view mercurial/repair.py @ 46582:b0a3ca02d17a

copies-rust: implement PartialEqual manually Now that we know that each (dest, rev) pair has at most a unique CopySource, we can simplify comparison a lot. This "simple" step buy a good share of the previous slowdown back in some case: Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 43.304637 s, 34.443661 s, -8.860976 s, × 0.7954, 90 µs/rev Full benchmark: Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 1 revs, 0.000043 s, 0.000043 s, +0.000000 s, × 1.0000, 43 µs/rev mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 6 revs, 0.000114 s, 0.000117 s, +0.000003 s, × 1.0263, 19 µs/rev mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 1032 revs, 0.004937 s, 0.004892 s, -0.000045 s, × 0.9909, 4 µs/rev pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 9 revs, 0.000339 s, 0.000196 s, -0.000143 s, × 0.5782, 21 µs/rev pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 1 revs, 0.000049 s, 0.000050 s, +0.000001 s, × 1.0204, 50 µs/rev pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 7 revs, 0.000202 s, 0.000117 s, -0.000085 s, × 0.5792, 16 µs/rev pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 1 revs, 0.000409 s, 0.6f1f4a s, -0.000087 s, × 0.7873, 322 µs/rev pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 6 revs, 0.011984 s, 0.011949 s, -0.000035 s, × 0.9971, 1991 µs/rev pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 4785 revs, 0.050820 s, 0.050802 s, -0.000018 s, × 0.9996, 10 µs/rev pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 6780 revs, 0.087953 s, 0.088090 s, +0.000137 s, × 1.0016, 12 µs/rev pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 5441 revs, 0.062902 s, 0.062079 s, -0.000823 s, × 0.9869, 11 µs/rev pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 43645 revs, 0.679234 s, 0.635337 s, -0.043897 s, × 0.9354, 14 µs/rev pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 2 revs, 0.013095 s, 0.013262 s, +0.000167 s, × 1.0128, 6631 µs/rev pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 11316 revs, 0.120910 s, 0.120085 s, -0.000825 s, × 0.9932, 10 µs/rev netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 2 revs, 0.000087 s, 0.000085 s, -0.000002 s, × 0.9770, 42 µs/rev netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 2 revs, 0.000107 s, 0.000110 s, +0.000003 s, × 1.0280, 55 µs/rev netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 3 revs, 0.000186 s, 0.000177 s, -0.000009 s, × 0.9516, 59 µs/rev netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 9 revs, 0.000754 s, 0.000743 s, -0.000011 s, × 0.9854, 82 µs/rev netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 1421 revs, 0.010443 s, 0.010168 s, -0.000275 s, × 0.9737, 7 µs/rev netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 1533 revs, 0.015697 s, 0.015946 s, +0.000249 s, × 1.0159, 10 µs/rev netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 5750 revs, 0.063528 s, 0.062712 s, -0.000816 s, × 0.9872, 10 µs/rev netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 66949 revs, 0.545515 s, 0.523832 s, -0.021683 s, × 0.9603, 7 µs/rev mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 2 revs, 0.000089 s, 0.000090 s, +0.000001 s, × 1.0112, 45 µs/rev mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 8 revs, 0.000265 s, 0.000264 s, -0.000001 s, × 0.9962, 33 µs/rev mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 9 revs, 0.000381 s, 0.000187 s, -0.000194 s, × 0.4908, 20 µs/rev mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 7 revs, 0.000672 s, 0.000665 s, -0.000007 s, × 0.9896, 95 µs/rev mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 3 revs, 0.003497 s, 0.003556 s, +0.000059 s, × 1.0169, 1185 µs/rev mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.073204 