
 
     def lookupbranch(self, key):
         if self.branchmap().hasbranch(key):
             return key
 
         return scmutil.revsymbol(self, key).branch()
 
     def known(self, nodes):
         cl = self.changelog
         get_rev = cl.index.get_rev
         filtered = cl.filteredrevs
         result = []
         for n in nodes:
             r = get_rev(n)
             resp = not (r is None or r in filtered)
             result.append(resp)
         return result
 
     def local(self):
         return self
 
     def publishing(self):
         # it's safe (and desirable) to trust the publish flag unconditionally
         # so that we don't finalize changes shared between users via ssh or nfs
         return self.ui.configbool(b'phases', b'publish', untrusted=True)
 
     def cancopy(self):
         # so statichttprepo's override of local() works
         if not self.local():
             return False
         if not self.publishing():
             return True
         # if publishing we can't copy if there is filtered content
         return not self.filtered(b'visible').changelog.filteredrevs
 
     def shared(self):
         '''the type of shared repository (None if not shared)'''
         if self.sharedpath != self.path:
             return b'store'
         return None
 
     def wjoin(self, f, *insidef):
         return self.vfs.reljoin(self.root, f, *insidef)
 
     def setparents(self, p1, p2=nullid):
         self[None].setparents(p1, p2)
         self._quick_access_changeid_invalidate()
 
     def filectx(self, path, changeid=None, fileid=None, changectx=None):
         """changeid must be a changeset revision, if specified.
         fileid can be a file revision or node."""
         return context.filectx(
             self, path, changeid, fileid, changectx=changectx
         )
 
     def getcwd(self):
         return self.dirstate.getcwd()
 
     def pathto(self, f, cwd=None):
         return self.dirstate.pathto(f, cwd)
 
     def _loadfilter(self, filter):
         if filter not in self._filterpats:
             l = []
             for pat, cmd in self.ui.configitems(filter):
                 if cmd == b'!':
                     continue
                 mf = matchmod.match(self.root, b'', [pat])
                 fn = None
                 params = cmd
                 for name, filterfn in pycompat.iteritems(self._datafilters):
                     if cmd.startswith(name):
                         fn = filterfn
                         params = cmd[len(name) :].lstrip()
                         break
                 if not fn:
                     fn = lambda s, c, **kwargs: procutil.filter(s, c)
                     fn.__name__ = 'commandfilter'
                 # Wrap old filters not supporting keyword arguments
                 if not pycompat.getargspec(fn)[2]:
                     oldfn = fn
                     fn = lambda s, c, oldfn=oldfn, **kwargs: oldfn(s, c)
                     fn.__name__ = 'compat-' + oldfn.__name__
                 l.append((mf, fn, params))
             self._filterpats[filter] = l
         return self._filterpats[filter]
 
     def _filter(self, filterpats, filename, data):
         for mf, fn, cmd in filterpats:
             if mf(filename):
                 self.ui.debug(
                     b"filtering %s through %s\n"
                     % (filename, cmd or pycompat.sysbytes(fn.__name__))
                 )
                 data = fn(data, cmd, ui=self.ui, repo=self, filename=filename)
                 break
 
         return data
 
     @unfilteredpropertycache
     def _encodefilterpats(self):
         return self._loadfilter(b'encode')
 
     @unfilteredpropertycache
     def _decodefilterpats(self):
         return self._loadfilter(b'decode')
 
     def adddatafilter(self, name, filter):
         self._datafilters[name] = filter
 
     def wread(self, filename):
         if self.wvfs.islink(filename):
             data = self.wvfs.readlink(filename)
         else:
             data = self.wvfs.read(filename)
         return self._filter(self._encodefilterpats, filename, data)
 
     def wwrite(self, filename, data, flags, backgroundclose=False, **kwargs):
         """write ``data`` into ``filename`` in the working directory
 
         This returns length of written (maybe decoded) data.
         """
         data = self._filter(self._decodefilterpats, filename, data)
         if b'l' in flags:
             self.wvfs.symlink(data, filename)
         else:
             self.wvfs.write(
                 filename, data, backgroundclose=backgroundclose, **kwargs
             )
             if b'x' in flags:
                 self.wvfs.setflags(filename, False, True)
             else:
                 self.wvfs.setflags(filename, False, False)
         return len(data)
 
     def wwritedata(self, filename, data):
         return self._filter(self._decodefilterpats, filename, data)
 
     def currenttransaction(self):
         """return the current transaction or None if non exists"""
         if self._transref:
             tr = self._transref()
         else:
             tr = None
 
         if tr and tr.running():
             return tr
         return None
 
     def transaction(self, desc, report=None):
         if self.ui.configbool(b'devel', b'all-warnings') or self.ui.configbool(
             b'devel', b'check-locks'
         ):
             if self._currentlock(self._lockref) is None:
                 raise error.ProgrammingError(b'transaction requires locking')
         tr = self.currenttransaction()
         if tr is not None:
             return tr.nest(name=desc)
 
         # abort here if the journal already exists
         if self.svfs.exists(b"journal"):
             raise error.RepoError(
                 _(b"abandoned transaction found"),
                 hint=_(b"run 'hg recover' to clean up transaction"),
             )
 
         idbase = b"%.40f#%f" % (random.random(), time.time())
         ha = hex(hashutil.sha1(idbase).digest())
         txnid = b'TXN:' + ha
         self.hook(b'pretxnopen', throw=True, txnname=desc, txnid=txnid)
 
         self._writejournal(desc)
         renames = [(vfs, x, undoname(x)) for vfs, x in self._journalfiles()]
         if report:
             rp = report
         else:
             rp = self.ui.warn
         vfsmap = {b'plain': self.vfs, b'store': self.svfs}  # root of .hg/
         # we must avoid cyclic reference between repo and transaction.
         reporef = weakref.ref(self)
         # Code to track tag movement
         #
         # Since tags are all handled as file content, it is actually quite hard
         # to track these movement from a code perspective. So we fallback to a
         # tracking at the repository level. One could envision to track changes
         # to the '.hgtags' file through changegroup apply but that fails to
         # cope with case where transaction expose new heads without changegroup
         # being involved (eg: phase movement).
         #
         # For now, We gate the feature behind a flag since this likely comes
         # with performance impacts. The current code run more often than needed
         # and do not use caches as much as it could.  The current focus is on
         # the behavior of the feature so we disable it by default. The flag
         # will be removed when we are happy with the performance impact.
         #
         # Once this feature is no longer experimental move the following
         # documentation to the appropriate help section:
         #
         # The ``HG_TAG_MOVED`` variable will be set if the transaction touched
         # tags (new or changed or deleted tags). In addition the details of
         # these changes are made available in a file at:
         #     ``REPOROOT/.hg/changes/tags.changes``.
         # Make sure you check for HG_TAG_MOVED before reading that file as it
         # might exist from a previous transaction even if no tag were touched
         # in this one. Changes are recorded in a line base format::
         #
         #     <action> <hex-node> <tag-name>\n
         #
         # Actions are defined as follow:
         #   "-R": tag is removed,
         #   "+A": tag is added,
         #   "-M": tag is moved (old value),
         #   "+M": tag is moved (new value),
         tracktags = lambda x: None
         # experimental config: experimental.hook-track-tags
         shouldtracktags = self.ui.configbool(
             b'experimental', b'hook-track-tags'
         )
         if desc != b'strip' and shouldtracktags:
             oldheads = self.changelog.headrevs()
 
             def tracktags(tr2):
                 repo = reporef()
                 oldfnodes = tagsmod.fnoderevs(repo.ui, repo, oldheads)
                 newheads = repo.changelog.headrevs()
                 newfnodes = tagsmod.fnoderevs(repo.ui, repo, newheads)
                 # notes: we compare lists here.
                 # As we do it only once buiding set would not be cheaper
                 changes = tagsmod.difftags(repo.ui, repo, oldfnodes, newfnodes)
                 if changes:
                     tr2.hookargs[b'tag_moved'] = b'1'
                     with repo.vfs(
                         b'changes/tags.changes', b'w', atomictemp=True
                     ) as changesfile:
                         # note: we do not register the file to the transaction
                         # because we needs it to still exist on the transaction
                         # is close (for txnclose hooks)
                         tagsmod.writediff(changesfile, changes)
 
         def validate(tr2):
             """will run pre-closing hooks"""
             # XXX the transaction API is a bit lacking here so we take a hacky
             # path for now
             #
             # We cannot add this as a "pending" hooks since the 'tr.hookargs'
             # dict is copied before these run. In addition we needs the data
             # available to in memory hooks too.
             #
             # Moreover, we also need to make sure this runs before txnclose
             # hooks and there is no "pending" mechanism that would execute
             # logic only if hooks are about to run.
             #
             # Fixing this limitation of the transaction is also needed to track
             # other families of changes (bookmarks, phases, obsolescence).
             #
             # This will have to be fixed before we remove the experimental
             # gating.
             tracktags(tr2)
             repo = reporef()
 
             singleheadopt = (b'experimental', b'single-head-per-branch')
             singlehead = repo.ui.configbool(*singleheadopt)
             if singlehead:
                 singleheadsub = repo.ui.configsuboptions(*singleheadopt)[1]
                 accountclosed = singleheadsub.get(
                     b"account-closed-heads", False
                 )
                 if singleheadsub.get(b"public-changes-only", False):
                     filtername = b"immutable"
                 else:
                     filtername = b"visible"
                 scmutil.enforcesinglehead(
                     repo, tr2, desc, accountclosed, filtername
                 )
             if hook.hashook(repo.ui, b'pretxnclose-bookmark'):
                 for name, (old, new) in sorted(
                     tr.changes[b'bookmarks'].items()
                 ):
                     args = tr.hookargs.copy()
                     args.update(bookmarks.preparehookargs(name, old, new))
                     repo.hook(
                         b'pretxnclose-bookmark',
                         throw=True,
                         **pycompat.strkwargs(args)
                     )
             if hook.hashook(repo.ui, b'pretxnclose-phase'):
                 cl = repo.unfiltered().changelog
                 for revs, (old, new) in tr.changes[b'phases']:
                     for rev in revs:
                         args = tr.hookargs.copy()
                         node = hex(cl.node(rev))
                         args.update(phases.preparehookargs(node, old, new))
                         repo.hook(
                             b'pretxnclose-phase',
                             throw=True,
                             **pycompat.strkwargs(args)
                         )
 
             repo.hook(
                 b'pretxnclose', throw=True, **pycompat.strkwargs(tr.hookargs)
             )
 
         def releasefn(tr, success):
             repo = reporef()
             if repo is None:
                 # If the repo has been GC'd (and this release function is being
                 # called from transaction.__del__), there's not much we can do,
                 # so just leave the unfinished transaction there and let the
                 # user run `hg recover`.
                 return
             if success:
                 # this should be explicitly invoked here, because
                 # in-memory changes aren't written out at closing
                 # transaction, if tr.addfilegenerator (via
                 # dirstate.write or so) isn't invoked while
                 # transaction running
                 repo.dirstate.write(None)
             else:
                 # discard all changes (including ones already written
                 # out) in this transaction
                 narrowspec.restorebackup(self, b'journal.narrowspec')
                 narrowspec.restorewcbackup(self, b'journal.narrowspec.dirstate')
                 repo.dirstate.restorebackup(None, b'journal.dirstate')
 
                 repo.invalidate(clearfilecache=True)
 
         tr = transaction.transaction(
             rp,
             self.svfs,
             vfsmap,
             b"journal",
             b"undo",
             aftertrans(renames),
             self.store.createmode,
             validator=validate,
             releasefn=releasefn,
             checkambigfiles=_cachedfiles,
             name=desc,
         )
         tr.changes[b'origrepolen'] = len(self)
         tr.changes[b'obsmarkers'] = set()
         tr.changes[b'phases'] = []
         tr.changes[b'bookmarks'] = {}
 
         tr.hookargs[b'txnid'] = txnid
         tr.hookargs[b'txnname'] = desc
         tr.hookargs[b'changes'] = tr.changes
         # note: writing the fncache only during finalize mean that the file is
         # outdated when running hooks. As fncache is used for streaming clone,
         # this is not expected to break anything that happen during the hooks.
         tr.addfinalize(b'flush-fncache', self.store.write)
 
         def txnclosehook(tr2):
             """To be run if transaction is successful, will schedule a hook run"""
             # Don't reference tr2 in hook() so we don't hold a reference.
             # This reduces memory consumption when there are multiple
             # transactions per lock. This can likely go away if issue5045
             # fixes the function accumulation.
             hookargs = tr2.hookargs
 
             def hookfunc(unused_success):
                 repo = reporef()
                 if hook.hashook(repo.ui, b'txnclose-bookmark'):
                     bmchanges = sorted(tr.changes[b'bookmarks'].items())
                     for name, (old, new) in bmchanges:
                         args = tr.hookargs.copy()
                         args.update(bookmarks.preparehookargs(name, old, new))
                         repo.hook(
                             b'txnclose-bookmark',
                             throw=False,
                             **pycompat.strkwargs(args)
                         )
 
                 if hook.hashook(repo.ui, b'txnclose-phase'):
                     cl = repo.unfiltered().changelog
                     phasemv = sorted(
                         tr.changes[b'phases'], key=lambda r: r[0][0]
                     )
                     for revs, (old, new) in phasemv:
                         for rev in revs:
                             args = tr.hookargs.copy()
                             node = hex(cl.node(rev))
                             args.update(phases.preparehookargs(node, old, new))
                             repo.hook(
                                 b'txnclose-phase',
                                 throw=False,
                                 **pycompat.strkwargs(args)
                             )
 
                 repo.hook(
                     b'txnclose', throw=False, **pycompat.strkwargs(hookargs)
                 )
 
             reporef()._afterlock(hookfunc)
 
         tr.addfinalize(b'txnclose-hook', txnclosehook)
         # Include a leading "-" to make it happen before the transaction summary
         # reports registered via scmutil.registersummarycallback() whose names
         # are 00-txnreport etc. That way, the caches will be warm when the
         # callbacks run.
         tr.addpostclose(b'-warm-cache', self._buildcacheupdater(tr))
 
         def txnaborthook(tr2):
             """To be run if transaction is aborted"""
             reporef().hook(
                 b'txnabort', throw=False, **pycompat.strkwargs(tr2.hookargs)
             )
 
         tr.addabort(b'txnabort-hook', txnaborthook)
         # avoid eager cache invalidation. in-memory data should be identical
         # to stored data if transaction has no error.
         tr.addpostclose(b'refresh-filecachestats', self._refreshfilecachestats)
         self._transref = weakref.ref(tr)
         scmutil.registersummarycallback(self, tr, desc)
         return tr
 
     def _journalfiles(self):
         return (
             (self.svfs, b'journal'),
             (self.svfs, b'journal.narrowspec'),
             (self.vfs, b'journal.narrowspec.dirstate'),
             (self.vfs, b'journal.dirstate'),
             (self.vfs, b'journal.branch'),
             (self.vfs, b'journal.desc'),
             (bookmarks.bookmarksvfs(self), b'journal.bookmarks'),
             (self.svfs, b'journal.phaseroots'),
         )
 
     def undofiles(self):
         return [(vfs, undoname(x)) for vfs, x in self._journalfiles()]
 
