mercurial/exchange.py

exchange: extract pull function from localrepo

The localrepo class if far too big. Push and pull logic are extracted and
reworked to better fit with the fact we exchange more than bundle now.

This changeset extract the pulh code. later changeset will slowly slice it into
smaller brick.

The localrepo.pull method is kept for now to limit impact on user code. But it
will be ultimately removed, now that the public API is hold by peer.

# exchange.py - utily to exchange data between repo.
#
# Copyright 2005-2007 Matt Mackall <[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 i18n import _
from node import hex, nullid
import errno
import util, scmutil, changegroup
import discovery, phases, obsolete, bookmarks


class pushoperation(object):
    """A object that represent a single push operation

    It purpose is to carry push related state and very common operation.

    A new should be created at the begining of each push and discarded
    afterward.
    """

    def __init__(self, repo, remote, force=False, revs=None, newbranch=False):
        # repo we push from
        self.repo = repo
        self.ui = repo.ui
        # repo we push to
        self.remote = remote
        # force option provided
        self.force = force
        # revs to be pushed (None is "all")
        self.revs = revs
        # allow push of new branch
        self.newbranch = newbranch
        # did a local lock get acquired?
        self.locallocked = None
        # Integer version of the push result
        # - None means nothing to push
        # - 0 means HTTP error
        # - 1 means we pushed and remote head count is unchanged *or*
        #   we have outgoing changesets but refused to push
        # - other values as described by addchangegroup()
        self.ret = None
        # discover.outgoing object (contains common and outgoin data)
        self.outgoing = None
        # all remote heads before the push
        self.remoteheads = None
        # testable as a boolean indicating if any nodes are missing locally.
        self.incoming = None
        # set of all heads common after changeset bundle push
        self.commonheads = None

def push(repo, remote, force=False, revs=None, newbranch=False):
    '''Push outgoing changesets (limited by revs) from a local
    repository to remote. Return an integer:
      - None means nothing to push
      - 0 means HTTP error
      - 1 means we pushed and remote head count is unchanged *or*
        we have outgoing changesets but refused to push
      - other values as described by addchangegroup()
    '''
    pushop = pushoperation(repo, remote, force, revs, newbranch)
    if pushop.remote.local():
        missing = (set(pushop.repo.requirements)
                   - pushop.remote.local().supported)
        if missing:
            msg = _("required features are not"
                    " supported in the destination:"
                    " %s") % (', '.join(sorted(missing)))
            raise util.Abort(msg)

    # there are two ways to push to remote repo:
    #
    # addchangegroup assumes local user can lock remote
    # repo (local filesystem, old ssh servers).
    #
    # unbundle assumes local user cannot lock remote repo (new ssh
    # servers, http servers).

    if not pushop.remote.canpush():
        raise util.Abort(_("destination does not support push"))
    # get local lock as we might write phase data
    locallock = None
    try:
        locallock = pushop.repo.lock()
        pushop.locallocked = True
    except IOError, err:
        pushop.locallocked = False
        if err.errno != errno.EACCES:
            raise
        # source repo cannot be locked.
        # We do not abort the push, but just disable the local phase
        # synchronisation.
        msg = 'cannot lock source repository: %s\n' % err
        pushop.ui.debug(msg)
    try:
        pushop.repo.checkpush(pushop.force, pushop.revs)
        lock = None
        unbundle = pushop.remote.capable('unbundle')
        if not unbundle:
            lock = pushop.remote.lock()
        try:
            _pushdiscovery(pushop)
            if _pushcheckoutgoing(pushop):
                _pushchangeset(pushop)
            _pushcomputecommonheads(pushop)
            _pushsyncphase(pushop)
            _pushobsolete(pushop)
        finally:
            if lock is not None:
                lock.release()
    finally:
        if locallock is not None:
            locallock.release()

