shelve: also create class representing whole directory of shelves

It's a little annoying to have to create and pass in a vfs into
`listshelves()`. This patch attempts to start addressing that by
creating a class that represents a directory containing shelves (the
directory can be either `.hg/shelved/` or `.hg/shelve-backup/`).

Differential Revision: https://phab.mercurial-scm.org/D9743

mercurial/shelve.py

@@ -1,1186 +1,1192 b''
 # shelve.py - save/restore working directory state
 #
 # Copyright 2013 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """save and restore changes to the working directory
 
 The "hg shelve" command saves changes made to the working directory
 and reverts those changes, resetting the working directory to a clean
 state.
 
 Later on, the "hg unshelve" command restores the changes saved by "hg
 shelve". Changes can be restored even after updating to a different
 parent, in which case Mercurial's merge machinery will resolve any
 conflicts if necessary.
 
 You can have more than one shelved change outstanding at a time; each
 shelved change has a distinct name. For details, see the help for "hg
 shelve".
 """
 from __future__ import absolute_import
 
 import collections
 import errno
 import itertools
 import stat
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     nullid,
     nullrev,
 )
 from . import (
     bookmarks,
     bundle2,
     changegroup,
     cmdutil,
     discovery,
     error,
     exchange,
     hg,
     lock as lockmod,
     mdiff,
     merge,
     mergestate as mergestatemod,
     patch,
     phases,
     pycompat,
     repair,
     scmutil,
     templatefilters,
     util,
     vfs as vfsmod,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 backupdir = b'shelve-backup'
 shelvedir = b'shelved'
 shelvefileextensions = [b'hg', b'patch', b'shelve']
 
 # we never need the user, so we use a
 # generic user for all shelve operations
 shelveuser = b'shelve@localhost'
 
 
+class ShelfDir(object):
+    def __init__(self, repo, for_backups=False):
+        if for_backups:
+            self.vfs = vfsmod.vfs(repo.vfs.join(backupdir))
+        else:
+            self.vfs = vfsmod.vfs(repo.vfs.join(shelvedir))
+
+    def get(self, name):
+        return Shelf(self.vfs, name)
+
+
 class Shelf(object):
     """Represents a shelf, including possibly multiple files storing it.
 
     Old shelves will have a .patch and a .hg file. Newer shelves will
     also have a .shelve file. This class abstracts away some of the
     differences and lets you work with the shelf as a whole.
     """
 
     def __init__(self, vfs, name):
         self.vfs = vfs
         self.name = name
 
-    @staticmethod
-    def open(repo, name):
-        return Shelf(vfsmod.vfs(repo.vfs.join(shelvedir)), name)
-
-    @staticmethod
-    def open_backup(repo, name):
-        return Shelf(vfsmod.vfs(repo.vfs.join(backupdir)), name)
-
     def exists(self):
         return self.vfs.exists(self.name + b'.patch') and self.vfs.exists(
             self.name + b'.hg'
         )
 
     def mtime(self):
         return self.vfs.stat(self.name + b'.patch')[stat.ST_MTIME]
 
     def writeinfo(self, info):
         scmutil.simplekeyvaluefile(self.vfs, self.name + b'.shelve').write(info)
 
     def hasinfo(self):
         return self.vfs.exists(self.name + b'.shelve')
 
     def readinfo(self):
         return scmutil.simplekeyvaluefile(
             self.vfs, self.name + b'.shelve'
         ).read()
 
     def writebundle(self, repo, bases, node):
         cgversion = changegroup.safeversion(repo)
         if cgversion == b'01':
             btype = b'HG10BZ'
             compression = None
         else:
             btype = b'HG20'
             compression = b'BZ'
 
         repo = repo.unfiltered()
 
         outgoing = discovery.outgoing(
             repo, missingroots=bases, ancestorsof=[node]
         )
         cg = changegroup.makechangegroup(repo, outgoing, cgversion, b'shelve')
 
         bundle_filename = self.vfs.join(self.name + b'.hg')
         bundle2.writebundle(
             repo.ui,
             cg,
             bundle_filename,
             btype,
             self.vfs,
             compression=compression,
         )
 
     def applybundle(self, repo, tr):
         filename = self.name + b'.hg'
         fp = self.vfs(filename)
         try:
             targetphase = phases.internal
             if not phases.supportinternal(repo):
                 targetphase = phases.secret
             gen = exchange.readbundle(repo.ui, fp, filename, self.vfs)
             pretip = repo[b'tip']
             bundle2.applybundle(
                 repo,
                 gen,
                 tr,
                 source=b'unshelve',
                 url=b'bundle:' + self.vfs.join(filename),
                 targetphase=targetphase,
             )
             shelvectx = repo[b'tip']
             if pretip == shelvectx:
                 shelverev = tr.changes[b'revduplicates'][-1]
                 shelvectx = repo[shelverev]
             return shelvectx
         finally:
             fp.close()
 
     def open_patch(self, mode=b'rb'):
         return self.vfs(self.name + b'.patch', mode)
 