s, 0.071345 s, -0.001859 s, × 0.9746, 11890 µs/rev mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006482 s, 0.006551 s, +0.000069 s, × 1.0106, 4 µs/rev mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.005066 s, 0.005078 s, +0.000012 s, × 1.0024, 123 µs/rev mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 7839 revs, 0.065707 s, 0.065823 s, +0.000116 s, × 1.0018, 8 µs/rev mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.026800 s, 0.027050 s, +0.000250 s, × 1.0093, 43 µs/rev mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 30263 revs, 0.203856 s, 0.202443 s, -0.001413 s, × 0.9931, 6 µs/rev mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 153721 revs, 1.293394 s, 1.261583 s, -0.031811 s, × 0.9754, 8 µs/rev mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 204976 revs, 1.698239 s, 1.643869 s, -0.054370 s, × 0.9680, 8 µs/rev mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 2 revs, 0.000875 s, 0.000868 s, -0.000007 s, × 0.9920, 434 µs/rev mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 2 revs, 0.000891 s, 0.000887 s, -0.000004 s, × 0.9955, 443 µs/rev mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 4 revs, 0.000292 s, 0.000168 s, -0.000124 s, × 0.5753, 42 µs/rev mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 2 revs, 0.003939 s, 0.001160 s, -0.002779 s, × 0.2945, 580 µs/rev mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 1 revs, 0.033027 s, 0.033016 s, -0.000011 s, × 0.9997, 33016 µs/rev mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.073703 s, 0.073312 s, -0.39ae31 s, × 0.9947, 12218 µs/rev mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006469 s, 0.006485 s, +0.000016 s, × 1.0025, 4 µs/rev mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.005278 s, 0.005494 s, +0.000216 s, × 1.0409, 134 µs/rev mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 6657 revs, 0.064995 s, 0.064879 s, -0.000116 s, × 0.9982, 9 µs/rev mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 40314 revs, 0.301041 s, 0.301469 s, +0.000428 s, × 1.0014, 7 µs/rev mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 38690 revs, 0.285575 s, 0.297113 s, +0.011538 s, × 1.0404, 7 µs/rev mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 8598 revs, 0.085597 s, 0.085890 s, +0.000293 s, × 1.0034, 9 µs/rev mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.027118 s, 0.027718 s, +0.000600 s, × 1.0221, 45 µs/rev mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 2.119204 s, 2.048949 s, -0.070255 s, × 0.9668, 21 µs/rev mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 52031 revs, 0.701479 s, 0.685924 s, -0.015555 s, × 0.9778, 13 µs/rev mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 4.482399 s, 4.482891 s, +0.000492 s, × 1.0001, 12 µs/rev mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 34414 revs, 0.574082 s, 0.577633 s, +0.003551 s, × 1.0062, 16 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 4.480366 s, 4.397816 s, -0.082550 s, × 0.9816, 12 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 4.369070 s, 4.370538 s, +0.001468 s, × 1.0003, 12 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 1.592506 s, 1.570439 s, -0.022067 s, × 0.9861, 8 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 87.824489 s, 88.388512 s, +0.564023 s, × 1.0064, 386 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 43.304637 s, 34.443661 s, -8.860976 s, × 0.7954, 90 µs/rev private : 459513 revs, 33.853687 s, 27.370148 s, -6.483539 s, × 0.8085, 59 µs/rev Differential Revision: https://phab.mercurial-scm.org/D9653
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Wed, 16 Dec 2020 11:11:05 +0100
parents cd9154343160
children b4c2a2af25e2
line wrap: on
line source