     @unfilteredmethod
     def _writejournal(self, desc):
         self.dirstate.savebackup(None, b'journal.dirstate')
         narrowspec.savewcbackup(self, b'journal.narrowspec.dirstate')
         narrowspec.savebackup(self, b'journal.narrowspec')
         self.vfs.write(
             b"journal.branch", encoding.fromlocal(self.dirstate.branch())
         )
         self.vfs.write(b"journal.desc", b"%d\n%s\n" % (len(self), desc))
         bookmarksvfs = bookmarks.bookmarksvfs(self)
         bookmarksvfs.write(
             b"journal.bookmarks", bookmarksvfs.tryread(b"bookmarks")
         )
         self.svfs.write(b"journal.phaseroots", self.svfs.tryread(b"phaseroots"))
 
     def recover(self):
         with self.lock():
             if self.svfs.exists(b"journal"):
                 self.ui.status(_(b"rolling back interrupted transaction\n"))
                 vfsmap = {
                     b'': self.svfs,
                     b'plain': self.vfs,
                 }
                 transaction.rollback(
                     self.svfs,
                     vfsmap,
                     b"journal",
                     self.ui.warn,
                     checkambigfiles=_cachedfiles,
                 )
                 self.invalidate()
                 return True
             else:
                 self.ui.warn(_(b"no interrupted transaction available\n"))
                 return False
 
     def rollback(self, dryrun=False, force=False):
         wlock = lock = dsguard = None
         try:
             wlock = self.wlock()
             lock = self.lock()
             if self.svfs.exists(b"undo"):
                 dsguard = dirstateguard.dirstateguard(self, b'rollback')
 
                 return self._rollback(dryrun, force, dsguard)
             else:
                 self.ui.warn(_(b"no rollback information available\n"))
                 return 1
         finally:
             release(dsguard, lock, wlock)
 
     @unfilteredmethod  # Until we get smarter cache management
     def _rollback(self, dryrun, force, dsguard):
         ui = self.ui
         try:
             args = self.vfs.read(b'undo.desc').splitlines()
             (oldlen, desc, detail) = (int(args[0]), args[1], None)
             if len(args) >= 3:
                 detail = args[2]
             oldtip = oldlen - 1
 
             if detail and ui.verbose:
                 msg = _(
                     b'repository tip rolled back to revision %d'
                     b' (undo %s: %s)\n'
                 ) % (oldtip, desc, detail)
             else:
                 msg = _(
                     b'repository tip rolled back to revision %d (undo %s)\n'
                 ) % (oldtip, desc)
         except IOError:
             msg = _(b'rolling back unknown transaction\n')
             desc = None
 
         if not force and self[b'.'] != self[b'tip'] and desc == b'commit':
             raise error.Abort(
                 _(
                     b'rollback of last commit while not checked out '
                     b'may lose data'
                 ),
                 hint=_(b'use -f to force'),
             )
 
         ui.status(msg)
         if dryrun:
             return 0
 
         parents = self.dirstate.parents()
         self.destroying()
         vfsmap = {b'plain': self.vfs, b'': self.svfs}
         transaction.rollback(
             self.svfs, vfsmap, b'undo', ui.warn, checkambigfiles=_cachedfiles
         )
         bookmarksvfs = bookmarks.bookmarksvfs(self)
         if bookmarksvfs.exists(b'undo.bookmarks'):
             bookmarksvfs.rename(
                 b'undo.bookmarks', b'bookmarks', checkambig=True
             )
         if self.svfs.exists(b'undo.phaseroots'):
             self.svfs.rename(b'undo.phaseroots', b'phaseroots', checkambig=True)
         self.invalidate()
 
         has_node = self.changelog.index.has_node
         parentgone = any(not has_node(p) for p in parents)
         if parentgone:
             # prevent dirstateguard from overwriting already restored one
             dsguard.close()
 
             narrowspec.restorebackup(self, b'undo.narrowspec')
             narrowspec.restorewcbackup(self, b'undo.narrowspec.dirstate')
             self.dirstate.restorebackup(None, b'undo.dirstate')
             try:
                 branch = self.vfs.read(b'undo.branch')
                 self.dirstate.setbranch(encoding.tolocal(branch))
             except IOError:
                 ui.warn(
                     _(
                         b'named branch could not be reset: '
                         b'current branch is still \'%s\'\n'
                     )
                     % self.dirstate.branch()
                 )
 
             parents = tuple([p.rev() for p in self[None].parents()])
             if len(parents) > 1:
                 ui.status(
                     _(
                         b'working directory now based on '
                         b'revisions %d and %d\n'
                     )
                     % parents
                 )
             else:
                 ui.status(
                     _(b'working directory now based on revision %d\n') % parents
                 )
             mergestatemod.mergestate.clean(self)
 
         # TODO: if we know which new heads may result from this rollback, pass
         # them to destroy(), which will prevent the branchhead cache from being
         # invalidated.
         self.destroyed()
         return 0
 
     def _buildcacheupdater(self, newtransaction):
         """called during transaction to build the callback updating cache
 
         Lives on the repository to help extension who might want to augment
         this logic. For this purpose, the created transaction is passed to the
         method.
         """
         # we must avoid cyclic reference between repo and transaction.
         reporef = weakref.ref(self)
 
         def updater(tr):
             repo = reporef()
             repo.updatecaches(tr)
 
         return updater
 
     @unfilteredmethod
     def updatecaches(self, tr=None, full=False):
         """warm appropriate caches
 
         If this function is called after a transaction closed. The transaction
         will be available in the 'tr' argument. This can be used to selectively
         update caches relevant to the changes in that transaction.
 
         If 'full' is set, make sure all caches the function knows about have
         up-to-date data. Even the ones usually loaded more lazily.
         """
         if tr is not None and tr.hookargs.get(b'source') == b'strip':
             # During strip, many caches are invalid but
             # later call to `destroyed` will refresh them.
             return
 
         if tr is None or tr.changes[b'origrepolen'] < len(self):
             # accessing the 'served' branchmap should refresh all the others,
             self.ui.debug(b'updating the branch cache\n')
             self.filtered(b'served').branchmap()
             self.filtered(b'served.hidden').branchmap()
 
         if full:
             unfi = self.unfiltered()
 
             self.changelog.update_caches(transaction=tr)
             self.manifestlog.update_caches(transaction=tr)
 
             rbc = unfi.revbranchcache()
             for r in unfi.changelog:
                 rbc.branchinfo(r)
             rbc.write()
 
             # ensure the working copy parents are in the manifestfulltextcache
             for ctx in self[b'.'].parents():
                 ctx.manifest()  # accessing the manifest is enough
 
             # accessing fnode cache warms the cache
             tagsmod.fnoderevs(self.ui, unfi, unfi.changelog.revs())
             # accessing tags warm the cache
             self.tags()
             self.filtered(b'served').tags()
 
             # The `full` arg is documented as updating even the lazily-loaded
             # caches immediately, so we're forcing a write to cause these caches
             # to be warmed up even if they haven't explicitly been requested
             # yet (if they've never been used by hg, they won't ever have been
             # written, even if they're a subset of another kind of cache that
             # *has* been used).
             for filt in repoview.filtertable.keys():
                 filtered = self.filtered(filt)
                 filtered.branchmap().write(filtered)
 
     def invalidatecaches(self):
 
         if '_tagscache' in vars(self):
             # can't use delattr on proxy
             del self.__dict__['_tagscache']
 
         self._branchcaches.clear()
         self.invalidatevolatilesets()
         self._sparsesignaturecache.clear()
 
     def invalidatevolatilesets(self):
         self.filteredrevcache.clear()
         obsolete.clearobscaches(self)
         self._quick_access_changeid_invalidate()
 
     def invalidatedirstate(self):
         """Invalidates the dirstate, causing the next call to dirstate
         to check if it was modified since the last time it was read,
         rereading it if it has.
 
         This is different to dirstate.invalidate() that it doesn't always
         rereads the dirstate. Use dirstate.invalidate() if you want to
         explicitly read the dirstate again (i.e. restoring it to a previous
         known good state)."""
         if hasunfilteredcache(self, 'dirstate'):
             for k in self.dirstate._filecache:
                 try:
                     delattr(self.dirstate, k)
                 except AttributeError:
                     pass
             delattr(self.unfiltered(), 'dirstate')
 
     def invalidate(self, clearfilecache=False):
         """Invalidates both store and non-store parts other than dirstate
 
         If a transaction is running, invalidation of store is omitted,
         because discarding in-memory changes might cause inconsistency
         (e.g. incomplete fncache causes unintentional failure, but
         redundant one doesn't).
         """
         unfiltered = self.unfiltered()  # all file caches are stored unfiltered
         for k in list(self._filecache.keys()):
             # dirstate is invalidated separately in invalidatedirstate()
             if k == b'dirstate':
                 continue
             if (
                 k == b'changelog'
                 and self.currenttransaction()
                 and self.changelog._delayed
             ):
                 # The changelog object may store unwritten revisions. We don't
                 # want to lose them.
                 # TODO: Solve the problem instead of working around it.
                 continue
 
             if clearfilecache:
                 del self._filecache[k]
             try:
                 delattr(unfiltered, k)
             except AttributeError:
                 pass
         self.invalidatecaches()
         if not self.currenttransaction():
             # TODO: Changing contents of store outside transaction
             # causes inconsistency. We should make in-memory store
             # changes detectable, and abort if changed.
             self.store.invalidatecaches()
 
     def invalidateall(self):
         """Fully invalidates both store and non-store parts, causing the
         subsequent operation to reread any outside changes."""
         # extension should hook this to invalidate its caches
         self.invalidate()
         self.invalidatedirstate()
 
     @unfilteredmethod
     def _refreshfilecachestats(self, tr):
         """Reload stats of cached files so that they are flagged as valid"""
         for k, ce in self._filecache.items():
             k = pycompat.sysstr(k)
             if k == 'dirstate' or k not in self.__dict__:
                 continue
             ce.refresh()
 
     def _lock(
         self,
         vfs,
         lockname,
         wait,
         releasefn,
         acquirefn,
         desc,
     ):
         timeout = 0
         warntimeout = 0
         if wait:
             timeout = self.ui.configint(b"ui", b"timeout")
             warntimeout = self.ui.configint(b"ui", b"timeout.warn")
         # internal config: ui.signal-safe-lock
         signalsafe = self.ui.configbool(b'ui', b'signal-safe-lock')
 
         l = lockmod.trylock(
             self.ui,
             vfs,
             lockname,
             timeout,
             warntimeout,
             releasefn=releasefn,
             acquirefn=acquirefn,
             desc=desc,
             signalsafe=signalsafe,
         )
         return l
 
     def _afterlock(self, callback):
         """add a callback to be run when the repository is fully unlocked
 
         The callback will be executed when the outermost lock is released
         (with wlock being higher level than 'lock')."""
         for ref in (self._wlockref, self._lockref):
             l = ref and ref()
             if l and l.held:
                 l.postrelease.append(callback)
                 break
         else:  # no lock have been found.
             callback(True)
 
     def lock(self, wait=True):
         """Lock the repository store (.hg/store) and return a weak reference
         to the lock. Use this before modifying the store (e.g. committing or
         stripping). If you are opening a transaction, get a lock as well.)
 
         If both 'lock' and 'wlock' must be acquired, ensure you always acquires
         'wlock' first to avoid a dead-lock hazard."""
         l = self._currentlock(self._lockref)
         if l is not None:
             l.lock()
             return l
 
         l = self._lock(
             vfs=self.svfs,
             lockname=b"lock",
             wait=wait,
             releasefn=None,
             acquirefn=self.invalidate,
             desc=_(b'repository %s') % self.origroot,
         )
         self._lockref = weakref.ref(l)
         return l
 
     def wlock(self, wait=True):
         """Lock the non-store parts of the repository (everything under
         .hg except .hg/store) and return a weak reference to the lock.
 
         Use this before modifying files in .hg.
 
