view hgext3rd/topic/discovery.py @ 5222:ba53591d4aab stable

head-checking: filter out obsolete heads when checking for new heads

This does not affect any tests right now, but this will be useful for the next
changeset. This is also the start of a more aggressive removal of obsolete
heads in places where it does not make sense to take them into account.

from __future__ import absolute_import

import collections
import weakref

from mercurial.i18n import _
from mercurial import (
    bundle2,
    discovery,
    error,
    exchange,
    extensions,
    util,
)
from . import (
    common,
    compat,
)

# hg <= 4.5 (b4d85bc122bd)
try:
    from mercurial import wireproto  # pytype: disable=import-error
    wireproto.branchmap
except (AttributeError, ImportError):
    from mercurial import wireprotov1server as wireproto

def _headssummary(orig, pushop, *args, **kwargs):
    # In mercurial > 4.3, we receive the pushop as arguments
    repo = pushop.repo.unfiltered()
    remote = pushop.remote

    publishing = (b'phases' not in remote.listkeys(b'namespaces')
                  or bool(remote.listkeys(b'phases').get(b'publishing', False)))

    if not common.hastopicext(pushop.repo):
        return orig(pushop, *args, **kwargs)
    elif ((publishing or not remote.capable(b'topics'))
            and not getattr(pushop, 'publish', False)):
        return orig(pushop, *args, **kwargs)

    publishedset = ()
    remotebranchmap = None
    origremotebranchmap = remote.branchmap
    publishednode = [c.node() for c in pushop.outdatedphases]
    publishedset = repo.revs(b'ancestors(%ln + %ln)',
                             publishednode,
                             pushop.remotephases.publicheads)

    getrev = compat.getgetrev(repo.unfiltered().changelog)

    def remotebranchmap():
        # drop topic information from changeset about to be published
        result = collections.defaultdict(list)
        for branch, heads in compat.branchmapitems(origremotebranchmap()):
            if b':' not in branch:
                result[branch].extend(heads)
            else:
                namedbranch = branch.split(b':', 1)[0]
                for h in heads:
                    r = getrev(h)
                    if r is not None and r in publishedset:
                        result[namedbranch].append(h)
                    else:
                        result[branch].append(h)
        for heads in result.values():
            heads.sort()
        return result

    class repocls(repo.__class__):
        # awful hack to see branch as "branch:topic"
        def __getitem__(self, key):
            ctx = super(repocls, self).__getitem__(key)
            oldbranch = ctx.branch
            rev = ctx.rev()

            def branch():
                branch = oldbranch()
                if rev in publishedset:
                    return branch
                topic = ctx.topic()
                if topic:
                    branch = b"%s:%s" % (branch, topic)
                return branch

            ctx.branch = branch
            return ctx

        def revbranchcache(self):
            rbc = super(repocls, self).revbranchcache()
            localchangelog = self.changelog

            def branchinfo(rev, changelog=None):
                if changelog is None:
                    changelog = localchangelog
                branch, close = changelog.branchinfo(rev)
                if rev in publishedset:
                    return branch, close
                topic = repo[rev].topic()
                if topic:
                    branch = b"%s:%s" % (branch, topic)
                return branch, close

            rbc.branchinfo = branchinfo
            return rbc

    oldrepocls = repo.__class__
    try:
        repo.__class__ = repocls
        if remotebranchmap is not None:
            remote.branchmap = remotebranchmap
        unxx = repo.filtered(b'unfiltered-topic')
        repo.unfiltered = lambda: unxx
        pushop.repo = repo
        summary = orig(pushop)
        for key, value in summary.items():
            if b':' in key: # This is a topic
                if value[0] is None and value[1]:
                    summary[key] = ([value[1][0]], ) + value[1:]
        return summary
    finally:
        if r'unfiltered' in vars(repo):
            del repo.unfiltered
        repo.__class__ = oldrepocls
        if remotebranchmap is not None:
            remote.branchmap = origremotebranchmap

def wireprotobranchmap(orig, repo, proto):
    if not common.hastopicext(repo):
        return orig(repo, proto)
    oldrepo = repo.__class__
    try:
        class repocls(repo.__class__):
            def branchmap(self):
                usetopic = not self.publishing()
                return super(repocls, self).branchmap(topic=usetopic)
        repo.__class__ = repocls
        return orig(repo, proto)
    finally:
        repo.__class__ = oldrepo


def _get_branch_name(ctx):
    # make it easy for extension with the branch logic there
    return ctx.branch()


def _filter_obsolete_heads(repo, heads):
    """filter heads to return non-obsolete ones

