view mercurial/bookmarks.py @ 48687:f8f2ecdde4b5

branchmap: skip obsolete revisions while computing heads

It's time to make this part of core Mercurial obsolescence-aware.

Not considering obsolete revisions when computing heads is clearly what
Mercurial should do. But there are a couple of small issues:

- Let's say tip of the repo is obsolete. There are two ways of finding tiprev
  for branchcache (both are in use): looking at input data for update() and
  looking at computed heads after update(). Previously, repo tip would be
  tiprev of the branchcache. With this patch, an obsolete revision can no
  longer be tiprev. And depending on what way we use for finding tiprev (input
  data vs computed heads) we'll get a different result. This is relevant when
  recomputing cache key from cache contents, and may lead to updating cache for
  obsolete revisions multiple times (not from scratch, because it still would
  be considered valid for a subset of revisions in the repo).

- If all commits on a branch are obsolete, the branchcache will include that
  branch, but the list of heads will be empty (that's why there's now `if not
  heads` when recomputing tiprev/tipnode from cache contents). Having an entry
  for every branch is currently required for notify extension (and
  test-notify.t to pass), because notify doesn't handle revsets in its
  subscription config very well and will throw an error if e.g. a branch
  doesn't exist.

- Cloning static HTTP repos may try to stat() a non-existent obsstore file. The
  issue is that we now care about obsolescence during clone, but statichttpvfs
  doesn't implement a stat method, so a regular vfs.stat() is used, and it
  assumes that file is local and calls os.stat().  During a clone, we're trying
  to stat() .hg/store/obsstore, but in static HTTP case we provide a literal
  URL to the obsstore file on the remote as if it were a local file path. On
  windows it actually results in a failure in test-static-http.t.

The first issue is going to be addressed in a series dedicated to making sure
branchcache is properly and timely written on disk (it wasn't perfect even
before this patch, but there aren't enough tests to demonstrate that). The
second issue will be addressed in a future patch for notify extension that will
make it not raise an exception if a branch doesn't exist. And the third one was
partially addressed in the previous patch in this series and will be properly
fixed in a future patch when this series is accepted.

filteredhash() grows a keyword argument to make sure that branchcache is also
invalidated when there are new obsolete revisions in its repo view. This way
the on-disk cache format is unchanged and compatible between versions (although
it will obviously be recomputed when switching versions before/after this patch
and the repo has obsolete revisions).

There's one test that uses plain `hg up` without arguments while updated to a
pruned commit. To make this test pass, simply return current working directory
parent. Later in this series this code will be replaced by what prune command
does: updating to the closest non-obsolete ancestor.

Test changes:

test-branch-change.t: update branch head and cache update message. The head of
default listed in hg heads is changed because revision 2 was rewritten as 7,
and 1 is the closest ancestor on the same branch, so it's the head of default
now.

The cache invalidation message appears now because of the cache hash change,
since we're now accounting for obsolete revisions. Here's some context:

"served.hidden" repo filter means everything is visible (no filtered
revisions), so before this series branch2-served.hidden file would not contain
any cache hash, only revnum and node. Now it also has a hash when there are
obsolete changesets in the repo. The command that the message appears for is
changing branch of 5 and 6, which are now obsolete, so the cache hash changes.

In general, when cache is simply out-of-date, it can be updated using the old
version as a base. But if cache hash differs, then the cache for that
particular repo filter is recomputed (at least with the current
implementation). This is what happens here.

test-obsmarker-template.t: the pull reports 2 heads changed, but after that the
repo correctly sees only 1. The new message could be better, but it's still an
improvement over the previous one where hg pull suggested merging with an
obsolete revision.

test-obsolete.t: we can see these revisions in hg log --hidden, but they
shouldn't be considered heads even with --hidden.

test-rebase-obsolete{,2}.t: there were new heads created previously after
making new orphan changesets, but they weren't detected. Now we are properly
detecting and reporting them.

test-rebase-obsolete4.t: there's only one head now because the other head is
pruned and was falsely reported before.

test-static-http.t: add obsstore to the list of requested files. This file
doesn't exist on the remotes, but clients want it anyway (they get 404). This
is fine, because there are other nonexistent files that clients request, like
.hg/bookmarks or .hg/cache/tags2-served.

