upgrade-repo: colorize some of the output

Having clear color for requirement added and removed is useful.

mercurial/color.py

@@ -1,574 +1,577 b''
 # utility for color output for Mercurial commands
 #
 # Copyright (C) 2007 Kevin Christen <[e-mail]> and other
 #
 # 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 re
 
 from .i18n import _
 from .pycompat import getattr
 
 from . import (
     encoding,
     pycompat,
 )
 
 from .utils import stringutil
 
 try:
     import curses
 
     # Mapping from effect name to terminfo attribute name (or raw code) or
     # color number.  This will also force-load the curses module.
     _baseterminfoparams = {
         b'none': (True, b'sgr0', b''),
         b'standout': (True, b'smso', b''),
         b'underline': (True, b'smul', b''),
         b'reverse': (True, b'rev', b''),
         b'inverse': (True, b'rev', b''),
         b'blink': (True, b'blink', b''),
         b'dim': (True, b'dim', b''),
         b'bold': (True, b'bold', b''),
         b'invisible': (True, b'invis', b''),
         b'italic': (True, b'sitm', b''),
         b'black': (False, curses.COLOR_BLACK, b''),
         b'red': (False, curses.COLOR_RED, b''),
         b'green': (False, curses.COLOR_GREEN, b''),
         b'yellow': (False, curses.COLOR_YELLOW, b''),
         b'blue': (False, curses.COLOR_BLUE, b''),
         b'magenta': (False, curses.COLOR_MAGENTA, b''),
         b'cyan': (False, curses.COLOR_CYAN, b''),
         b'white': (False, curses.COLOR_WHITE, b''),
     }
 except ImportError:
     curses = None
     _baseterminfoparams = {}
 
 # start and stop parameters for effects
 _effects = {
     b'none': 0,
     b'black': 30,
     b'red': 31,
     b'green': 32,
     b'yellow': 33,
     b'blue': 34,
     b'magenta': 35,
     b'cyan': 36,
     b'white': 37,
     b'bold': 1,
     b'italic': 3,
     b'underline': 4,
     b'inverse': 7,
     b'dim': 2,
     b'black_background': 40,
     b'red_background': 41,
     b'green_background': 42,
     b'yellow_background': 43,
     b'blue_background': 44,
     b'purple_background': 45,
     b'cyan_background': 46,
     b'white_background': 47,
 }
 
 _defaultstyles = {
     b'grep.match': b'red bold',
     b'grep.linenumber': b'green',
     b'grep.rev': b'blue',
     b'grep.sep': b'cyan',
     b'grep.filename': b'magenta',
     b'grep.user': b'magenta',
     b'grep.date': b'magenta',
     b'grep.inserted': b'green bold',
     b'grep.deleted': b'red bold',
     b'bookmarks.active': b'green',
     b'branches.active': b'none',
     b'branches.closed': b'black bold',
     b'branches.current': b'green',
     b'branches.inactive': b'none',
     b'diff.changed': b'white',
     b'diff.deleted': b'red',
     b'diff.deleted.changed': b'red bold underline',
     b'diff.deleted.unchanged': b'red',
     b'diff.diffline': b'bold',
     b'diff.extended': b'cyan bold',
     b'diff.file_a': b'red bold',
     b'diff.file_b': b'green bold',
     b'diff.hunk': b'magenta',
     b'diff.inserted': b'green',
     b'diff.inserted.changed': b'green bold underline',
     b'diff.inserted.unchanged': b'green',
     b'diff.tab': b'',
     b'diff.trailingwhitespace': b'bold red_background',
     b'changeset.public': b'',
     b'changeset.draft': b'',
     b'changeset.secret': b'',
     b'diffstat.deleted': b'red',
     b'diffstat.inserted': b'green',
     b'formatvariant.name.mismatchconfig': b'red',
     b'formatvariant.name.mismatchdefault': b'yellow',
     b'formatvariant.name.uptodate': b'green',
     b'formatvariant.repo.mismatchconfig': b'red',
     b'formatvariant.repo.mismatchdefault': b'yellow',
     b'formatvariant.repo.uptodate': b'green',
     b'formatvariant.config.special': b'yellow',
     b'formatvariant.config.default': b'green',
     b'formatvariant.default': b'',
     b'histedit.remaining': b'red bold',
     b'ui.addremove.added': b'green',
     b'ui.addremove.removed': b'red',
     b'ui.error': b'red',
     b'ui.prompt': b'yellow',
     b'log.changeset': b'yellow',
     b'patchbomb.finalsummary': b'',
     b'patchbomb.from': b'magenta',
     b'patchbomb.to': b'cyan',
     b'patchbomb.subject': b'green',
     b'patchbomb.diffstats': b'',
     b'rebase.rebased': b'blue',
     b'rebase.remaining': b'red bold',
     b'resolve.resolved': b'green bold',
     b'resolve.unresolved': b'red bold',
     b'shelve.age': b'cyan',
     b'shelve.newest': b'green bold',
     b'shelve.name': b'blue bold',
     b'status.added': b'green bold',
     b'status.clean': b'none',
     b'status.copied': b'none',
     b'status.deleted': b'cyan bold underline',
     b'status.ignored': b'black bold',
     b'status.modified': b'blue bold',
     b'status.removed': b'red bold',
     b'status.unknown': b'magenta bold underline',
     b'tags.normal': b'green',
     b'tags.local': b'black bold',
+    b'upgrade-repo.requirement.preserved': b'cyan',
+    b'upgrade-repo.requirement.added': b'green',
+    b'upgrade-repo.requirement.removed': b'red',
 }
 
 
 def loadcolortable(ui, extname, colortable):
     _defaultstyles.update(colortable)
 
 
 def _terminfosetup(ui, mode, formatted):
     '''Initialize terminfo data and the terminal if we're in terminfo mode.'''
 