    _pushbookmark(pushop)
    return pushop.ret

def _pushdiscovery(pushop):
    # discovery
    unfi = pushop.repo.unfiltered()
    fci = discovery.findcommonincoming
    commoninc = fci(unfi, pushop.remote, force=pushop.force)
    common, inc, remoteheads = commoninc
    fco = discovery.findcommonoutgoing
    outgoing = fco(unfi, pushop.remote, onlyheads=pushop.revs,
                   commoninc=commoninc, force=pushop.force)
    pushop.outgoing = outgoing
    pushop.remoteheads = remoteheads
    pushop.incoming = inc

def _pushcheckoutgoing(pushop):
    outgoing = pushop.outgoing
    unfi = pushop.repo.unfiltered()
    if not outgoing.missing:
        # nothing to push
        scmutil.nochangesfound(unfi.ui, unfi, outgoing.excluded)
        return False
    # something to push
    if not pushop.force:
        # if repo.obsstore == False --> no obsolete
        # then, save the iteration
        if unfi.obsstore:
            # this message are here for 80 char limit reason
            mso = _("push includes obsolete changeset: %s!")
            mst = "push includes %s changeset: %s!"
            # plain versions for i18n tool to detect them
            _("push includes unstable changeset: %s!")
            _("push includes bumped changeset: %s!")
            _("push includes divergent changeset: %s!")
            # If we are to push if there is at least one
            # obsolete or unstable changeset in missing, at
            # least one of the missinghead will be obsolete or
            # unstable. So checking heads only is ok
            for node in outgoing.missingheads:
                ctx = unfi[node]
                if ctx.obsolete():
                    raise util.Abort(mso % ctx)
                elif ctx.troubled():
                    raise util.Abort(_(mst)
                                     % (ctx.troubles()[0],
                                        ctx))
        newbm = pushop.ui.configlist('bookmarks', 'pushing')
        discovery.checkheads(unfi, pushop.remote, outgoing,
                             pushop.remoteheads,
                             pushop.newbranch,
                             bool(pushop.incoming),
                             newbm)
    return True

def _pushchangeset(pushop):
    """Make the actual push of changeset bundle to remote repo"""
    outgoing = pushop.outgoing
    unbundle = pushop.remote.capable('unbundle')
    # TODO: get bundlecaps from remote
    bundlecaps = None
    # create a changegroup from local
    if pushop.revs is None and not (outgoing.excluded
                            or pushop.repo.changelog.filteredrevs):
        # push everything,
        # use the fast path, no race possible on push
        bundler = changegroup.bundle10(pushop.repo, bundlecaps)
        cg = pushop.repo._changegroupsubset(outgoing,
                                            bundler,
                                            'push',
                                            fastpath=True)
    else:
        cg = pushop.repo.getlocalbundle('push', outgoing, bundlecaps)

    # apply changegroup to remote
    if unbundle:
        # local repo finds heads on server, finds out what
        # revs it must push. once revs transferred, if server
        # finds it has different heads (someone else won
        # commit/push race), server aborts.
        if pushop.force:
            remoteheads = ['force']
        else:
            remoteheads = pushop.remoteheads
        # ssh: return remote's addchangegroup()
        # http: return remote's addchangegroup() or 0 for error
        pushop.ret = pushop.remote.unbundle(cg, remoteheads,
                                            'push')
    else:
        # we return an integer indicating remote head count
        # change
        pushop.ret = pushop.remote.addchangegroup(cg, 'push',
                                                              pushop.repo.url())

def _pushcomputecommonheads(pushop):
    unfi = pushop.repo.unfiltered()
    if pushop.ret:
        # push succeed, synchronize target of the push
        cheads = pushop.outgoing.missingheads
    elif pushop.revs is None:
        # All out push fails. synchronize all common
        cheads = pushop.outgoing.commonheads
    else:
        # I want cheads = heads(::missingheads and ::commonheads)
        # (missingheads is revs with secret changeset filtered out)
        #
        # This can be expressed as:
        #     cheads = ( (missingheads and ::commonheads)
        #              + (commonheads and ::missingheads))"
        #              )
        #
        # while trying to push we already computed the following:
        #     common = (::commonheads)
        #     missing = ((commonheads::missingheads) - commonheads)
        #
        # We can pick:
        # * missingheads part of common (::commonheads)
        common = set(pushop.outgoing.common)
        nm = pushop.repo.changelog.nodemap
        cheads = [node for node in pushop.revs if nm[node] in common]
        # and
        # * commonheads parents on missing
        revset = unfi.set('%ln and parents(roots(%ln))',
                         pushop.outgoing.commonheads,
                         pushop.outgoing.missing)
        cheads.extend(c.node() for c in revset)
    pushop.commonheads = cheads