     def _backupfilename(self, backupvfs, filename):
         def gennames(base):
             yield base
             base, ext = base.rsplit(b'.', 1)
             for i in itertools.count(1):
                 yield b'%s-%d.%s' % (base, i, ext)
 
         for n in gennames(filename):
             if not backupvfs.exists(n):
                 return backupvfs.join(n)
 
     def movetobackup(self, backupvfs):
         if not backupvfs.isdir():
             backupvfs.makedir()
         for suffix in shelvefileextensions:
             filename = self.name + b'.' + suffix
             if self.vfs.exists(filename):
                 util.rename(
                     self.vfs.join(filename),
                     self._backupfilename(backupvfs, filename),
                 )
 
     def delete(self):
         for ext in shelvefileextensions:
             self.vfs.tryunlink(self.name + b'.' + ext)
 
 
 class shelvedstate(object):
     """Handle persistence during unshelving operations.
 
     Handles saving and restoring a shelved state. Ensures that different
     versions of a shelved state are possible and handles them appropriately.
     """
 
     _version = 2
     _filename = b'shelvedstate'
     _keep = b'keep'
     _nokeep = b'nokeep'
     # colon is essential to differentiate from a real bookmark name
     _noactivebook = b':no-active-bookmark'
     _interactive = b'interactive'
 
     @classmethod
     def _verifyandtransform(cls, d):
         """Some basic shelvestate syntactic verification and transformation"""
         try:
             d[b'originalwctx'] = bin(d[b'originalwctx'])
             d[b'pendingctx'] = bin(d[b'pendingctx'])
             d[b'parents'] = [bin(h) for h in d[b'parents'].split(b' ')]
             d[b'nodestoremove'] = [
                 bin(h) for h in d[b'nodestoremove'].split(b' ')
             ]
         except (ValueError, TypeError, KeyError) as err:
             raise error.CorruptedState(pycompat.bytestr(err))
 
     @classmethod
     def _getversion(cls, repo):
         """Read version information from shelvestate file"""
         fp = repo.vfs(cls._filename)
         try:
             version = int(fp.readline().strip())
         except ValueError as err:
             raise error.CorruptedState(pycompat.bytestr(err))
         finally:
             fp.close()
         return version
 
     @classmethod
     def _readold(cls, repo):
         """Read the old position-based version of a shelvestate file"""
         # Order is important, because old shelvestate file uses it
         # to detemine values of fields (i.g. name is on the second line,
         # originalwctx is on the third and so forth). Please do not change.
         keys = [
             b'version',
             b'name',
             b'originalwctx',
             b'pendingctx',
             b'parents',
             b'nodestoremove',
             b'branchtorestore',
             b'keep',
             b'activebook',
         ]
         # this is executed only seldomly, so it is not a big deal
         # that we open this file twice
         fp = repo.vfs(cls._filename)
         d = {}
         try:
             for key in keys:
                 d[key] = fp.readline().strip()
         finally:
             fp.close()
         return d
 
     @classmethod
     def load(cls, repo):
         version = cls._getversion(repo)
         if version < cls._version:
             d = cls._readold(repo)
         elif version == cls._version:
             d = scmutil.simplekeyvaluefile(repo.vfs, cls._filename).read(
                 firstlinenonkeyval=True
             )
         else:
             raise error.Abort(
                 _(
                     b'this version of shelve is incompatible '
                     b'with the version used in this repo'
                 )
             )
 
         cls._verifyandtransform(d)
         try:
             obj = cls()
             obj.name = d[b'name']
             obj.wctx = repo[d[b'originalwctx']]
             obj.pendingctx = repo[d[b'pendingctx']]
             obj.parents = d[b'parents']
             obj.nodestoremove = d[b'nodestoremove']
             obj.branchtorestore = d.get(b'branchtorestore', b'')
             obj.keep = d.get(b'keep') == cls._keep
             obj.activebookmark = b''
             if d.get(b'activebook', b'') != cls._noactivebook:
                 obj.activebookmark = d.get(b'activebook', b'')
             obj.interactive = d.get(b'interactive') == cls._interactive
         except (error.RepoLookupError, KeyError) as err:
             raise error.CorruptedState(pycompat.bytestr(err))
 
         return obj
 
     @classmethod
     def save(
         cls,
         repo,
         name,
         originalwctx,
         pendingctx,
         nodestoremove,
         branchtorestore,
         keep=False,
         activebook=b'',
         interactive=False,
     ):
         info = {
             b"name": name,
             b"originalwctx": hex(originalwctx.node()),
             b"pendingctx": hex(pendingctx.node()),
             b"parents": b' '.join([hex(p) for p in repo.dirstate.parents()]),
             b"nodestoremove": b' '.join([hex(n) for n in nodestoremove]),
             b"branchtorestore": branchtorestore,
             b"keep": cls._keep if keep else cls._nokeep,
             b"activebook": activebook or cls._noactivebook,
         }
         if interactive:
             info[b'interactive'] = cls._interactive
         scmutil.simplekeyvaluefile(repo.vfs, cls._filename).write(
             info, firstline=(b"%d" % cls._version)
         )
 
