Method cancel

src/zookeeper/group.cpp:200–238

Future<bool> GroupProcess::cancel(const Group::Membership& membership)
{
  if (error.isSome()) {
    return Failure(error.get());
  } else if (owned.count(membership.id()) == 0) {
    // TODO(benh): Should this be an error? Right now a user can't
    // differentiate when 'false' means they can't cancel because it's
    // not owned or because it's already been cancelled (explicitly by
    // them or implicitly due to session expiration or operator
    // error).
    return false;
  }

  if (state != READY) {
    Cancel* cancel = new Cancel(membership);
    pending.cancels.push(cancel);
    return cancel->promise.future();
  }

  // TODO(benh): Only attempt if the pending queue is empty so that a
  // client can assume a happens-before ordering of operations (i.e.,
  // the first request will happen before the second, etc).

  Result<bool> cancellation = doCancel(membership);

  if (cancellation.isNone()) { // Try again later.
    if (!retrying) {
      delay(RETRY_INTERVAL, self(), &GroupProcess::retry, RETRY_INTERVAL);
      retrying = true;
    }
    Cancel* cancel = new Cancel(membership);
    pending.cancels.push(cancel);
    return cancel->promise.future();
  } else if (cancellation.isError()) {
    return Failure(cancellation.error());
  }

  return cancellation.get();
}


Future<Option<string>> GroupProcess::data(const Group::Membership& membership)