bookmarks: hide dict behind bmstore class

This should make it clearer that the bmstore doesn't expose all dict APIs.

mercurial/bookmarks.py

@@ -1,917 +1,937
 # Mercurial bookmark support code
 #
 # Copyright 2008 David Soria Parra <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 import struct
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     short,
     wdirid,
 )
 from . import (
     encoding,
     error,
     obsutil,
     pycompat,
     scmutil,
     txnutil,
     util,
 )
 
 # label constants
 # until 3.5, bookmarks.current was the advertised name, not
 # bookmarks.active, so we must use both to avoid breaking old
 # custom styles
 activebookmarklabel = 'bookmarks.active bookmarks.current'
 
 def _getbkfile(repo):
     """Hook so that extensions that mess with the store can hook bm storage.
 
     For core, this just handles wether we should see pending
     bookmarks or the committed ones. Other extensions (like share)
     may need to tweak this behavior further.
     """
     fp, pending = txnutil.trypending(repo.root, repo.vfs, 'bookmarks')
     return fp
 
-class bmstore(dict):
+class bmstore(object):
     """Storage for bookmarks.
 
     This object should do all bookmark-related reads and writes, so
     that it's fairly simple to replace the storage underlying
     bookmarks without having to clone the logic surrounding
     bookmarks. This type also should manage the active bookmark, if
     any.
 
     This particular bmstore implementation stores bookmarks as
     {hash}\s{name}\n (the same format as localtags) in
     .hg/bookmarks. The mapping is stored as {name: nodeid}.
     """
 
     def __init__(self, repo):
-        dict.__init__(self)
         self._repo = repo
+        self._refmap = refmap = {}  # refspec: node
         self._clean = True
         self._aclean = True
         nm = repo.changelog.nodemap
         tonode = bin # force local lookup
-        setitem = dict.__setitem__
         try:
             with _getbkfile(repo) as bkfile:
                 for line in bkfile:
                     line = line.strip()
                     if not line:
                         continue
                     try:
                         sha, refspec = line.split(' ', 1)
                         node = tonode(sha)
                         if node in nm:
                             refspec = encoding.tolocal(refspec)
-                            setitem(self, refspec, node)
+                            refmap[refspec] = node
                     except (TypeError, ValueError):
                         # TypeError:
                         # - bin(...)
                         # ValueError:
                         # - node in nm, for non-20-bytes entry
                         # - split(...), for string without ' '
                         repo.ui.warn(_('malformed line in .hg/bookmarks: %r\n')
                                      % pycompat.bytestr(line))
         except IOError as inst:
             if inst.errno != errno.ENOENT:
                 raise
         self._active = _readactive(repo, self)
 
     @property
     def active(self):
         return self._active
 
     @active.setter
     def active(self, mark):
-        if mark is not None and mark not in self:
+        if mark is not None and mark not in self._refmap:
             raise AssertionError('bookmark %s does not exist!' % mark)
 
         self._active = mark
         self._aclean = False
 
-    def __setitem__(self, *args, **kwargs):
-        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")
+    def __len__(self):
+        return len(self._refmap)
+
+    def __iter__(self):
+        return iter(self._refmap)
+
+    def iteritems(self):
+        return self._refmap.iteritems()
+
+    def items(self):
+        return self._refmap.items()
+
+    # TODO: maybe rename to allnames()?
+    def keys(self):
+        return self._refmap.keys()
+
+    # TODO: maybe rename to allnodes()? but nodes would have to be deduplicated
+    def values(self):
+        return self._refmap.values()
+
+    def __contains__(self, mark):
+        return mark in self._refmap
+
+    def __getitem__(self, mark):
+        return self._refmap[mark]
+
+    def get(self, mark, default=None):
+        return self._refmap.get(mark, default)
 
     def _set(self, key, value):
         self._clean = False
-        return dict.__setitem__(self, key, value)
-
-    def __delitem__(self, key):
-        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")
+        self._refmap[key] = value
 
     def _del(self, key):
         self._clean = False
-        return dict.__delitem__(self, key)
-
-    def update(self, *others):
-        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")
+        del self._refmap[key]
 
     def changectx(self, mark):
-        return self._repo[self[mark]]
+        node = self._refmap[mark]
+        return self._repo[node]
 
     def applychanges(self, repo, tr, changes):
         """Apply a list of changes to bookmarks
         """
         bmchanges = tr.changes.get('bookmarks')
         for name, node in changes:
-            old = self.get(name)
+            old = self._refmap.get(name)
             if node is None:
                 self._del(name)
             else:
                 self._set(name, node)
             if bmchanges is not None:
                 # if a previous value exist preserve the "initial" value
                 previous = bmchanges.get(name)
                 if previous is not None:
                     old = previous[0]
                 bmchanges[name] = (old, node)
         self._recordchange(tr)
 
     def _recordchange(self, tr):
         """record that bookmarks have been changed in a transaction
 