         If both 'lock' and 'wlock' must be acquired, ensure you always acquires
         'wlock' first to avoid a dead-lock hazard."""
         l = self._wlockref and self._wlockref()
         if l is not None and l.held:
             l.lock()
             return l
 
         # We do not need to check for non-waiting lock acquisition.  Such
         # acquisition would not cause dead-lock as they would just fail.
         if wait and (
             self.ui.configbool(b'devel', b'all-warnings')
             or self.ui.configbool(b'devel', b'check-locks')
         ):
             if self._currentlock(self._lockref) is not None:
                 self.ui.develwarn(b'"wlock" acquired after "lock"')
 
         def unlock():
             if self.dirstate.pendingparentchange():
                 self.dirstate.invalidate()
             else:
                 self.dirstate.write(None)
 
             self._filecache[b'dirstate'].refresh()
 
         l = self._lock(
             self.vfs,
             b"wlock",
             wait,
             unlock,
             self.invalidatedirstate,
             _(b'working directory of %s') % self.origroot,
         )
         self._wlockref = weakref.ref(l)
         return l
 
     def _currentlock(self, lockref):
         """Returns the lock if it's held, or None if it's not."""
         if lockref is None:
             return None
         l = lockref()
         if l is None or not l.held:
             return None
         return l
 
     def currentwlock(self):
         """Returns the wlock if it's held, or None if it's not."""
         return self._currentlock(self._wlockref)
 
     def checkcommitpatterns(self, wctx, match, status, fail):
         """check for commit arguments that aren't committable"""
         if match.isexact() or match.prefix():
             matched = set(status.modified + status.added + status.removed)
 
             for f in match.files():
                 f = self.dirstate.normalize(f)
                 if f == b'.' or f in matched or f in wctx.substate:
                     continue
                 if f in status.deleted:
                     fail(f, _(b'file not found!'))
                 # Is it a directory that exists or used to exist?
                 if self.wvfs.isdir(f) or wctx.p1().hasdir(f):
                     d = f + b'/'
                     for mf in matched:
                         if mf.startswith(d):
                             break
                     else:
                         fail(f, _(b"no match under directory!"))
                 elif f not in self.dirstate:
                     fail(f, _(b"file not tracked!"))
 
     @unfilteredmethod
     def commit(
         self,
         text=b"",
         user=None,
         date=None,
         match=None,
         force=False,
         editor=None,
         extra=None,
     ):
         """Add a new revision to current repository.
 
         Revision information is gathered from the working directory,
         match can be used to filter the committed files. If editor is
         supplied, it is called to get a commit message.
         """
         if extra is None:
             extra = {}
 
         def fail(f, msg):
             raise error.InputError(b'%s: %s' % (f, msg))
 
         if not match:
             match = matchmod.always()
 
         if not force:
             match.bad = fail
 
         # lock() for recent changelog (see issue4368)
         with self.wlock(), self.lock():
             wctx = self[None]
             merge = len(wctx.parents()) > 1
 
             if not force and merge and not match.always():
                 raise error.Abort(
                     _(
                         b'cannot partially commit a merge '
                         b'(do not specify files or patterns)'
                     )
                 )
 
             status = self.status(match=match, clean=force)
             if force:
                 status.modified.extend(
                     status.clean
                 )  # mq may commit clean files
 
             # check subrepos
             subs, commitsubs, newstate = subrepoutil.precommit(
                 self.ui, wctx, status, match, force=force
             )
 
             # make sure all explicit patterns are matched
             if not force:
                 self.checkcommitpatterns(wctx, match, status, fail)
 
             cctx = context.workingcommitctx(
                 self, status, text, user, date, extra
             )
 
             ms = mergestatemod.mergestate.read(self)
             mergeutil.checkunresolved(ms)
 
             # internal config: ui.allowemptycommit
             if cctx.isempty() and not self.ui.configbool(
                 b'ui', b'allowemptycommit'
             ):
                 self.ui.debug(b'nothing to commit, clearing merge state\n')
                 ms.reset()
                 return None
 
             if merge and cctx.deleted():
                 raise error.Abort(_(b"cannot commit merge with missing files"))
 
             if editor:
                 cctx._text = editor(self, cctx, subs)
             edited = text != cctx._text
 
             # Save commit message in case this transaction gets rolled back
             # (e.g. by a pretxncommit hook).  Leave the content alone on
             # the assumption that the user will use the same editor again.
             msgfn = self.savecommitmessage(cctx._text)
 
             # commit subs and write new state
             if subs:
                 uipathfn = scmutil.getuipathfn(self)
                 for s in sorted(commitsubs):
                     sub = wctx.sub(s)
                     self.ui.status(
                         _(b'committing subrepository %s\n')
                         % uipathfn(subrepoutil.subrelpath(sub))
                     )
                     sr = sub.commit(cctx._text, user, date)
                     newstate[s] = (newstate[s][0], sr)
                 subrepoutil.writestate(self, newstate)
 
             p1, p2 = self.dirstate.parents()
             hookp1, hookp2 = hex(p1), (p2 != nullid and hex(p2) or b'')
             try:
                 self.hook(
                     b"precommit", throw=True, parent1=hookp1, parent2=hookp2
                 )
                 with self.transaction(b'commit'):
                     ret = self.commitctx(cctx, True)
                     # update bookmarks, dirstate and mergestate
                     bookmarks.update(self, [p1, p2], ret)
                     cctx.markcommitted(ret)
                     ms.reset()
             except:  # re-raises
                 if edited:
                     self.ui.write(
                         _(b'note: commit message saved in %s\n') % msgfn
                     )
                     self.ui.write(
                         _(
                             b"note: use 'hg commit --logfile "
                             b".hg/last-message.txt --edit' to reuse it\n"
                         )
                     )
                 raise
 
         def commithook(unused_success):
             # hack for command that use a temporary commit (eg: histedit)
             # temporary commit got stripped before hook release
             if self.changelog.hasnode(ret):
                 self.hook(
                     b"commit", node=hex(ret), parent1=hookp1, parent2=hookp2
                 )
 
         self._afterlock(commithook)
         return ret
 
     @unfilteredmethod
     def commitctx(self, ctx, error=False, origctx=None):
         return commit.commitctx(self, ctx, error=error, origctx=origctx)
 
     @unfilteredmethod
     def destroying(self):
         """Inform the repository that nodes are about to be destroyed.
         Intended for use by strip and rollback, so there's a common
         place for anything that has to be done before destroying history.
 
         This is mostly useful for saving state that is in memory and waiting
         to be flushed when the current lock is released. Because a call to
         destroyed is imminent, the repo will be invalidated causing those
         changes to stay in memory (waiting for the next unlock), or vanish
         completely.
         """
         # When using the same lock to commit and strip, the phasecache is left
         # dirty after committing. Then when we strip, the repo is invalidated,
         # causing those changes to disappear.
         if '_phasecache' in vars(self):
             self._phasecache.write()
 
     @unfilteredmethod
     def destroyed(self):
         """Inform the repository that nodes have been destroyed.
         Intended for use by strip and rollback, so there's a common
         place for anything that has to be done after destroying history.
         """
         # When one tries to:
         # 1) destroy nodes thus calling this method (e.g. strip)
         # 2) use phasecache somewhere (e.g. commit)
         #
         # then 2) will fail because the phasecache contains nodes that were
         # removed. We can either remove phasecache from the filecache,
         # causing it to reload next time it is accessed, or simply filter
         # the removed nodes now and write the updated cache.
         self._phasecache.filterunknown(self)
         self._phasecache.write()
 
         # refresh all repository caches
         self.updatecaches()
 
         # Ensure the persistent tag cache is updated.  Doing it now
         # means that the tag cache only has to worry about destroyed
         # heads immediately after a strip/rollback.  That in turn
         # guarantees that "cachetip == currenttip" (comparing both rev
         # and node) always means no nodes have been added or destroyed.
 
         # XXX this is suboptimal when qrefresh'ing: we strip the current
         # head, refresh the tag cache, then immediately add a new head.
         # But I think doing it this way is necessary for the "instant
         # tag cache retrieval" case to work.
         self.invalidate()
 
     def status(
         self,
         node1=b'.',
         node2=None,
         match=None,
         ignored=False,
         clean=False,
         unknown=False,
         listsubrepos=False,
     ):
         '''a convenience method that calls node1.status(node2)'''
         return self[node1].status(
             node2, match, ignored, clean, unknown, listsubrepos
         )
 
     def addpostdsstatus(self, ps):
         """Add a callback to run within the wlock, at the point at which status
         fixups happen.
 
         On status completion, callback(wctx, status) will be called with the
         wlock held, unless the dirstate has changed from underneath or the wlock
         couldn't be grabbed.
 
         Callbacks should not capture and use a cached copy of the dirstate --
         it might change in the meanwhile. Instead, they should access the
         dirstate via wctx.repo().dirstate.
 
         This list is emptied out after each status run -- extensions should
         make sure it adds to this list each time dirstate.status is called.
         Extensions should also make sure they don't call this for statuses
         that don't involve the dirstate.
         """
 
         # The list is located here for uniqueness reasons -- it is actually
         # managed by the workingctx, but that isn't unique per-repo.
         self._postdsstatus.append(ps)
 
     def postdsstatus(self):
         """Used by workingctx to get the list of post-dirstate-status hooks."""
         return self._postdsstatus
 
     def clearpostdsstatus(self):
         """Used by workingctx to clear post-dirstate-status hooks."""
         del self._postdsstatus[:]
 
     def heads(self, start=None):
         if start is None:
             cl = self.changelog
             headrevs = reversed(cl.headrevs())
             return [cl.node(rev) for rev in headrevs]
 
         heads = self.changelog.heads(start)
         # sort the output in rev descending order
         return sorted(heads, key=self.changelog.rev, reverse=True)
 
     def branchheads(self, branch=None, start=None, closed=False):
         """return a (possibly filtered) list of heads for the given branch
 
         Heads are returned in topological order, from newest to oldest.
         If branch is None, use the dirstate branch.
         If start is not None, return only heads reachable from start.
         If closed is True, return heads that are marked as closed as well.
         """
         if branch is None:
             branch = self[None].branch()
         branches = self.branchmap()
         if not branches.hasbranch(branch):
             return []
         # the cache returns heads ordered lowest to highest
         bheads = list(reversed(branches.branchheads(branch, closed=closed)))
         if start is not None:
             # filter out the heads that cannot be reached from startrev
             fbheads = set(self.changelog.nodesbetween([start], bheads)[2])
             bheads = [h for h in bheads if h in fbheads]
         return bheads
 
     def branches(self, nodes):
         if not nodes:
             nodes = [self.changelog.tip()]
         b = []
         for n in nodes:
             t = n
             while True:
                 p = self.changelog.parents(n)
                 if p[1] != nullid or p[0] == nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
         return b
 
     def between(self, pairs):
         r = []
 
         for top, bottom in pairs:
             n, l, i = top, [], 0
             f = 1
 
             while n != bottom and n != nullid:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
                     f = f * 2
                 n = p
                 i += 1
 
             r.append(l)
 
         return r
 
     def checkpush(self, pushop):
         """Extensions can override this function if additional checks have
         to be performed before pushing, or call it if they override push
         command.
         """
 
     @unfilteredpropertycache
     def prepushoutgoinghooks(self):
         """Return util.hooks consists of a pushop with repo, remote, outgoing
         methods, which are called before pushing changesets.
         """
         return util.hooks()
 
     def pushkey(self, namespace, key, old, new):
         try:
             tr = self.currenttransaction()
             hookargs = {}
             if tr is not None:
                 hookargs.update(tr.hookargs)
             hookargs = pycompat.strkwargs(hookargs)
             hookargs['namespace'] = namespace
             hookargs['key'] = key
             hookargs['old'] = old
             hookargs['new'] = new
             self.hook(b'prepushkey', throw=True, **hookargs)
         except error.HookAbort as exc:
             self.ui.write_err(_(b"pushkey-abort: %s\n") % exc)
             if exc.hint:
                 self.ui.write_err(_(b"(%s)\n") % exc.hint)
             return False
         self.ui.debug(b'pushing key for "%s:%s"\n' % (namespace, key))
         ret = pushkey.push(self, namespace, key, old, new)
 
         def runhook(unused_success):
             self.hook(
                 b'pushkey',
                 namespace=namespace,
                 key=key,
                 old=old,
                 new=new,
                 ret=ret,
             )
 
         self._afterlock(runhook)
         return ret
 
     def listkeys(self, namespace):
         self.hook(b'prelistkeys', throw=True, namespace=namespace)
         self.ui.debug(b'listing keys for "%s"\n' % namespace)
         values = pushkey.list(self, namespace)
         self.hook(b'listkeys', namespace=namespace, values=values)
         return values
 
     def debugwireargs(self, one, two, three=None, four=None, five=None):
         '''used to test argument passing over the wire'''
         return b"%s %s %s %s %s" % (
             one,
             two,
             pycompat.bytestr(three),
             pycompat.bytestr(four),
             pycompat.bytestr(five),
         )
 
     def savecommitmessage(self, text):
         fp = self.vfs(b'last-message.txt', b'wb')
         try:
             fp.write(text)
         finally:
             fp.close()
         return self.pathto(fp.name[len(self.root) + 1 :])
 
 
 # used to avoid circular references so destructors work
 def aftertrans(files):
     renamefiles = [tuple(t) for t in files]
 
     def a():
         for vfs, src, dest in renamefiles:
             # if src and dest refer to a same file, vfs.rename is a no-op,
             # leaving both src and dest on disk. delete dest to make sure
             # the rename couldn't be such a no-op.
             vfs.tryunlink(dest)
             try:
                 vfs.rename(src, dest)
             except OSError:  # journal file does not yet exist
                 pass
 
     return a
 
 
 def undoname(fn):
     base, name = os.path.split(fn)
     assert name.startswith(b'journal')
     return os.path.join(base, name.replace(b'journal', b'undo', 1))
 
 
 def instance(ui, path, create, intents=None, createopts=None):
     localpath = util.urllocalpath(path)
     if create:
         createrepository(ui, localpath, createopts=createopts)
 
     return makelocalrepository(ui, localpath, intents=intents)
 
 
 def islocal(path):
     return True
 
 
 def defaultcreateopts(ui, createopts=None):
     """Populate the default creation options for a repository.
 