     # If we failed to load curses, we go ahead and return.
     if curses is None:
         return
     # Otherwise, see what the config file says.
     if mode not in (b'auto', b'terminfo'):
         return
     ui._terminfoparams.update(_baseterminfoparams)
 
     for key, val in ui.configitems(b'color'):
         if key.startswith(b'color.'):
             newval = (False, int(val), b'')
             ui._terminfoparams[key[6:]] = newval
         elif key.startswith(b'terminfo.'):
             newval = (True, b'', val.replace(b'\\E', b'\x1b'))
             ui._terminfoparams[key[9:]] = newval
     try:
         curses.setupterm()
     except curses.error:
         ui._terminfoparams.clear()
         return
 
     for key, (b, e, c) in ui._terminfoparams.copy().items():
         if not b:
             continue
         if not c and not curses.tigetstr(pycompat.sysstr(e)):
             # Most terminals don't support dim, invis, etc, so don't be
             # noisy and use ui.debug().
             ui.debug(b"no terminfo entry for %s\n" % e)
             del ui._terminfoparams[key]
     if not curses.tigetstr('setaf') or not curses.tigetstr('setab'):
         # Only warn about missing terminfo entries if we explicitly asked for
         # terminfo mode and we're in a formatted terminal.
         if mode == b"terminfo" and formatted:
             ui.warn(
                 _(
                     b"no terminfo entry for setab/setaf: reverting to "
                     b"ECMA-48 color\n"
                 )
             )
         ui._terminfoparams.clear()
 
 
 def setup(ui):
     """configure color on a ui
 
     That function both set the colormode for the ui object and read
     the configuration looking for custom colors and effect definitions."""
     mode = _modesetup(ui)
     ui._colormode = mode
     if mode and mode != b'debug':
         configstyles(ui)
 
 
 def _modesetup(ui):
     if ui.plain(b'color'):
         return None
     config = ui.config(b'ui', b'color')
     if config == b'debug':
         return b'debug'
 
     auto = config == b'auto'
     always = False
     if not auto and stringutil.parsebool(config):
         # We want the config to behave like a boolean, "on" is actually auto,
         # but "always" value is treated as a special case to reduce confusion.
         if (
             ui.configsource(b'ui', b'color') == b'--color'
             or config == b'always'
         ):
             always = True
         else:
             auto = True
 
     if not always and not auto:
         return None
 
     formatted = always or (
         encoding.environ.get(b'TERM') != b'dumb' and ui.formatted()
     )
 
     mode = ui.config(b'color', b'mode')
 
     # If pager is active, color.pagermode overrides color.mode.
     if getattr(ui, 'pageractive', False):
         mode = ui.config(b'color', b'pagermode', mode)
 
     realmode = mode
     if pycompat.iswindows:
         from . import win32
 
         term = encoding.environ.get(b'TERM')
         # TERM won't be defined in a vanilla cmd.exe environment.
 
         # UNIX-like environments on Windows such as Cygwin and MSYS will
         # set TERM. They appear to make a best effort attempt at setting it
         # to something appropriate. However, not all environments with TERM
         # defined support ANSI.
         ansienviron = term and b'xterm' in term
 
         if mode == b'auto':
             # Since "ansi" could result in terminal gibberish, we error on the
             # side of selecting "win32". However, if w32effects is not defined,
             # we almost certainly don't support "win32", so don't even try.
             # w32effects is not populated when stdout is redirected, so checking
             # it first avoids win32 calls in a state known to error out.
             if ansienviron or not w32effects or win32.enablevtmode():
                 realmode = b'ansi'
             else:
                 realmode = b'win32'
         # An empty w32effects is a clue that stdout is redirected, and thus
         # cannot enable VT mode.
         elif mode == b'ansi' and w32effects and not ansienviron:
             win32.enablevtmode()
     elif mode == b'auto':
         realmode = b'ansi'
 
     def modewarn():
         # only warn if color.mode was explicitly set and we're in
         # a formatted terminal
         if mode == realmode and formatted:
             ui.warn(_(b'warning: failed to set color mode to %s\n') % mode)
 
     if realmode == b'win32':
         ui._terminfoparams.clear()
         if not w32effects:
             modewarn()
             return None
     elif realmode == b'ansi':
         ui._terminfoparams.clear()
     elif realmode == b'terminfo':
         _terminfosetup(ui, mode, formatted)
         if not ui._terminfoparams:
             ## FIXME Shouldn't we return None in this case too?
             modewarn()
             realmode = b'ansi'
     else:
         return None
 
     if always or (auto and formatted):
         return realmode
     return None
 
 
 def configstyles(ui):
     ui._styles.update(_defaultstyles)
     for status, cfgeffects in ui.configitems(b'color'):
         if b'.' not in status or status.startswith((b'color.', b'terminfo.')):
             continue
         cfgeffects = ui.configlist(b'color', status)
         if cfgeffects:
             good = []
             for e in cfgeffects:
                 if valideffect(ui, e):
                     good.append(e)
                 else:
                     ui.warn(
                         _(
                             b"ignoring unknown color/effect %s "
                             b"(configured in color.%s)\n"
                         )
                         % (stringutil.pprint(e), status)
                     )
             ui._styles[status] = b' '.join(good)
 
 
 def _activeeffects(ui):
     '''Return the effects map for the color mode set on the ui.'''
     if ui._colormode == b'win32':
         return w32effects
     elif ui._colormode is not None:
         return _effects
     return {}
 
 
 def valideffect(ui, effect):
     """Determine if the effect is valid or not."""
     return (not ui._terminfoparams and effect in _activeeffects(ui)) or (
         effect in ui._terminfoparams or effect[:-11] in ui._terminfoparams
     )
 
 
 def _effect_str(ui, effect):
     '''Helper function for render_effects().'''
 
     bg = False
     if effect.endswith(b'_background'):
         bg = True
         effect = effect[:-11]
     try:
         attr, val, termcode = ui._terminfoparams[effect]
     except KeyError:
         return b''
     if attr:
         if termcode:
             return termcode
         else:
             return curses.tigetstr(pycompat.sysstr(val))
     elif bg:
         return curses.tparm(curses.tigetstr('setab'), val)
     else:
         return curses.tparm(curses.tigetstr('setaf'), val)
 
 
 def _mergeeffects(text, start, stop):
     """Insert start sequence at every occurrence of stop sequence
 