Differential Revision: https://phab.mercurial-scm.org/D12097

# 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,
)
from .pycompat import getattr
from . import (
    encoding,
    error,
    obsutil,
    pycompat,
    requirements,
    scmutil,
    txnutil,
    util,
)
from .utils import (
    urlutil,
)

# 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 = b'bookmarks.active bookmarks.current'


def bookmarksinstore(repo):
    return requirements.BOOKMARKS_IN_STORE_REQUIREMENT in repo.requirements


def bookmarksvfs(repo):
    return repo.svfs if bookmarksinstore(repo) else repo.vfs


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, bookmarksvfs(repo), b'bookmarks'
    )
    return fp


class bmstore(object):
    r"""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):
        self._repo = repo
        self._refmap = refmap = {}  # refspec: node
        self._nodemap = nodemap = {}  # node: sorted([refspec, ...])
        self._clean = True
        self._aclean = True
        has_node = repo.changelog.index.has_node
        tonode = bin  # force local lookup
        try:
            with _getbkfile(repo) as bkfile:
                for line in bkfile:
                    line = line.strip()
                    if not line:
                        continue
                    try:
                        sha, refspec = line.split(b' ', 1)
                        node = tonode(sha)
                        if has_node(node):
                            refspec = encoding.tolocal(refspec)
                            refmap[refspec] = node
                            nrefs = nodemap.get(node)
                            if nrefs is None:
                                nodemap[node] = [refspec]
                            else:
                                nrefs.append(refspec)
                                if nrefs[-2] > refspec:
                                    # bookmarks weren't sorted before 4.5
                                    nrefs.sort()
                    except (TypeError, ValueError):
                        # TypeError:
                        # - bin(...)
                        # ValueError:
                        # - node in nm, for non-20-bytes entry
                        # - split(...), for string without ' '
                        bookmarkspath = b'.hg/bookmarks'
                        if bookmarksinstore(repo):
                            bookmarkspath = b'.hg/store/bookmarks'
                        repo.ui.warn(
                            _(b'malformed line in %s: %r\n')
                            % (bookmarkspath, 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._refmap:
            raise AssertionError(b'bookmark %s does not exist!' % mark)

        self._active = mark
        self._aclean = False

    def __len__(self):
        return len(self._refmap)

    def __iter__(self):
        return iter(self._refmap)

    def iteritems(self):
        return pycompat.iteritems(self._refmap)

    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
    # could be self._nodemap.keys()
    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, mark, node):
        self._clean = False
        if mark in self._refmap:
            self._del(mark)
        self._refmap[mark] = node
        nrefs = self._nodemap.get(node)
        if nrefs is None:
            self._nodemap[node] = [mark]
        else:
            nrefs.append(mark)
            nrefs.sort()

    def _del(self, mark):
        if mark not in self._refmap:
            return
        self._clean = False
        node = self._refmap.pop(mark)
        nrefs = self._nodemap[node]
        if len(nrefs) == 1:
            assert nrefs[0] == mark
            del self._nodemap[node]
        else:
            nrefs.remove(mark)

    def names(self, node):
        """Return a sorted list of bookmarks pointing to the specified node"""
        return self._nodemap.get(node, [])

    def applychanges(self, repo, tr, changes):
        """Apply a list of changes to bookmarks"""
        bmchanges = tr.changes.get(b'bookmarks')
        for name, node in changes:
            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."""
        location = b'' if bookmarksinstore(self._repo) else b'plain'
        tr.addfilegenerator(
            b'bookmarks',
            (b'bookmarks',),
            self._write,
            location=location,
            post_finalize=True,
        )
        tr.hookargs[b'bookmark_moved'] = b'1'

    def _writerepo(self, repo):
        """Factored out for extensibility"""
        rbm = repo._bookmarks
        if rbm.active not in self._refmap:
            rbm.active = None
            rbm._writeactive()

        if bookmarksinstore(repo):
            vfs = repo.svfs
            lock = repo.lock()
        else:
            vfs = repo.vfs
            lock = repo.wlock()
        with lock:
            with vfs(b'bookmarks', b'w', atomictemp=True, checkambig=True) as f:
                self._write(f)

    def _writeactive(self):
        if self._aclean:
            return
        with self._repo.wlock():
            if self._active is not None:
                with self._repo.vfs(
                    b'bookmarks.current', b'w', atomictemp=True, checkambig=True
                ) as f:
                    f.write(encoding.fromlocal(self._active))
            else:
                self._repo.vfs.tryunlink(b'bookmarks.current')
        self._aclean = True