def _pushsyncphase(pushop):
    """synchronise phase information locally and remotly"""
    unfi = pushop.repo.unfiltered()
    cheads = pushop.commonheads
    if pushop.ret:
        # push succeed, synchronize target of the push
        cheads = pushop.outgoing.missingheads
    elif pushop.revs is None:
        # All out push fails. synchronize all common
        cheads = pushop.outgoing.commonheads
    else:
        # I want cheads = heads(::missingheads and ::commonheads)
        # (missingheads is revs with secret changeset filtered out)
        #
        # This can be expressed as:
        #     cheads = ( (missingheads and ::commonheads)
        #              + (commonheads and ::missingheads))"
        #              )
        #
        # while trying to push we already computed the following:
        #     common = (::commonheads)
        #     missing = ((commonheads::missingheads) - commonheads)
        #
        # We can pick:
        # * missingheads part of common (::commonheads)
        common = set(pushop.outgoing.common)
        nm = pushop.repo.changelog.nodemap
        cheads = [node for node in pushop.revs if nm[node] in common]
        # and
        # * commonheads parents on missing
        revset = unfi.set('%ln and parents(roots(%ln))',
                         pushop.outgoing.commonheads,
                         pushop.outgoing.missing)
        cheads.extend(c.node() for c in revset)
    pushop.commonheads = cheads
    # even when we don't push, exchanging phase data is useful
    remotephases = pushop.remote.listkeys('phases')
    if (pushop.ui.configbool('ui', '_usedassubrepo', False)
        and remotephases    # server supports phases
        and pushop.ret is None # nothing was pushed
        and remotephases.get('publishing', False)):
        # When:
        # - this is a subrepo push
        # - and remote support phase
        # - and no changeset was pushed
        # - and remote is publishing
        # We may be in issue 3871 case!
        # We drop the possible phase synchronisation done by
        # courtesy to publish changesets possibly locally draft
        # on the remote.
        remotephases = {'publishing': 'True'}
    if not remotephases: # old server or public only rer
        _localphasemove(pushop, cheads)
        # don't push any phase data as there is nothing to push
    else:
        ana = phases.analyzeremotephases(pushop.repo, cheads,
                                         remotephases)
        pheads, droots = ana
        ### Apply remote phase on local
        if remotephases.get('publishing', False):
            _localphasemove(pushop, cheads)
        else: # publish = False
            _localphasemove(pushop, pheads)
            _localphasemove(pushop, cheads, phases.draft)
        ### Apply local phase on remote

        # Get the list of all revs draft on remote by public here.
        # XXX Beware that revset break if droots is not strictly
        # XXX root we may want to ensure it is but it is costly
        outdated =  unfi.set('heads((%ln::%ln) and public())',
                             droots, cheads)
        for newremotehead in outdated:
            r = pushop.remote.pushkey('phases',
                                      newremotehead.hex(),
                                      str(phases.draft),
                                      str(phases.public))
            if not r:
                pushop.ui.warn(_('updating %s to public failed!\n')
                                       % newremotehead)

def _localphasemove(pushop, nodes, phase=phases.public):
    """move <nodes> to <phase> in the local source repo"""
    if pushop.locallocked:
        phases.advanceboundary(pushop.repo, phase, nodes)
    else:
        # repo is not locked, do not change any phases!
        # Informs the user that phases should have been moved when
        # applicable.
        actualmoves = [n for n in nodes if phase < pushop.repo[n].phase()]
        phasestr = phases.phasenames[phase]
        if actualmoves:
            pushop.ui.status(_('cannot lock source repo, skipping '
                               'local %s phase update\n') % phasestr)