     >>> s = _mergeeffects(b'cyan', b'[C]', b'|')
     >>> s = _mergeeffects(s + b'yellow', b'[Y]', b'|')
     >>> s = _mergeeffects(b'ma' + s + b'genta', b'[M]', b'|')
     >>> s = _mergeeffects(b'red' + s, b'[R]', b'|')
     >>> s
     '[R]red[M]ma[Y][C]cyan|[R][M][Y]yellow|[R][M]genta|'
     """
     parts = []
     for t in text.split(stop):
         if not t:
             continue
         parts.extend([start, t, stop])
     return b''.join(parts)
 
 
 def _render_effects(ui, text, effects):
     """Wrap text in commands to turn on each effect."""
     if not text:
         return text
     if ui._terminfoparams:
         start = b''.join(
             _effect_str(ui, effect) for effect in [b'none'] + effects.split()
         )
         stop = _effect_str(ui, b'none')
     else:
         activeeffects = _activeeffects(ui)
         start = [
             pycompat.bytestr(activeeffects[e])
             for e in [b'none'] + effects.split()
         ]
         start = b'\033[' + b';'.join(start) + b'm'
         stop = b'\033[' + pycompat.bytestr(activeeffects[b'none']) + b'm'
     return _mergeeffects(text, start, stop)
 
 
 _ansieffectre = re.compile(br'\x1b\[[0-9;]*m')
 
 
 def stripeffects(text):
     """Strip ANSI control codes which could be inserted by colorlabel()"""
     return _ansieffectre.sub(b'', text)
 
 
 def colorlabel(ui, msg, label):
     """add color control code according to the mode"""
     if ui._colormode == b'debug':
         if label and msg:
             if msg.endswith(b'\n'):
                 msg = b"[%s|%s]\n" % (label, msg[:-1])
             else:
                 msg = b"[%s|%s]" % (label, msg)
     elif ui._colormode is not None:
         effects = []
         for l in label.split():
             s = ui._styles.get(l, b'')
             if s:
                 effects.append(s)
             elif valideffect(ui, l):
                 effects.append(l)
         effects = b' '.join(effects)
         if effects:
             msg = b'\n'.join(
                 [
                     _render_effects(ui, line, effects)
                     for line in msg.split(b'\n')
                 ]
             )
     return msg
 
 
 w32effects = None
 if pycompat.iswindows:
     import ctypes
 
     _kernel32 = ctypes.windll.kernel32  # pytype: disable=module-attr
 
     _WORD = ctypes.c_ushort
 
     _INVALID_HANDLE_VALUE = -1
 
     class _COORD(ctypes.Structure):
         _fields_ = [('X', ctypes.c_short), ('Y', ctypes.c_short)]
 
     class _SMALL_RECT(ctypes.Structure):
         _fields_ = [
             ('Left', ctypes.c_short),
             ('Top', ctypes.c_short),
             ('Right', ctypes.c_short),
             ('Bottom', ctypes.c_short),
         ]
 
     class _CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):
         _fields_ = [
             ('dwSize', _COORD),
             ('dwCursorPosition', _COORD),
             ('wAttributes', _WORD),
             ('srWindow', _SMALL_RECT),
             ('dwMaximumWindowSize', _COORD),
         ]
 
     _STD_OUTPUT_HANDLE = 0xFFFFFFF5  # (DWORD)-11
     _STD_ERROR_HANDLE = 0xFFFFFFF4  # (DWORD)-12
 
     _FOREGROUND_BLUE = 0x0001
     _FOREGROUND_GREEN = 0x0002
     _FOREGROUND_RED = 0x0004
     _FOREGROUND_INTENSITY = 0x0008
 
     _BACKGROUND_BLUE = 0x0010
     _BACKGROUND_GREEN = 0x0020
     _BACKGROUND_RED = 0x0040
     _BACKGROUND_INTENSITY = 0x0080
 
     _COMMON_LVB_REVERSE_VIDEO = 0x4000
     _COMMON_LVB_UNDERSCORE = 0x8000
 
     # http://msdn.microsoft.com/en-us/library/ms682088%28VS.85%29.aspx
     w32effects = {
         b'none': -1,
         b'black': 0,
         b'red': _FOREGROUND_RED,
         b'green': _FOREGROUND_GREEN,
         b'yellow': _FOREGROUND_RED | _FOREGROUND_GREEN,
         b'blue': _FOREGROUND_BLUE,
         b'magenta': _FOREGROUND_BLUE | _FOREGROUND_RED,
         b'cyan': _FOREGROUND_BLUE | _FOREGROUND_GREEN,
         b'white': _FOREGROUND_RED | _FOREGROUND_GREEN | _FOREGROUND_BLUE,
         b'bold': _FOREGROUND_INTENSITY,
         b'black_background': 0x100,  # unused value > 0x0f
         b'red_background': _BACKGROUND_RED,
         b'green_background': _BACKGROUND_GREEN,
         b'yellow_background': _BACKGROUND_RED | _BACKGROUND_GREEN,
         b'blue_background': _BACKGROUND_BLUE,
         b'purple_background': _BACKGROUND_BLUE | _BACKGROUND_RED,
         b'cyan_background': _BACKGROUND_BLUE | _BACKGROUND_GREEN,
         b'white_background': (
             _BACKGROUND_RED | _BACKGROUND_GREEN | _BACKGROUND_BLUE
         ),
         b'bold_background': _BACKGROUND_INTENSITY,
         b'underline': _COMMON_LVB_UNDERSCORE,  # double-byte charsets only
         b'inverse': _COMMON_LVB_REVERSE_VIDEO,  # double-byte charsets only
     }
 
     passthrough = {
         _FOREGROUND_INTENSITY,
         _BACKGROUND_INTENSITY,
         _COMMON_LVB_UNDERSCORE,
         _COMMON_LVB_REVERSE_VIDEO,
     }
 