     @classmethod
     def clear(cls, repo):
         repo.vfs.unlinkpath(cls._filename, ignoremissing=True)
 
 
 def cleanupoldbackups(repo):
     vfs = vfsmod.vfs(repo.vfs.join(backupdir))
     maxbackups = repo.ui.configint(b'shelve', b'maxbackups')
     hgfiles = listshelves(vfs)
     if maxbackups > 0 and maxbackups < len(hgfiles):
         bordermtime = hgfiles[maxbackups - 1][0]
     else:
         bordermtime = None
     for mtime, name in hgfiles[maxbackups:]:
         if mtime == bordermtime:
             # keep it, because timestamp can't decide exact order of backups
             continue
         Shelf.open_backup(repo, name).delete()
 
 
 def _backupactivebookmark(repo):
     activebookmark = repo._activebookmark
     if activebookmark:
         bookmarks.deactivate(repo)
     return activebookmark
 
 
 def _restoreactivebookmark(repo, mark):
     if mark:
         bookmarks.activate(repo, mark)
 
 
 def _aborttransaction(repo, tr):
     """Abort current transaction for shelve/unshelve, but keep dirstate"""
     dirstatebackupname = b'dirstate.shelve'
     repo.dirstate.savebackup(tr, dirstatebackupname)
     tr.abort()
     repo.dirstate.restorebackup(None, dirstatebackupname)
 
 
 def getshelvename(repo, parent, opts):
     """Decide on the name this shelve is going to have"""
 
     def gennames():
         yield label
         for i in itertools.count(1):
             yield b'%s-%02d' % (label, i)
 
     name = opts.get(b'name')
     label = repo._activebookmark or parent.branch() or b'default'
     # slashes aren't allowed in filenames, therefore we rename it
     label = label.replace(b'/', b'_')
     label = label.replace(b'\\', b'_')
     # filenames must not start with '.' as it should not be hidden
     if label.startswith(b'.'):
         label = label.replace(b'.', b'_', 1)
 
     if name:
-        if Shelf.open(repo, name).exists():
+        if ShelfDir(repo).get(name).exists():
             e = _(b"a shelved change named '%s' already exists") % name
             raise error.Abort(e)
 
         # ensure we are not creating a subdirectory or a hidden file
         if b'/' in name or b'\\' in name:
             raise error.Abort(
                 _(b'shelved change names can not contain slashes')
             )
         if name.startswith(b'.'):
             raise error.Abort(_(b"shelved change names can not start with '.'"))
 
     else:
+        shelf_dir = ShelfDir(repo)
         for n in gennames():
-            if not Shelf.open(repo, n).exists():
+            if not shelf_dir.get(n).exists():
                 name = n
                 break
 
     return name
 
 
 def mutableancestors(ctx):
     """return all mutable ancestors for ctx (included)
 
     Much faster than the revset ancestors(ctx) & draft()"""
     seen = {nullrev}
     visit = collections.deque()
     visit.append(ctx)
     while visit:
         ctx = visit.popleft()
         yield ctx.node()
         for parent in ctx.parents():
             rev = parent.rev()
             if rev not in seen:
                 seen.add(rev)
                 if parent.mutable():
                     visit.append(parent)
 
 
 def getcommitfunc(extra, interactive, editor=False):
     def commitfunc(ui, repo, message, match, opts):
         hasmq = util.safehasattr(repo, b'mq')
         if hasmq:
             saved, repo.mq.checkapplied = repo.mq.checkapplied, False
 
         targetphase = phases.internal
         if not phases.supportinternal(repo):
             targetphase = phases.secret
         overrides = {(b'phases', b'new-commit'): targetphase}
         try:
             editor_ = False
             if editor:
                 editor_ = cmdutil.getcommiteditor(
                     editform=b'shelve.shelve', **pycompat.strkwargs(opts)
                 )
             with repo.ui.configoverride(overrides):
                 return repo.commit(
                     message,
                     shelveuser,
                     opts.get(b'date'),
                     match,
                     editor=editor_,
                     extra=extra,
                 )
         finally:
             if hasmq:
                 repo.mq.checkapplied = saved
 
     def interactivecommitfunc(ui, repo, *pats, **opts):
         opts = pycompat.byteskwargs(opts)
         match = scmutil.match(repo[b'.'], pats, {})
         message = opts[b'message']
         return commitfunc(ui, repo, message, match, opts)
 
     return interactivecommitfunc if interactive else commitfunc
 
 
 def _nothingtoshelvemessaging(ui, repo, pats, opts):
     stat = repo.status(match=scmutil.match(repo[None], pats, opts))
     if stat.deleted:
         ui.status(
             _(b"nothing changed (%d missing files, see 'hg status')\n")
             % len(stat.deleted)
         )
     else:
         ui.status(_(b"nothing changed\n"))
 