    def _write(self, fp):
        for name, node in sorted(pycompat.iteritems(self._refmap)):
            fp.write(b"%s %s\n" % (hex(node), encoding.fromlocal(name)))
        self._clean = True
        self._repo.invalidatevolatilesets()

    def expandname(self, bname):
        if bname == b'.':
            if self.active:
                return self.active
            else:
                raise error.RepoLookupError(_(b"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[b'.'].node()
        if mark in self._refmap and not force:
            if target:
                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._repo[self[mark]]
                divs = [
                    self._refmap[b]
                    for b in self._refmap
                    if b.split(b'@', 1)[0] == mark.split(b'@', 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(
                        _(b"moving bookmark '%s' forward from %s\n")
                        % (mark, short(bmctx.node()))
                    )
                    return delbms
            raise error.Abort(
                _(b"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(
                _(b"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(
                    _(
                        b"bookmark %s matches a changeset hash\n"
                        b"(did you leave a -r out of an 'hg bookmark' "
                        b"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
    """
    # No readline() in osutil.posixfile, reading everything is
    # cheap.
    content = repo.vfs.tryread(b'bookmarks.current')
    mark = encoding.tolocal((content.splitlines() or [b''])[0])
    if mark == b'' or mark not in marks:
        mark = None
    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(b'@', 1)[0] == bm.split(b'@', 1)[0]
    ]
    for mark in divergent:
        if mark == b'@' or b'@' 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(
            b'headsforactive() only makes sense with an active bookmark'
        )
    name = repo._activebookmark.split(b'@', 1)[0]
    heads = []
    for mark, n in pycompat.iteritems(repo._bookmarks):
        if mark.split(b'@', 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[b'.'].node()
    elif activemark:
        ui.status(_(b"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 = [
            repo[marks[b]]
            for b in marks
            if b.split(b'@', 1)[0] == active.split(b'@', 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, repo[marks[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(b'bookmark') as tr:
            marks.applychanges(repo, tr, bmchanges)
    return bool(bmchanges)


def isdivergent(b):
    return b'@' in b and not b.endswith(b'@')


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 pycompat.iteritems(marks):
        # don't expose local divergent bookmarks
        if hasnode(v) and not isdivergent(k):
            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):
    if isdivergent(key):
        return False
    if bookmarksinstore(repo):
        wlock = util.nullcontextmanager()
    else:
        wlock = repo.wlock()
    with wlock, repo.lock(), repo.transaction(b'bookmarks') as tr:
        marks = repo._bookmarks
        existing = hex(marks.get(key, b''))
        if existing != old and existing != new:
            return False
        if new == b'':
            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 ID is a binary node 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'@':
        b = b''
    # try to use an @pathalias suffix
    # if an @pathalias already exists, we overwrite (update) it
    if path.startswith(b"file:"):
        path = urlutil.url(path).path
    for name, p in urlutil.list_paths(ui):
        loc = p.rawloc
        if loc.startswith(b"file:"):
            loc = urlutil.url(loc).path
        if path == loc:
            return b'%s@%s' % (b, name)

    # assign a unique "@number" suffix newly
    for x in range(1, 100):
        n = b'%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(b'>20sH')


def binaryencode(repo, 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 = repo.nodeconstants.wdirid
        binarydata.append(_binaryentry.pack(node, len(book)))
        binarydata.append(book)
    return b''.join(binarydata)


def binarydecode(repo, 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(_(b'bad bookmark stream'))
            break
        node, length = _binaryentry.unpack(entry)
        bookmark = stream.read(length)
        if len(bookmark) < length:
            if entry:
                raise error.Abort(_(b'bad bookmark stream'))
        if node == repo.nodeconstants.wdirid:
            node = None
        books.append((bookmark, node))
    return books


def mirroring_remote(ui, repo, remotemarks):
    """computes the bookmark changes that set the local bookmarks to
    remotemarks"""
    changed = []
    localmarks = repo._bookmarks
    for (b, id) in pycompat.iteritems(remotemarks):
        if id != localmarks.get(b, None) and id in repo:
            changed.append((b, id, ui.debug, _(b"updating bookmark %s\n") % b))
    for b in localmarks:
        if b not in remotemarks:
            changed.append(
                (b, None, ui.debug, _(b"removing bookmark %s\n") % b)
            )
    return changed