     stdout = _kernel32.GetStdHandle(
         _STD_OUTPUT_HANDLE
     )  # don't close the handle returned
     if stdout is None or stdout == _INVALID_HANDLE_VALUE:
         w32effects = None
     else:
         csbi = _CONSOLE_SCREEN_BUFFER_INFO()
         if not _kernel32.GetConsoleScreenBufferInfo(stdout, ctypes.byref(csbi)):
             # stdout may not support GetConsoleScreenBufferInfo()
             # when called from subprocess or redirected
             w32effects = None
         else:
             origattr = csbi.wAttributes
             ansire = re.compile(
                 br'\033\[([^m]*)m([^\033]*)(.*)', re.MULTILINE | re.DOTALL
             )
 
     def win32print(ui, writefunc, text, **opts):
         label = opts.get('label', b'')
         attr = origattr
 
         def mapcolor(val, attr):
             if val == -1:
                 return origattr
             elif val in passthrough:
                 return attr | val
             elif val > 0x0F:
                 return (val & 0x70) | (attr & 0x8F)
             else:
                 return (val & 0x07) | (attr & 0xF8)
 
         # determine console attributes based on labels
         for l in label.split():
             style = ui._styles.get(l, b'')
             for effect in style.split():
                 try:
                     attr = mapcolor(w32effects[effect], attr)
                 except KeyError:
                     # w32effects could not have certain attributes so we skip
                     # them if not found
                     pass
         # hack to ensure regexp finds data
         if not text.startswith(b'\033['):
             text = b'\033[m' + text
 
         # Look for ANSI-like codes embedded in text
         m = re.match(ansire, text)
 
         try:
             while m:
                 for sattr in m.group(1).split(b';'):
                     if sattr:
                         attr = mapcolor(int(sattr), attr)
                 ui.flush()
                 _kernel32.SetConsoleTextAttribute(stdout, attr)
                 writefunc(m.group(2))
                 m = re.match(ansire, m.group(3))
         finally:
             # Explicitly reset original attributes
             ui.flush()
             _kernel32.SetConsoleTextAttribute(stdout, origattr)

mercurial/upgrade.py

@@ -1,1387 +1,1393 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
 
 import stat
 
 from .i18n import _
 from .pycompat import getattr
 from . import (
     changelog,
     copies,
     error,
     filelog,
     hg,
     localrepo,
     manifest,
     pycompat,
     revlog,
     scmutil,
     util,
     vfs as vfsmod,
 )
 
 from .utils import compression
 
 # list of requirements that request a clone of all revlog if added/removed
 RECLONES_REQUIREMENTS = {
     b'generaldelta',
     localrepo.SPARSEREVLOG_REQUIREMENT,
 }
 
 
 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.
         b'revlogv1',
         # 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.
         b'treemanifest',
         # 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.
         b'shared',
     }
 
 
 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 = {
         localrepo.SPARSEREVLOG_REQUIREMENT,
         localrepo.SIDEDATA_REQUIREMENT,
         localrepo.COPIESSDC_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',
         b'revlogv1',
         b'store',
         localrepo.SPARSEREVLOG_REQUIREMENT,
         localrepo.SIDEDATA_REQUIREMENT,
         localrepo.COPIESSDC_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',
         localrepo.SPARSEREVLOG_REQUIREMENT,
         localrepo.SIDEDATA_REQUIREMENT,
         localrepo.COPIESSDC_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 preservedrequirements(repo):
     return set()
 
 
 deficiency = 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 ``deficiency`` or ``optimisation``. A deficiency is 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 ``deficiency`` 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.
     """
 
     def __init__(self, name, type, description, upgrademessage):
         self.name = name
         self.type = type
         self.description = description
         self.upgrademessage = upgrademessage
 
     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 = deficiency
     ### 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 ``deficiency`` 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
 
     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'
 
     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 sparserevlog(requirementformatvariant):
     name = b'sparserevlog'
 
     _requirement = localrepo.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 = localrepo.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 copiessdc(requirementformatvariant):
     name = b'copies-sdc'
 
     _requirement = localrepo.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):
         return repo.ui.config(b'format', b'revlog-compression')
 
 
 @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 finddeficiencies(repo):
     """returns a list of deficiencies that the repo suffer from"""
     deficiencies = []
 
     # 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):
             deficiencies.append(fv)
 
     return deficiencies
 
 
 # search without '-' to support older form on newer client.
 #
 # We don't enforce backward compatibility for debug command so this
 # might eventually be dropped. However, having to use two different
 # forms in script when comparing result is anoying enough to add
 # backward compatibility for a while.
 legacy_opts_map = {
     b'redeltaparent': b're-delta-parent',
     b'redeltamultibase': b're-delta-multibase',
     b'redeltaall': b're-delta-all',
     b'redeltafulladd': b're-delta-fulladd',
 }
 
 
 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.
     optimizations = []
 
     optimizations.append(
         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'
             ),
         )
     )
 
     optimizations.append(
         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'
             ),
         )
     )
 
     optimizations.append(
         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'
             ),
         )
     )
 
     optimizations.append(
         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'
             ),
         )
     )
 
     return optimizations
 
 
 def determineactions(repo, deficiencies, sourcereqs, destreqs):
     """Determine upgrade actions that will be performed.
 
     Given a list of improvements as returned by ``finddeficiencies`` 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 = []
 
     knownreqs = supporteddestrequirements(repo)
 
     for d in deficiencies:
         name = d.name
 
         # If the action is a requirement that doesn't show up in the
         # destination requirements, prune the action.
         if name in knownreqs and name not in destreqs:
             continue
 
         newactions.append(d)
 
     # FUTURE consider adding some optimizations here for certain transitions.
     # e.g. adding generaldelta could schedule parent redeltas.
 
     return newactions
 
 
 def _revlogfrompath(repo, path):
     """Obtain a revlog from a repo path.
 