# repair.py - functions for repository repair for mercurial
#
# Copyright 2005, 2006 Chris Mason <mason@suse.com>
# Copyright 2007 Matt Mackall
#
# 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

from .i18n import _
from .node import (
    hex,
    short,
)
from . import (
    bundle2,
    changegroup,
    discovery,
    error,
    exchange,
    obsolete,
    obsutil,
    pathutil,
    phases,
    pycompat,
    requirements,
    scmutil,
    util,
)
from .utils import (
    hashutil,
    stringutil,
)


def backupbundle(
    repo, bases, heads, node, suffix, compress=True, obsolescence=True
):
    """create a bundle with the specified revisions as a backup"""

    backupdir = b"strip-backup"
    vfs = repo.vfs
    if not vfs.isdir(backupdir):
        vfs.mkdir(backupdir)

    # Include a hash of all the nodes in the filename for uniqueness
    allcommits = repo.set(b'%ln::%ln', bases, heads)
    allhashes = sorted(c.hex() for c in allcommits)
    totalhash = hashutil.sha1(b''.join(allhashes)).digest()
    name = b"%s/%s-%s-%s.hg" % (
        backupdir,
        short(node),
        hex(totalhash[:4]),
        suffix,
    )

    cgversion = changegroup.localversion(repo)
    comp = None
    if cgversion != b'01':
        bundletype = b"HG20"
        if compress:
            comp = b'BZ'
    elif compress:
        bundletype = b"HG10BZ"
    else:
        bundletype = b"HG10UN"

    outgoing = discovery.outgoing(repo, missingroots=bases, ancestorsof=heads)
    contentopts = {
        b'cg.version': cgversion,
        b'obsolescence': obsolescence,
        b'phases': True,
    }
    return bundle2.writenewbundle(
        repo.ui,
        repo,
        b'strip',
        name,
        bundletype,
        outgoing,
        contentopts,
        vfs,
        compression=comp,
    )


def _collectfiles(repo, striprev):
    """find out the filelogs affected by the strip"""
    files = set()

    for x in pycompat.xrange(striprev, len(repo)):
        files.update(repo[x].files())

    return sorted(files)


def _collectrevlog(revlog, striprev):
    _, brokenset = revlog.getstrippoint(striprev)
    return [revlog.linkrev(r) for r in brokenset]


def _collectbrokencsets(repo, files, striprev):
    """return the changesets which will be broken by the truncation"""
    s = set()

    for revlog in manifestrevlogs(repo):
        s.update(_collectrevlog(revlog, striprev))
    for fname in files:
        s.update(_collectrevlog(repo.file(fname), striprev))

    return s


def strip(ui, repo, nodelist, backup=True, topic=b'backup'):
    # This function requires the caller to lock the repo, but it operates
    # within a transaction of its own, and thus requires there to be no current
    # transaction when it is called.
    if repo.currenttransaction() is not None:
        raise error.ProgrammingError(b'cannot strip from inside a transaction')

    # Simple way to maintain backwards compatibility for this
    # argument.
    if backup in [b'none', b'strip']:
        backup = False

    repo = repo.unfiltered()
    repo.destroying()
    vfs = repo.vfs
    # load bookmark before changelog to avoid side effect from outdated
    # changelog (see repo._refreshchangelog)
    repo._bookmarks
    cl = repo.changelog

    # TODO handle undo of merge sets
    if isinstance(nodelist, bytes):
        nodelist = [nodelist]
    striplist = [cl.rev(node) for node in nodelist]
    striprev = min(striplist)

    files = _collectfiles(repo, striprev)
    saverevs = _collectbrokencsets(repo, files, striprev)

    # Some revisions with rev > striprev may not be descendants of striprev.
    # We have to find these revisions and put them in a bundle, so that
    # we can restore them after the truncations.
    # To create the bundle we use repo.changegroupsubset which requires
    # the list of heads and bases of the set of interesting revisions.
    # (head = revision in the set that has no descendant in the set;
    #  base = revision in the set that has no ancestor in the set)
    tostrip = set(striplist)
    saveheads = set(saverevs)
    for r in cl.revs(start=striprev + 1):
        if any(p in tostrip for p in cl.parentrevs(r)):
            tostrip.add(r)

        if r not in tostrip:
            saverevs.add(r)
            saveheads.difference_update(cl.parentrevs(r))
            saveheads.add(r)
    saveheads = [cl.node(r) for r in saveheads]