         The transaction is then responsible for updating the file content."""
         tr.addfilegenerator('bookmarks', ('bookmarks',), self._write,
                             location='plain')
         tr.hookargs['bookmark_moved'] = '1'
 
     def _writerepo(self, repo):
         """Factored out for extensibility"""
         rbm = repo._bookmarks
-        if rbm.active not in self:
+        if rbm.active not in self._refmap:
             rbm.active = None
             rbm._writeactive()
 
         with repo.wlock():
             file_ = repo.vfs('bookmarks', 'w', atomictemp=True,
                              checkambig=True)
             try:
                 self._write(file_)
             except: # re-raises
                 file_.discard()
                 raise
             finally:
                 file_.close()
 
     def _writeactive(self):
         if self._aclean:
             return
         with self._repo.wlock():
             if self._active is not None:
                 f = self._repo.vfs('bookmarks.current', 'w', atomictemp=True,
                                    checkambig=True)
                 try:
                     f.write(encoding.fromlocal(self._active))
                 finally:
                     f.close()
             else:
                 self._repo.vfs.tryunlink('bookmarks.current')
         self._aclean = True
 
     def _write(self, fp):
-        for name, node in sorted(self.iteritems()):
+        for name, node in sorted(self._refmap.iteritems()):
             fp.write("%s %s\n" % (hex(node), encoding.fromlocal(name)))
         self._clean = True
         self._repo.invalidatevolatilesets()
 
     def expandname(self, bname):
         if bname == '.':
             if self.active:
                 return self.active
             else:
                 raise error.Abort(_("no active bookmark"))
         return bname
 
     def checkconflict(self, mark, force=False, target=None):
         """check repo for a potential clash of mark with an existing bookmark,
         branch, or hash
 
         If target is supplied, then check that we are moving the bookmark
         forward.
 
         If force is supplied, then forcibly move the bookmark to a new commit
         regardless if it is a move forward.
 
         If divergent bookmark are to be deleted, they will be returned as list.
         """
         cur = self._repo['.'].node()
-        if mark in self and not force:
+        if mark in self._refmap and not force:
             if target:
-                if self[mark] == target and target == cur:
+                if self._refmap[mark] == target and target == cur:
                     # re-activating a bookmark
                     return []
                 rev = self._repo[target].rev()
                 anc = self._repo.changelog.ancestors([rev])
                 bmctx = self.changectx(mark)
-                divs = [self[b] for b in self
+                divs = [self._refmap[b] for b in self._refmap
                         if b.split('@', 1)[0] == mark.split('@', 1)[0]]
 
                 # allow resolving a single divergent bookmark even if moving
                 # the bookmark across branches when a revision is specified
                 # that contains a divergent bookmark
                 if bmctx.rev() not in anc and target in divs:
                     return divergent2delete(self._repo, [target], mark)
 
                 deletefrom = [b for b in divs
                               if self._repo[b].rev() in anc or b == target]
                 delbms = divergent2delete(self._repo, deletefrom, mark)
                 if validdest(self._repo, bmctx, self._repo[target]):
                     self._repo.ui.status(
                         _("moving bookmark '%s' forward from %s\n") %
                         (mark, short(bmctx.node())))
                     return delbms
             raise error.Abort(_("bookmark '%s' already exists "
                                 "(use -f to force)") % mark)
         if ((mark in self._repo.branchmap() or
              mark == self._repo.dirstate.branch()) and not force):
             raise error.Abort(
                 _("a bookmark cannot have the name of an existing branch"))
         if len(mark) > 3 and not force:
             try:
                 shadowhash = scmutil.isrevsymbol(self._repo, mark)
             except error.LookupError:  # ambiguous identifier
                 shadowhash = False
             if shadowhash:
                 self._repo.ui.warn(
                     _("bookmark %s matches a changeset hash\n"
                       "(did you leave a -r out of an 'hg bookmark' "
                       "command?)\n")
                     % mark)
         return []
 