     An instance of the appropriate class is returned.
     """
     if path == b'00changelog.i':
         return changelog.changelog(repo.svfs)
     elif path.endswith(b'00manifest.i'):
         mandir = path[: -len(b'00manifest.i')]
         return manifest.manifestrevlog(repo.svfs, tree=mandir)
     else:
         # reverse of "/".join(("data", path + ".i"))
         return filelog.filelog(repo.svfs, path[5:-2])
 
 
 def _copyrevlog(tr, destrepo, oldrl, unencodedname):
     """copy all relevant files for `oldrl` into `destrepo` store
 
     Files are copied "as is" without any transformation. The copy is performed
     without extra checks. Callers are responsible for making sure the copied
     content is compatible with format of the destination repository.
     """
     oldrl = getattr(oldrl, '_revlog', oldrl)
     newrl = _revlogfrompath(destrepo, unencodedname)
     newrl = getattr(newrl, '_revlog', newrl)
 
     oldvfs = oldrl.opener
     newvfs = newrl.opener
     oldindex = oldvfs.join(oldrl.indexfile)
     newindex = newvfs.join(newrl.indexfile)
     olddata = oldvfs.join(oldrl.datafile)
     newdata = newvfs.join(newrl.datafile)
 
     with newvfs(newrl.indexfile, b'w'):
         pass  # create all the directories
 
     util.copyfile(oldindex, newindex)
     copydata = oldrl.opener.exists(oldrl.datafile)
     if copydata:
         util.copyfile(olddata, newdata)
 
     if not (
         unencodedname.endswith(b'00changelog.i')
         or unencodedname.endswith(b'00manifest.i')
     ):
         destrepo.svfs.fncache.add(unencodedname)
         if copydata:
             destrepo.svfs.fncache.add(unencodedname[:-2] + b'.d')
 
 
 UPGRADE_CHANGELOG = object()
 UPGRADE_MANIFEST = object()
 UPGRADE_FILELOG = object()
 
 UPGRADE_ALL_REVLOGS = frozenset(
     [UPGRADE_CHANGELOG, UPGRADE_MANIFEST, UPGRADE_FILELOG]
 )
 
 
 def getsidedatacompanion(srcrepo, dstrepo):
     sidedatacompanion = None
     removedreqs = srcrepo.requirements - dstrepo.requirements
     addedreqs = dstrepo.requirements - srcrepo.requirements
     if localrepo.SIDEDATA_REQUIREMENT in removedreqs:
 
         def sidedatacompanion(rl, rev):
             rl = getattr(rl, '_revlog', rl)
             if rl.flags(rev) & revlog.REVIDX_SIDEDATA:
                 return True, (), {}
             return False, (), {}
 
     elif localrepo.COPIESSDC_REQUIREMENT in addedreqs:
         sidedatacompanion = copies.getsidedataadder(srcrepo, dstrepo)
     elif localrepo.COPIESSDC_REQUIREMENT in removedreqs:
         sidedatacompanion = copies.getsidedataremover(srcrepo, dstrepo)
     return sidedatacompanion
 
 
 def matchrevlog(revlogfilter, entry):
     """check is a revlog is selected for cloning
 
     The store entry is checked against the passed filter"""
     if entry.endswith(b'00changelog.i'):
         return UPGRADE_CHANGELOG in revlogfilter
     elif entry.endswith(b'00manifest.i'):
         return UPGRADE_MANIFEST in revlogfilter
     return UPGRADE_FILELOG in revlogfilter
 
 
 def _clonerevlogs(
     ui,
     srcrepo,
     dstrepo,
     tr,
     deltareuse,
     forcedeltabothparents,
     revlogs=UPGRADE_ALL_REVLOGS,
 ):
     """Copy revlogs between 2 repos."""
     revcount = 0
     srcsize = 0
     srcrawsize = 0
     dstsize = 0
     fcount = 0
     frevcount = 0
     fsrcsize = 0
     frawsize = 0
     fdstsize = 0
     mcount = 0
     mrevcount = 0
     msrcsize = 0
     mrawsize = 0
     mdstsize = 0
     crevcount = 0
     csrcsize = 0
     crawsize = 0
     cdstsize = 0
 
     alldatafiles = list(srcrepo.store.walk())
 
     # Perform a pass to collect metadata. This validates we can open all
     # source files and allows a unified progress bar to be displayed.
     for unencoded, encoded, size in alldatafiles:
         if unencoded.endswith(b'.d'):
             continue
 
         rl = _revlogfrompath(srcrepo, unencoded)
 
         info = rl.storageinfo(
             exclusivefiles=True,
             revisionscount=True,
             trackedsize=True,
             storedsize=True,
         )
 
         revcount += info[b'revisionscount'] or 0
         datasize = info[b'storedsize'] or 0
         rawsize = info[b'trackedsize'] or 0
 
         srcsize += datasize
         srcrawsize += rawsize
 
         # This is for the separate progress bars.
         if isinstance(rl, changelog.changelog):
             crevcount += len(rl)
             csrcsize += datasize
             crawsize += rawsize
         elif isinstance(rl, manifest.manifestrevlog):
             mcount += 1
             mrevcount += len(rl)
             msrcsize += datasize
             mrawsize += rawsize
         elif isinstance(rl, filelog.filelog):
             fcount += 1
             frevcount += len(rl)
             fsrcsize += datasize
             frawsize += rawsize
         else:
             error.ProgrammingError(b'unknown revlog type')
 
     if not revcount:
         return
 
     ui.write(
         _(
             b'migrating %d total revisions (%d in filelogs, %d in manifests, '
             b'%d in changelog)\n'
         )
         % (revcount, frevcount, mrevcount, crevcount)
     )
     ui.write(
         _(b'migrating %s in store; %s tracked data\n')
         % ((util.bytecount(srcsize), util.bytecount(srcrawsize)))
     )
 
     # Used to keep track of progress.
     progress = None
 
     def oncopiedrevision(rl, rev, node):
         progress.increment()
 
     sidedatacompanion = getsidedatacompanion(srcrepo, dstrepo)
 