    # compute base nodes
    if saverevs:
        descendants = set(cl.descendants(saverevs))
        saverevs.difference_update(descendants)
    savebases = [cl.node(r) for r in saverevs]
    stripbases = [cl.node(r) for r in tostrip]

    stripobsidx = obsmarkers = ()
    if repo.ui.configbool(b'devel', b'strip-obsmarkers'):
        obsmarkers = obsutil.exclusivemarkers(repo, stripbases)
    if obsmarkers:
        stripobsidx = [
            i for i, m in enumerate(repo.obsstore) if m in obsmarkers
        ]

    newbmtarget, updatebm = _bookmarkmovements(repo, tostrip)

    backupfile = None
    node = nodelist[-1]
    if backup:
        backupfile = _createstripbackup(repo, stripbases, node, topic)
    # create a changegroup for all the branches we need to keep
    tmpbundlefile = None
    if saveheads:
        # do not compress temporary bundle if we remove it from disk later
        #
        # We do not include obsolescence, it might re-introduce prune markers
        # we are trying to strip.  This is harmless since the stripped markers
        # are already backed up and we did not touched the markers for the
        # saved changesets.
        tmpbundlefile = backupbundle(
            repo,
            savebases,
            saveheads,
            node,
            b'temp',
            compress=False,
            obsolescence=False,
        )

    with ui.uninterruptible():
        try:
            with repo.transaction(b"strip") as tr:
                # TODO this code violates the interface abstraction of the
                # transaction and makes assumptions that file storage is
                # using append-only files. We'll need some kind of storage
                # API to handle stripping for us.
                oldfiles = set(tr._offsetmap.keys())
                oldfiles.update(tr._newfiles)

                tr.startgroup()
                cl.strip(striprev, tr)
                stripmanifest(repo, striprev, tr, files)

                for fn in files:
                    repo.file(fn).strip(striprev, tr)
                tr.endgroup()

                entries = tr.readjournal()

                for file, troffset in entries:
                    if file in oldfiles:
                        continue
                    with repo.svfs(file, b'a', checkambig=True) as fp:
                        fp.truncate(troffset)
                    if troffset == 0:
                        repo.store.markremoved(file)

                deleteobsmarkers(repo.obsstore, stripobsidx)
                del repo.obsstore
                repo.invalidatevolatilesets()
                repo._phasecache.filterunknown(repo)

            if tmpbundlefile:
                ui.note(_(b"adding branch\n"))
                f = vfs.open(tmpbundlefile, b"rb")
                gen = exchange.readbundle(ui, f, tmpbundlefile, vfs)
                if not repo.ui.verbose:
                    # silence internal shuffling chatter
                    repo.ui.pushbuffer()
                tmpbundleurl = b'bundle:' + vfs.join(tmpbundlefile)
                txnname = b'strip'
                if not isinstance(gen, bundle2.unbundle20):
                    txnname = b"strip\n%s" % util.hidepassword(tmpbundleurl)
                with repo.transaction(txnname) as tr:
                    bundle2.applybundle(
                        repo, gen, tr, source=b'strip', url=tmpbundleurl
                    )
                if not repo.ui.verbose:
                    repo.ui.popbuffer()
                f.close()

            with repo.transaction(b'repair') as tr:
                bmchanges = [(m, repo[newbmtarget].node()) for m in updatebm]
                repo._bookmarks.applychanges(repo, tr, bmchanges)

            # remove undo files
            for undovfs, undofile in repo.undofiles():
                try:
                    undovfs.unlink(undofile)
                except OSError as e:
                    if e.errno != errno.ENOENT:
                        ui.warn(
                            _(b'error removing %s: %s\n')
                            % (
                                undovfs.join(undofile),
                                stringutil.forcebytestr(e),
                            )
                        )

        except:  # re-raises
            if backupfile:
                ui.warn(
                    _(b"strip failed, backup bundle stored in '%s'\n")
                    % vfs.join(backupfile)
                )
            if tmpbundlefile:
                ui.warn(
                    _(b"strip failed, unrecovered changes stored in '%s'\n")
                    % vfs.join(tmpbundlefile)
                )
                ui.warn(
                    _(
                        b"(fix the problem, then recover the changesets with "
                        b"\"hg unbundle '%s'\")\n"
                    )
                    % vfs.join(tmpbundlefile)
                )
            raise
        else:
            if tmpbundlefile:
                # Remove temporary bundle only if there were no exceptions
                vfs.unlink(tmpbundlefile)

    repo.destroyed()
    # return the backup file path (or None if 'backup' was False) so
    # extensions can use it
    return backupfile