 
 def _shelvecreatedcommit(repo, node, name, match):
     info = {b'node': hex(node)}
-    shelf = Shelf.open(repo, name)
+    shelf = ShelfDir(repo).get(name)
     shelf.writeinfo(info)
     bases = list(mutableancestors(repo[node]))
     shelf.writebundle(repo, bases, node)
     with shelf.open_patch(b'wb') as fp:
         cmdutil.exportfile(
             repo, [node], fp, opts=mdiff.diffopts(git=True), match=match
         )
 
 
 def _includeunknownfiles(repo, pats, opts, extra):
     s = repo.status(match=scmutil.match(repo[None], pats, opts), unknown=True)
     if s.unknown:
         extra[b'shelve_unknown'] = b'\0'.join(s.unknown)
         repo[None].add(s.unknown)
 
 
 def _finishshelve(repo, tr):
     if phases.supportinternal(repo):
         tr.close()
     else:
         _aborttransaction(repo, tr)
 
 
 def createcmd(ui, repo, pats, opts):
     """subcommand that creates a new shelve"""
     with repo.wlock():
         cmdutil.checkunfinished(repo)
         return _docreatecmd(ui, repo, pats, opts)
 
 
 def _docreatecmd(ui, repo, pats, opts):
     wctx = repo[None]
     parents = wctx.parents()
     parent = parents[0]
     origbranch = wctx.branch()
 
     if parent.node() != nullid:
         desc = b"changes to: %s" % parent.description().split(b'\n', 1)[0]
     else:
         desc = b'(changes in empty repository)'
 
     if not opts.get(b'message'):
         opts[b'message'] = desc
 
     lock = tr = activebookmark = None
     try:
         lock = repo.lock()
 
         # use an uncommitted transaction to generate the bundle to avoid
         # pull races. ensure we don't print the abort message to stderr.
         tr = repo.transaction(b'shelve', report=lambda x: None)
 
         interactive = opts.get(b'interactive', False)
         includeunknown = opts.get(b'unknown', False) and not opts.get(
             b'addremove', False
         )
 
         name = getshelvename(repo, parent, opts)
         activebookmark = _backupactivebookmark(repo)
         extra = {b'internal': b'shelve'}
         if includeunknown:
             _includeunknownfiles(repo, pats, opts, extra)
 
         if _iswctxonnewbranch(repo) and not _isbareshelve(pats, opts):
             # In non-bare shelve we don't store newly created branch
             # at bundled commit
             repo.dirstate.setbranch(repo[b'.'].branch())
 
         commitfunc = getcommitfunc(extra, interactive, editor=True)
         if not interactive:
             node = cmdutil.commit(ui, repo, commitfunc, pats, opts)
         else:
             node = cmdutil.dorecord(
                 ui,
                 repo,
                 commitfunc,
                 None,
                 False,
                 cmdutil.recordfilter,
                 *pats,
                 **pycompat.strkwargs(opts)
             )
         if not node:
             _nothingtoshelvemessaging(ui, repo, pats, opts)
             return 1
 
         # Create a matcher so that prefetch doesn't attempt to fetch
         # the entire repository pointlessly, and as an optimisation
         # for movedirstate, if needed.
         match = scmutil.matchfiles(repo, repo[node].files())
         _shelvecreatedcommit(repo, node, name, match)
 
         ui.status(_(b'shelved as %s\n') % name)
         if opts[b'keep']:
             with repo.dirstate.parentchange():
                 scmutil.movedirstate(repo, parent, match)
         else:
             hg.update(repo, parent.node())
             ms = mergestatemod.mergestate.read(repo)
             if not ms.unresolvedcount():
                 ms.reset()
 
         if origbranch != repo[b'.'].branch() and not _isbareshelve(pats, opts):
             repo.dirstate.setbranch(origbranch)
 
         _finishshelve(repo, tr)
     finally:
         _restoreactivebookmark(repo, activebookmark)
         lockmod.release(tr, lock)
 
 
 def _isbareshelve(pats, opts):
     return (
         not pats
         and not opts.get(b'interactive', False)
         and not opts.get(b'include', False)
         and not opts.get(b'exclude', False)
     )
 
 
 def _iswctxonnewbranch(repo):
     return repo[None].branch() != repo[b'.'].branch()
 
 
 def cleanupcmd(ui, repo):
     """subcommand that deletes all shelves"""
 
     with repo.wlock():
         vfs = vfsmod.vfs(repo.vfs.join(shelvedir))
         backupvfs = vfsmod.vfs(repo.vfs.join(backupdir))
         for _mtime, name in listshelves(vfs):
             Shelf(vfs, name).movetobackup(backupvfs)
             cleanupoldbackups(repo)
 
 
 def deletecmd(ui, repo, pats):
     """subcommand that deletes a specific shelve"""
     if not pats:
         raise error.InputError(_(b'no shelved changes specified!'))
     with repo.wlock():
         backupvfs = vfsmod.vfs(repo.vfs.join(backupdir))
         for name in pats:
-            shelf = Shelf.open(repo, name)
+            shelf = ShelfDir(repo).get(name)
             if not shelf.exists():
                 raise error.InputError(
                     _(b"shelved change '%s' not found") % name
                 )
             shelf.movetobackup(backupvfs)
             cleanupoldbackups(repo)
 
