view hgext3rd/topic/server.py @ 5139:19b8ffd23795

topic: option to hide topic changesets to plain client

This is the first version of an option that make topic changeset hidden to
client without the extension. It might become the default in the future.

# 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 import (
    extensions,
    repoview,
    repoviewutil,
    wireprototypes,
    wireprotov1peer,
    wireprotov1server,
)

from . import (
    common,
    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:
        filteredrevs = frozenset(filteredrevs | extrafiltered)
    return filteredrevs

def wireprotocommand(name, args=b'', permission=b'pull'):
    try:
        from mercurial.wireprotov1server import wireprotocommand
    except (ImportError, AttributeError):
        # hg <= 4.6 (b4d85bc122bd)
        from mercurial.wireproto import wireprotocommand
    return wireprotocommand(name, args, permission=permission)

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 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')
    return caps

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

    class topicpeerexecutor(wireprotov1peer.peerexecutor):

        def callcommand(self, command, args):
            if command == b'heads':
                if 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

    if FILTERNAME not in repoview.filtertable:
        repoview.filtertable[FILTERNAME] = computeunservedtopic
        repoviewutil.subsettable[FILTERNAME] = b'immutable'
        repoviewutil.subsettable[b'served'] = FILTERNAME