 def _readactive(repo, marks):
     """
     Get the active bookmark. We can have an active bookmark that updates
     itself as we commit. This function returns the name of that bookmark.
     It is stored in .hg/bookmarks.current
     """
     mark = None
     try:
         file = repo.vfs('bookmarks.current')
     except IOError as inst:
         if inst.errno != errno.ENOENT:
             raise
         return None
     try:
         # No readline() in osutil.posixfile, reading everything is
         # cheap.
         # Note that it's possible for readlines() here to raise
         # IOError, since we might be reading the active mark over
         # static-http which only tries to load the file when we try
         # to read from it.
         mark = encoding.tolocal((file.readlines() or [''])[0])
         if mark == '' or mark not in marks:
             mark = None
     except IOError as inst:
         if inst.errno != errno.ENOENT:
             raise
         return None
     finally:
         file.close()
     return mark
 
 def activate(repo, mark):
     """
     Set the given bookmark to be 'active', meaning that this bookmark will
     follow new commits that are made.
     The name is recorded in .hg/bookmarks.current
     """
     repo._bookmarks.active = mark
     repo._bookmarks._writeactive()
 
 def deactivate(repo):
     """
     Unset the active bookmark in this repository.
     """
     repo._bookmarks.active = None
     repo._bookmarks._writeactive()
 
 def isactivewdirparent(repo):
     """
     Tell whether the 'active' bookmark (the one that follows new commits)
     points to one of the parents of the current working directory (wdir).
 
     While this is normally the case, it can on occasion be false; for example,
     immediately after a pull, the active bookmark can be moved to point
     to a place different than the wdir. This is solved by running `hg update`.
     """
     mark = repo._activebookmark
     marks = repo._bookmarks
     parents = [p.node() for p in repo[None].parents()]
     return (mark in marks and marks[mark] in parents)
 
 def divergent2delete(repo, deletefrom, bm):
     """find divergent versions of bm on nodes in deletefrom.
 
     the list of bookmark to delete."""
     todelete = []
     marks = repo._bookmarks
     divergent = [b for b in marks if b.split('@', 1)[0] == bm.split('@', 1)[0]]
     for mark in divergent:
         if mark == '@' or '@' not in mark:
             # can't be divergent by definition
             continue
         if mark and marks[mark] in deletefrom:
             if mark != bm:
                 todelete.append(mark)
     return todelete
 
 def headsforactive(repo):
     """Given a repo with an active bookmark, return divergent bookmark nodes.
 
     Args:
       repo: A repository with an active bookmark.
 
     Returns:
       A list of binary node ids that is the full list of other
       revisions with bookmarks divergent from the active bookmark. If
       there were no divergent bookmarks, then this list will contain
       only one entry.
     """
     if not repo._activebookmark:
         raise ValueError(
             'headsforactive() only makes sense with an active bookmark')
     name = repo._activebookmark.split('@', 1)[0]
     heads = []
     for mark, n in repo._bookmarks.iteritems():
         if mark.split('@', 1)[0] == name:
             heads.append(n)
     return heads
 
 def calculateupdate(ui, repo):
     '''Return a tuple (activemark, movemarkfrom) indicating the active bookmark
     and where to move the active bookmark from, if needed.'''
     checkout, movemarkfrom = None, None
     activemark = repo._activebookmark
     if isactivewdirparent(repo):
         movemarkfrom = repo['.'].node()
     elif activemark:
         ui.status(_("updating to active bookmark %s\n") % activemark)
         checkout = activemark
     return (checkout, movemarkfrom)
 
 def update(repo, parents, node):
     deletefrom = parents
     marks = repo._bookmarks
     active = marks.active
     if not active:
         return False
 
     bmchanges = []
     if marks[active] in parents:
         new = repo[node]
         divs = [marks.changectx(b) for b in marks
                 if b.split('@', 1)[0] == active.split('@', 1)[0]]
         anc = repo.changelog.ancestors([new.rev()])
         deletefrom = [b.node() for b in divs if b.rev() in anc or b == new]
         if validdest(repo, marks.changectx(active), new):
             bmchanges.append((active, new.node()))
 
     for bm in divergent2delete(repo, deletefrom, active):
         bmchanges.append((bm, None))
 