def merging_from_remote(ui, repo, remotemarks, path, explicit=()):
    """computes the bookmark changes that merge remote bookmarks into the
    local bookmarks, based on comparebookmarks"""
    localmarks = repo._bookmarks
    (
        addsrc,
        adddst,
        advsrc,
        advdst,
        diverge,
        differ,
        invalid,
        same,
    ) = comparebookmarks(repo, remotemarks, localmarks)

    status = ui.status
    warn = ui.warn
    if ui.configbool(b'ui', b'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, _(b"adding remote bookmark %s\n") % b)
            )
        elif b in explicit:
            explicit.remove(b)
            ui.warn(
                _(b"remote bookmark %s points to locally missing %s\n")
                % (b, hex(scid)[:12])
            )

    for b, scid, dcid in advsrc:
        changed.append((b, scid, status, _(b"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, _(b"importing bookmark %s\n") % b))
        else:
            db = _diverge(ui, b, path, localmarks, scid)
            if db:
                changed.append(
                    (
                        db,
                        scid,
                        warn,
                        _(b"divergent bookmark %s stored as %s\n") % (b, db),
                    )
                )
            else:
                warn(
                    _(
                        b"warning: failed to assign numbered name "
                        b"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, _(b"importing bookmark %s\n") % b))
    for b, scid, dcid in differ:
        if b in explicit:
            explicit.remove(b)
            ui.warn(
                _(b"remote bookmark %s points to locally missing %s\n")
                % (b, hex(scid)[:12])
            )
    return changed


def updatefromremote(
    ui, repo, remotemarks, path, trfunc, explicit=(), mode=None
):
    if mode == b'ignore':
        # This should move to an higher level to avoid fetching bookmark at all
        return
    ui.debug(b"checking for updated bookmarks\n")
    if mode == b'mirror':
        changed = mirroring_remote(ui, repo, remotemarks)
    else:
        changed = merging_from_remote(ui, repo, remotemarks, path, explicit)

    if changed:
        tr = trfunc()
        changes = []
        key = lambda t: (t[0], t[1] or b'')
        for b, node, writer, msg in sorted(changed, key=key):
            changes.append((b, node))
            writer(msg)
        repo._bookmarks.applychanges(repo, tr, changes)


def incoming(ui, repo, peer, mode=None):
    """Show bookmarks incoming from other to repo"""
    if mode == b'ignore':
        ui.status(_(b"bookmarks exchange disabled with this path\n"))
        return 0
    ui.status(_(b"searching for changed bookmarks\n"))

    with peer.commandexecutor() as e:
        remotemarks = unhexlifybookmarks(
            e.callcommand(
                b'listkeys',
                {
                    b'namespace': b'bookmarks',
                },
            ).result()
        )

    incomings = []
    if ui.debugflag:
        getid = lambda id: id
    else:
        getid = lambda id: id[:12]
    if ui.verbose:

        def add(b, id, st):
            incomings.append(b"   %-25s %s %s\n" % (b, getid(id), st))

    else:

        def add(b, id, st):
            incomings.append(b"   %-25s %s\n" % (b, getid(id)))

    if mode == b'mirror':
        localmarks = repo._bookmarks
        allmarks = set(remotemarks.keys()) | set(localmarks.keys())
        for b in sorted(allmarks):
            loc = localmarks.get(b)
            rem = remotemarks.get(b)
            if loc == rem:
                continue
            elif loc is None:
                add(b, hex(rem), _(b'added'))
            elif rem is None:
                add(b, hex(repo.nullid), _(b'removed'))
            else:
                add(b, hex(rem), _(b'changed'))
    else:
        r = comparebookmarks(repo, remotemarks, repo._bookmarks)
        addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r

        for b, scid, dcid in addsrc:
            # i18n: "added" refers to a bookmark
            add(b, hex(scid), _(b'added'))
        for b, scid, dcid in advsrc:
            # i18n: "advanced" refers to a bookmark
            add(b, hex(scid), _(b'advanced'))
        for b, scid, dcid in diverge:
            # i18n: "diverged" refers to a bookmark
            add(b, hex(scid), _(b'diverged'))
        for b, scid, dcid in differ:
            # i18n: "changed" refers to a bookmark
            add(b, hex(scid), _(b'changed'))

    if not incomings:
        ui.status(_(b"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(_(b"searching for changed bookmarks\n"))

