annotate hgext3rd/topic/server.py @ 6652:92fd4581f569

topic: return our special executor classes for each instance

It looks like globally patching classes once when the extension is being
initialized is not a great idea (23cad1a872b6), because people might use other
extensions that get initialized earlier than topic or only for certain repos.
Replacing global executor classes is less safe than wrapping certain functions
that should return newly instantiated objects of said classes, so let's do that
instead.

# 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 (
    error,
    extensions,
    localrepo,
    repoview,
    util,
    wireprototypes,
    wireprotov1peer,
    wireprotov1server,
)

from mercurial.utils import repoviewutil

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

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)

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)

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()  # pytype: disable=module-attr
            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

    def wp_commandexecutor(self):
        return topicpeerexecutor(self)

    wireprotov1peer.wirepeer.commandexecutor = wp_commandexecutor

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