def softstrip(ui, repo, nodelist, backup=True, topic=b'backup'):
    """perform a "soft" strip using the archived phase"""
    tostrip = [c.node() for c in repo.set(b'sort(%ln::)', nodelist)]
    if not tostrip:
        return None

    backupfile = None
    if backup:
        node = tostrip[0]
        backupfile = _createstripbackup(repo, tostrip, node, topic)

    newbmtarget, updatebm = _bookmarkmovements(repo, tostrip)
    with repo.transaction(b'strip') as tr:
        phases.retractboundary(repo, tr, phases.archived, tostrip)
        bmchanges = [(m, repo[newbmtarget].node()) for m in updatebm]
        repo._bookmarks.applychanges(repo, tr, bmchanges)
    return backupfile


def _bookmarkmovements(repo, tostrip):
    # compute necessary bookmark movement
    bm = repo._bookmarks
    updatebm = []
    for m in bm:
        rev = repo[bm[m]].rev()
        if rev in tostrip:
            updatebm.append(m)
    newbmtarget = None
    # If we need to move bookmarks, compute bookmark
    # targets. Otherwise we can skip doing this logic.
    if updatebm:
        # For a set s, max(parents(s) - s) is the same as max(heads(::s - s)),
        # but is much faster
        newbmtarget = repo.revs(b'max(parents(%ld) - (%ld))', tostrip, tostrip)
        if newbmtarget:
            newbmtarget = repo[newbmtarget.first()].node()
        else:
            newbmtarget = b'.'
    return newbmtarget, updatebm


def _createstripbackup(repo, stripbases, node, topic):
    # backup the changeset we are about to strip
    vfs = repo.vfs
    cl = repo.changelog
    backupfile = backupbundle(repo, stripbases, cl.heads(), node, topic)
    repo.ui.status(_(b"saved backup bundle to %s\n") % vfs.join(backupfile))
    repo.ui.log(
        b"backupbundle", b"saved backup bundle to %s\n", vfs.join(backupfile)
    )
    return backupfile


def safestriproots(ui, repo, nodes):
    """return list of roots of nodes where descendants are covered by nodes"""
    torev = repo.unfiltered().changelog.rev
    revs = {torev(n) for n in nodes}
    # tostrip = wanted - unsafe = wanted - ancestors(orphaned)
    # orphaned = affected - wanted
    # affected = descendants(roots(wanted))
    # wanted = revs
    revset = b'%ld - ( ::( (roots(%ld):: and not _phase(%s)) -%ld) )'
    tostrip = set(repo.revs(revset, revs, revs, phases.internal, revs))
    notstrip = revs - tostrip
    if notstrip:
        nodestr = b', '.join(sorted(short(repo[n].node()) for n in notstrip))
        ui.warn(
            _(b'warning: orphaned descendants detected, not stripping %s\n')
            % nodestr
        )
    return [c.node() for c in repo.set(b'roots(%ld)', tostrip)]


class stripcallback(object):
    """used as a transaction postclose callback"""

    def __init__(self, ui, repo, backup, topic):
        self.ui = ui
        self.repo = repo
        self.backup = backup
        self.topic = topic or b'backup'
        self.nodelist = []

    def addnodes(self, nodes):
        self.nodelist.extend(nodes)

    def __call__(self, tr):
        roots = safestriproots(self.ui, self.repo, self.nodelist)
        if roots:
            strip(self.ui, self.repo, roots, self.backup, self.topic)


def delayedstrip(ui, repo, nodelist, topic=None, backup=True):
    """like strip, but works inside transaction and won't strip irreverent revs

    nodelist must explicitly contain all descendants. Otherwise a warning will
    be printed that some nodes are not stripped.

