code: function SlowLog(conf) {
    this._conf = conf;
  
    // log commands slower than this number of microseconds
    // disabled by default
    this._slowerThan = -1;
  
    // maximum length of the slow log
    this._maxLen = 128;
  
    // set up log records array
    this.reset();
  
    // log record for the current executing command
    this._record = null;
  
    function onConfigLoad() {
      this._slowerThan = conf.get(ConfigKey.SLOWLOG_LOG_SLOWER_THAN);
      this._maxLen = conf.get(ConfigKey.SLOWLOG_MAX_LEN);
    }
  
    function onSlowerThan(key, value) {
      this._slowerThan = value;
    }
  
    function onMaxLen(key, value) {
      // minimum record length is one, if a user wishes
      // to disable slow logs they should set slowlog-log-slower-than to -1
      this._maxLen = Math.max(value, 1);
    }
  
    onConfigLoad = onConfigLoad.bind(this);
    onSlowerThan = onSlowerThan.bind(this);
    onMaxLen = onMaxLen.bind(this);
  
    this._conf.once('load', onConfigLoad.bind(this));
  
    this._conf.on(ConfigKey.SLOWLOG_LOG_SLOWER_THAN, onSlowerThan);
    this._conf.on(ConfigKey.SLOWLOG_MAX_LEN, onMaxLen);
  
    // bind stop here as it is called as a before
    // function on the response
    this.stop = this.stop.bind(this);
  }
docs: Encapsulates the slow log queries storage.
  
  @param conf The server configuration.