view mercurial/bundlerepo.py @ 39506:b66ea3fc3a86

sparse-revlog: set max delta chain length to on thousand The new snapshot system used in the sparse-revlog case gave us some small size benefit so far. However its most important property is to gracefully handle harder limit on delta chainlength. Long delta chain has a very detrimental impact on read (and write) performance in revlog. Being able to shorter them provide a great boost. However, shorting delta used to result significantly lower compression ratio. The intermediate snapshots effectively suppress most of this effect (even all in some case). # Effect on the test repository The repository we use for test is not "realistic" but can still show this in action using an unreasonably low chain limit. Limiting the chain length show a sizeable increase but stay under control: +6% for limit=15; +15% for limit=10. Without the snapshot system the increase is significantly bigger: +45% for limit=15; +80% for limit=10. Even slightly larger than without delta chain limit, the resulting size is still smaller than before we started doing snapshots. Here is a table for comparison. *Since the repository is not branchy, the initial sparse-revlog version does not bring much benefit compare to the non-sparse one): chain length limit | none | limit=15 | limit=10 | without sparse-revlog | 62 818 987 | 112 664 615 | 131 222 574 | without snapshot | 74 365 490 | 108 211 410 | 133 857 764 | with snapshot | 59 230 936 | 63 002 924 | 68 415 329 | # Effect On Real Life Repositories The series provides significant benefits on all kind of repositories. Using `hg debugupgraderepo -o redeltaparent --run`, we recomputed delta chain for various repositories with different settings: - delta chain length: unlimited or 1000 limit - sparse-revlog: enabled or disabled - this series: applied or not applied We can observe multiple types of effect: - On very branchy repositories: * The delta chain limit as low impact on the repo size. * Intermediate snapshot greatly reduces manifest size: - pypy: -80% - netbeans: -95% * The delta chain limit is effective, without a size impact: - netbeans average: 613 -> 282 - private #1 average: 1 068 -> 307 - On more linear repository: * Intermediate snapshot limit the impact of delta chain limit: - mozilla: without the series: +360% with the series: +25% * The delta chain limit provides large improvement: - mozilla's average chain length: unlimited: 15 338 limited: 469 * Despite the chain length limit, the manifest size is reduced: - mercurial: -25% - mozilla: -30% It is clear that the use of chains of intermediate snapshots provide large benefits both in storage size and delta chains quality. We should now switch our effort toward making sure the write performance are acceptable. Then, `sparse-revlog` will be a suitable format for all new repository. # Raw Statistic * no-sparse: general delta repository not using sparse-revlog * no-snapshot: sparse-revlog repository not using this series * snapshot: sparse-revlog repository using this series mercurial Manifest Size: limit | none | 1000 ------------|-------------|------------ no-sparse | 8 021 373 | 8 199 366 no-snapshot | 8 103 561 | 8 259 719 snapshot | 6 137 116 | 6 126 433 Manifest Chain length data limit || none || 1000 || value || average | max || average | max || ------------||---------|---------||---------|---------|| no-sparse || 307 | 1456 || 279 | 1000 || no-snapshot || 312 | 1456 || 283 | 1000 || snapshot || 248 | 1208 || 241 | 1000 || Full Store Size limit | none | 1000 ------------|-------------|------------ no-sparse | 51 013 198 | 51 201 574 no-snapshot | 50 930 795 | 51 141 006 snapshot | 48 072 037 | 48 093 572 pypy Manifest Size: limit | none | 1000 ------------|-------------|------------ no-sparse | 193 987 784 | 193 987 784 no-snapshot | 163 171 745 | 163 312 229 snapshot | 34 605 900 | 34 600 750 Manifest Chain length data limit || none || 1000 || value || average | max || average | max || ------------||---------|---------||---------|---------|| no-sparse || 101 | 692 || 101 | 692 || no-snapshot || 151 | 1307 || 148 | 1000 || snapshot || 128 | 1309 || 125 | 1000 || Full Store Size limit | none | 1000 ------------|-------------|------------ no-sparse | 495 931 473 | 495 931 473 no-snapshot | 465 441 017 | 465 581 501 snapshot | 355 467 301 | 355 472 451 Mozilla Manifest Size: limit | none | 1000 ------------|----------------|--------------- no-sparse | 416 757 148 | 1 869 009 668 no-snapshot | 401 592 370 | 1 843 493 795 snapshot | 224 359 521 | 284 615 500 Manifest Chain length data limit || none || 1000 || value || average | max || average | max || ------------||---------|---------||---------|---------|| no-sparse || 15 333 | 58 980 || 468 | 1 000 || no-snapshot || 15 336 | 58 980 || 469 | 1 000 || snapshot || 15 338 | 58 983 || 469 | 1 000 || Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 2 712 477 887 | 4 164 995 451 no-snapshot | 2 698 887 835 | 4 141 054 304 snapshot | 2 518 130 385 | 2 578 587 596 Netbeans Manifest Size: limit | none | 1000 ------------|----------------|--------------- no-sparse | 4 766 794 101 | 4 870 642 687 no-snapshot | 4 334 806 082 | 4 428 681 309 snapshot | 232 659 666 | 240 330 665 Manifest Chain length data limit || none || 1000 || value || average | max || average | max || ------------||---------|---------||---------|---------|| no-sparse || 597 | 6802 || 254 | 1 000 || no-snapshot || 648 | 6 802 || 305 | 1 000 || snapshot || 613 | 6 804 || 282 | 1 000 || Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 5 807 347 998 | 5 911 196 584 no-snapshot | 5 375 398 602 | 5 469 273 829 snapshot | 1 282 519 928 | 1 290 190 927 Private repo #1 Manifest Size: limit | none | 1000 ------------|-----------------|--------------- no-sparse | 41 389 010 840 | 41 398 162 091 no-snapshot | 9 737 319 435 | 10 223 773 150 snapshot | 744 215 807 | 747 961 822 Manifest Chain length data limit || none || 1000 || value || average | max || average | max || ------------||---------|---------||---------|---------|| no-sparse || 245 | 8 885 || 81 | 1 000 || no-snapshot || 1 225 | 8 885 || 336 | 1 000 || snapshot || 1 068 | 7 909 || 307 | 1 000 || Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 49 646 065 126 | 49 655 216 377 no-snapshot | 17 924 862 856 | 18 411 316 571 snapshot | 9 009 024 710 | 9 012 770 725 Private repo #2 We currently have less data available for that repository. * Before is a sparse-revlog repository without this series * After is a sparse-revlog repository with this series + 1000 chain limit Manifest Size: Before: 1 531 485 040 bytes After: 1 091 422 451 bytes Manifest Chain: Before: 2 218 avg; 6 575 Max After: 442 avg; 1 000 Max Full Store Size Before: 15 203 955 615 after: 8 207 180 693
author Boris Feld <boris.feld@octobus.net>
date Fri, 07 Sep 2018 11:18:45 -0400
parents 0d97530eb535
children 089fc0db0954
line wrap: on
line source