 
 def listshelves(vfs):
     """return all shelves in repo as list of (time, name)"""
     try:
         names = vfs.listdir()
     except OSError as err:
         if err.errno != errno.ENOENT:
             raise
         return []
     info = []
     seen = set()
     for filename in names:
         name = filename.rsplit(b'.', 1)[0]
         if name in seen:
             continue
         seen.add(name)
         shelf = Shelf(vfs, name)
         if not shelf.exists():
             continue
         mtime = shelf.mtime()
         info.append((mtime, name))
     return sorted(info, reverse=True)
 
 
 def listcmd(ui, repo, pats, opts):
     """subcommand that displays the list of shelves"""
     pats = set(pats)
     width = 80
     if not ui.plain():
         width = ui.termwidth()
     namelabel = b'shelve.newest'
     ui.pager(b'shelve')
     vfs = vfsmod.vfs(repo.vfs.join(shelvedir))
+    shelf_dir = ShelfDir(repo)
     for mtime, name in listshelves(vfs):
         if pats and name not in pats:
             continue
         ui.write(name, label=namelabel)
         namelabel = b'shelve.name'
         if ui.quiet:
             ui.write(b'\n')
             continue
         ui.write(b' ' * (16 - len(name)))
         used = 16
         date = dateutil.makedate(mtime)
         age = b'(%s)' % templatefilters.age(date, abbrev=True)
         ui.write(age, label=b'shelve.age')
         ui.write(b' ' * (12 - len(age)))
         used += 12
-        with Shelf.open(repo, name).open_patch() as fp:
+        with shelf_dir.get(name).open_patch() as fp:
             while True:
                 line = fp.readline()
                 if not line:
                     break
                 if not line.startswith(b'#'):
                     desc = line.rstrip()
                     if ui.formatted():
                         desc = stringutil.ellipsis(desc, width - used)
                     ui.write(desc)
                     break
             ui.write(b'\n')
             if not (opts[b'patch'] or opts[b'stat']):
                 continue
             difflines = fp.readlines()
             if opts[b'patch']:
                 for chunk, label in patch.difflabel(iter, difflines):
                     ui.write(chunk, label=label)
             if opts[b'stat']:
                 for chunk, label in patch.diffstatui(difflines, width=width):
                     ui.write(chunk, label=label)
 
 
 def patchcmds(ui, repo, pats, opts):
     """subcommand that displays shelves"""
     if len(pats) == 0:
         vfs = vfsmod.vfs(repo.vfs.join(shelvedir))
         shelves = listshelves(vfs)
         if not shelves:
             raise error.Abort(_(b"there are no shelves to show"))
         mtime, name = shelves[0]
         pats = [name]
 
+    shelf_dir = ShelfDir(repo)
     for shelfname in pats:
-        if not Shelf.open(repo, shelfname).exists():
+        if not shelf_dir.get(shelfname).exists():
             raise error.Abort(_(b"cannot find shelf %s") % shelfname)
 
     listcmd(ui, repo, pats, opts)
 
 
 def checkparents(repo, state):
     """check parent while resuming an unshelve"""
     if state.parents != repo.dirstate.parents():
         raise error.Abort(
             _(b'working directory parents do not match unshelve state')
         )
 
 
 def _loadshelvedstate(ui, repo, opts):
     try:
         state = shelvedstate.load(repo)
         if opts.get(b'keep') is None:
             opts[b'keep'] = state.keep
     except IOError as err:
         if err.errno != errno.ENOENT:
             raise
         cmdutil.wrongtooltocontinue(repo, _(b'unshelve'))
     except error.CorruptedState as err:
         ui.debug(pycompat.bytestr(err) + b'\n')
         if opts.get(b'continue'):
             msg = _(b'corrupted shelved state file')
             hint = _(
                 b'please run hg unshelve --abort to abort unshelve '
                 b'operation'
             )
             raise error.Abort(msg, hint=hint)
         elif opts.get(b'abort'):
             shelvedstate.clear(repo)
             raise error.Abort(
                 _(
                     b'could not read shelved state file, your '
                     b'working copy may be in an unexpected state\n'
                     b'please update to some commit\n'
                 )
             )
     return state
 
 
 def unshelveabort(ui, repo, state):
     """subcommand that abort an in-progress unshelve"""
     with repo.lock():
         try:
             checkparents(repo, state)
 
             merge.clean_update(state.pendingctx)
             if state.activebookmark and state.activebookmark in repo._bookmarks:
                 bookmarks.activate(repo, state.activebookmark)
             mergefiles(ui, repo, state.wctx, state.pendingctx)
             if not phases.supportinternal(repo):
                 repair.strip(
                     ui, repo, state.nodestoremove, backup=False, topic=b'shelve'
                 )
         finally:
             shelvedstate.clear(repo)
             ui.warn(_(b"unshelve of '%s' aborted\n") % state.name)
 