     if bmchanges:
         with repo.lock(), repo.transaction('bookmark') as tr:
             marks.applychanges(repo, tr, bmchanges)
     return bool(bmchanges)
 
 def listbinbookmarks(repo):
     # We may try to list bookmarks on a repo type that does not
     # support it (e.g., statichttprepository).
     marks = getattr(repo, '_bookmarks', {})
 
     hasnode = repo.changelog.hasnode
     for k, v in marks.iteritems():
         # don't expose local divergent bookmarks
         if hasnode(v) and ('@' not in k or k.endswith('@')):
             yield k, v
 
 def listbookmarks(repo):
     d = {}
     for book, node in listbinbookmarks(repo):
         d[book] = hex(node)
     return d
 
 def pushbookmark(repo, key, old, new):
     with repo.wlock(), repo.lock(), repo.transaction('bookmarks') as tr:
         marks = repo._bookmarks
         existing = hex(marks.get(key, ''))
         if existing != old and existing != new:
             return False
         if new == '':
             changes = [(key, None)]
         else:
             if new not in repo:
                 return False
             changes = [(key, repo[new].node())]
         marks.applychanges(repo, tr, changes)
         return True
 
 def comparebookmarks(repo, srcmarks, dstmarks, targets=None):
     '''Compare bookmarks between srcmarks and dstmarks
 
     This returns tuple "(addsrc, adddst, advsrc, advdst, diverge,
     differ, invalid)", each are list of bookmarks below:
 
     :addsrc:  added on src side (removed on dst side, perhaps)
     :adddst:  added on dst side (removed on src side, perhaps)
     :advsrc:  advanced on src side
     :advdst:  advanced on dst side
     :diverge: diverge
     :differ:  changed, but changeset referred on src is unknown on dst
     :invalid: unknown on both side
     :same:    same on both side
 
     Each elements of lists in result tuple is tuple "(bookmark name,
     changeset ID on source side, changeset ID on destination
     side)". Each changeset IDs are 40 hexadecimal digit string or
     None.
 
     Changeset IDs of tuples in "addsrc", "adddst", "differ" or
      "invalid" list may be unknown for repo.
 
     If "targets" is specified, only bookmarks listed in it are
     examined.
     '''
 
     if targets:
         bset = set(targets)
     else:
         srcmarkset = set(srcmarks)
         dstmarkset = set(dstmarks)
         bset = srcmarkset | dstmarkset
 
     results = ([], [], [], [], [], [], [], [])
     addsrc = results[0].append
     adddst = results[1].append
     advsrc = results[2].append
     advdst = results[3].append
     diverge = results[4].append
     differ = results[5].append
     invalid = results[6].append
     same = results[7].append
 
     for b in sorted(bset):
         if b not in srcmarks:
             if b in dstmarks:
                 adddst((b, None, dstmarks[b]))
             else:
                 invalid((b, None, None))
         elif b not in dstmarks:
             addsrc((b, srcmarks[b], None))
         else:
             scid = srcmarks[b]
             dcid = dstmarks[b]
             if scid == dcid:
                 same((b, scid, dcid))
             elif scid in repo and dcid in repo:
                 sctx = repo[scid]
                 dctx = repo[dcid]
                 if sctx.rev() < dctx.rev():
                     if validdest(repo, sctx, dctx):
                         advdst((b, scid, dcid))
                     else:
                         diverge((b, scid, dcid))
                 else:
                     if validdest(repo, dctx, sctx):
                         advsrc((b, scid, dcid))
                     else:
                         diverge((b, scid, dcid))
             else:
                 # it is too expensive to examine in detail, in this case
                 differ((b, scid, dcid))
 
     return results
 
 def _diverge(ui, b, path, localmarks, remotenode):
     '''Return appropriate diverged bookmark for specified ``path``
 
     This returns None, if it is failed to assign any divergent
     bookmark name.
 
