view hgext3rd/topic/topicmap.py @ 6336:453861da6922

topic: use fully qualified branch name during exchange

For the entire duration of exchange process, we now use branch//namespace/topic
format for branchmap, head checking, etc.

Sometimes we still need to disable this feature (e.g. when pushing to a repo
that doesn't have topic extension enabled), but every other case should be
handled using the new fqbn format. This applies both to internal API, such as
having fqbn as branchmap keys and even making ctx.branch() return fqbn, and to
UI, such as users seeing fqbn in hg branches output and messages from hg push.

Things to note: now we're wrapping revbranchcache.branchinfo() during the
extension setup, instead of doing it only in one place in _headssummary().
We're also using override_context_branch context manager that makes
ctx.branch() return fqbn also in cases when we call the original
_headssummary().

There are still places in the UI where branch names are not in fqbn format,
because they don't take part in the exchange process.

import contextlib
import hashlib

from mercurial.i18n import _
from mercurial.node import nullid
from mercurial import (
    branchmap,
    changegroup,
    extensions,
    repoview,
    util,
)

from . import (
    common,
    compat,
)

basefilter = set([b'base', b'immutable'])
def topicfilter(name):
    """return a "topic" version of a filter level"""
    if name in basefilter:
        return name
    elif name is None:
        return None
    elif name.endswith(b'-topic'):
        return name
    else:
        return name + b'-topic'

def istopicfilter(filtername):
    if filtername is None:
        return False
    return filtername.endswith(b'-topic')

def gettopicrepo(repo):
    if not common.hastopicext(repo):
        return repo
    filtername = topicfilter(repo.filtername)
    if filtername == repo.filtername:
        return repo
    return repo.filtered(filtername)

def _setuptopicfilter(ui):
    """extend the filter related mapping with topic related one"""
    funcmap = repoview.filtertable
    partialmap = branchmap.subsettable

    # filter level not affected by topic that we should not override

    for plainname in list(funcmap):
        newfilter = topicfilter(plainname)
        if newfilter == plainname:
            continue

        def revsfunc(repo, name=plainname):
            return repoview.filterrevs(repo, name)

        base = topicfilter(partialmap[plainname])

        if newfilter not in funcmap:
            funcmap[newfilter] = revsfunc
            partialmap[newfilter] = base
    funcmap[b'unfiltered-topic'] = lambda repo: frozenset()
    partialmap[b'unfiltered-topic'] = b'visible-topic'

def _phaseshash(repo, maxrev):
    """uniq ID for a phase matching a set of rev"""
    revs = set()
    cl = repo.changelog
    fr = cl.filteredrevs
    getrev = compat.getgetrev(cl)
    for n in compat.nonpublicphaseroots(repo):
        r = getrev(n)
        if r not in fr and r < maxrev:
            revs.add(r)
    key = nullid
    revs = sorted(revs)
    if revs:
        s = hashlib.sha1()
        for rev in revs:
            s.update(b'%d;' % rev)
        key = s.digest()
    return key

def modsetup(ui):
    """call at uisetup time to install various wrappings"""
    _setuptopicfilter(ui)
    _wrapbmcache(ui)
    extensions.wrapfunction(changegroup.cg1unpacker, 'apply', cgapply)
    compat.overridecommitstatus(commitstatus)

def cgapply(orig, self, repo, *args, **kwargs):
    """make sure a topicmap is used when applying a changegroup"""
    other = repo.filtered(topicfilter(repo.filtername))
    return orig(self, other, *args, **kwargs)

def commitstatus(orig, repo, node, branch, bheads=None, tip=None, opts=None):
    # wrap commit status use the topic branch heads
    ctx = repo[node]
    if ctx.topic() and ctx.branch() == branch:
        bheads = repo.branchheads(b"%s:%s" % (branch, ctx.topic()))

    ret = orig(repo, node, branch, bheads=bheads, tip=tip, opts=opts)

