annotate hgext3rd/topic/server.py @ 6935:954d7ea5cd67 stable tip

stack: when stack base is obsolete, pick any successor, even if at random

There are situations when s0 is obsolete and we also cannot pick just one
successor for it to use in stack. In such a case, let's pick the "latest"
successor from the first set.

We're assuming that obsutil.successorssets() returns data in the same order (it
should, since it makes sure to sort data internally). Keeping that in mind,
while the successor picked for s0 by this code is not based on any sort of
sophisticated logic, it should nonetheless be the same every time.

This patch is probably not going to completely break anything that was
previously working fine, because the previous behavior was to just abort with
an exception.

# topic/server.py - server specific behavior with topic
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from mercurial.i18n import _

from mercurial import (
    branchmap,
    error,
    extensions,
    localrepo,
    repoview,
    util,
    wireprototypes,
    wireprotov1peer,
    wireprotov1server,
)

from . import (
    common,
    compat,
    constants,
)

### Visibility restriction
#
# Serving draft changesets with topics to clients without topic extension can
# confuse them, because they won't see the topic label and will consider them
# normal anonymous heads. Instead we have the option to not serve changesets
# with topics to clients without topic support.
#
# To achieve this, we alter the behavior of the standard `heads` commands and
# introduce a new `heads` command that only clients with topic will know about.

# compat version of the wireprotocommand decorator, taken from evolve compat

FILTERNAME = b'served-no-topic'

def computeunservedtopic(repo, visibilityexceptions=None):
    assert not repo.changelog.filteredrevs
    filteredrevs = repoview.filtertable[b'served'](repo, visibilityexceptions).copy()
    mutable = repoview.filtertable[b'immutable'](repo, visibilityexceptions)
    consider = mutable - filteredrevs
    cl = repo.changelog
    extrafiltered = set()
    for r in consider:
        if cl.changelogrevision(r).extra.get(constants.extrakey, b''):
            extrafiltered.add(r)
    if extrafiltered:
        extrafiltered = set(repo.revs('%ld::%ld', extrafiltered, consider))
        filteredrevs = frozenset(filteredrevs | extrafiltered)
    return filteredrevs

def wrapheads(orig, repo, proto):
    """wrap head to hide topic^W draft changeset to old client"""
    hidetopics = repo.ui.configbool(b'experimental', b'topic.server-gate-topic-changesets')
    if common.hastopicext(repo) and hidetopics:
        h = repo.filtered(FILTERNAME).heads()
        return wireprototypes.bytesresponse(wireprototypes.encodelist(h) + b'\n')
    return orig(repo, proto)

def topicheads(repo, proto):
    """Same as the normal wireprotocol command, but accessing with a different end point."""
    h = repo.heads()
    return wireprototypes.bytesresponse(wireprototypes.encodelist(h) + b'\n')

def tns_heads(repo, proto, namespaces):
    """wireprotocol command to filter heads based on topic namespaces"""
    if not common.hastopicext(repo):
        return topicheads(repo, proto)

    namespaces = wireprototypes.decodelist(namespaces)
    if b'*' in namespaces:
        # pulling all topic namespaces, all changesets are visible
        h = repo.heads()
    else:
        # only changesets in the selected topic namespaces are visible
        h = []
        entries = compat.bcentries(repo.branchmaptns())
        for branch, nodes in compat.branchmapitems(entries):
            namedbranch, tns, topic = common.parsefqbn(branch)
            if tns == b'none' or tns in namespaces:
                h.extend(nodes)
    return wireprototypes.bytesresponse(wireprototypes.encodelist(h) + b'\n')

def wireprotocaps(orig, repo, proto):
    """advertise the new topic specific `head` command for client with topic"""
    caps = orig(repo, proto)
    if common.hastopicext(repo) and repo.peer().capable(b'topics'):
        caps.append(b'_exttopics_heads')
        if repo.ui.configbool(b'phases', b'publish'):
            mode = b'all'
        elif repo.ui.configbool(b'experimental', b'topic.publish-bare-branch'):
            mode = b'auto'
        else:
            mode = b'none'
        caps.append(b'ext-topics-publish=%s' % mode)
        caps.append(b'ext-topics-tns-heads')
    return caps

def setupserver(ui):
    extensions.wrapfunction(wireprotov1server, 'heads', wrapheads)
    wireprotov1server.commands.pop(b'heads')
    wireprotov1server.wireprotocommand(b'heads', permission=b'pull')(wireprotov1server.heads)
    wireprotov1server.wireprotocommand(b'_exttopics_heads', permission=b'pull')(topicheads)
    wireprotov1server.wireprotocommand(b'tns_heads', b'namespaces', permission=b'pull')(tns_heads)
    extensions.wrapfunction(wireprotov1server, '_capabilities', wireprotocaps)

    if util.safehasattr(wireprotov1peer, 'future'):
        # hg <= 5.9 (c424ff4807e6)
        @wireprotov1peer.batchable
        def wp_tns_heads(self, namespaces):
            f = wireprotov1peer.future()
            yield {b'namespaces': wireprototypes.encodelist(namespaces)}, f
            d = f.value
            try:
                yield wireprototypes.decodelist(d[:-1])
            except ValueError:
                self._abort(error.ResponseError(_(b"unexpected response:"), d))
    else:
        @wireprotov1peer.batchable
        def wp_tns_heads(self, namespaces):
            def decode(d):
                try:
                    return wireprototypes.decodelist(d[:-1])
                except ValueError:
                    self._abort(error.ResponseError(_(b"unexpected response:"), d))

            return {b'namespaces': wireprototypes.encodelist(namespaces)}, decode

    wireprotov1peer.wirepeer.tns_heads = wp_tns_heads

    class topicpeerexecutor(wireprotov1peer.peerexecutor):

        def callcommand(self, command, args):
            if command == b'heads':
                if self._peer.capable(b'ext-topics-tns-heads'):
                    command = b'tns_heads'
                    if self._peer.ui.configbool(b'_internal', b'tns-explicit-target', False):
                        args[b'namespaces'] = [b'*']
                    else:
                        args[b'namespaces'] = self._peer.ui.configlist(b'experimental', b'tns-default-pull-namespaces', [b'*'])
                elif self._peer.capable(b'_exttopics_heads'):
                    command = b'_exttopics_heads'
                    if getattr(self._peer, '_exttopics_heads', None) is None:
                        self._peer._exttopics_heads = self._peer.heads
            s = super(topicpeerexecutor, self)
            return s.callcommand(command, args)

    wireprotov1peer.peerexecutor = topicpeerexecutor

    class topiccommandexecutor(localrepo.localcommandexecutor):
        def callcommand(self, command, args):
            if command == b'heads':
                if self._peer.capable(b'ext-topics-tns-heads'):
                    command = b'tns_heads'
                    if self._peer.ui.configbool(b'_internal', b'tns-explicit-target', False):
                        args[b'namespaces'] = [b'*']
                    else:
                        args[b'namespaces'] = self._peer.ui.configlist(b'experimental', b'tns-default-pull-namespaces', [b'*'])
            s = super(topiccommandexecutor, self)
            return s.callcommand(command, args)

    localrepo.localcommandexecutor = topiccommandexecutor

    if FILTERNAME not in repoview.filtertable:
        repoview.filtertable[FILTERNAME] = computeunservedtopic
        # hg <= 4.9 (caebe5e7f4bd)
        branchmap.subsettable[FILTERNAME] = b'immutable'
        branchmap.subsettable[b'served'] = FILTERNAME