     # Do the actual copying.
     # FUTURE this operation can be farmed off to worker processes.
     seen = set()
     for unencoded, encoded, size in alldatafiles:
         if unencoded.endswith(b'.d'):
             continue
 
         oldrl = _revlogfrompath(srcrepo, unencoded)
 
         if isinstance(oldrl, changelog.changelog) and b'c' not in seen:
             ui.write(
                 _(
                     b'finished migrating %d manifest revisions across %d '
                     b'manifests; change in size: %s\n'
                 )
                 % (mrevcount, mcount, util.bytecount(mdstsize - msrcsize))
             )
 
             ui.write(
                 _(
                     b'migrating changelog containing %d revisions '
                     b'(%s in store; %s tracked data)\n'
                 )
                 % (
                     crevcount,
                     util.bytecount(csrcsize),
                     util.bytecount(crawsize),
                 )
             )
             seen.add(b'c')
             progress = srcrepo.ui.makeprogress(
                 _(b'changelog revisions'), total=crevcount
             )
         elif isinstance(oldrl, manifest.manifestrevlog) and b'm' not in seen:
             ui.write(
                 _(
                     b'finished migrating %d filelog revisions across %d '
                     b'filelogs; change in size: %s\n'
                 )
                 % (frevcount, fcount, util.bytecount(fdstsize - fsrcsize))
             )
 
             ui.write(
                 _(
                     b'migrating %d manifests containing %d revisions '
                     b'(%s in store; %s tracked data)\n'
                 )
                 % (
                     mcount,
                     mrevcount,
                     util.bytecount(msrcsize),
                     util.bytecount(mrawsize),
                 )
             )
             seen.add(b'm')
             if progress:
                 progress.complete()
             progress = srcrepo.ui.makeprogress(
                 _(b'manifest revisions'), total=mrevcount
             )
         elif b'f' not in seen:
             ui.write(
                 _(
                     b'migrating %d filelogs containing %d revisions '
                     b'(%s in store; %s tracked data)\n'
                 )
                 % (
                     fcount,
                     frevcount,
                     util.bytecount(fsrcsize),
                     util.bytecount(frawsize),
                 )
             )
             seen.add(b'f')
             if progress:
                 progress.complete()
             progress = srcrepo.ui.makeprogress(
                 _(b'file revisions'), total=frevcount
             )
 
         if matchrevlog(revlogs, unencoded):
             ui.note(
                 _(b'cloning %d revisions from %s\n') % (len(oldrl), unencoded)
             )
             newrl = _revlogfrompath(dstrepo, unencoded)
             oldrl.clone(
                 tr,
                 newrl,
                 addrevisioncb=oncopiedrevision,
                 deltareuse=deltareuse,
                 forcedeltabothparents=forcedeltabothparents,
                 sidedatacompanion=sidedatacompanion,
             )
         else:
             msg = _(b'blindly copying %s containing %i revisions\n')
             ui.note(msg % (unencoded, len(oldrl)))
             _copyrevlog(tr, dstrepo, oldrl, unencoded)
 
             newrl = _revlogfrompath(dstrepo, unencoded)
 
         info = newrl.storageinfo(storedsize=True)
         datasize = info[b'storedsize'] or 0
 
         dstsize += datasize
 
         if isinstance(newrl, changelog.changelog):
             cdstsize += datasize
         elif isinstance(newrl, manifest.manifestrevlog):
             mdstsize += datasize
         else:
             fdstsize += datasize
 
     progress.complete()
 
     ui.write(
         _(
             b'finished migrating %d changelog revisions; change in size: '
             b'%s\n'
         )
         % (crevcount, util.bytecount(cdstsize - csrcsize))
     )
 
     ui.write(
         _(
             b'finished migrating %d total revisions; total change in store '
             b'size: %s\n'
         )
         % (revcount, util.bytecount(dstsize - srcsize))
     )
 
 
 def _filterstorefile(srcrepo, dstrepo, requirements, path, mode, st):
     """Determine whether to copy a store file during upgrade.
 
     This function is called when migrating store files from ``srcrepo`` to
     ``dstrepo`` as part of upgrading a repository.
 
     Args:
       srcrepo: repo we are copying from
       dstrepo: repo we are copying to
       requirements: set of requirements for ``dstrepo``
       path: store file being examined
       mode: the ``ST_MODE`` file type of ``path``
       st: ``stat`` data structure for ``path``
 
     Function should return ``True`` if the file is to be copied.
     """
     # Skip revlogs.
     if path.endswith((b'.i', b'.d')):
         return False
     # Skip transaction related files.
     if path.startswith(b'undo'):
         return False
     # Only copy regular files.
     if mode != stat.S_IFREG:
         return False
     # Skip other skipped files.
     if path in (b'lock', b'fncache'):
         return False
 
     return True
 
 
 def _finishdatamigration(ui, srcrepo, dstrepo, requirements):
     """Hook point for extensions to perform additional actions during upgrade.
 
     This function is called after revlogs and store files have been copied but
     before the new store is swapped into the original location.
     """
 
 
 def _upgraderepo(
     ui, srcrepo, dstrepo, requirements, actions, revlogs=UPGRADE_ALL_REVLOGS
 ):
     """Do the low-level work of upgrading a repository.
 
     The upgrade is effectively performed as a copy between a source
     repository and a temporary destination repository.
 
     The source repository is unmodified for as long as possible so the
     upgrade can abort at any time without causing loss of service for
     readers and without corrupting the source repository.
     """
     assert srcrepo.currentwlock()
     assert dstrepo.currentwlock()
 
     ui.write(
         _(
             b'(it is safe to interrupt this process any time before '
             b'data migration completes)\n'
         )
     )
 
     if b're-delta-all' in actions:
         deltareuse = revlog.revlog.DELTAREUSENEVER
     elif b're-delta-parent' in actions:
         deltareuse = revlog.revlog.DELTAREUSESAMEREVS
     elif b're-delta-multibase' in actions:
         deltareuse = revlog.revlog.DELTAREUSESAMEREVS
     elif b're-delta-fulladd' in actions:
         deltareuse = revlog.revlog.DELTAREUSEFULLADD
     else:
         deltareuse = revlog.revlog.DELTAREUSEALWAYS
 
     with dstrepo.transaction(b'upgrade') as tr:
         _clonerevlogs(
             ui,
             srcrepo,
             dstrepo,
             tr,
             deltareuse,
             b're-delta-multibase' in actions,
             revlogs=revlogs,
         )
 