# bundlerepo.py - repository class for viewing uncompressed bundles
#
# Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""Repository class for viewing uncompressed bundles.

This provides a read-only repository interface to bundles as if they
were part of the actual repository.
"""

from __future__ import absolute_import

import os
import shutil

from .i18n import _
from .node import nullid

from . import (
    bundle2,
    changegroup,
    changelog,
    cmdutil,
    discovery,
    error,
    exchange,
    filelog,
    localrepo,
    manifest,
    mdiff,
    node as nodemod,
    pathutil,
    phases,
    pycompat,
    revlog,
    util,
    vfs as vfsmod,
)

class bundlerevlog(revlog.revlog):
    def __init__(self, opener, indexfile, cgunpacker, linkmapper):
        # How it works:
        # To retrieve a revision, we need to know the offset of the revision in
        # the bundle (an unbundle object). We store this offset in the index
        # (start). The base of the delta is stored in the base field.
        #
        # To differentiate a rev in the bundle from a rev in the revlog, we
        # check revision against repotiprev.
        opener = vfsmod.readonlyvfs(opener)
        revlog.revlog.__init__(self, opener, indexfile)
        self.bundle = cgunpacker
        n = len(self)
        self.repotiprev = n - 1
        self.bundlerevs = set() # used by 'bundle()' revset expression
        for deltadata in cgunpacker.deltaiter():
            node, p1, p2, cs, deltabase, delta, flags = deltadata

            size = len(delta)
            start = cgunpacker.tell() - size

            link = linkmapper(cs)
            if node in self.nodemap:
                # this can happen if two branches make the same change
                self.bundlerevs.add(self.nodemap[node])
                continue

            for p in (p1, p2):
                if p not in self.nodemap:
                    raise error.LookupError(p, self.indexfile,
                                            _("unknown parent"))

            if deltabase not in self.nodemap:
                raise LookupError(deltabase, self.indexfile,
                                  _('unknown delta base'))

            baserev = self.rev(deltabase)
            # start, size, full unc. size, base (unused), link, p1, p2, node
            e = (revlog.offset_type(start, flags), size, -1, baserev, link,
                 self.rev(p1), self.rev(p2), node)
            self.index.append(e)
            self.nodemap[node] = n
            self.bundlerevs.add(n)
            n += 1

    def _chunk(self, rev, df=None):
        # Warning: in case of bundle, the diff is against what we stored as
        # delta base, not against rev - 1
        # XXX: could use some caching
        if rev <= self.repotiprev:
            return revlog.revlog._chunk(self, rev)
        self.bundle.seek(self.start(rev))
        return self.bundle.read(self.length(rev))

    def revdiff(self, rev1, rev2):
        """return or calculate a delta between two revisions"""
        if rev1 > self.repotiprev and rev2 > self.repotiprev:
            # hot path for bundle
            revb = self.index[rev2][3]
            if revb == rev1:
                return self._chunk(rev2)
        elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:
            return revlog.revlog.revdiff(self, rev1, rev2)

        return mdiff.textdiff(self.revision(rev1, raw=True),
                              self.revision(rev2, raw=True))

    def revision(self, nodeorrev, _df=None, raw=False):
        """return an uncompressed revision of a given node or revision
        number.
        """
        if isinstance(nodeorrev, int):
            rev = nodeorrev
            node = self.node(rev)
        else:
            node = nodeorrev
            rev = self.rev(node)

        if node == nullid:
            return ""

        rawtext = None
        chain = []
        iterrev = rev
        # reconstruct the revision if it is from a changegroup
        while iterrev > self.repotiprev:
            if self._cache and self._cache[1] == iterrev:
                rawtext = self._cache[2]
                break
            chain.append(iterrev)
            iterrev = self.index[iterrev][3]
        if rawtext is None:
            rawtext = self.baserevision(iterrev)

        while chain:
            delta = self._chunk(chain.pop())
            rawtext = mdiff.patches(rawtext, [delta])

        text, validatehash = self._processflags(rawtext, self.flags(rev),
                                                'read', raw=raw)
        if validatehash:
            self.checkhash(text, node, rev=rev)
        self._cache = (node, rev, rawtext)
        return text

    def baserevision(self, nodeorrev):
        # Revlog subclasses may override 'revision' method to modify format of
        # content retrieved from revlog. To use bundlerevlog with such class one
        # needs to override 'baserevision' and make more specific call here.
        return revlog.revlog.revision(self, nodeorrev, raw=True)