    # logic copy-pasted from cmdutil.commitstatus()
    if opts is None:
        opts = {}
    if ctx.topic():
        return ret
    parents = ctx.parents()

    if (not opts.get(b'amend') and bheads and node not in bheads and not
        [x for x in parents if x.node() in bheads and x.branch() == branch]):
        repo.ui.status(_(b"(consider using topic for lightweight branches."
                         b" See 'hg help topic')\n"))

    return ret

def _wrapbmcache(ui):
    class topiccache(_topiccache, branchmap.branchcache):
        pass
    branchmap.branchcache = topiccache

    try:
        # Mercurial 5.0
        class remotetopiccache(_topiccache, branchmap.remotebranchcache):
            pass
        branchmap.remotebranchcache = remotetopiccache

        def _wrapupdatebmcachemethod(orig, self, repo):
            # pass in the bound method as the original
            return _wrapupdatebmcache(orig.__get__(self), repo)
        extensions.wrapfunction(branchmap.BranchMapCache, 'updatecache', _wrapupdatebmcachemethod)
    except AttributeError:
        # hg <= 4.9 (3461814417f3)
        extensions.wrapfunction(branchmap, 'updatecache', _wrapupdatebmcache)


def _wrapupdatebmcache(orig, repo):
    previous = getattr(repo, '_autobranchmaptopic', False)
    try:
        repo._autobranchmaptopic = False
        return orig(repo)
    finally:
        repo._autobranchmaptopic = previous

# needed to prevent reference used for 'super()' call using in branchmap.py to
# no go into cycle. (yes, URG)
_oldbranchmap = branchmap.branchcache

@contextlib.contextmanager
def oldbranchmap():
    previous = branchmap.branchcache
    try:
        branchmap.branchcache = _oldbranchmap
        yield
    finally:
        branchmap.branchcache = previous

class _topiccache(object): # combine me with branchmap.branchcache

    def __init__(self, *args, **kwargs):
        # super() call may fail otherwise
        with oldbranchmap():
            super(_topiccache, self).__init__(*args, **kwargs)
        self.phaseshash = None

    def copy(self):
        """return an deep copy of the branchcache object"""
        entries = compat.bcentries(self)
        args = (entries, self.tipnode, self.tiprev, self.filteredhash,
                self._closednodes)
        if util.safehasattr(self, '_repo'):
            # hg <= 5.7 (6266d19556ad)
            args = (self._repo,) + args
        new = self.__class__(*args)
        new.phaseshash = self.phaseshash
        return new

    def load(self, repo, lineiter):
        """call branchmap.load(), and then transform branch names to be in the
        new "//" format
        """
        super(_topiccache, self).load(repo, lineiter)
        entries = compat.bcentries(self)

        for branch in tuple(entries):
            formatted = common.formatfqbn(branch=branch)
            if branch != formatted:
                entries[formatted] = entries.pop(branch)

    def validfor(self, repo):
        """Is the cache content valid regarding a repo

        - False when cached tipnode is unknown or if we detect a strip.
        - True when cache is up to date or a subset of current repo."""
        valid = super(_topiccache, self).validfor(repo)
        if not valid:
            return False
        elif not istopicfilter(repo.filtername) or self.phaseshash is None:
            # phasehash at None means this is a branchmap
            # come from non topic thing
            return True
        else:
            try:
                valid = self.phaseshash == _phaseshash(repo, self.tiprev)
                return valid
            except IndexError:
                return False

    def write(self, repo):
        """write cache to disk if it's not topic-only, but first transform
        cache keys from branches in "//" format into bare branch names
        """
        # we expect mutable set to be small enough to be that computing it all
        # the time will be fast enough
        if not istopicfilter(repo.filtername):
            cache = self.copy()
            entries = compat.bcentries(cache)

            for formatted in tuple(entries):
                branch, tns, topic = common.parsefqbn(formatted)
                if branch != formatted:
                    entries[branch] = entries.pop(formatted)

            super(_topiccache, cache).write(repo)

    def update(self, repo, revgen):
        """Given a branchhead cache, self, that may have extra nodes or be
        missing heads, and a generator of nodes that are strictly a superset of
        heads missing, this function updates self to be correct.
        """
        if not istopicfilter(repo.filtername):
            return super(_topiccache, self).update(repo, revgen)

        # See topic.discovery._headssummary(), where repo.unfiltered gets
        # overridden to return .filtered('unfiltered-topic'). revbranchcache
        # only can be created for unfiltered repo (filtername is None), so we
        # do that here, and this revbranchcache will be cached inside repo.
        # When we get rid of *-topic filters, then this workaround can be
        # removed too.
        repo.unfiltered().revbranchcache()

        super(_topiccache, self).update(repo, revgen)
        self.phaseshash = _phaseshash(repo, self.tiprev)