     # Now copy other files in the store directory.
     # The sorted() makes execution deterministic.
     for p, kind, st in sorted(srcrepo.store.vfs.readdir(b'', stat=True)):
         if not _filterstorefile(srcrepo, dstrepo, requirements, p, kind, st):
             continue
 
         srcrepo.ui.write(_(b'copying %s\n') % p)
         src = srcrepo.store.rawvfs.join(p)
         dst = dstrepo.store.rawvfs.join(p)
         util.copyfile(src, dst, copystat=True)
 
     _finishdatamigration(ui, srcrepo, dstrepo, requirements)
 
     ui.write(_(b'data fully migrated to temporary repository\n'))
 
     backuppath = pycompat.mkdtemp(prefix=b'upgradebackup.', dir=srcrepo.path)
     backupvfs = vfsmod.vfs(backuppath)
 
     # Make a backup of requires file first, as it is the first to be modified.
     util.copyfile(srcrepo.vfs.join(b'requires'), backupvfs.join(b'requires'))
 
     # We install an arbitrary requirement that clients must not support
     # as a mechanism to lock out new clients during the data swap. This is
     # better than allowing a client to continue while the repository is in
     # an inconsistent state.
     ui.write(
         _(
             b'marking source repository as being upgraded; clients will be '
             b'unable to read from repository\n'
         )
     )
     scmutil.writerequires(
         srcrepo.vfs, srcrepo.requirements | {b'upgradeinprogress'}
     )
 
     ui.write(_(b'starting in-place swap of repository data\n'))
     ui.write(_(b'replaced files will be backed up at %s\n') % backuppath)
 
     # Now swap in the new store directory. Doing it as a rename should make
     # the operation nearly instantaneous and atomic (at least in well-behaved
     # environments).
     ui.write(_(b'replacing store...\n'))
     tstart = util.timer()
     util.rename(srcrepo.spath, backupvfs.join(b'store'))
     util.rename(dstrepo.spath, srcrepo.spath)
     elapsed = util.timer() - tstart
     ui.write(
         _(
             b'store replacement complete; repository was inconsistent for '
             b'%0.1fs\n'
         )
         % elapsed
     )
 
     # We first write the requirements file. Any new requirements will lock
     # out legacy clients.
     ui.write(
         _(
             b'finalizing requirements file and making repository readable '
             b'again\n'
         )
     )
     scmutil.writerequires(srcrepo.vfs, requirements)
 
     # The lock file from the old store won't be removed because nothing has a
     # reference to its new location. So clean it up manually. Alternatively, we
     # could update srcrepo.svfs and other variables to point to the new
     # location. This is simpler.
     backupvfs.unlink(b'store/lock')
 
     return backuppath
 
 
 def upgraderepo(
     ui,
     repo,
     run=False,
     optimize=None,
     backup=True,
     manifest=None,
     changelog=None,
 ):
     """Upgrade a repository in place."""
     if optimize is None:
         optimize = []
     optimize = set(legacy_opts_map.get(o, o) for o in optimize)
     repo = repo.unfiltered()
 
     revlogs = set(UPGRADE_ALL_REVLOGS)
     specentries = ((b'c', changelog), (b'm', manifest))
     specified = [(y, x) for (y, x) in specentries if x is not None]
     if specified:
         # we have some limitation on revlogs to be recloned
         if any(x for y, x in specified):
             revlogs = set()
             for r, enabled in specified:
                 if enabled:
                     if r == b'c':
                         revlogs.add(UPGRADE_CHANGELOG)
                     elif r == b'm':
                         revlogs.add(UPGRADE_MANIFEST)
         else:
             # none are enabled
             for r, __ in specified:
                 if r == b'c':
                     revlogs.discard(UPGRADE_CHANGELOG)
                 elif r == b'm':
                     revlogs.discard(UPGRADE_MANIFEST)
 
     # Ensure the repository can be upgraded.
     missingreqs = requiredsourcerequirements(repo) - repo.requirements
     if missingreqs:
         raise error.Abort(
             _(b'cannot upgrade repository; requirement missing: %s')
             % _(b', ').join(sorted(missingreqs))
         )
 
     blockedreqs = blocksourcerequirements(repo) & repo.requirements
     if blockedreqs:
         raise error.Abort(
             _(
                 b'cannot upgrade repository; unsupported source '
                 b'requirement: %s'
             )
             % _(b', ').join(sorted(blockedreqs))
         )
 
     # FUTURE there is potentially a need to control the wanted requirements via
     # command arguments or via an extension hook point.
     newreqs = localrepo.newreporequirements(
         repo.ui, localrepo.defaultcreateopts(repo.ui)
     )
     newreqs.update(preservedrequirements(repo))
 
     noremovereqs = (
         repo.requirements - newreqs - supportremovedrequirements(repo)
     )
     if noremovereqs:
         raise error.Abort(
             _(
                 b'cannot upgrade repository; requirement would be '
                 b'removed: %s'
             )
             % _(b', ').join(sorted(noremovereqs))
         )
 
     noaddreqs = newreqs - repo.requirements - allowednewrequirements(repo)
     if noaddreqs:
         raise error.Abort(
             _(
                 b'cannot upgrade repository; do not support adding '
                 b'requirement: %s'
             )
             % _(b', ').join(sorted(noaddreqs))
         )
 
     unsupportedreqs = newreqs - supporteddestrequirements(repo)
     if unsupportedreqs:
         raise error.Abort(
             _(
                 b'cannot upgrade repository; do not support '
                 b'destination requirement: %s'
             )
             % _(b', ').join(sorted(unsupportedreqs))
         )
 