def _pushobsolete(pushop):
    """utility function to push obsolete markers to a remote"""
    pushop.ui.debug('try to push obsolete markers to remote\n')
    repo = pushop.repo
    remote = pushop.remote
    if (obsolete._enabled and repo.obsstore and
        'obsolete' in remote.listkeys('namespaces')):
        rslts = []
        remotedata = repo.listkeys('obsolete')
        for key in sorted(remotedata, reverse=True):
            # reverse sort to ensure we end with dump0
            data = remotedata[key]
            rslts.append(remote.pushkey('obsolete', key, '', data))
        if [r for r in rslts if not r]:
            msg = _('failed to push some obsolete markers!\n')
            repo.ui.warn(msg)

def _pushbookmark(pushop):
    """Update bookmark position on remote"""
    ui = pushop.ui
    repo = pushop.repo.unfiltered()
    remote = pushop.remote
    ui.debug("checking for updated bookmarks\n")
    revnums = map(repo.changelog.rev, pushop.revs or [])
    ancestors = [a for a in repo.changelog.ancestors(revnums, inclusive=True)]
    (addsrc, adddst, advsrc, advdst, diverge, differ, invalid
     ) = bookmarks.compare(repo, repo._bookmarks, remote.listkeys('bookmarks'),
                           srchex=hex)

    for b, scid, dcid in advsrc:
        if ancestors and repo[scid].rev() not in ancestors:
            continue
        if remote.pushkey('bookmarks', b, dcid, scid):
            ui.status(_("updating bookmark %s\n") % b)
        else:
            ui.warn(_('updating bookmark %s failed!\n') % b)


def pull(repo, remote, heads=None, force=False):
    if remote.local():
        missing = set(remote.requirements) - repo.supported
        if missing:
            msg = _("required features are not"
                    " supported in the destination:"
                    " %s") % (', '.join(sorted(missing)))
            raise util.Abort(msg)

    # don't open transaction for nothing or you break future useful
    # rollback call
    tr = None
    trname = 'pull\n' + util.hidepassword(remote.url())
    lock = repo.lock()
    try:
        tmp = discovery.findcommonincoming(repo.unfiltered(), remote,
                                           heads=heads, force=force)
        common, fetch, rheads = tmp
        if not fetch:
            repo.ui.status(_("no changes found\n"))
            result = 0
        else:
            tr = repo.transaction(trname)
            if heads is None and list(common) == [nullid]:
                repo.ui.status(_("requesting all changes\n"))
            elif heads is None and remote.capable('changegroupsubset'):
                # issue1320, avoid a race if remote changed after discovery
                heads = rheads

            if remote.capable('getbundle'):
                # TODO: get bundlecaps from remote
                cg = remote.getbundle('pull', common=common,
                                      heads=heads or rheads)
            elif heads is None:
                cg = remote.changegroup(fetch, 'pull')
            elif not remote.capable('changegroupsubset'):
                raise util.Abort(_("partial pull cannot be done because "
                                       "other repository doesn't support "
                                       "changegroupsubset."))
            else:
                cg = remote.changegroupsubset(fetch, heads, 'pull')
            result = repo.addchangegroup(cg, 'pull', remote.url())

        # compute target subset
        if heads is None:
            # We pulled every thing possible
            # sync on everything common
            subset = common + rheads
        else:
            # We pulled a specific subset
            # sync on this subset
            subset = heads

        # Get remote phases data from remote
        remotephases = remote.listkeys('phases')
        publishing = bool(remotephases.get('publishing', False))
        if remotephases and not publishing:
            # remote is new and unpublishing
            pheads, _dr = phases.analyzeremotephases(repo, subset,
                                                     remotephases)
            phases.advanceboundary(repo, phases.public, pheads)
            phases.advanceboundary(repo, phases.draft, subset)
        else:
            # Remote is old or publishing all common changesets
            # should be seen as public
            phases.advanceboundary(repo, phases.public, subset)

        def gettransaction():
            if tr is None:
                return repo.transaction(trname)
            return tr

        obstr = obsolete.syncpull(repo, remote, gettransaction)
        if obstr is not None:
            tr = obstr

        if tr is not None:
            tr.close()
    finally:
        if tr is not None:
            tr.release()
        lock.release()

    return result