     This reuses already existing one with "@number" suffix, if it
     refers ``remotenode``.
     '''
     if b == '@':
         b = ''
     # try to use an @pathalias suffix
     # if an @pathalias already exists, we overwrite (update) it
     if path.startswith("file:"):
         path = util.url(path).path
     for p, u in ui.configitems("paths"):
         if u.startswith("file:"):
             u = util.url(u).path
         if path == u:
             return '%s@%s' % (b, p)
 
     # assign a unique "@number" suffix newly
     for x in range(1, 100):
         n = '%s@%d' % (b, x)
         if n not in localmarks or localmarks[n] == remotenode:
             return n
 
     return None
 
 def unhexlifybookmarks(marks):
     binremotemarks = {}
     for name, node in marks.items():
         binremotemarks[name] = bin(node)
     return binremotemarks
 
 _binaryentry = struct.Struct('>20sH')
 
 def binaryencode(bookmarks):
     """encode a '(bookmark, node)' iterable into a binary stream
 
     the binary format is:
 
         <node><bookmark-length><bookmark-name>
 
     :node: is a 20 bytes binary node,
     :bookmark-length: an unsigned short,
     :bookmark-name: the name of the bookmark (of length <bookmark-length>)
 
     wdirid (all bits set) will be used as a special value for "missing"
     """
     binarydata = []
     for book, node in bookmarks:
         if not node: # None or ''
             node = wdirid
         binarydata.append(_binaryentry.pack(node, len(book)))
         binarydata.append(book)
     return ''.join(binarydata)
 
 def binarydecode(stream):
     """decode a binary stream into an '(bookmark, node)' iterable
 
     the binary format is:
 
         <node><bookmark-length><bookmark-name>
 
     :node: is a 20 bytes binary node,
     :bookmark-length: an unsigned short,
     :bookmark-name: the name of the bookmark (of length <bookmark-length>))
 
     wdirid (all bits set) will be used as a special value for "missing"
     """
     entrysize = _binaryentry.size
     books = []
     while True:
         entry = stream.read(entrysize)
         if len(entry) < entrysize:
             if entry:
                 raise error.Abort(_('bad bookmark stream'))
             break
         node, length = _binaryentry.unpack(entry)
         bookmark = stream.read(length)
         if len(bookmark) < length:
             if entry:
                 raise error.Abort(_('bad bookmark stream'))
         if node == wdirid:
             node = None
         books.append((bookmark, node))
     return books
 
 def updatefromremote(ui, repo, remotemarks, path, trfunc, explicit=()):
     ui.debug("checking for updated bookmarks\n")
     localmarks = repo._bookmarks
     (addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same
     ) = comparebookmarks(repo, remotemarks, localmarks)
 
     status = ui.status
     warn = ui.warn
     if ui.configbool('ui', 'quietbookmarkmove'):
         status = warn = ui.debug
 
     explicit = set(explicit)
     changed = []
     for b, scid, dcid in addsrc:
         if scid in repo: # add remote bookmarks for changes we already have
             changed.append((b, scid, status,
                             _("adding remote bookmark %s\n") % (b)))
         elif b in explicit:
             explicit.remove(b)
             ui.warn(_("remote bookmark %s points to locally missing %s\n")
                     % (b, hex(scid)[:12]))
 
     for b, scid, dcid in advsrc:
         changed.append((b, scid, status,
                         _("updating bookmark %s\n") % (b)))
     # remove normal movement from explicit set
     explicit.difference_update(d[0] for d in changed)
 
     for b, scid, dcid in diverge:
         if b in explicit:
             explicit.discard(b)
             changed.append((b, scid, status,
                             _("importing bookmark %s\n") % (b)))
         else:
             db = _diverge(ui, b, path, localmarks, scid)
             if db:
                 changed.append((db, scid, warn,
                                 _("divergent bookmark %s stored as %s\n") %
                                 (b, db)))
             else:
                 warn(_("warning: failed to assign numbered name "
                        "to divergent bookmark %s\n") % (b))
     for b, scid, dcid in adddst + advdst:
         if b in explicit:
             explicit.discard(b)
             changed.append((b, scid, status,
                             _("importing bookmark %s\n") % (b)))
     for b, scid, dcid in differ:
         if b in explicit:
             explicit.remove(b)
             ui.warn(_("remote bookmark %s points to locally missing %s\n")
                     % (b, hex(scid)[:12]))
 
     if changed:
         tr = trfunc()
         changes = []
         for b, node, writer, msg in sorted(changed):
             changes.append((b, node))
             writer(msg)
         localmarks.applychanges(repo, tr, changes)
 
 def incoming(ui, repo, peer):
     '''Show bookmarks incoming from other to repo
     '''
     ui.status(_("searching for changed bookmarks\n"))
 
     with peer.commandexecutor() as e:
         remotemarks = unhexlifybookmarks(e.callcommand('listkeys', {
             'namespace': 'bookmarks',
         }).result())
 