     A dictionary of explicitly requested creation options can be passed
     in. Missing keys will be populated.
     """
     createopts = dict(createopts or {})
 
     if b'backend' not in createopts:
         # experimental config: storage.new-repo-backend
         createopts[b'backend'] = ui.config(b'storage', b'new-repo-backend')
 
     return createopts
 
 
 def newreporequirements(ui, createopts):
     """Determine the set of requirements for a new local repository.
 
     Extensions can wrap this function to specify custom requirements for
     new repositories.
     """
     # If the repo is being created from a shared repository, we copy
     # its requirements.
     if b'sharedrepo' in createopts:
         requirements = set(createopts[b'sharedrepo'].requirements)
         if createopts.get(b'sharedrelative'):
             requirements.add(requirementsmod.RELATIVE_SHARED_REQUIREMENT)
         else:
             requirements.add(requirementsmod.SHARED_REQUIREMENT)
 
         return requirements
 
     if b'backend' not in createopts:
         raise error.ProgrammingError(
             b'backend key not present in createopts; '
             b'was defaultcreateopts() called?'
         )
 
     if createopts[b'backend'] != b'revlogv1':
         raise error.Abort(
             _(
                 b'unable to determine repository requirements for '
                 b'storage backend: %s'
             )
             % createopts[b'backend']
         )
 
     requirements = {requirementsmod.REVLOGV1_REQUIREMENT}
     if ui.configbool(b'format', b'usestore'):
         requirements.add(b'store')
         if ui.configbool(b'format', b'usefncache'):
             requirements.add(b'fncache')
             if ui.configbool(b'format', b'dotencode'):
                 requirements.add(b'dotencode')
 
     compengines = ui.configlist(b'format', b'revlog-compression')
     for compengine in compengines:
         if compengine in util.compengines:
             break
     else:
         raise error.Abort(
             _(
                 b'compression engines %s defined by '
                 b'format.revlog-compression not available'
             )
             % b', '.join(b'"%s"' % e for e in compengines),
             hint=_(
                 b'run "hg debuginstall" to list available '
                 b'compression engines'
             ),
         )
 
     # zlib is the historical default and doesn't need an explicit requirement.
     if compengine == b'zstd':
         requirements.add(b'revlog-compression-zstd')
     elif compengine != b'zlib':
         requirements.add(b'exp-compression-%s' % compengine)
 
     if scmutil.gdinitconfig(ui):
-        requirements.add(b'generaldelta')
+        requirements.add(requirementsmod.GENERALDELTA_REQUIREMENT)
         if ui.configbool(b'format', b'sparse-revlog'):
             requirements.add(requirementsmod.SPARSEREVLOG_REQUIREMENT)
 
     # experimental config: format.exp-use-side-data
     if ui.configbool(b'format', b'exp-use-side-data'):
         requirements.add(requirementsmod.SIDEDATA_REQUIREMENT)
     # experimental config: format.exp-use-copies-side-data-changeset
     if ui.configbool(b'format', b'exp-use-copies-side-data-changeset'):
         requirements.add(requirementsmod.SIDEDATA_REQUIREMENT)
         requirements.add(requirementsmod.COPIESSDC_REQUIREMENT)
     if ui.configbool(b'experimental', b'treemanifest'):
         requirements.add(requirementsmod.TREEMANIFEST_REQUIREMENT)
 
     revlogv2 = ui.config(b'experimental', b'revlogv2')
     if revlogv2 == b'enable-unstable-format-and-corrupt-my-data':
         requirements.remove(requirementsmod.REVLOGV1_REQUIREMENT)
         # generaldelta is implied by revlogv2.
-        requirements.discard(b'generaldelta')
+        requirements.discard(requirementsmod.GENERALDELTA_REQUIREMENT)
         requirements.add(requirementsmod.REVLOGV2_REQUIREMENT)
     # experimental config: format.internal-phase
     if ui.configbool(b'format', b'internal-phase'):
         requirements.add(requirementsmod.INTERNAL_PHASE_REQUIREMENT)
 
     if createopts.get(b'narrowfiles'):
         requirements.add(requirementsmod.NARROW_REQUIREMENT)
 
     if createopts.get(b'lfs'):
         requirements.add(b'lfs')
 
     if ui.configbool(b'format', b'bookmarks-in-store'):
         requirements.add(bookmarks.BOOKMARKS_IN_STORE_REQUIREMENT)
 
     if ui.configbool(b'format', b'use-persistent-nodemap'):
         requirements.add(requirementsmod.NODEMAP_REQUIREMENT)
 
     # if share-safe is enabled, let's create the new repository with the new
     # requirement
     if ui.configbool(b'format', b'use-share-safe'):
         requirements.add(requirementsmod.SHARESAFE_REQUIREMENT)
 
     return requirements
 
 
 def checkrequirementscompat(ui, requirements):
     """Checks compatibility of repository requirements enabled and disabled.
 
     Returns a set of requirements which needs to be dropped because dependend
     requirements are not enabled. Also warns users about it"""
 
     dropped = set()
 
     if b'store' not in requirements:
         if bookmarks.BOOKMARKS_IN_STORE_REQUIREMENT in requirements:
             ui.warn(
                 _(
                     b'ignoring enabled \'format.bookmarks-in-store\' config '
                     b'beacuse it is incompatible with disabled '
                     b'\'format.usestore\' config\n'
                 )
             )
             dropped.add(bookmarks.BOOKMARKS_IN_STORE_REQUIREMENT)
 
         if (
             requirementsmod.SHARED_REQUIREMENT in requirements
             or requirementsmod.RELATIVE_SHARED_REQUIREMENT in requirements
         ):
             raise error.Abort(
                 _(
                     b"cannot create shared repository as source was created"
                     b" with 'format.usestore' config disabled"
                 )
             )
 
         if requirementsmod.SHARESAFE_REQUIREMENT in requirements:
             ui.warn(
                 _(
                     b"ignoring enabled 'format.use-share-safe' config because "
                     b"it is incompatible with disabled 'format.usestore'"
                     b" config\n"
                 )
             )
             dropped.add(requirementsmod.SHARESAFE_REQUIREMENT)
 
     return dropped
 
 
 def filterknowncreateopts(ui, createopts):
     """Filters a dict of repo creation options against options that are known.
 
     Receives a dict of repo creation options and returns a dict of those
     options that we don't know how to handle.
 
     This function is called as part of repository creation. If the
     returned dict contains any items, repository creation will not
     be allowed, as it means there was a request to create a repository
     with options not recognized by loaded code.
 
     Extensions can wrap this function to filter out creation options
     they know how to handle.
     """
     known = {
         b'backend',
         b'lfs',
         b'narrowfiles',
         b'sharedrepo',
         b'sharedrelative',
         b'shareditems',
         b'shallowfilestore',
     }
 
     return {k: v for k, v in createopts.items() if k not in known}
 
 
 def createrepository(ui, path, createopts=None):
     """Create a new repository in a vfs.
 
     ``path`` path to the new repo's working directory.
     ``createopts`` options for the new repository.
 
     The following keys for ``createopts`` are recognized:
 
     backend
        The storage backend to use.
     lfs
        Repository will be created with ``lfs`` requirement. The lfs extension
        will automatically be loaded when the repository is accessed.
     narrowfiles
        Set up repository to support narrow file storage.
     sharedrepo
        Repository object from which storage should be shared.
     sharedrelative
        Boolean indicating if the path to the shared repo should be
        stored as relative. By default, the pointer to the "parent" repo
        is stored as an absolute path.
     shareditems
        Set of items to share to the new repository (in addition to storage).
     shallowfilestore
        Indicates that storage for files should be shallow (not all ancestor
        revisions are known).
     """
     createopts = defaultcreateopts(ui, createopts=createopts)
 
     unknownopts = filterknowncreateopts(ui, createopts)
 
     if not isinstance(unknownopts, dict):
         raise error.ProgrammingError(
             b'filterknowncreateopts() did not return a dict'
         )
 
     if unknownopts:
         raise error.Abort(
             _(
                 b'unable to create repository because of unknown '
                 b'creation option: %s'
             )
             % b', '.join(sorted(unknownopts)),
             hint=_(b'is a required extension not loaded?'),
         )
 
     requirements = newreporequirements(ui, createopts=createopts)
     requirements -= checkrequirementscompat(ui, requirements)
 
     wdirvfs = vfsmod.vfs(path, expandpath=True, realpath=True)
 
     hgvfs = vfsmod.vfs(wdirvfs.join(b'.hg'))
     if hgvfs.exists():
         raise error.RepoError(_(b'repository %s already exists') % path)
 
     if b'sharedrepo' in createopts:
         sharedpath = createopts[b'sharedrepo'].sharedpath
 
         if createopts.get(b'sharedrelative'):
             try:
                 sharedpath = os.path.relpath(sharedpath, hgvfs.base)
             except (IOError, ValueError) as e:
                 # ValueError is raised on Windows if the drive letters differ
                 # on each path.
                 raise error.Abort(
                     _(b'cannot calculate relative path'),
                     hint=stringutil.forcebytestr(e),
                 )
 
     if not wdirvfs.exists():
         wdirvfs.makedirs()
 
     hgvfs.makedir(notindexed=True)
     if b'sharedrepo' not in createopts:
         hgvfs.mkdir(b'cache')
     hgvfs.mkdir(b'wcache')
 
     if b'store' in requirements and b'sharedrepo' not in createopts:
         hgvfs.mkdir(b'store')
 
         # We create an invalid changelog outside the store so very old
         # Mercurial versions (which didn't know about the requirements
         # file) encounter an error on reading the changelog. This
         # effectively locks out old clients and prevents them from
         # mucking with a repo in an unknown format.
         #
         # The revlog header has version 65535, which won't be recognized by
         # such old clients.
         hgvfs.append(
             b'00changelog.i',
             b'\0\0\xFF\xFF dummy changelog to prevent using the old repo '
             b'layout',
         )
 
     # Filter the requirements into working copy and store ones
     wcreq, storereq = scmutil.filterrequirements(requirements)
     # write working copy ones
     scmutil.writerequires(hgvfs, wcreq)
     # If there are store requirements and the current repository
     # is not a shared one, write stored requirements
     # For new shared repository, we don't need to write the store
     # requirements as they are already present in store requires
     if storereq and b'sharedrepo' not in createopts:
         storevfs = vfsmod.vfs(hgvfs.join(b'store'), cacheaudited=True)
         scmutil.writerequires(storevfs, storereq)
 
     # Write out file telling readers where to find the shared store.
     if b'sharedrepo' in createopts:
         hgvfs.write(b'sharedpath', sharedpath)
 
     if createopts.get(b'shareditems'):
         shared = b'\n'.join(sorted(createopts[b'shareditems'])) + b'\n'
         hgvfs.write(b'shared', shared)
 
 
 def poisonrepository(repo):
     """Poison a repository instance so it can no longer be used."""
     # Perform any cleanup on the instance.
     repo.close()
 
     # Our strategy is to replace the type of the object with one that
     # has all attribute lookups result in error.
     #
     # But we have to allow the close() method because some constructors
     # of repos call close() on repo references.
     class poisonedrepository(object):
         def __getattribute__(self, item):
             if item == 'close':
                 return object.__getattribute__(self, item)
 
             raise error.ProgrammingError(
                 b'repo instances should not be used after unshare'
             )
 
         def close(self):
             pass
 
     # We may have a repoview, which intercepts __setattr__. So be sure
     # we operate at the lowest level possible.
     object.__setattr__(repo, '__class__', poisonedrepository)

mercurial/requirements.py

@@ -1,77 +1,79 b''
 # requirements.py - objects and functions related to repository requirements
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
+GENERALDELTA_REQUIREMENT = b'generaldelta'
+
 # When narrowing is finalized and no longer subject to format changes,
 # we should move this to just "narrow" or similar.
 NARROW_REQUIREMENT = b'narrowhg-experimental'
 
 # Enables sparse working directory usage
 SPARSE_REQUIREMENT = b'exp-sparse'
 
 # Enables the internal phase which is used to hide changesets instead
 # of stripping them
 INTERNAL_PHASE_REQUIREMENT = b'internal-phase'
 
 # Stores manifest in Tree structure
 TREEMANIFEST_REQUIREMENT = b'treemanifest'
 
 REVLOGV1_REQUIREMENT = b'revlogv1'
 
 # Increment the sub-version when the revlog v2 format changes to lock out old
 # clients.
 REVLOGV2_REQUIREMENT = b'exp-revlogv2.1'
 
 # A repository with the sparserevlog feature will have delta chains that
 # can spread over a larger span. Sparse reading cuts these large spans into
 # pieces, so that each piece isn't too big.
 # Without the sparserevlog capability, reading from the repository could use
 # huge amounts of memory, because the whole span would be read at once,
 # including all the intermediate revisions that aren't pertinent for the chain.
 # This is why once a repository has enabled sparse-read, it becomes required.
 SPARSEREVLOG_REQUIREMENT = b'sparserevlog'
 