    def addrevision(self, *args, **kwargs):
        raise NotImplementedError

    def addgroup(self, *args, **kwargs):
        raise NotImplementedError

    def strip(self, *args, **kwargs):
        raise NotImplementedError

    def checksize(self):
        raise NotImplementedError

class bundlechangelog(bundlerevlog, changelog.changelog):
    def __init__(self, opener, cgunpacker):
        changelog.changelog.__init__(self, opener)
        linkmapper = lambda x: x
        bundlerevlog.__init__(self, opener, self.indexfile, cgunpacker,
                              linkmapper)

    def baserevision(self, nodeorrev):
        # Although changelog doesn't override 'revision' method, some extensions
        # may replace this class with another that does. Same story with
        # manifest and filelog classes.

        # This bypasses filtering on changelog.node() and rev() because we need
        # revision text of the bundle base even if it is hidden.
        oldfilter = self.filteredrevs
        try:
            self.filteredrevs = ()
            return changelog.changelog.revision(self, nodeorrev, raw=True)
        finally:
            self.filteredrevs = oldfilter

class bundlemanifest(bundlerevlog, manifest.manifestrevlog):
    def __init__(self, opener, cgunpacker, linkmapper, dirlogstarts=None,
                 dir=''):
        manifest.manifestrevlog.__init__(self, opener, tree=dir)
        bundlerevlog.__init__(self, opener, self.indexfile, cgunpacker,
                              linkmapper)
        if dirlogstarts is None:
            dirlogstarts = {}
            if self.bundle.version == "03":
                dirlogstarts = _getfilestarts(self.bundle)
        self._dirlogstarts = dirlogstarts
        self._linkmapper = linkmapper

    def baserevision(self, nodeorrev):
        node = nodeorrev
        if isinstance(node, int):
            node = self.node(node)

        if node in self.fulltextcache:
            result = '%s' % self.fulltextcache[node]
        else:
            result = manifest.manifestrevlog.revision(self, nodeorrev, raw=True)
        return result

    def dirlog(self, d):
        if d in self._dirlogstarts:
            self.bundle.seek(self._dirlogstarts[d])
            return bundlemanifest(
                self.opener, self.bundle, self._linkmapper,
                self._dirlogstarts, dir=d)
        return super(bundlemanifest, self).dirlog(d)

class bundlefilelog(filelog.filelog):
    def __init__(self, opener, path, cgunpacker, linkmapper):
        filelog.filelog.__init__(self, opener, path)
        self._revlog = bundlerevlog(opener, self.indexfile,
                                    cgunpacker, linkmapper)

    def baserevision(self, nodeorrev):
        return filelog.filelog.revision(self, nodeorrev, raw=True)

class bundlepeer(localrepo.localpeer):
    def canpush(self):
        return False

class bundlephasecache(phases.phasecache):
    def __init__(self, *args, **kwargs):
        super(bundlephasecache, self).__init__(*args, **kwargs)
        if util.safehasattr(self, 'opener'):
            self.opener = vfsmod.readonlyvfs(self.opener)

    def write(self):
        raise NotImplementedError

    def _write(self, fp):
        raise NotImplementedError

    def _updateroots(self, phase, newroots, tr):
        self.phaseroots[phase] = newroots
        self.invalidate()
        self.dirty = True

def _getfilestarts(cgunpacker):
    filespos = {}
    for chunkdata in iter(cgunpacker.filelogheader, {}):
        fname = chunkdata['filename']
        filespos[fname] = cgunpacker.tell()
        for chunk in iter(lambda: cgunpacker.deltachunk(None), {}):
            pass
    return filespos

class bundlerepository(localrepo.localrepository):
    """A repository instance that is a union of a local repo and a bundle.

