Method doJoin

src/zookeeper/group.cpp:597–645

Result<Group::Membership> GroupProcess::doJoin(
    const string& data,
    const Option<string>& label)
{
  CHECK_EQ(state, READY);

  const string path = znode + "/" + (label.isSome() ? (label.get() + "_") : "");

  // Create a new ephemeral node to represent a new member and use the
  // the specified data as its contents.
  string result;

  const int code = zk->create(
      path,
      data,
      acl,
      ZOO_SEQUENCE | ZOO_EPHEMERAL,
      &result);

  if (code == ZINVALIDSTATE || (code != ZOK && zk->retryable(code))) {
    CHECK_NE(zk->getState(), ZOO_AUTH_FAILED_STATE);
    return None();
  } else if (code != ZOK) {
    return Error(
        "Failed to create ephemeral node at '" + path +
        "' in ZooKeeper: " + zk->message(code));
  }

  // Invalidate the cache (it will/should get immediately populated
  // via the 'updated' callback of our ZooKeeper watcher).
  memberships = None();

  // Save the sequence number but only grab the basename. Example:
  // "/path/to/znode/label_0000000131" => "0000000131".
  const string basename = strings::tokenize(result, "/").back();

  // Strip the label before grabbing the sequence number.
  const string node = label.isSome()
      ? strings::remove(basename, label.get() + "_")
      : basename;

  Try<int32_t> sequence = numify<int32_t>(node);
  CHECK_SOME(sequence);

  Promise<bool>* cancelled = new Promise<bool>();
  owned[sequence.get()] = cancelled;

  return Group::Membership(sequence.get(), label, cancelled->future());
}


Result<bool> GroupProcess::doCancel(const Group::Membership& membership)