 # A repository with the sidedataflag requirement will allow to store extra
 # information for revision without altering their original hashes.
 SIDEDATA_REQUIREMENT = b'exp-sidedata-flag'
 
 # A repository with the the copies-sidedata-changeset requirement will store
 # copies related information in changeset's sidedata.
 COPIESSDC_REQUIREMENT = b'exp-copies-sidedata-changeset'
 
 # The repository use persistent nodemap for the changelog and the manifest.
 NODEMAP_REQUIREMENT = b'persistent-nodemap'
 
 # Denotes that the current repository is a share
 SHARED_REQUIREMENT = b'shared'
 
 # Denotes that current repository is a share and the shared source path is
 # relative to the current repository root path
 RELATIVE_SHARED_REQUIREMENT = b'relshared'
 
 # A repository with share implemented safely. The repository has different
 # store and working copy requirements i.e. both `.hg/requires` and
 # `.hg/store/requires` are present.
 SHARESAFE_REQUIREMENT = b'share-safe'
 
 # List of requirements which are working directory specific
 # These requirements cannot be shared between repositories if they
 # share the same store
 # * sparse is a working directory specific functionality and hence working
 #   directory specific requirement
 # * SHARED_REQUIREMENT and RELATIVE_SHARED_REQUIREMENT are requirements which
 #   represents that the current working copy/repository shares store of another
 #   repo. Hence both of them should be stored in working copy
 # * SHARESAFE_REQUIREMENT needs to be stored in working dir to mark that rest of
 #   the requirements are stored in store's requires
 WORKING_DIR_REQUIREMENTS = {
     SPARSE_REQUIREMENT,
     SHARED_REQUIREMENT,
     RELATIVE_SHARED_REQUIREMENT,
     SHARESAFE_REQUIREMENT,
 }

mercurial/upgrade_utils/actions.py

@@ -1,1011 +1,1011 b''
 # upgrade.py - functions for in place upgrade of Mercurial repository
 #
 # Copyright (c) 2016-present, Gregory Szorc
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 from ..i18n import _
 from .. import (
     error,
     localrepo,
     requirements,
     revlog,
     util,
 )
 
 from ..utils import compression
 
 # list of requirements that request a clone of all revlog if added/removed
 RECLONES_REQUIREMENTS = {
-    b'generaldelta',
+    requirements.GENERALDELTA_REQUIREMENT,
     requirements.SPARSEREVLOG_REQUIREMENT,
 }
 
 
 def preservedrequirements(repo):
     return set()
 
 
 FORMAT_VARIANT = b'deficiency'
 OPTIMISATION = b'optimization'
 
 
 class improvement(object):
     """Represents an improvement that can be made as part of an upgrade.
 
     The following attributes are defined on each instance:
 
     name
        Machine-readable string uniquely identifying this improvement. It
        will be mapped to an action later in the upgrade process.
 
     type
        Either ``FORMAT_VARIANT`` or ``OPTIMISATION``.
        A format variant is where we change the storage format. Not all format
        variant changes are an obvious problem.
        An optimization is an action (sometimes optional) that
        can be taken to further improve the state of the repository.
 
     description
        Message intended for humans explaining the improvement in more detail,
        including the implications of it. For ``FORMAT_VARIANT`` types, should be
        worded in the present tense. For ``OPTIMISATION`` types, should be
        worded in the future tense.
 
     upgrademessage
        Message intended for humans explaining what an upgrade addressing this
        issue will do. Should be worded in the future tense.
 
     postupgrademessage
        Message intended for humans which will be shown post an upgrade
        operation when the improvement will be added
 
     postdowngrademessage
        Message intended for humans which will be shown post an upgrade
        operation in which this improvement was removed
 
     touches_filelogs (bool)
         Whether this improvement touches filelogs
 
     touches_manifests (bool)
         Whether this improvement touches manifests
 
     touches_changelog (bool)
         Whether this improvement touches changelog
 
     touches_requirements (bool)
         Whether this improvement changes repository requirements
     """
 
     def __init__(self, name, type, description, upgrademessage):
         self.name = name
         self.type = type
         self.description = description
         self.upgrademessage = upgrademessage
         self.postupgrademessage = None
         self.postdowngrademessage = None
         # By default for now, we assume every improvement touches
         # all the things
         self.touches_filelogs = True
         self.touches_manifests = True
         self.touches_changelog = True
         self.touches_requirements = True
 
     def __eq__(self, other):
         if not isinstance(other, improvement):
             # This is what python tell use to do
             return NotImplemented
         return self.name == other.name
 
     def __ne__(self, other):
         return not (self == other)
 
     def __hash__(self):
         return hash(self.name)
 
 
 allformatvariant = []
 
 
 def registerformatvariant(cls):
     allformatvariant.append(cls)
     return cls
 
 
 class formatvariant(improvement):
     """an improvement subclass dedicated to repository format"""
 
     type = FORMAT_VARIANT
     ### The following attributes should be defined for each class:
 
     # machine-readable string uniquely identifying this improvement. it will be
     # mapped to an action later in the upgrade process.
     name = None
 
     # message intended for humans explaining the improvement in more detail,
     # including the implications of it ``FORMAT_VARIANT`` types, should be
     # worded
     # in the present tense.
     description = None
 
     # message intended for humans explaining what an upgrade addressing this
     # issue will do. should be worded in the future tense.
     upgrademessage = None
 
     # value of current Mercurial default for new repository
     default = None
 
     # Message intended for humans which will be shown post an upgrade
     # operation when the improvement will be added
     postupgrademessage = None
 
     # Message intended for humans which will be shown post an upgrade
     # operation in which this improvement was removed
     postdowngrademessage = None
 
     # By default for now, we assume every improvement touches all the things
     touches_filelogs = True
     touches_manifests = True
     touches_changelog = True
     touches_requirements = True
 
     def __init__(self):
         raise NotImplementedError()
 
     @staticmethod
     def fromrepo(repo):
         """current value of the variant in the repository"""
         raise NotImplementedError()
 
     @staticmethod
     def fromconfig(repo):
         """current value of the variant in the configuration"""
         raise NotImplementedError()
 
 
 class requirementformatvariant(formatvariant):
     """formatvariant based on a 'requirement' name.
 
     Many format variant are controlled by a 'requirement'. We define a small
     subclass to factor the code.
     """
 
     # the requirement that control this format variant
     _requirement = None
 
     @staticmethod
     def _newreporequirements(ui):
         return localrepo.newreporequirements(
             ui, localrepo.defaultcreateopts(ui)
         )
 
     @classmethod
     def fromrepo(cls, repo):
         assert cls._requirement is not None
         return cls._requirement in repo.requirements
 
     @classmethod
     def fromconfig(cls, repo):
         assert cls._requirement is not None
         return cls._requirement in cls._newreporequirements(repo.ui)
 
 
 @registerformatvariant
 class fncache(requirementformatvariant):
     name = b'fncache'
 
     _requirement = b'fncache'
 
     default = True
 
     description = _(
         b'long and reserved filenames may not work correctly; '
         b'repository performance is sub-optimal'
     )
 
     upgrademessage = _(
         b'repository will be more resilient to storing '
         b'certain paths and performance of certain '
         b'operations should be improved'
     )
 
 
 @registerformatvariant
 class dotencode(requirementformatvariant):
     name = b'dotencode'
 
     _requirement = b'dotencode'
 
     default = True
 
     description = _(
         b'storage of filenames beginning with a period or '
         b'space may not work correctly'
     )
 
     upgrademessage = _(
         b'repository will be better able to store files '
         b'beginning with a space or period'
     )
 
 
 @registerformatvariant
 class generaldelta(requirementformatvariant):
     name = b'generaldelta'
 
-    _requirement = b'generaldelta'
+    _requirement = requirements.GENERALDELTA_REQUIREMENT
 
     default = True
 
     description = _(
         b'deltas within internal storage are unable to '
         b'choose optimal revisions; repository is larger and '
         b'slower than it could be; interaction with other '
         b'repositories may require extra network and CPU '
         b'resources, making "hg push" and "hg pull" slower'
     )
 
     upgrademessage = _(
         b'repository storage will be able to create '
         b'optimal deltas; new repository data will be '
         b'smaller and read times should decrease; '
         b'interacting with other repositories using this '
         b'storage model should require less network and '
         b'CPU resources, making "hg push" and "hg pull" '
         b'faster'
     )
 
 
 @registerformatvariant
 class sharesafe(requirementformatvariant):
     name = b'share-safe'
     _requirement = requirements.SHARESAFE_REQUIREMENT
 
     default = False
 
     description = _(
         b'old shared repositories do not share source repository '
         b'requirements and config. This leads to various problems '
         b'when the source repository format is upgraded or some new '
         b'extensions are enabled.'
     )
 
     upgrademessage = _(
         b'Upgrades a repository to share-safe format so that future '
         b'shares of this repository share its requirements and configs.'
     )
 
     postdowngrademessage = _(
         b'repository downgraded to not use share safe mode, '
         b'existing shares will not work and needs to'
         b' be reshared.'
     )
 
     postupgrademessage = _(
         b'repository upgraded to share safe mode, existing'
         b' shares will still work in old non-safe mode. '
         b'Re-share existing shares to use them in safe mode'
         b' New shares will be created in safe mode.'
     )
 
     # upgrade only needs to change the requirements
     touches_filelogs = False
     touches_manifests = False
     touches_changelog = False
     touches_requirements = True
 
 
 @registerformatvariant
 class sparserevlog(requirementformatvariant):
     name = b'sparserevlog'
 
     _requirement = requirements.SPARSEREVLOG_REQUIREMENT
 
     default = True
 
     description = _(
         b'in order to limit disk reading and memory usage on older '
         b'version, the span of a delta chain from its root to its '
         b'end is limited, whatever the relevant data in this span. '
         b'This can severly limit Mercurial ability to build good '
         b'chain of delta resulting is much more storage space being '
         b'taken and limit reusability of on disk delta during '
         b'exchange.'
     )
 
     upgrademessage = _(
         b'Revlog supports delta chain with more unused data '
         b'between payload. These gaps will be skipped at read '
         b'time. This allows for better delta chains, making a '
         b'better compression and faster exchange with server.'
     )
 
 
 @registerformatvariant
 class sidedata(requirementformatvariant):
     name = b'sidedata'
 
     _requirement = requirements.SIDEDATA_REQUIREMENT
 
     default = False
 
     description = _(
         b'Allows storage of extra data alongside a revision, '
         b'unlocking various caching options.'
     )
 
     upgrademessage = _(b'Allows storage of extra data alongside a revision.')
 
 
 @registerformatvariant
 class persistentnodemap(requirementformatvariant):
     name = b'persistent-nodemap'
 
     _requirement = requirements.NODEMAP_REQUIREMENT
 
     default = False
 
     description = _(
         b'persist the node -> rev mapping on disk to speedup lookup'
     )
 
     upgrademessage = _(b'Speedup revision lookup by node id.')
 
 
 @registerformatvariant
 class copiessdc(requirementformatvariant):
     name = b'copies-sdc'
 
     _requirement = requirements.COPIESSDC_REQUIREMENT
 
     default = False
 
     description = _(b'Stores copies information alongside changesets.')
 
     upgrademessage = _(
         b'Allows to use more efficient algorithm to deal with ' b'copy tracing.'
     )
 
 
 @registerformatvariant
 class removecldeltachain(formatvariant):
     name = b'plain-cl-delta'
 
     default = True
 
     description = _(
         b'changelog storage is using deltas instead of '
         b'raw entries; changelog reading and any '
         b'operation relying on changelog data are slower '
         b'than they could be'
     )
 
     upgrademessage = _(
         b'changelog storage will be reformated to '
         b'store raw entries; changelog reading will be '
         b'faster; changelog size may be reduced'
     )
 
     @staticmethod
     def fromrepo(repo):
         # Mercurial 4.0 changed changelogs to not use delta chains. Search for
         # changelogs with deltas.
         cl = repo.changelog
         chainbase = cl.chainbase
         return all(rev == chainbase(rev) for rev in cl)
 
     @staticmethod
     def fromconfig(repo):
         return True
 
 
 @registerformatvariant
 class compressionengine(formatvariant):
     name = b'compression'
     default = b'zlib'
 
     description = _(
         b'Compresion algorithm used to compress data. '
         b'Some engine are faster than other'
     )
 
     upgrademessage = _(
         b'revlog content will be recompressed with the new algorithm.'
     )
 
     @classmethod
     def fromrepo(cls, repo):
         # we allow multiple compression engine requirement to co-exist because
         # strickly speaking, revlog seems to support mixed compression style.
         #
         # The compression used for new entries will be "the last one"
         compression = b'zlib'
         for req in repo.requirements:
             prefix = req.startswith
             if prefix(b'revlog-compression-') or prefix(b'exp-compression-'):
                 compression = req.split(b'-', 2)[2]
         return compression
 
     @classmethod
     def fromconfig(cls, repo):
         compengines = repo.ui.configlist(b'format', b'revlog-compression')
         # return the first valid value as the selection code would do
         for comp in compengines:
             if comp in util.compengines:
                 return comp
 
         # no valide compression found lets display it all for clarity
         return b','.join(compengines)
 
 
 @registerformatvariant
 class compressionlevel(formatvariant):
     name = b'compression-level'
     default = b'default'
 
     description = _(b'compression level')
 
     upgrademessage = _(b'revlog content will be recompressed')
 