 
 def hgabortunshelve(ui, repo):
     """logic to  abort unshelve using 'hg abort"""
     with repo.wlock():
         state = _loadshelvedstate(ui, repo, {b'abort': True})
         return unshelveabort(ui, repo, state)
 
 
 def mergefiles(ui, repo, wctx, shelvectx):
     """updates to wctx and merges the changes from shelvectx into the
     dirstate."""
     with ui.configoverride({(b'ui', b'quiet'): True}):
         hg.update(repo, wctx.node())
         ui.pushbuffer(True)
         cmdutil.revert(ui, repo, shelvectx)
         ui.popbuffer()
 
 
 def restorebranch(ui, repo, branchtorestore):
     if branchtorestore and branchtorestore != repo.dirstate.branch():
         repo.dirstate.setbranch(branchtorestore)
         ui.status(
             _(b'marked working directory as branch %s\n') % branchtorestore
         )
 
 
 def unshelvecleanup(ui, repo, name, opts):
     """remove related files after an unshelve"""
     if not opts.get(b'keep'):
         backupvfs = vfsmod.vfs(repo.vfs.join(backupdir))
-        Shelf.open(repo, name).movetobackup(backupvfs)
+        ShelfDir(repo).get(name).movetobackup(backupvfs)
         cleanupoldbackups(repo)
 
 
 def unshelvecontinue(ui, repo, state, opts):
     """subcommand to continue an in-progress unshelve"""
     # We're finishing off a merge. First parent is our original
     # parent, second is the temporary "fake" commit we're unshelving.
     interactive = state.interactive
     basename = state.name
     with repo.lock():
         checkparents(repo, state)
         ms = mergestatemod.mergestate.read(repo)
         if list(ms.unresolved()):
             raise error.Abort(
                 _(b"unresolved conflicts, can't continue"),
                 hint=_(b"see 'hg resolve', then 'hg unshelve --continue'"),
             )
 
         shelvectx = repo[state.parents[1]]
         pendingctx = state.pendingctx
 
         with repo.dirstate.parentchange():
             repo.setparents(state.pendingctx.node(), nullid)
             repo.dirstate.write(repo.currenttransaction())
 
         targetphase = phases.internal
         if not phases.supportinternal(repo):
             targetphase = phases.secret
         overrides = {(b'phases', b'new-commit'): targetphase}
         with repo.ui.configoverride(overrides, b'unshelve'):
             with repo.dirstate.parentchange():
                 repo.setparents(state.parents[0], nullid)
                 newnode, ispartialunshelve = _createunshelvectx(
                     ui, repo, shelvectx, basename, interactive, opts
                 )
 
         if newnode is None:
             shelvectx = state.pendingctx
             msg = _(
                 b'note: unshelved changes already existed '
                 b'in the working copy\n'
             )
             ui.status(msg)
         else:
             # only strip the shelvectx if we produced one
             state.nodestoremove.append(newnode)
             shelvectx = repo[newnode]
 
         merge.update(pendingctx)
         mergefiles(ui, repo, state.wctx, shelvectx)
         restorebranch(ui, repo, state.branchtorestore)
 
         if not phases.supportinternal(repo):
             repair.strip(
                 ui, repo, state.nodestoremove, backup=False, topic=b'shelve'
             )
         shelvedstate.clear(repo)
         if not ispartialunshelve:
             unshelvecleanup(ui, repo, state.name, opts)
         _restoreactivebookmark(repo, state.activebookmark)
         ui.status(_(b"unshelve of '%s' complete\n") % state.name)
 
 
 def hgcontinueunshelve(ui, repo):
     """logic to resume unshelve using 'hg continue'"""
     with repo.wlock():
         state = _loadshelvedstate(ui, repo, {b'continue': True})
         return unshelvecontinue(ui, repo, state, {b'keep': state.keep})
 
 
 def _commitworkingcopychanges(ui, repo, opts, tmpwctx):
     """Temporarily commit working copy changes before moving unshelve commit"""
     # Store pending changes in a commit and remember added in case a shelve
     # contains unknown files that are part of the pending change
     s = repo.status()
     addedbefore = frozenset(s.added)
     if not (s.modified or s.added or s.removed):
         return tmpwctx, addedbefore
     ui.status(
         _(
             b"temporarily committing pending changes "
             b"(restore with 'hg unshelve --abort')\n"
         )
     )
     extra = {b'internal': b'shelve'}
     commitfunc = getcommitfunc(extra=extra, interactive=False, editor=False)
     tempopts = {}
     tempopts[b'message'] = b"pending changes temporary commit"
     tempopts[b'date'] = opts.get(b'date')
     with ui.configoverride({(b'ui', b'quiet'): True}):
         node = cmdutil.commit(ui, repo, commitfunc, [], tempopts)
     tmpwctx = repo[node]
     return tmpwctx, addedbefore
 