     # Find and validate all improvements that can be made.
     alloptimizations = findoptimizations(repo)
 
     # Apply and Validate arguments.
     optimizations = []
     for o in alloptimizations:
         if o.name in optimize:
             optimizations.append(o)
             optimize.discard(o.name)
 
     if optimize:  # anything left is unknown
         raise error.Abort(
             _(b'unknown optimization action requested: %s')
             % b', '.join(sorted(optimize)),
             hint=_(b'run without arguments to see valid optimizations'),
         )
 
     deficiencies = finddeficiencies(repo)
     actions = determineactions(repo, deficiencies, repo.requirements, newreqs)
     actions.extend(
         o
         for o in sorted(optimizations)
         # determineactions could have added optimisation
         if o not in actions
     )
 
     removedreqs = repo.requirements - newreqs
     addedreqs = newreqs - repo.requirements
 
     if revlogs != UPGRADE_ALL_REVLOGS:
         incompatible = RECLONES_REQUIREMENTS & (removedreqs | addedreqs)
         if incompatible:
             msg = _(
                 b'ignoring revlogs selection flags, format requirements '
                 b'change: %s\n'
             )
             ui.warn(msg % b', '.join(sorted(incompatible)))
             revlogs = UPGRADE_ALL_REVLOGS
 
+    def write_labeled(l, label):
+        first = True
+        for r in sorted(l):
+            if not first:
+                ui.write(b', ')
+            ui.write(r, label=label)
+            first = False
+
     def printrequirements():
         ui.write(_(b'requirements\n'))
-        ui.write(
-            _(b'   preserved: %s\n')
-            % _(b', ').join(sorted(newreqs & repo.requirements))
+        ui.write(_(b'   preserved: '))
+        write_labeled(
+            newreqs & repo.requirements, "upgrade-repo.requirement.preserved"
         )
-
+        ui.write((b'\n'))
+        removed = repo.requirements - newreqs
         if repo.requirements - newreqs:
-            ui.write(
-                _(b'   removed: %s\n')
-                % _(b', ').join(sorted(repo.requirements - newreqs))
-            )
-
-        if newreqs - repo.requirements:
-            ui.write(
-                _(b'   added: %s\n')
-                % _(b', ').join(sorted(newreqs - repo.requirements))
-            )
-
+            ui.write(_(b'   removed: '))
+            write_labeled(removed, "upgrade-repo.requirement.removed")
+            ui.write((b'\n'))
+        added = newreqs - repo.requirements
+        if added:
+            ui.write(_(b'   added: '))
+            write_labeled(added, "upgrade-repo.requirement.added")
+            ui.write((b'\n'))
         ui.write(b'\n')
 
     def printupgradeactions():
         for a in actions:
             ui.write(b'%s\n   %s\n\n' % (a.name, a.upgrademessage))
 
     if not run:
         fromconfig = []
         onlydefault = []
 
         for d in deficiencies:
             if d.fromconfig(repo):
                 fromconfig.append(d)
             elif d.default:
                 onlydefault.append(d)
 
         if fromconfig or onlydefault:
 
             if fromconfig:
                 ui.write(
                     _(
                         b'repository lacks features recommended by '
                         b'current config options:\n\n'
                     )
                 )
                 for i in fromconfig:
                     ui.write(b'%s\n   %s\n\n' % (i.name, i.description))
 
             if onlydefault:
                 ui.write(
                     _(
                         b'repository lacks features used by the default '
                         b'config options:\n\n'
                     )
                 )
                 for i in onlydefault:
                     ui.write(b'%s\n   %s\n\n' % (i.name, i.description))
 
             ui.write(b'\n')
         else:
             ui.write(
                 _(
                     b'(no feature deficiencies found in existing '
                     b'repository)\n'
                 )
             )
 
         ui.write(
             _(
                 b'performing an upgrade with "--run" will make the following '
                 b'changes:\n\n'
             )
         )
 
         printrequirements()
         printupgradeactions()
 
         unusedoptimize = [i for i in alloptimizations if i not in actions]
 
         if unusedoptimize:
             ui.write(
                 _(
                     b'additional optimizations are available by specifying '
                     b'"--optimize <name>":\n\n'
                 )
             )
             for i in unusedoptimize:
                 ui.write(_(b'%s\n   %s\n\n') % (i.name, i.description))
         return
 
     # Else we're in the run=true case.
     ui.write(_(b'upgrade will perform the following actions:\n\n'))
     printrequirements()
     printupgradeactions()
 
     upgradeactions = [a.name for a in actions]
 
     ui.write(_(b'beginning upgrade...\n'))
     with repo.wlock(), repo.lock():
         ui.write(_(b'repository locked and read-only\n'))
         # Our strategy for upgrading the repository is to create a new,
         # temporary repository, write data to it, then do a swap of the
         # data. There are less heavyweight ways to do this, but it is easier
         # to create a new repo object than to instantiate all the components
         # (like the store) separately.
         tmppath = pycompat.mkdtemp(prefix=b'upgrade.', dir=repo.path)
         backuppath = None
         try:
             ui.write(
                 _(
                     b'creating temporary repository to stage migrated '
                     b'data: %s\n'
                 )
                 % tmppath
             )
 
             # clone ui without using ui.copy because repo.ui is protected
             repoui = repo.ui.__class__(repo.ui)
             dstrepo = hg.repository(repoui, path=tmppath, create=True)
 
             with dstrepo.wlock(), dstrepo.lock():
                 backuppath = _upgraderepo(
                     ui, repo, dstrepo, newreqs, upgradeactions, revlogs=revlogs
                 )
             if not (backup or backuppath is None):
                 ui.write(_(b'removing old repository content%s\n') % backuppath)
                 repo.vfs.rmtree(backuppath, forcibly=True)
                 backuppath = None
 
         finally:
             ui.write(_(b'removing temporary repository %s\n') % tmppath)
             repo.vfs.rmtree(tmppath, forcibly=True)
 
             if backuppath:
                 ui.warn(
                     _(b'copy of old repository backed up at %s\n') % backuppath
                 )
                 ui.warn(
                     _(
                         b'the old repository will not be deleted; remove '
                         b'it to free up disk space once the upgraded '
                         b'repository is verified\n'
                     )
                 )