     @classmethod
     def fromrepo(cls, repo):
         comp = compressionengine.fromrepo(repo)
         level = None
         if comp == b'zlib':
             level = repo.ui.configint(b'storage', b'revlog.zlib.level')
         elif comp == b'zstd':
             level = repo.ui.configint(b'storage', b'revlog.zstd.level')
         if level is None:
             return b'default'
         return bytes(level)
 
     @classmethod
     def fromconfig(cls, repo):
         comp = compressionengine.fromconfig(repo)
         level = None
         if comp == b'zlib':
             level = repo.ui.configint(b'storage', b'revlog.zlib.level')
         elif comp == b'zstd':
             level = repo.ui.configint(b'storage', b'revlog.zstd.level')
         if level is None:
             return b'default'
         return bytes(level)
 
 
 def find_format_upgrades(repo):
     """returns a list of format upgrades which can be perform on the repo"""
     upgrades = []
 
     # We could detect lack of revlogv1 and store here, but they were added
     # in 0.9.2 and we don't support upgrading repos without these
     # requirements, so let's not bother.
 
     for fv in allformatvariant:
         if not fv.fromrepo(repo):
             upgrades.append(fv)
 
     return upgrades
 
 
 def find_format_downgrades(repo):
     """returns a list of format downgrades which will be performed on the repo
     because of disabled config option for them"""
 
     downgrades = []
 
     for fv in allformatvariant:
         if fv.name == b'compression':
             # If there is a compression change between repository
             # and config, destination repository compression will change
             # and current compression will be removed.
             if fv.fromrepo(repo) != fv.fromconfig(repo):
                 downgrades.append(fv)
             continue
         # format variant exist in repo but does not exist in new repository
         # config
         if fv.fromrepo(repo) and not fv.fromconfig(repo):
             downgrades.append(fv)
 
     return downgrades
 
 
 ALL_OPTIMISATIONS = []
 
 
 def register_optimization(obj):
     ALL_OPTIMISATIONS.append(obj)
     return obj
 
 
 register_optimization(
     improvement(
         name=b're-delta-parent',
         type=OPTIMISATION,
         description=_(
             b'deltas within internal storage will be recalculated to '
             b'choose an optimal base revision where this was not '
             b'already done; the size of the repository may shrink and '
             b'various operations may become faster; the first time '
             b'this optimization is performed could slow down upgrade '
             b'execution considerably; subsequent invocations should '
             b'not run noticeably slower'
         ),
         upgrademessage=_(
             b'deltas within internal storage will choose a new '
             b'base revision if needed'
         ),
     )
 )
 
 register_optimization(
     improvement(
         name=b're-delta-multibase',
         type=OPTIMISATION,
         description=_(
             b'deltas within internal storage will be recalculated '
             b'against multiple base revision and the smallest '
             b'difference will be used; the size of the repository may '
             b'shrink significantly when there are many merges; this '
             b'optimization will slow down execution in proportion to '
             b'the number of merges in the repository and the amount '
             b'of files in the repository; this slow down should not '
             b'be significant unless there are tens of thousands of '
             b'files and thousands of merges'
         ),
         upgrademessage=_(
             b'deltas within internal storage will choose an '
             b'optimal delta by computing deltas against multiple '
             b'parents; may slow down execution time '
             b'significantly'
         ),
     )
 )
 
 register_optimization(
     improvement(
         name=b're-delta-all',
         type=OPTIMISATION,
         description=_(
             b'deltas within internal storage will always be '
             b'recalculated without reusing prior deltas; this will '
             b'likely make execution run several times slower; this '
             b'optimization is typically not needed'
         ),
         upgrademessage=_(
             b'deltas within internal storage will be fully '
             b'recomputed; this will likely drastically slow down '
             b'execution time'
         ),
     )
 )
 
 register_optimization(
     improvement(
         name=b're-delta-fulladd',
         type=OPTIMISATION,
         description=_(
             b'every revision will be re-added as if it was new '
             b'content. It will go through the full storage '
             b'mechanism giving extensions a chance to process it '
             b'(eg. lfs). This is similar to "re-delta-all" but even '
             b'slower since more logic is involved.'
         ),
         upgrademessage=_(
             b'each revision will be added as new content to the '
             b'internal storage; this will likely drastically slow '
             b'down execution time, but some extensions might need '
             b'it'
         ),
     )
 )
 
 
 def findoptimizations(repo):
     """Determine optimisation that could be used during upgrade"""
     # These are unconditionally added. There is logic later that figures out
     # which ones to apply.
     return list(ALL_OPTIMISATIONS)
 
 
 def determine_upgrade_actions(
     repo, format_upgrades, optimizations, sourcereqs, destreqs
 ):
     """Determine upgrade actions that will be performed.
 
     Given a list of improvements as returned by ``find_format_upgrades`` and
     ``findoptimizations``, determine the list of upgrade actions that
     will be performed.
 
     The role of this function is to filter improvements if needed, apply
     recommended optimizations from the improvements list that make sense,
     etc.
 
     Returns a list of action names.
     """
     newactions = []
 
     for d in format_upgrades:
         name = d._requirement
 
         # If the action is a requirement that doesn't show up in the
         # destination requirements, prune the action.
         if name is not None and name not in destreqs:
             continue
 
         newactions.append(d)
 
     newactions.extend(o for o in sorted(optimizations) if o not in newactions)
 
     # FUTURE consider adding some optimizations here for certain transitions.
     # e.g. adding generaldelta could schedule parent redeltas.
 
     return newactions
 
 
 class UpgradeOperation(object):
     """represent the work to be done during an upgrade"""
 
     def __init__(
         self,
         ui,
         new_requirements,
         current_requirements,
         upgrade_actions,
         removed_actions,
         revlogs_to_process,
         backup_store,
     ):
         self.ui = ui
         self.new_requirements = new_requirements
         self.current_requirements = current_requirements
         # list of upgrade actions the operation will perform
         self.upgrade_actions = upgrade_actions
         self._upgrade_actions_names = set([a.name for a in upgrade_actions])
         self.removed_actions = removed_actions
         self.revlogs_to_process = revlogs_to_process
         # requirements which will be added by the operation
         self._added_requirements = (
             self.new_requirements - self.current_requirements
         )
         # requirements which will be removed by the operation
         self._removed_requirements = (
             self.current_requirements - self.new_requirements
         )
         # requirements which will be preserved by the operation
         self._preserved_requirements = (
             self.current_requirements & self.new_requirements
         )
         # optimizations which are not used and it's recommended that they
         # should use them
         all_optimizations = findoptimizations(None)
         self.unused_optimizations = [
             i for i in all_optimizations if i not in self.upgrade_actions
         ]
 
         # delta reuse mode of this upgrade operation
         self.delta_reuse_mode = revlog.revlog.DELTAREUSEALWAYS
         if b're-delta-all' in self._upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSENEVER
         elif b're-delta-parent' in self._upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSESAMEREVS
         elif b're-delta-multibase' in self._upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSESAMEREVS
         elif b're-delta-fulladd' in self._upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSEFULLADD
 
         # should this operation force re-delta of both parents
         self.force_re_delta_both_parents = (
             b're-delta-multibase' in self._upgrade_actions_names
         )
 
         # should this operation create a backup of the store
         self.backup_store = backup_store
 
         # whether the operation touches different revlogs at all or not
         self.touches_filelogs = self._touches_filelogs()
         self.touches_manifests = self._touches_manifests()
         self.touches_changelog = self._touches_changelog()
         # whether the operation touches requirements file or not
         self.touches_requirements = self._touches_requirements()
         self.touches_store = (
             self.touches_filelogs
             or self.touches_manifests
             or self.touches_changelog
         )
         # does the operation only touches repository requirement
         self.requirements_only = (
             self.touches_requirements and not self.touches_store
         )
 
     def _touches_filelogs(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_filelogs:
                 return True
         for a in self.removed_actions:
             if a.touches_filelogs:
                 return True
         return False
 
     def _touches_manifests(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_manifests:
                 return True
         for a in self.removed_actions:
             if a.touches_manifests:
                 return True
         return False
 
     def _touches_changelog(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_changelog:
                 return True
         for a in self.removed_actions:
             if a.touches_changelog:
                 return True
         return False
 
     def _touches_requirements(self):
         for a in self.upgrade_actions:
             # optimisations are used to re-process revlogs and does not result
             # in a requirement being added or removed
             if a.type == OPTIMISATION:
                 pass
             elif a.touches_requirements:
                 return True
         for a in self.removed_actions:
             if a.touches_requirements:
                 return True
 
         return False
 
     def _write_labeled(self, l, label):
         """
         Utility function to aid writing of a list under one label
         """
         first = True
         for r in sorted(l):
             if not first:
                 self.ui.write(b', ')
             self.ui.write(r, label=label)
             first = False
 
     def print_requirements(self):
         self.ui.write(_(b'requirements\n'))
         self.ui.write(_(b'   preserved: '))
         self._write_labeled(
             self._preserved_requirements, "upgrade-repo.requirement.preserved"
         )
         self.ui.write((b'\n'))
         if self._removed_requirements:
             self.ui.write(_(b'   removed: '))
             self._write_labeled(
                 self._removed_requirements, "upgrade-repo.requirement.removed"
             )
             self.ui.write((b'\n'))
         if self._added_requirements:
             self.ui.write(_(b'   added: '))
             self._write_labeled(
                 self._added_requirements, "upgrade-repo.requirement.added"
             )
             self.ui.write((b'\n'))
         self.ui.write(b'\n')
 
     def print_optimisations(self):
         optimisations = [
             a for a in self.upgrade_actions if a.type == OPTIMISATION
         ]
         optimisations.sort(key=lambda a: a.name)
         if optimisations:
             self.ui.write(_(b'optimisations: '))
             self._write_labeled(
                 [a.name for a in optimisations],
                 "upgrade-repo.optimisation.performed",
             )
             self.ui.write(b'\n\n')
 
     def print_upgrade_actions(self):
         for a in self.upgrade_actions:
             self.ui.status(b'%s\n   %s\n\n' % (a.name, a.upgrademessage))
 
     def print_affected_revlogs(self):
         if not self.revlogs_to_process:
             self.ui.write((b'no revlogs to process\n'))
         else:
             self.ui.write((b'processed revlogs:\n'))
             for r in sorted(self.revlogs_to_process):
                 self.ui.write((b'  - %s\n' % r))
         self.ui.write((b'\n'))
 
     def print_unused_optimizations(self):
         for i in self.unused_optimizations:
             self.ui.status(_(b'%s\n   %s\n\n') % (i.name, i.description))
 
     def has_upgrade_action(self, name):
         """ Check whether the upgrade operation will perform this action """
         return name in self._upgrade_actions_names
 
     def print_post_op_messages(self):
         """ print post upgrade operation warning messages """
         for a in self.upgrade_actions:
             if a.postupgrademessage is not None:
                 self.ui.warn(b'%s\n' % a.postupgrademessage)
         for a in self.removed_actions:
             if a.postdowngrademessage is not None:
                 self.ui.warn(b'%s\n' % a.postdowngrademessage)
 
 
 ###  Code checking if a repository can got through the upgrade process at all. #
 
 
 def requiredsourcerequirements(repo):
     """Obtain requirements required to be present to upgrade a repo.
 
     An upgrade will not be allowed if the repository doesn't have the
     requirements returned by this function.
     """
     return {
         # Introduced in Mercurial 0.9.2.
         requirements.REVLOGV1_REQUIREMENT,
         # Introduced in Mercurial 0.9.2.
         b'store',
     }
 
 
 def blocksourcerequirements(repo):
     """Obtain requirements that will prevent an upgrade from occurring.
 
     An upgrade cannot be performed if the source repository contains a
     requirements in the returned set.
     """
     return {
         # The upgrade code does not yet support these experimental features.
         # This is an artificial limitation.
         requirements.TREEMANIFEST_REQUIREMENT,
         # This was a precursor to generaldelta and was never enabled by default.
         # It should (hopefully) not exist in the wild.
         b'parentdelta',
         # Upgrade should operate on the actual store, not the shared link.
         requirements.SHARED_REQUIREMENT,
     }
 
 
 def check_source_requirements(repo):
     """Ensure that no existing requirements prevent the repository upgrade"""
 
     required = requiredsourcerequirements(repo)
     missingreqs = required - repo.requirements
     if missingreqs:
         msg = _(b'cannot upgrade repository; requirement missing: %s')
         missingreqs = b', '.join(sorted(missingreqs))
         raise error.Abort(msg % missingreqs)
 
     blocking = blocksourcerequirements(repo)
     blockingreqs = blocking & repo.requirements
     if blockingreqs:
         m = _(b'cannot upgrade repository; unsupported source requirement: %s')
         blockingreqs = b', '.join(sorted(blockingreqs))
         raise error.Abort(m % blockingreqs)
 
 
 ### Verify the validity of the planned requirement changes ####################
 
 
 def supportremovedrequirements(repo):
     """Obtain requirements that can be removed during an upgrade.
 
     If an upgrade were to create a repository that dropped a requirement,
     the dropped requirement must appear in the returned set for the upgrade
     to be allowed.
     """
     supported = {
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.SIDEDATA_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def supporteddestrequirements(repo):
     """Obtain requirements that upgrade supports in the destination.
 
     If the result of the upgrade would create requirements not in this set,
     the upgrade is disallowed.
 
     Extensions should monkeypatch this to add their custom requirements.
     """
     supported = {
         b'dotencode',
         b'fncache',
-        b'generaldelta',
+        requirements.GENERALDELTA_REQUIREMENT,
         requirements.REVLOGV1_REQUIREMENT,
         b'store',
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.SIDEDATA_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def allowednewrequirements(repo):
     """Obtain requirements that can be added to a repository during upgrade.
 
