'''enable experimental obsolescence feature of Mercurial

OBSOLESCENCE IS AN EXPERIMENTAL FEATURE MAKE SURE YOU UNDERSTOOD THE INVOLVED
CONCEPT BEFORE USING IT.

/!\ THIS EXTENSION IS INTENDED FOR SERVER SIDE ONLY USAGE /!\

For client side usages it is recommended to use the evolve extension for
improved user interface.'''

import mercurial.obsolete
mercurial.obsolete._enabled = True

from mercurial import wireproto
from mercurial import extension

def srv_pushobsmarkers(repo, proto):
    """wireprotocol command"""
    fp = StringIO()
    proto.redirect()
    proto.getfile(fp)
    data = fp.getvalue()
    fp.close()
    lock = repo.lock()
    try:
        tr = repo.transaction('pushkey: obsolete markers')
        try:
            repo.obsstore.mergemarkers(tr, data)
            tr.close()
        finally:
            tr.release()
    finally:
        lock.release()
    return wireproto.pushres(0)

def srv_pullobsmarkers(repo, proto, others):
    opts = wireproto.options('', ['heads', 'common'], others)
    for k, v in opts.iteritems():
        if k in ('heads', 'common'):
            opts[k] = wireproto.decodelist(v)
    obsdata = _getobsmarkersstream(repo, **opts)
    length = '%20i' % len(obsdata.getvalue())
    def data():
        yield length
        for c in proto.groupchunks(obsdata):
            yield c
    return wireproto.streamres(data())

def capabilities(orig, repo, proto):
    """wrapper to advertise new capability"""
    caps = orig(repo, proto)
    if obsolete._enabled:
        caps += ' _evoext_pushobsmarkers_0'
        caps += ' _evoext_pullobsmarkers_0'
    return caps

def extsetup(ui):
    wireproto.commands['evoext_pushobsmarkers_0'] = (srv_pushobsmarkers, '')
    wireproto.commands['evoext_pullobsmarkers_0'] = (srv_pullobsmarkers, '*')
    extensions.wrapfunction(wireproto, 'capabilities', capabilities)