    remotemarks = unhexlifybookmarks(other.listkeys(b'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(b"   %-25s %s %s\n" % (b, getid(id), st))

    else:

        def add(b, id, st):
            outgoings.append(b"   %-25s %s\n" % (b, getid(id)))

    for b, scid, dcid in addsrc:
        # i18n: "added refers to a bookmark
        add(b, hex(scid), _(b'added'))
    for b, scid, dcid in adddst:
        # i18n: "deleted" refers to a bookmark
        add(b, b' ' * 40, _(b'deleted'))
    for b, scid, dcid in advsrc:
        # i18n: "advanced" refers to a bookmark
        add(b, hex(scid), _(b'advanced'))
    for b, scid, dcid in diverge:
        # i18n: "diverged" refers to a bookmark
        add(b, hex(scid), _(b'diverged'))
    for b, scid, dcid in differ:
        # i18n: "changed" refers to a bookmark
        add(b, hex(scid), _(b'changed'))

    if not outgoings:
        ui.status(_(b"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(
                b'listkeys',
                {
                    b'namespace': b'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.isancestorof(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.InputError(
            _(b"bookmark names cannot consist entirely of whitespace")
        )
    scmutil.checknewlabel(repo, mark, b'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.InputError(_(b"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.InputError(_(b"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[b'.'].node()
    newact = None
    changes = []

    # unhide revs if any
    if rev:
        repo = scmutil.unhidehashlikerevs(repo, [rev], b'nowarn')

    ctx = scmutil.revsingle(repo, rev, None)
    # bookmarking wdir means creating a bookmark on p1 and activating it
    activatenew = not inactive and ctx.rev() is None
    if ctx.node() is None:
        ctx = ctx.p1()
    tgt = ctx.node()
    assert tgt

    for mark in names:
        mark = checkformat(repo, mark)
        if newact is None:
            newact = mark
        if inactive and mark == repo._activebookmark:
            deactivate(repo)
            continue
        for bm in marks.checkconflict(mark, force, tgt):
            changes.append((bm, None))
        changes.append((mark, tgt))

    # nothing changed but for the one deactivated above
    if not changes:
        return

    if ctx.hidden():
        repo.ui.warn(_(b"bookmarking hidden changeset %s\n") % ctx.hex()[:12])

        if ctx.obsolete():
            msg = obsutil._getfilteredreason(repo, ctx.hex()[:12], ctx)
            repo.ui.warn(b"(%s)\n" % msg)

    marks.applychanges(repo, tr, changes)
    if activatenew and cur == marks[newact]:
        activate(repo, newact)
    elif cur != tgt and newact == repo._activebookmark:
        deactivate(repo)


def _printbookmarks(ui, repo, fm, bmarks):
    """private method to print bookmarks

    Provides a way for extensions to control how bookmarks are printed (e.g.
    prepend or postpend names)
    """
    hexfn = fm.hexfunc
    if len(bmarks) == 0 and fm.isplain():
        ui.status(_(b"no bookmarks set\n"))
    for bmark, (n, prefix, label) in sorted(pycompat.iteritems(bmarks)):
        fm.startitem()
        fm.context(repo=repo)
        if not ui.quiet:
            fm.plain(b' %s ' % prefix, label=label)
        fm.write(b'bookmark', b'%s', bmark, label=label)
        pad = b" " * (25 - encoding.colwidth(bmark))
        fm.condwrite(
            not ui.quiet,
            b'rev node',
            pad + b' %d:%s',
            repo.changelog.rev(n),
            hexfn(n),
            label=label,
        )
        fm.data(active=(activebookmarklabel in label))
        fm.plain(b'\n')


def printbookmarks(ui, repo, fm, names=None):
    """print bookmarks by the given formatter

    Provides a way for extensions to control how bookmarks are printed.
    """
    marks = repo._bookmarks
    bmarks = {}
    for bmark in names or marks:
        if bmark not in marks:
            raise error.InputError(_(b"bookmark '%s' does not exist") % bmark)
        active = repo._activebookmark
        if bmark == active:
            prefix, label = b'*', activebookmarklabel
        else:
            prefix, label = b' ', b''

        bmarks[bmark] = (marks[bmark], prefix, label)
    _printbookmarks(ui, repo, fm, bmarks)


def preparehookargs(name, old, new):
    if new is None:
        new = b''
    if old is None:
        old = b''
    return {b'bookmark': name, b'node': hex(new), b'oldnode': hex(old)}