 
 def _unshelverestorecommit(ui, repo, tr, basename):
     """Recreate commit in the repository during the unshelve"""
     repo = repo.unfiltered()
     node = None
-    shelf = Shelf.open(repo, basename)
+    shelf = ShelfDir(repo).get(basename)
     if shelf.hasinfo():
         node = shelf.readinfo()[b'node']
     if node is None or node not in repo:
         with ui.configoverride({(b'ui', b'quiet'): True}):
             shelvectx = shelf.applybundle(repo, tr)
         # We might not strip the unbundled changeset, so we should keep track of
         # the unshelve node in case we need to reuse it (eg: unshelve --keep)
         if node is None:
             info = {b'node': hex(shelvectx.node())}
             shelf.writeinfo(info)
     else:
         shelvectx = repo[node]
 
     return repo, shelvectx
 
 
 def _createunshelvectx(ui, repo, shelvectx, basename, interactive, opts):
     """Handles the creation of unshelve commit and updates the shelve if it
     was partially unshelved.
 
     If interactive is:
 
       * False: Commits all the changes in the working directory.
       * True: Prompts the user to select changes to unshelve and commit them.
               Update the shelve with remaining changes.
 
     Returns the node of the new commit formed and a bool indicating whether
     the shelve was partially unshelved.Creates a commit ctx to unshelve
     interactively or non-interactively.
 
     The user might want to unshelve certain changes only from the stored
     shelve in interactive. So, we would create two commits. One with requested
     changes to unshelve at that time and the latter is shelved for future.
 
     Here, we return both the newnode which is created interactively and a
     bool to know whether the shelve is partly done or completely done.
     """
     opts[b'message'] = shelvectx.description()
     opts[b'interactive-unshelve'] = True
     pats = []
     if not interactive:
         newnode = repo.commit(
             text=shelvectx.description(),
             extra=shelvectx.extra(),
             user=shelvectx.user(),
             date=shelvectx.date(),
         )
         return newnode, False
 
     commitfunc = getcommitfunc(shelvectx.extra(), interactive=True, editor=True)
     newnode = cmdutil.dorecord(
         ui,
         repo,
         commitfunc,
         None,
         False,
         cmdutil.recordfilter,
         *pats,
         **pycompat.strkwargs(opts)
     )
     snode = repo.commit(
         text=shelvectx.description(),
         extra=shelvectx.extra(),
         user=shelvectx.user(),
     )
     if snode:
         m = scmutil.matchfiles(repo, repo[snode].files())
         _shelvecreatedcommit(repo, snode, basename, m)
 
     return newnode, bool(snode)
 
 
 def _rebaserestoredcommit(
     ui,
     repo,
     opts,
     tr,
     oldtiprev,
     basename,
     pctx,
     tmpwctx,
     shelvectx,
     branchtorestore,
     activebookmark,
 ):
     """Rebase restored commit from its original location to a destination"""
     # If the shelve is not immediately on top of the commit
     # we'll be merging with, rebase it to be on top.
     interactive = opts.get(b'interactive')
     if tmpwctx.node() == shelvectx.p1().node() and not interactive:
         # We won't skip on interactive mode because, the user might want to
         # unshelve certain changes only.
         return shelvectx, False
 
     overrides = {
         (b'ui', b'forcemerge'): opts.get(b'tool', b''),
         (b'phases', b'new-commit'): phases.secret,
     }
     with repo.ui.configoverride(overrides, b'unshelve'):
         ui.status(_(b'rebasing shelved changes\n'))
         stats = merge.graft(
             repo,
             shelvectx,
             labels=[b'working-copy', b'shelve'],
             keepconflictparent=True,
         )
         if stats.unresolvedcount:
             tr.close()
 
             nodestoremove = [
                 repo.changelog.node(rev)
                 for rev in pycompat.xrange(oldtiprev, len(repo))
             ]
             shelvedstate.save(
                 repo,
                 basename,
                 pctx,
                 tmpwctx,
                 nodestoremove,
                 branchtorestore,
                 opts.get(b'keep'),
                 activebookmark,
                 interactive,
             )
             raise error.ConflictResolutionRequired(b'unshelve')
 
         with repo.dirstate.parentchange():
             repo.setparents(tmpwctx.node(), nullid)
             newnode, ispartialunshelve = _createunshelvectx(
                 ui, repo, shelvectx, basename, interactive, opts
             )
 
         if newnode is None:
             shelvectx = tmpwctx
             msg = _(
                 b'note: unshelved changes already existed '
                 b'in the working copy\n'
             )
             ui.status(msg)
         else:
             shelvectx = repo[newnode]
             merge.update(tmpwctx)
 
     return shelvectx, ispartialunshelve
 
 
 def _forgetunknownfiles(repo, shelvectx, addedbefore):
     # Forget any files that were unknown before the shelve, unknown before
     # unshelve started, but are now added.
     shelveunknown = shelvectx.extra().get(b'shelve_unknown')
     if not shelveunknown:
         return
     shelveunknown = frozenset(shelveunknown.split(b'\0'))
     addedafter = frozenset(repo.status().added)
     toforget = (addedafter & shelveunknown) - addedbefore
     repo[None].forget(toforget)
 
