gistfile1.js

// saves data to db
Chat.prototype.save = function Chat_save(channel, key, value, callback)
{
  var _chat = this;

  this._db.put(channel+':'+key, value, function(err)
  {
    if (err) return callback(err);

    // update local
    _chat[channel][key] = value;

    return callback(null);
  });
}

gistfile2.js

  level(filename, {keyEncoding: 'utf8', valueEncoding: 'json'}, function(err, db)
  {
    if (err) return callback(err);

    _chat._db = db;