    Will do a backup if `backup` is True. The last non-None "topic" will be
    used as the backup topic name. The default backup topic name is "backup".
    """
    tr = repo.currenttransaction()
    if not tr:
        nodes = safestriproots(ui, repo, nodelist)
        return strip(ui, repo, nodes, backup=backup, topic=topic)
    # transaction postclose callbacks are called in alphabet order.
    # use '\xff' as prefix so we are likely to be called last.
    callback = tr.getpostclose(b'\xffstrip')
    if callback is None:
        callback = stripcallback(ui, repo, backup=backup, topic=topic)
        tr.addpostclose(b'\xffstrip', callback)
    if topic:
        callback.topic = topic
    callback.addnodes(nodelist)


def stripmanifest(repo, striprev, tr, files):
    for revlog in manifestrevlogs(repo):
        revlog.strip(striprev, tr)


def manifestrevlogs(repo):
    yield repo.manifestlog.getstorage(b'')
    if scmutil.istreemanifest(repo):
        # This logic is safe if treemanifest isn't enabled, but also
        # pointless, so we skip it if treemanifest isn't enabled.
        for unencoded, encoded, size in repo.store.datafiles():
            if unencoded.startswith(b'meta/') and unencoded.endswith(
                b'00manifest.i'
            ):
                dir = unencoded[5:-12]
                yield repo.manifestlog.getstorage(dir)


def rebuildfncache(ui, repo):
    """Rebuilds the fncache file from repo history.

    Missing entries will be added. Extra entries will be removed.
    """
    repo = repo.unfiltered()

    if b'fncache' not in repo.requirements:
        ui.warn(
            _(
                b'(not rebuilding fncache because repository does not '
                b'support fncache)\n'
            )
        )
        return

    with repo.lock():
        fnc = repo.store.fncache
        fnc.ensureloaded(warn=ui.warn)

        oldentries = set(fnc.entries)
        newentries = set()
        seenfiles = set()

        progress = ui.makeprogress(
            _(b'rebuilding'), unit=_(b'changesets'), total=len(repo)
        )
        for rev in repo:
            progress.update(rev)

            ctx = repo[rev]
            for f in ctx.files():
                # This is to minimize I/O.
                if f in seenfiles:
                    continue
                seenfiles.add(f)

                i = b'data/%s.i' % f
                d = b'data/%s.d' % f

                if repo.store._exists(i):
                    newentries.add(i)
                if repo.store._exists(d):
                    newentries.add(d)

        progress.complete()

        if requirements.TREEMANIFEST_REQUIREMENT in repo.requirements:
            # This logic is safe if treemanifest isn't enabled, but also
            # pointless, so we skip it if treemanifest isn't enabled.
            for dir in pathutil.dirs(seenfiles):
                i = b'meta/%s/00manifest.i' % dir
                d = b'meta/%s/00manifest.d' % dir

                if repo.store._exists(i):
                    newentries.add(i)
                if repo.store._exists(d):
                    newentries.add(d)

        addcount = len(newentries - oldentries)
        removecount = len(oldentries - newentries)
        for p in sorted(oldentries - newentries):
            ui.write(_(b'removing %s\n') % p)
        for p in sorted(newentries - oldentries):
            ui.write(_(b'adding %s\n') % p)

        if addcount or removecount:
            ui.write(
                _(b'%d items added, %d removed from fncache\n')
                % (addcount, removecount)
            )
            fnc.entries = newentries
            fnc._dirty = True

            with repo.transaction(b'fncache') as tr:
                fnc.write(tr)
        else:
            ui.write(_(b'fncache already up to date\n'))


def deleteobsmarkers(obsstore, indices):
    """Delete some obsmarkers from obsstore and return how many were deleted

    'indices' is a list of ints which are the indices
    of the markers to be deleted.

    Every invocation of this function completely rewrites the obsstore file,
    skipping the markers we want to be removed. The new temporary file is
    created, remaining markers are written there and on .close() this file
    gets atomically renamed to obsstore, thus guaranteeing consistency."""
    if not indices:
        # we don't want to rewrite the obsstore with the same content
        return

    left = []
    current = obsstore._all
    n = 0
    for i, m in enumerate(current):
        if i in indices:
            n += 1
            continue
        left.append(m)

    newobsstorefile = obsstore.svfs(b'obsstore', b'w', atomictemp=True)
    for bytes in obsolete.encodemarkers(left, True, obsstore._version):
        newobsstorefile.write(bytes)
    newobsstorefile.close()
    return n