    Instances represent a read-only repository composed of a local repository
    with the contents of a bundle file applied. The repository instance is
    conceptually similar to the state of a repository after an
    ``hg unbundle`` operation. However, the contents of the bundle are never
    applied to the actual base repository.
    """
    def __init__(self, ui, repopath, bundlepath):
        self._tempparent = None
        try:
            localrepo.localrepository.__init__(self, ui, repopath)
        except error.RepoError:
            self._tempparent = pycompat.mkdtemp()
            localrepo.instance(ui, self._tempparent, 1)
            localrepo.localrepository.__init__(self, ui, self._tempparent)
        self.ui.setconfig('phases', 'publish', False, 'bundlerepo')

        if repopath:
            self._url = 'bundle:' + util.expandpath(repopath) + '+' + bundlepath
        else:
            self._url = 'bundle:' + bundlepath

        self.tempfile = None
        f = util.posixfile(bundlepath, "rb")
        bundle = exchange.readbundle(ui, f, bundlepath)

        if isinstance(bundle, bundle2.unbundle20):
            self._bundlefile = bundle
            self._cgunpacker = None

            cgpart = None
            for part in bundle.iterparts(seekable=True):
                if part.type == 'changegroup':
                    if cgpart:
                        raise NotImplementedError("can't process "
                                                  "multiple changegroups")
                    cgpart = part

                self._handlebundle2part(bundle, part)

            if not cgpart:
                raise error.Abort(_("No changegroups found"))

            # This is required to placate a later consumer, which expects
            # the payload offset to be at the beginning of the changegroup.
            # We need to do this after the iterparts() generator advances
            # because iterparts() will seek to end of payload after the
            # generator returns control to iterparts().
            cgpart.seek(0, os.SEEK_SET)

        elif isinstance(bundle, changegroup.cg1unpacker):
            if bundle.compressed():
                f = self._writetempbundle(bundle.read, '.hg10un',
                                          header='HG10UN')
                bundle = exchange.readbundle(ui, f, bundlepath, self.vfs)

            self._bundlefile = bundle
            self._cgunpacker = bundle
        else:
            raise error.Abort(_('bundle type %s cannot be read') %
                              type(bundle))

        # dict with the mapping 'filename' -> position in the changegroup.
        self._cgfilespos = {}

        self.firstnewrev = self.changelog.repotiprev + 1
        phases.retractboundary(self, None, phases.draft,
                               [ctx.node() for ctx in self[self.firstnewrev:]])

    def _handlebundle2part(self, bundle, part):
        if part.type != 'changegroup':
            return

        cgstream = part
        version = part.params.get('version', '01')
        legalcgvers = changegroup.supportedincomingversions(self)
        if version not in legalcgvers:
            msg = _('Unsupported changegroup version: %s')
            raise error.Abort(msg % version)
        if bundle.compressed():
            cgstream = self._writetempbundle(part.read, '.cg%sun' % version)

        self._cgunpacker = changegroup.getunbundler(version, cgstream, 'UN')

    def _writetempbundle(self, readfn, suffix, header=''):
        """Write a temporary file to disk
        """
        fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-",
                                        suffix=suffix)
        self.tempfile = temp

        with os.fdopen(fdtemp, r'wb') as fptemp:
            fptemp.write(header)
            while True:
                chunk = readfn(2**18)
                if not chunk:
                    break
                fptemp.write(chunk)

        return self.vfs.open(self.tempfile, mode="rb")

    @localrepo.unfilteredpropertycache
    def _phasecache(self):
        return bundlephasecache(self, self._phasedefaults)

    @localrepo.unfilteredpropertycache
    def changelog(self):
        # consume the header if it exists
        self._cgunpacker.changelogheader()
        c = bundlechangelog(self.svfs, self._cgunpacker)
        self.manstart = self._cgunpacker.tell()
        return c

    def _constructmanifest(self):
        self._cgunpacker.seek(self.manstart)
        # consume the header if it exists
        self._cgunpacker.manifestheader()
        linkmapper = self.unfiltered().changelog.rev
        m = bundlemanifest(self.svfs, self._cgunpacker, linkmapper)
        self.filestart = self._cgunpacker.tell()
        return m

    def _consumemanifest(self):
        """Consumes the manifest portion of the bundle, setting filestart so the
        file portion can be read."""
        self._cgunpacker.seek(self.manstart)
        self._cgunpacker.manifestheader()
        for delta in self._cgunpacker.deltaiter():
            pass
        self.filestart = self._cgunpacker.tell()