     This is used to disallow proposed requirements from being added when
     they weren't present before.
 
     We use a list of allowed requirement additions instead of a list of known
     bad additions because the whitelist approach is safer and will prevent
     future, unknown requirements from accidentally being added.
     """
     supported = {
         b'dotencode',
         b'fncache',
-        b'generaldelta',
+        requirements.GENERALDELTA_REQUIREMENT,
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.SIDEDATA_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def check_requirements_changes(repo, new_reqs):
     old_reqs = repo.requirements
 
     support_removal = supportremovedrequirements(repo)
     no_remove_reqs = old_reqs - new_reqs - support_removal
     if no_remove_reqs:
         msg = _(b'cannot upgrade repository; requirement would be removed: %s')
         no_remove_reqs = b', '.join(sorted(no_remove_reqs))
         raise error.Abort(msg % no_remove_reqs)
 
     support_addition = allowednewrequirements(repo)
     no_add_reqs = new_reqs - old_reqs - support_addition
     if no_add_reqs:
         m = _(b'cannot upgrade repository; do not support adding requirement: ')
         no_add_reqs = b', '.join(sorted(no_add_reqs))
         raise error.Abort(m + no_add_reqs)
 
     supported = supporteddestrequirements(repo)
     unsupported_reqs = new_reqs - supported
     if unsupported_reqs:
         msg = _(
             b'cannot upgrade repository; do not support destination '
             b'requirement: %s'
         )
         unsupported_reqs = b', '.join(sorted(unsupported_reqs))
         raise error.Abort(msg % unsupported_reqs)

mercurial/wireprotov1server.py

@@ -1,748 +1,748 b''
 # wireprotov1server.py - Wire protocol version 1 server functionality
 #
 # Copyright 2005-2010 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import binascii
 import os
 
 from .i18n import _
 from .node import (
     hex,
     nullid,
 )
 from .pycompat import getattr
 
 from . import (
     bundle2,
     bundlecaches,
     changegroup as changegroupmod,
     discovery,
     encoding,
     error,
     exchange,
     pushkey as pushkeymod,
     pycompat,
     requirements as requirementsmod,
     streamclone,
     util,
     wireprototypes,
 )
 
 from .utils import (
     procutil,
     stringutil,
 )
 
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 bundle2requiredmain = _(b'incompatible Mercurial client; bundle2 required')
 bundle2requiredhint = _(
     b'see https://www.mercurial-scm.org/wiki/IncompatibleClient'
 )
 bundle2required = b'%s\n(%s)\n' % (bundle2requiredmain, bundle2requiredhint)
 
 
 def clientcompressionsupport(proto):
     """Returns a list of compression methods supported by the client.
 
     Returns a list of the compression methods supported by the client
     according to the protocol capabilities. If no such capability has
     been announced, fallback to the default of zlib and uncompressed.
     """
     for cap in proto.getprotocaps():
         if cap.startswith(b'comp='):
             return cap[5:].split(b',')
     return [b'zlib', b'none']
 
 
 # wire protocol command can either return a string or one of these classes.
 
 
 def getdispatchrepo(repo, proto, command):
     """Obtain the repo used for processing wire protocol commands.
 
     The intent of this function is to serve as a monkeypatch point for
     extensions that need commands to operate on different repo views under
     specialized circumstances.
     """
     viewconfig = repo.ui.config(b'server', b'view')
     return repo.filtered(viewconfig)
 
 
 def dispatch(repo, proto, command):
     repo = getdispatchrepo(repo, proto, command)
 
     func, spec = commands[command]
     args = proto.getargs(spec)
 
     return func(repo, proto, *args)
 
 
 def options(cmd, keys, others):
     opts = {}
     for k in keys:
         if k in others:
             opts[k] = others[k]
             del others[k]
     if others:
         procutil.stderr.write(
             b"warning: %s ignored unexpected arguments %s\n"
             % (cmd, b",".join(others))
         )
     return opts
 
 
 def bundle1allowed(repo, action):
     """Whether a bundle1 operation is allowed from the server.
 
     Priority is:
 
     1. server.bundle1gd.<action> (if generaldelta active)
     2. server.bundle1.<action>
     3. server.bundle1gd (if generaldelta active)
     4. server.bundle1
     """
     ui = repo.ui
-    gd = b'generaldelta' in repo.requirements
+    gd = requirementsmod.GENERALDELTA_REQUIREMENT in repo.requirements
 
     if gd:
         v = ui.configbool(b'server', b'bundle1gd.%s' % action)
         if v is not None:
             return v
 
     v = ui.configbool(b'server', b'bundle1.%s' % action)
     if v is not None:
         return v
 
     if gd:
         v = ui.configbool(b'server', b'bundle1gd')
         if v is not None:
             return v
 
     return ui.configbool(b'server', b'bundle1')
 
 
 commands = wireprototypes.commanddict()
 
 
 def wireprotocommand(name, args=None, permission=b'push'):
     """Decorator to declare a wire protocol command.
 
     ``name`` is the name of the wire protocol command being provided.
 
     ``args`` defines the named arguments accepted by the command. It is
     a space-delimited list of argument names. ``*`` denotes a special value
     that says to accept all named arguments.
 
     ``permission`` defines the permission type needed to run this command.
     Can be ``push`` or ``pull``. These roughly map to read-write and read-only,
     respectively. Default is to assume command requires ``push`` permissions
     because otherwise commands not declaring their permissions could modify
     a repository that is supposed to be read-only.
     """
     transports = {
         k for k, v in wireprototypes.TRANSPORTS.items() if v[b'version'] == 1
     }
 
     # Because SSHv2 is a mirror of SSHv1, we allow "batch" commands through to
     # SSHv2.
     # TODO undo this hack when SSH is using the unified frame protocol.
     if name == b'batch':
         transports.add(wireprototypes.SSHV2)
 
     if permission not in (b'push', b'pull'):
         raise error.ProgrammingError(
             b'invalid wire protocol permission; '
             b'got %s; expected "push" or "pull"' % permission
         )
 
     if args is None:
         args = b''
 
     if not isinstance(args, bytes):
         raise error.ProgrammingError(
             b'arguments for version 1 commands must be declared as bytes'
         )
 
     def register(func):
         if name in commands:
             raise error.ProgrammingError(
                 b'%s command already registered for version 1' % name
             )
         commands[name] = wireprototypes.commandentry(
             func, args=args, transports=transports, permission=permission
         )
 
         return func
 
     return register
 
 
 # TODO define a more appropriate permissions type to use for this.
 @wireprotocommand(b'batch', b'cmds *', permission=b'pull')
 def batch(repo, proto, cmds, others):
     unescapearg = wireprototypes.unescapebatcharg
     res = []
     for pair in cmds.split(b';'):
         op, args = pair.split(b' ', 1)
         vals = {}
         for a in args.split(b','):
             if a:
                 n, v = a.split(b'=')
                 vals[unescapearg(n)] = unescapearg(v)
         func, spec = commands[op]
 
         # Validate that client has permissions to perform this command.
         perm = commands[op].permission
         assert perm in (b'push', b'pull')
         proto.checkperm(perm)
 
         if spec:
             keys = spec.split()
             data = {}
             for k in keys:
                 if k == b'*':
                     star = {}
                     for key in vals.keys():
                         if key not in keys:
                             star[key] = vals[key]
                     data[b'*'] = star
                 else:
                     data[k] = vals[k]
             result = func(repo, proto, *[data[k] for k in keys])
         else:
             result = func(repo, proto)
         if isinstance(result, wireprototypes.ooberror):
             return result
 
         # For now, all batchable commands must return bytesresponse or
         # raw bytes (for backwards compatibility).
         assert isinstance(result, (wireprototypes.bytesresponse, bytes))
         if isinstance(result, wireprototypes.bytesresponse):
             result = result.data
         res.append(wireprototypes.escapebatcharg(result))
 
     return wireprototypes.bytesresponse(b';'.join(res))
 
 
 @wireprotocommand(b'between', b'pairs', permission=b'pull')
 def between(repo, proto, pairs):
     pairs = [wireprototypes.decodelist(p, b'-') for p in pairs.split(b" ")]
     r = []
     for b in repo.between(pairs):
         r.append(wireprototypes.encodelist(b) + b"\n")
 
     return wireprototypes.bytesresponse(b''.join(r))
 
 
 @wireprotocommand(b'branchmap', permission=b'pull')
 def branchmap(repo, proto):
     branchmap = repo.branchmap()
     heads = []
     for branch, nodes in pycompat.iteritems(branchmap):
         branchname = urlreq.quote(encoding.fromlocal(branch))
         branchnodes = wireprototypes.encodelist(nodes)
         heads.append(b'%s %s' % (branchname, branchnodes))
 
     return wireprototypes.bytesresponse(b'\n'.join(heads))
 
 
 @wireprotocommand(b'branches', b'nodes', permission=b'pull')
 def branches(repo, proto, nodes):
     nodes = wireprototypes.decodelist(nodes)
     r = []
     for b in repo.branches(nodes):
         r.append(wireprototypes.encodelist(b) + b"\n")
 
     return wireprototypes.bytesresponse(b''.join(r))
 
 
 @wireprotocommand(b'clonebundles', b'', permission=b'pull')
 def clonebundles(repo, proto):
     """Server command for returning info for available bundles to seed clones.
 
     Clients will parse this response and determine what bundle to fetch.
 
     Extensions may wrap this command to filter or dynamically emit data
     depending on the request. e.g. you could advertise URLs for the closest
     data center given the client's IP address.
     """
     return wireprototypes.bytesresponse(
         repo.vfs.tryread(bundlecaches.CB_MANIFEST_FILE)
     )
 
 
 wireprotocaps = [
     b'lookup',
     b'branchmap',
     b'pushkey',
     b'known',
     b'getbundle',
     b'unbundlehash',
 ]
 
 
 def _capabilities(repo, proto):
     """return a list of capabilities for a repo
 
     This function exists to allow extensions to easily wrap capabilities
     computation
 
     - returns a lists: easy to alter
     - change done here will be propagated to both `capabilities` and `hello`
       command without any other action needed.
     """
     # copy to prevent modification of the global list
     caps = list(wireprotocaps)
 
     # Command of same name as capability isn't exposed to version 1 of
     # transports. So conditionally add it.
     if commands.commandavailable(b'changegroupsubset', proto):
         caps.append(b'changegroupsubset')
 
     if streamclone.allowservergeneration(repo):
         if repo.ui.configbool(b'server', b'preferuncompressed'):
             caps.append(b'stream-preferred')
         requiredformats = repo.requirements & repo.supportedformats
         # if our local revlogs are just revlogv1, add 'stream' cap
         if not requiredformats - {requirementsmod.REVLOGV1_REQUIREMENT}:
             caps.append(b'stream')
         # otherwise, add 'streamreqs' detailing our local revlog format
         else:
             caps.append(b'streamreqs=%s' % b','.join(sorted(requiredformats)))
     if repo.ui.configbool(b'experimental', b'bundle2-advertise'):
         capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo, role=b'server'))
         caps.append(b'bundle2=' + urlreq.quote(capsblob))
     caps.append(b'unbundle=%s' % b','.join(bundle2.bundlepriority))
 
     if repo.ui.configbool(b'experimental', b'narrow'):
         caps.append(wireprototypes.NARROWCAP)
         if repo.ui.configbool(b'experimental', b'narrowservebrokenellipses'):
             caps.append(wireprototypes.ELLIPSESCAP)
 
     return proto.addcapabilities(repo, caps)
 
 
 # If you are writing an extension and consider wrapping this function. Wrap
 # `_capabilities` instead.
 @wireprotocommand(b'capabilities', permission=b'pull')
 def capabilities(repo, proto):
     caps = _capabilities(repo, proto)
     return wireprototypes.bytesresponse(b' '.join(sorted(caps)))
 
 
 @wireprotocommand(b'changegroup', b'roots', permission=b'pull')
 def changegroup(repo, proto, roots):
     nodes = wireprototypes.decodelist(roots)
     outgoing = discovery.outgoing(
         repo, missingroots=nodes, ancestorsof=repo.heads()
     )
     cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
     gen = iter(lambda: cg.read(32768), b'')
     return wireprototypes.streamres(gen=gen)
 
 
 @wireprotocommand(b'changegroupsubset', b'bases heads', permission=b'pull')
 def changegroupsubset(repo, proto, bases, heads):
     bases = wireprototypes.decodelist(bases)
     heads = wireprototypes.decodelist(heads)
     outgoing = discovery.outgoing(repo, missingroots=bases, ancestorsof=heads)
     cg = changegroupmod.makechangegroup(repo, outgoing, b'01', b'serve')
     gen = iter(lambda: cg.read(32768), b'')
     return wireprototypes.streamres(gen=gen)
 
 
 @wireprotocommand(b'debugwireargs', b'one two *', permission=b'pull')
 def debugwireargs(repo, proto, one, two, others):
     # only accept optional args from the known set
     opts = options(b'debugwireargs', [b'three', b'four'], others)
     return wireprototypes.bytesresponse(
         repo.debugwireargs(one, two, **pycompat.strkwargs(opts))
     )
 
 
 def find_pullbundle(repo, proto, opts, clheads, heads, common):
     """Return a file object for the first matching pullbundle.
 