    Given a list of heads (on the same named branch) return a new list of heads
    where the obsolete part have been skimmed out.
    """
    new_heads = []
    old_heads = heads[:]
    while old_heads:
        rh = old_heads.pop()
        ctx = repo[rh]
        current_name = _get_branch_name(ctx)
        # run this check early to skip the evaluation of the whole branch
        if not ctx.obsolete():
            new_heads.append(rh)
            continue

        # Get all revs/nodes on the branch exclusive to this head
        # (already filtered heads are "ignored"))
        sections_revs = repo.revs(
            b'only(%d, (%ld+%ld))', rh, old_heads, new_heads,
        )
        keep_revs = []
        for r in sections_revs:
            ctx = repo[r]
            if ctx.obsolete():
                continue
            if _get_branch_name(ctx) != current_name:
                continue
            keep_revs.append(r)
        for h in repo.revs(b'heads(%ld and (::%ld))', sections_revs, keep_revs):
            new_heads.append(h)
    new_heads.sort()
    return new_heads

# Discovery have deficiency around phases, branch can get new heads with pure
# phases change. This happened with a changeset was allowed to be pushed
# because it had a topic, but it later become public and create a new branch
# head.
#
# Handle this by doing an extra check for new head creation server side
def _nbheads(repo):
    data = {}
    for b in repo.branchmap().iterbranches():
        if b':' in b[0]:
            continue
        oldheads = [repo[n].rev() for n in b[1]]
        newheads = _filter_obsolete_heads(repo, oldheads)
        data[b[0]] = len(newheads)
    return data

def handlecheckheads(orig, op, inpart):
    """This is used to check for new heads when publishing changeset"""
    orig(op, inpart)
    if not common.hastopicext(op.repo) or op.repo.publishing():
        return
    tr = op.gettransaction()
    if tr.hookargs[b'source'] not in (b'push', b'serve'): # not a push
        return
    tr._prepushheads = _nbheads(op.repo)
    reporef = weakref.ref(op.repo)
    if util.safehasattr(tr, 'validator'): # hg <= 4.7
        oldvalidator = tr.validator
    else:
        oldvalidator = tr._validator

    def validator(tr):
        repo = reporef()
        if repo is not None:
            repo.invalidatecaches()
            finalheads = _nbheads(repo)
            for branch, oldnb in tr._prepushheads.items():
                newnb = finalheads.pop(branch, 0)
                if oldnb < newnb:
                    msg = _(b'push create a new head on branch "%s"' % branch)
                    raise error.Abort(msg)
            for branch, newnb in finalheads.items():
                if 1 < newnb:
                    msg = _(b'push create more than 1 head on new branch "%s"'
                            % branch)
                    raise error.Abort(msg)
        return oldvalidator(tr)
    if util.safehasattr(tr, 'validator'): # hg <= 4.7
        tr.validator = validator
    else:
        tr._validator = validator
handlecheckheads.params = frozenset()

def _pushb2phases(orig, pushop, bundler):
    if common.hastopicext(pushop.repo):
        checktypes = (b'check:heads', b'check:updated-heads')
        hascheck = any(p.type in checktypes for p in bundler._parts)
        if not hascheck and pushop.outdatedphases:
            exchange._pushb2ctxcheckheads(pushop, bundler)
    return orig(pushop, bundler)

def wireprotocaps(orig, repo, proto):
    caps = orig(repo, proto)
    if common.hastopicext(repo) and repo.peer().capable(b'topics'):
        caps.append(b'topics')
    return caps

def modsetup(ui):
    """run at uisetup time to install all destinations wrapping"""
    extensions.wrapfunction(discovery, '_headssummary', _headssummary)
    extensions.wrapfunction(wireproto, 'branchmap', wireprotobranchmap)
    extensions.wrapfunction(wireproto, '_capabilities', wireprotocaps)
    # we need a proper wrap b2 part stuff
    extensions.wrapfunction(bundle2, 'handlecheckheads', handlecheckheads)
    bundle2.handlecheckheads.params = frozenset()
    bundle2.parthandlermapping[b'check:heads'] = bundle2.handlecheckheads
    if util.safehasattr(bundle2, 'handlecheckupdatedheads'):
        # we still need a proper wrap b2 part stuff
        extensions.wrapfunction(bundle2, 'handlecheckupdatedheads', handlecheckheads)
        bundle2.handlecheckupdatedheads.params = frozenset()
        bundle2.parthandlermapping[b'check:updated-heads'] = bundle2.handlecheckupdatedheads
    extensions.wrapfunction(exchange, '_pushb2phases', _pushb2phases)
    exchange.b2partsgenmapping[b'phase'] = exchange._pushb2phases