    @localrepo.unfilteredpropertycache
    def manstart(self):
        self.changelog
        return self.manstart

    @localrepo.unfilteredpropertycache
    def filestart(self):
        self.manifestlog

        # If filestart was not set by self.manifestlog, that means the
        # manifestlog implementation did not consume the manifests from the
        # changegroup (ex: it might be consuming trees from a separate bundle2
        # part instead). So we need to manually consume it.
        if r'filestart' not in self.__dict__:
            self._consumemanifest()

        return self.filestart

    def url(self):
        return self._url

    def file(self, f):
        if not self._cgfilespos:
            self._cgunpacker.seek(self.filestart)
            self._cgfilespos = _getfilestarts(self._cgunpacker)

        if f in self._cgfilespos:
            self._cgunpacker.seek(self._cgfilespos[f])
            linkmapper = self.unfiltered().changelog.rev
            return bundlefilelog(self.svfs, f, self._cgunpacker, linkmapper)
        else:
            return super(bundlerepository, self).file(f)

    def close(self):
        """Close assigned bundle file immediately."""
        self._bundlefile.close()
        if self.tempfile is not None:
            self.vfs.unlink(self.tempfile)
        if self._tempparent:
            shutil.rmtree(self._tempparent, True)

    def cancopy(self):
        return False

    def peer(self):
        return bundlepeer(self)

    def getcwd(self):
        return pycompat.getcwd() # always outside the repo

    # Check if parents exist in localrepo before setting
    def setparents(self, p1, p2=nullid):
        p1rev = self.changelog.rev(p1)
        p2rev = self.changelog.rev(p2)
        msg = _("setting parent to node %s that only exists in the bundle\n")
        if self.changelog.repotiprev < p1rev:
            self.ui.warn(msg % nodemod.hex(p1))
        if self.changelog.repotiprev < p2rev:
            self.ui.warn(msg % nodemod.hex(p2))
        return super(bundlerepository, self).setparents(p1, p2)

def instance(ui, path, create, intents=None):
    if create:
        raise error.Abort(_('cannot create new bundle repository'))
    # internal config: bundle.mainreporoot
    parentpath = ui.config("bundle", "mainreporoot")
    if not parentpath:
        # try to find the correct path to the working directory repo
        parentpath = cmdutil.findrepo(pycompat.getcwd())
        if parentpath is None:
            parentpath = ''
    if parentpath:
        # Try to make the full path relative so we get a nice, short URL.
        # In particular, we don't want temp dir names in test outputs.
        cwd = pycompat.getcwd()
        if parentpath == cwd:
            parentpath = ''
        else:
            cwd = pathutil.normasprefix(cwd)
            if parentpath.startswith(cwd):
                parentpath = parentpath[len(cwd):]
    u = util.url(path)
    path = u.localpath()
    if u.scheme == 'bundle':
        s = path.split("+", 1)
        if len(s) == 1:
            repopath, bundlename = parentpath, s[0]
        else:
            repopath, bundlename = s
    else:
        repopath, bundlename = parentpath, path
    return bundlerepository(ui, repopath, bundlename)

class bundletransactionmanager(object):
    def transaction(self):
        return None

    def close(self):
        raise NotImplementedError

    def release(self):
        raise NotImplementedError

def getremotechanges(ui, repo, peer, onlyheads=None, bundlename=None,
                     force=False):
    '''obtains a bundle of changes incoming from peer

    "onlyheads" restricts the returned changes to those reachable from the
      specified heads.
    "bundlename", if given, stores the bundle to this file path permanently;
      otherwise it's stored to a temp file and gets deleted again when you call
      the returned "cleanupfn".
    "force" indicates whether to proceed on unrelated repos.