     Pullbundles are specified in .hg/pullbundles.manifest similar to
     clonebundles.
     For each entry, the bundle specification is checked for compatibility:
     - Client features vs the BUNDLESPEC.
     - Revisions shared with the clients vs base revisions of the bundle.
       A bundle can be applied only if all its base revisions are known by
       the client.
     - At least one leaf of the bundle's DAG is missing on the client.
     - Every leaf of the bundle's DAG is part of node set the client wants.
       E.g. do not send a bundle of all changes if the client wants only
       one specific branch of many.
     """
 
     def decodehexstring(s):
         return {binascii.unhexlify(h) for h in s.split(b';')}
 
     manifest = repo.vfs.tryread(b'pullbundles.manifest')
     if not manifest:
         return None
     res = bundlecaches.parseclonebundlesmanifest(repo, manifest)
     res = bundlecaches.filterclonebundleentries(repo, res)
     if not res:
         return None
     cl = repo.unfiltered().changelog
     heads_anc = cl.ancestors([cl.rev(rev) for rev in heads], inclusive=True)
     common_anc = cl.ancestors([cl.rev(rev) for rev in common], inclusive=True)
     compformats = clientcompressionsupport(proto)
     for entry in res:
         comp = entry.get(b'COMPRESSION')
         altcomp = util.compengines._bundlenames.get(comp)
         if comp and comp not in compformats and altcomp not in compformats:
             continue
         # No test yet for VERSION, since V2 is supported by any client
         # that advertises partial pulls
         if b'heads' in entry:
             try:
                 bundle_heads = decodehexstring(entry[b'heads'])
             except TypeError:
                 # Bad heads entry
                 continue
             if bundle_heads.issubset(common):
                 continue  # Nothing new
             if all(cl.rev(rev) in common_anc for rev in bundle_heads):
                 continue  # Still nothing new
             if any(
                 cl.rev(rev) not in heads_anc and cl.rev(rev) not in common_anc
                 for rev in bundle_heads
             ):
                 continue
         if b'bases' in entry:
             try:
                 bundle_bases = decodehexstring(entry[b'bases'])
             except TypeError:
                 # Bad bases entry
                 continue
             if not all(cl.rev(rev) in common_anc for rev in bundle_bases):
                 continue
         path = entry[b'URL']
         repo.ui.debug(b'sending pullbundle "%s"\n' % path)
         try:
             return repo.vfs.open(path)
         except IOError:
             repo.ui.debug(b'pullbundle "%s" not accessible\n' % path)
             continue
     return None
 
 
 @wireprotocommand(b'getbundle', b'*', permission=b'pull')
 def getbundle(repo, proto, others):
     opts = options(
         b'getbundle', wireprototypes.GETBUNDLE_ARGUMENTS.keys(), others
     )
     for k, v in pycompat.iteritems(opts):
         keytype = wireprototypes.GETBUNDLE_ARGUMENTS[k]
         if keytype == b'nodes':
             opts[k] = wireprototypes.decodelist(v)
         elif keytype == b'csv':
             opts[k] = list(v.split(b','))
         elif keytype == b'scsv':
             opts[k] = set(v.split(b','))
         elif keytype == b'boolean':
             # Client should serialize False as '0', which is a non-empty string
             # so it evaluates as a True bool.
             if v == b'0':
                 opts[k] = False
             else:
                 opts[k] = bool(v)
         elif keytype != b'plain':
             raise KeyError(b'unknown getbundle option type %s' % keytype)
 
     if not bundle1allowed(repo, b'pull'):
         if not exchange.bundle2requested(opts.get(b'bundlecaps')):
             if proto.name == b'http-v1':
                 return wireprototypes.ooberror(bundle2required)
             raise error.Abort(bundle2requiredmain, hint=bundle2requiredhint)
 
     try:
         clheads = set(repo.changelog.heads())
         heads = set(opts.get(b'heads', set()))
         common = set(opts.get(b'common', set()))
         common.discard(nullid)
         if (
             repo.ui.configbool(b'server', b'pullbundle')
             and b'partial-pull' in proto.getprotocaps()
         ):
             # Check if a pre-built bundle covers this request.
             bundle = find_pullbundle(repo, proto, opts, clheads, heads, common)
             if bundle:
                 return wireprototypes.streamres(
                     gen=util.filechunkiter(bundle), prefer_uncompressed=True
                 )
 
         if repo.ui.configbool(b'server', b'disablefullbundle'):
             # Check to see if this is a full clone.
             changegroup = opts.get(b'cg', True)
             if changegroup and not common and clheads == heads:
                 raise error.Abort(
                     _(b'server has pull-based clones disabled'),
                     hint=_(b'remove --pull if specified or upgrade Mercurial'),
                 )
 
         info, chunks = exchange.getbundlechunks(
             repo, b'serve', **pycompat.strkwargs(opts)
         )
         prefercompressed = info.get(b'prefercompressed', True)
     except error.Abort as exc:
         # cleanly forward Abort error to the client
         if not exchange.bundle2requested(opts.get(b'bundlecaps')):
             if proto.name == b'http-v1':
                 return wireprototypes.ooberror(exc.message + b'\n')
             raise  # cannot do better for bundle1 + ssh
         # bundle2 request expect a bundle2 reply
         bundler = bundle2.bundle20(repo.ui)
         manargs = [(b'message', exc.message)]
         advargs = []
         if exc.hint is not None:
             advargs.append((b'hint', exc.hint))
         bundler.addpart(bundle2.bundlepart(b'error:abort', manargs, advargs))
         chunks = bundler.getchunks()
         prefercompressed = False
 
     return wireprototypes.streamres(
         gen=chunks, prefer_uncompressed=not prefercompressed
     )
 
 
 @wireprotocommand(b'heads', permission=b'pull')
 def heads(repo, proto):
     h = repo.heads()
     return wireprototypes.bytesresponse(wireprototypes.encodelist(h) + b'\n')
 
 
 @wireprotocommand(b'hello', permission=b'pull')
 def hello(repo, proto):
     """Called as part of SSH handshake to obtain server info.
 
     Returns a list of lines describing interesting things about the
     server, in an RFC822-like format.
 
     Currently, the only one defined is ``capabilities``, which consists of a
     line of space separated tokens describing server abilities:
 
         capabilities: <token0> <token1> <token2>
     """
     caps = capabilities(repo, proto).data
     return wireprototypes.bytesresponse(b'capabilities: %s\n' % caps)
 
 
 @wireprotocommand(b'listkeys', b'namespace', permission=b'pull')
 def listkeys(repo, proto, namespace):
     d = sorted(repo.listkeys(encoding.tolocal(namespace)).items())
     return wireprototypes.bytesresponse(pushkeymod.encodekeys(d))
 
 
 @wireprotocommand(b'lookup', b'key', permission=b'pull')
 def lookup(repo, proto, key):
     try:
         k = encoding.tolocal(key)
         n = repo.lookup(k)
         r = hex(n)
         success = 1
     except Exception as inst:
         r = stringutil.forcebytestr(inst)
         success = 0
     return wireprototypes.bytesresponse(b'%d %s\n' % (success, r))
 
 
 @wireprotocommand(b'known', b'nodes *', permission=b'pull')
 def known(repo, proto, nodes, others):
     v = b''.join(
         b and b'1' or b'0' for b in repo.known(wireprototypes.decodelist(nodes))
     )
     return wireprototypes.bytesresponse(v)
 
 
 @wireprotocommand(b'protocaps', b'caps', permission=b'pull')
 def protocaps(repo, proto, caps):
     if proto.name == wireprototypes.SSHV1:
         proto._protocaps = set(caps.split(b' '))
     return wireprototypes.bytesresponse(b'OK')
 
 
 @wireprotocommand(b'pushkey', b'namespace key old new', permission=b'push')
 def pushkey(repo, proto, namespace, key, old, new):
     # compatibility with pre-1.8 clients which were accidentally
     # sending raw binary nodes rather than utf-8-encoded hex
     if len(new) == 20 and stringutil.escapestr(new) != new:
         # looks like it could be a binary node
         try:
             new.decode('utf-8')
             new = encoding.tolocal(new)  # but cleanly decodes as UTF-8
         except UnicodeDecodeError:
             pass  # binary, leave unmodified
     else:
         new = encoding.tolocal(new)  # normal path
 
     with proto.mayberedirectstdio() as output:
         r = (
             repo.pushkey(
                 encoding.tolocal(namespace),
                 encoding.tolocal(key),
                 encoding.tolocal(old),
                 new,
             )
             or False
         )
 
     output = output.getvalue() if output else b''
     return wireprototypes.bytesresponse(b'%d\n%s' % (int(r), output))
 
 
 @wireprotocommand(b'stream_out', permission=b'pull')
 def stream(repo, proto):
     """If the server supports streaming clone, it advertises the "stream"
     capability with a value representing the version and flags of the repo
     it is serving. Client checks to see if it understands the format.
     """
     return wireprototypes.streamreslegacy(streamclone.generatev1wireproto(repo))
 
 
 @wireprotocommand(b'unbundle', b'heads', permission=b'push')
 def unbundle(repo, proto, heads):
     their_heads = wireprototypes.decodelist(heads)
 
     with proto.mayberedirectstdio() as output:
         try:
             exchange.check_heads(repo, their_heads, b'preparing changes')
             cleanup = lambda: None
             try:
                 payload = proto.getpayload()
                 if repo.ui.configbool(b'server', b'streamunbundle'):
 
                     def cleanup():
                         # Ensure that the full payload is consumed, so
                         # that the connection doesn't contain trailing garbage.
                         for p in payload:
                             pass
 
                     fp = util.chunkbuffer(payload)
                 else:
                     # write bundle data to temporary file as it can be big
                     fp, tempname = None, None
 
                     def cleanup():
                         if fp:
                             fp.close()
                         if tempname:
                             os.unlink(tempname)
 
                     fd, tempname = pycompat.mkstemp(prefix=b'hg-unbundle-')
                     repo.ui.debug(
                         b'redirecting incoming bundle to %s\n' % tempname
                     )
                     fp = os.fdopen(fd, pycompat.sysstr(b'wb+'))
                     for p in payload:
                         fp.write(p)
                     fp.seek(0)
 
                 gen = exchange.readbundle(repo.ui, fp, None)
                 if isinstance(
                     gen, changegroupmod.cg1unpacker
                 ) and not bundle1allowed(repo, b'push'):
                     if proto.name == b'http-v1':
                         # need to special case http because stderr do not get to
                         # the http client on failed push so we need to abuse
                         # some other error type to make sure the message get to
                         # the user.
                         return wireprototypes.ooberror(bundle2required)
                     raise error.Abort(
                         bundle2requiredmain, hint=bundle2requiredhint
                     )
 
                 r = exchange.unbundle(
                     repo, gen, their_heads, b'serve', proto.client()
                 )
                 if util.safehasattr(r, b'addpart'):
                     # The return looks streamable, we are in the bundle2 case
                     # and should return a stream.
                     return wireprototypes.streamreslegacy(gen=r.getchunks())
                 return wireprototypes.pushres(
                     r, output.getvalue() if output else b''
                 )
 
             finally:
                 cleanup()
 
         except (error.BundleValueError, error.Abort, error.PushRaced) as exc:
             # handle non-bundle2 case first
             if not getattr(exc, 'duringunbundle2', False):
                 try:
                     raise
                 except error.Abort as exc:
                     # The old code we moved used procutil.stderr directly.
                     # We did not change it to minimise code change.
                     # This need to be moved to something proper.
                     # Feel free to do it.
                     procutil.stderr.write(exc.format())
                     procutil.stderr.flush()
                     return wireprototypes.pushres(
                         0, output.getvalue() if output else b''
                     )
                 except error.PushRaced:
                     return wireprototypes.pusherr(
                         pycompat.bytestr(exc),
                         output.getvalue() if output else b'',
                     )
 
             bundler = bundle2.bundle20(repo.ui)
             for out in getattr(exc, '_bundle2salvagedoutput', ()):
                 bundler.addpart(out)
             try:
                 try:
                     raise
                 except error.PushkeyFailed as exc:
                     # check client caps
                     remotecaps = getattr(exc, '_replycaps', None)
                     if (
                         remotecaps is not None
                         and b'pushkey' not in remotecaps.get(b'error', ())
                     ):
                         # no support remote side, fallback to Abort handler.
                         raise
                     part = bundler.newpart(b'error:pushkey')
                     part.addparam(b'in-reply-to', exc.partid)
                     if exc.namespace is not None:
                         part.addparam(
                             b'namespace', exc.namespace, mandatory=False
                         )
                     if exc.key is not None:
                         part.addparam(b'key', exc.key, mandatory=False)
                     if exc.new is not None:
                         part.addparam(b'new', exc.new, mandatory=False)
                     if exc.old is not None:
                         part.addparam(b'old', exc.old, mandatory=False)
                     if exc.ret is not None:
                         part.addparam(b'ret', exc.ret, mandatory=False)
             except error.BundleValueError as exc:
                 errpart = bundler.newpart(b'error:unsupportedcontent')
                 if exc.parttype is not None:
                     errpart.addparam(b'parttype', exc.parttype)
                 if exc.params:
                     errpart.addparam(b'params', b'\0'.join(exc.params))
             except error.Abort as exc:
                 manargs = [(b'message', exc.message)]
                 advargs = []
                 if exc.hint is not None:
                     advargs.append((b'hint', exc.hint))
                 bundler.addpart(
                     bundle2.bundlepart(b'error:abort', manargs, advargs)
                 )
             except error.PushRaced as exc:
                 bundler.newpart(
                     b'error:pushraced',
                     [(b'message', stringutil.forcebytestr(exc))],
                 )
             return wireprototypes.streamreslegacy(gen=bundler.getchunks())