     r = comparebookmarks(repo, remotemarks, repo._bookmarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
 
     incomings = []
     if ui.debugflag:
         getid = lambda id: id
     else:
         getid = lambda id: id[:12]
     if ui.verbose:
         def add(b, id, st):
             incomings.append("   %-25s %s %s\n" % (b, getid(id), st))
     else:
         def add(b, id, st):
             incomings.append("   %-25s %s\n" % (b, getid(id)))
     for b, scid, dcid in addsrc:
         # i18n: "added" refers to a bookmark
         add(b, hex(scid), _('added'))
     for b, scid, dcid in advsrc:
         # i18n: "advanced" refers to a bookmark
         add(b, hex(scid), _('advanced'))
     for b, scid, dcid in diverge:
         # i18n: "diverged" refers to a bookmark
         add(b, hex(scid), _('diverged'))
     for b, scid, dcid in differ:
         # i18n: "changed" refers to a bookmark
         add(b, hex(scid), _('changed'))
 
     if not incomings:
         ui.status(_("no changed bookmarks found\n"))
         return 1
 
     for s in sorted(incomings):
         ui.write(s)
 
     return 0
 
 def outgoing(ui, repo, other):
     '''Show bookmarks outgoing from repo to other
     '''
     ui.status(_("searching for changed bookmarks\n"))
 
     remotemarks = unhexlifybookmarks(other.listkeys('bookmarks'))
     r = comparebookmarks(repo, repo._bookmarks, remotemarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
 
     outgoings = []
     if ui.debugflag:
         getid = lambda id: id
     else:
         getid = lambda id: id[:12]
     if ui.verbose:
         def add(b, id, st):
             outgoings.append("   %-25s %s %s\n" % (b, getid(id), st))
     else:
         def add(b, id, st):
             outgoings.append("   %-25s %s\n" % (b, getid(id)))
     for b, scid, dcid in addsrc:
         # i18n: "added refers to a bookmark
         add(b, hex(scid), _('added'))
     for b, scid, dcid in adddst:
         # i18n: "deleted" refers to a bookmark
         add(b, ' ' * 40, _('deleted'))
     for b, scid, dcid in advsrc:
         # i18n: "advanced" refers to a bookmark
         add(b, hex(scid), _('advanced'))
     for b, scid, dcid in diverge:
         # i18n: "diverged" refers to a bookmark
         add(b, hex(scid), _('diverged'))
     for b, scid, dcid in differ:
         # i18n: "changed" refers to a bookmark
         add(b, hex(scid), _('changed'))
 
     if not outgoings:
         ui.status(_("no changed bookmarks found\n"))
         return 1
 
     for s in sorted(outgoings):
         ui.write(s)
 
     return 0
 
 def summary(repo, peer):
     '''Compare bookmarks between repo and other for "hg summary" output
 
     This returns "(# of incoming, # of outgoing)" tuple.
     '''
     with peer.commandexecutor() as e:
         remotemarks = unhexlifybookmarks(e.callcommand('listkeys', {
             'namespace': 'bookmarks',
         }).result())
 
     r = comparebookmarks(repo, remotemarks, repo._bookmarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
     return (len(addsrc), len(adddst))
 
 def validdest(repo, old, new):
     """Is the new bookmark destination a valid update from the old one"""
     repo = repo.unfiltered()
     if old == new:
         # Old == new -> nothing to update.
         return False
     elif not old:
         # old is nullrev, anything is valid.
         # (new != nullrev has been excluded by the previous check)
         return True
     elif repo.obsstore:
         return new.node() in obsutil.foreground(repo, [old.node()])
     else:
         # still an independent clause as it is lazier (and therefore faster)
         return old.descendant(new)
 
 def checkformat(repo, mark):
     """return a valid version of a potential bookmark name
 
     Raises an abort error if the bookmark name is not valid.
     """
     mark = mark.strip()
     if not mark:
         raise error.Abort(_("bookmark names cannot consist entirely of "
                             "whitespace"))
     scmutil.checknewlabel(repo, mark, 'bookmark')
     return mark
 
 def delete(repo, tr, names):
     """remove a mark from the bookmark store
 
     Raises an abort error if mark does not exist.
     """
     marks = repo._bookmarks
     changes = []
     for mark in names:
         if mark not in marks:
             raise error.Abort(_("bookmark '%s' does not exist") % mark)
         if mark == repo._activebookmark:
             deactivate(repo)
         changes.append((mark, None))
     marks.applychanges(repo, tr, changes)
 
 def rename(repo, tr, old, new, force=False, inactive=False):
     """rename a bookmark from old to new
 
     If force is specified, then the new name can overwrite an existing
     bookmark.
 