    Returns a tuple (local, csets, cleanupfn):

    "local" is a local repo from which to obtain the actual incoming
      changesets; it is a bundlerepo for the obtained bundle when the
      original "peer" is remote.
    "csets" lists the incoming changeset node ids.
    "cleanupfn" must be called without arguments when you're done processing
      the changes; it closes both the original "peer" and the one returned
      here.
    '''
    tmp = discovery.findcommonincoming(repo, peer, heads=onlyheads,
                                       force=force)
    common, incoming, rheads = tmp
    if not incoming:
        try:
            if bundlename:
                os.unlink(bundlename)
        except OSError:
            pass
        return repo, [], peer.close

    commonset = set(common)
    rheads = [x for x in rheads if x not in commonset]

    bundle = None
    bundlerepo = None
    localrepo = peer.local()
    if bundlename or not localrepo:
        # create a bundle (uncompressed if peer repo is not local)

        # developer config: devel.legacy.exchange
        legexc = ui.configlist('devel', 'legacy.exchange')
        forcebundle1 = 'bundle2' not in legexc and 'bundle1' in legexc
        canbundle2 = (not forcebundle1
                      and peer.capable('getbundle')
                      and peer.capable('bundle2'))
        if canbundle2:
            with peer.commandexecutor() as e:
                b2 = e.callcommand('getbundle', {
                    'source': 'incoming',
                    'common': common,
                    'heads': rheads,
                    'bundlecaps': exchange.caps20to10(repo, role='client'),
                    'cg': True,
                }).result()

                fname = bundle = changegroup.writechunks(ui,
                                                         b2._forwardchunks(),
                                                         bundlename)
        else:
            if peer.capable('getbundle'):
                with peer.commandexecutor() as e:
                    cg = e.callcommand('getbundle', {
                        'source': 'incoming',
                        'common': common,
                        'heads': rheads,
                    }).result()
            elif onlyheads is None and not peer.capable('changegroupsubset'):
                # compat with older servers when pulling all remote heads

                with peer.commandexecutor() as e:
                    cg = e.callcommand('changegroup', {
                        'nodes': incoming,
                        'source': 'incoming',
                    }).result()

                rheads = None
            else:
                with peer.commandexecutor() as e:
                    cg = e.callcommand('changegroupsubset', {
                        'bases': incoming,
                        'heads': rheads,
                        'source': 'incoming',
                    }).result()

            if localrepo:
                bundletype = "HG10BZ"
            else:
                bundletype = "HG10UN"
            fname = bundle = bundle2.writebundle(ui, cg, bundlename,
                                                     bundletype)
        # keep written bundle?
        if bundlename:
            bundle = None
        if not localrepo:
            # use the created uncompressed bundlerepo
            localrepo = bundlerepo = bundlerepository(repo.baseui, repo.root,
                                                      fname)
            # this repo contains local and peer now, so filter out local again
            common = repo.heads()
    if localrepo:
        # Part of common may be remotely filtered
        # So use an unfiltered version
        # The discovery process probably need cleanup to avoid that
        localrepo = localrepo.unfiltered()

    csets = localrepo.changelog.findmissing(common, rheads)

    if bundlerepo:
        reponodes = [ctx.node() for ctx in bundlerepo[bundlerepo.firstnewrev:]]

        with peer.commandexecutor() as e:
            remotephases = e.callcommand('listkeys', {
                'namespace': 'phases',
            }).result()

        pullop = exchange.pulloperation(bundlerepo, peer, heads=reponodes)
        pullop.trmanager = bundletransactionmanager()
        exchange._pullapplyphases(pullop, remotephases)

    def cleanup():
        if bundlerepo:
            bundlerepo.close()
        if bundle:
            os.unlink(bundle)
        peer.close()

    return (localrepo, csets, cleanup)