 
 def _finishunshelve(repo, oldtiprev, tr, activebookmark):
     _restoreactivebookmark(repo, activebookmark)
     # The transaction aborting will strip all the commits for us,
     # but it doesn't update the inmemory structures, so addchangegroup
     # hooks still fire and try to operate on the missing commits.
     # Clean up manually to prevent this.
     repo.unfiltered().changelog.strip(oldtiprev, tr)
     _aborttransaction(repo, tr)
 
 
 def _checkunshelveuntrackedproblems(ui, repo, shelvectx):
     """Check potential problems which may result from working
     copy having untracked changes."""
     wcdeleted = set(repo.status().deleted)
     shelvetouched = set(shelvectx.files())
     intersection = wcdeleted.intersection(shelvetouched)
     if intersection:
         m = _(b"shelved change touches missing files")
         hint = _(b"run hg status to see which files are missing")
         raise error.Abort(m, hint=hint)
 
 
 def unshelvecmd(ui, repo, *shelved, **opts):
     opts = pycompat.byteskwargs(opts)
     abortf = opts.get(b'abort')
     continuef = opts.get(b'continue')
     interactive = opts.get(b'interactive')
     if not abortf and not continuef:
         cmdutil.checkunfinished(repo)
     shelved = list(shelved)
     if opts.get(b"name"):
         shelved.append(opts[b"name"])
 
     if interactive and opts.get(b'keep'):
         raise error.InputError(
             _(b'--keep on --interactive is not yet supported')
         )
     if abortf or continuef:
         if abortf and continuef:
             raise error.InputError(_(b'cannot use both abort and continue'))
         if shelved:
             raise error.InputError(
                 _(
                     b'cannot combine abort/continue with '
                     b'naming a shelved change'
                 )
             )
         if abortf and opts.get(b'tool', False):
             ui.warn(_(b'tool option will be ignored\n'))
 
         state = _loadshelvedstate(ui, repo, opts)
         if abortf:
             return unshelveabort(ui, repo, state)
         elif continuef and interactive:
             raise error.InputError(
                 _(b'cannot use both continue and interactive')
             )
         elif continuef:
             return unshelvecontinue(ui, repo, state, opts)
     elif len(shelved) > 1:
         raise error.InputError(_(b'can only unshelve one change at a time'))
     elif not shelved:
         vfs = vfsmod.vfs(repo.vfs.join(shelvedir))
         shelved = listshelves(vfs)
         if not shelved:
             raise error.StateError(_(b'no shelved changes to apply!'))
         basename = shelved[0][1]
         ui.status(_(b"unshelving change '%s'\n") % basename)
     else:
         basename = shelved[0]
 
-    if not Shelf.open(repo, basename).exists():
+    if not ShelfDir(repo).get(basename).exists():
         raise error.InputError(_(b"shelved change '%s' not found") % basename)
 
     return _dounshelve(ui, repo, basename, opts)
 
 
 def _dounshelve(ui, repo, basename, opts):
     repo = repo.unfiltered()
     lock = tr = None
     try:
         lock = repo.lock()
         tr = repo.transaction(b'unshelve', report=lambda x: None)
         oldtiprev = len(repo)
 
         pctx = repo[b'.']
         tmpwctx = pctx
         # The goal is to have a commit structure like so:
         # ...-> pctx -> tmpwctx -> shelvectx
         # where tmpwctx is an optional commit with the user's pending changes
         # and shelvectx is the unshelved changes. Then we merge it all down
         # to the original pctx.
 
         activebookmark = _backupactivebookmark(repo)
         tmpwctx, addedbefore = _commitworkingcopychanges(
             ui, repo, opts, tmpwctx
         )
         repo, shelvectx = _unshelverestorecommit(ui, repo, tr, basename)
         _checkunshelveuntrackedproblems(ui, repo, shelvectx)
         branchtorestore = b''
         if shelvectx.branch() != shelvectx.p1().branch():
             branchtorestore = shelvectx.branch()
 
         shelvectx, ispartialunshelve = _rebaserestoredcommit(
             ui,
             repo,
             opts,
             tr,
             oldtiprev,
             basename,
             pctx,
             tmpwctx,
             shelvectx,
             branchtorestore,
             activebookmark,
         )
         overrides = {(b'ui', b'forcemerge'): opts.get(b'tool', b'')}
         with ui.configoverride(overrides, b'unshelve'):
             mergefiles(ui, repo, pctx, shelvectx)
         restorebranch(ui, repo, branchtorestore)
         shelvedstate.clear(repo)
         _finishunshelve(repo, oldtiprev, tr, activebookmark)
         _forgetunknownfiles(repo, shelvectx, addedbefore)
         if not ispartialunshelve:
             unshelvecleanup(ui, repo, basename, opts)
     finally:
         if tr:
             tr.release()
         lockmod.release(lock)