     If inactive is specified, then do not activate the new bookmark.
 
     Raises an abort error if old is not in the bookmark store.
     """
     marks = repo._bookmarks
     mark = checkformat(repo, new)
     if old not in marks:
         raise error.Abort(_("bookmark '%s' does not exist") % old)
     changes = []
     for bm in marks.checkconflict(mark, force):
         changes.append((bm, None))
     changes.extend([(mark, marks[old]), (old, None)])
     marks.applychanges(repo, tr, changes)
     if repo._activebookmark == old and not inactive:
         activate(repo, mark)
 
 def addbookmarks(repo, tr, names, rev=None, force=False, inactive=False):
     """add a list of bookmarks
 
     If force is specified, then the new name can overwrite an existing
     bookmark.
 
     If inactive is specified, then do not activate any bookmark. Otherwise, the
     first bookmark is activated.
 
     Raises an abort error if old is not in the bookmark store.
     """
     marks = repo._bookmarks
     cur = repo['.'].node()
     newact = None
     changes = []
     hiddenrev = None
 
     # unhide revs if any
     if rev:
         repo = scmutil.unhidehashlikerevs(repo, [rev], 'nowarn')
 
     for mark in names:
         mark = checkformat(repo, mark)
         if newact is None:
             newact = mark
         if inactive and mark == repo._activebookmark:
             deactivate(repo)
             return
         tgt = cur
         if rev:
             ctx = scmutil.revsingle(repo, rev)
             if ctx.hidden():
                 hiddenrev = ctx.hex()[:12]
             tgt = ctx.node()
         for bm in marks.checkconflict(mark, force, tgt):
             changes.append((bm, None))
         changes.append((mark, tgt))
 
     if hiddenrev:
         repo.ui.warn(_("bookmarking hidden changeset %s\n") % hiddenrev)
 
         if ctx.obsolete():
             msg = obsutil._getfilteredreason(repo, "%s" % hiddenrev, ctx)
             repo.ui.warn("(%s)\n" % msg)
 
     marks.applychanges(repo, tr, changes)
     if not inactive and cur == marks[newact] and not rev:
         activate(repo, newact)
     elif cur != tgt and newact == repo._activebookmark:
         deactivate(repo)
 
 def _printbookmarks(ui, repo, bmarks, **opts):
     """private method to print bookmarks
 
     Provides a way for extensions to control how bookmarks are printed (e.g.
     prepend or postpend names)
     """
     opts = pycompat.byteskwargs(opts)
     fm = ui.formatter('bookmarks', opts)
     hexfn = fm.hexfunc
     if len(bmarks) == 0 and fm.isplain():
         ui.status(_("no bookmarks set\n"))
     for bmark, (n, prefix, label) in sorted(bmarks.iteritems()):
         fm.startitem()
         if not ui.quiet:
             fm.plain(' %s ' % prefix, label=label)
         fm.write('bookmark', '%s', bmark, label=label)
         pad = " " * (25 - encoding.colwidth(bmark))
         fm.condwrite(not ui.quiet, 'rev node', pad + ' %d:%s',
                      repo.changelog.rev(n), hexfn(n), label=label)
         fm.data(active=(activebookmarklabel in label))
         fm.plain('\n')
     fm.end()
 
 def printbookmarks(ui, repo, **opts):
     """print bookmarks to a formatter
 
     Provides a way for extensions to control how bookmarks are printed.
     """
     marks = repo._bookmarks
     bmarks = {}
     for bmark, n in sorted(marks.iteritems()):
         active = repo._activebookmark
         if bmark == active:
             prefix, label = '*', activebookmarklabel
         else:
             prefix, label = ' ', ''
 
         bmarks[bmark] = (n, prefix, label)
     _printbookmarks(ui, repo, bmarks, **opts)
 
 def preparehookargs(name, old, new):
     if new is None:
         new = ''
     if old is None:
         old = ''
     return {'bookmark': name,
             'node': hex(new),
             'oldnode': hex(old)}