JDAQEvaluator.hh

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#ifndef __JDAQEVALUATOR__
#define __JDAQEVALUATOR__

#include "km3net-dataformat/online/JDAQUTCExtended.hh"
#include "km3net-dataformat/online/JDAQHeader.hh"
#include "km3net-dataformat/online/JDAQEventHeader.hh"


/**
 * \author mdejong
 */

namespace KM3NETDAQ {

  /**
   * Auxiliary class to determine time of DAQ objects.
   *
   * The time is relative to the fixed time defined in JDAQUTCExtended.\n
   * For DAQ events, the time is offset by the product of the event counter and a constant weight.\n
   * To correlate DAQ events with summary data, the weight should be set to a value such that 
   * this product is strictly less than half of the frame duration.
   */
  struct JDAQEvaluator {
    /**
     * Default constructor.
     */
    JDAQEvaluator()
    {}


    /**
     * Get time of object.
     *
     * \param  object          UTC time
     * \return                 time [s]
     */
    inline double operator()(const JDAQUTCExtended& object) const
    {
      return getTimeDifference(JDAQUTCExtended::getInstance(), object);
    }


    /**
     * Get time of object.
     *
     * \param  object          DAQ header
     * \return                 time [s]
     */
    inline double operator()(const JDAQHeader& object) const
    {
      return(*this)(object.getTimesliceStart());
    }


    /**
     * Get time of event.
     *
     * \param  object          event header
     * \return                 time [s]
     */
    inline double operator()(const JDAQEventHeader& object) const
    {
      return getTimeDifference(JDAQUTCExtended::getInstance(), object.getTimesliceStart())  +  object.getCounter() * getWeight();
    }


    /**
     * Get relative weight for JDAQEventHeader evaluation.
     *
     * This value should be less than half of the frame duration in units of seconds 
     * divided by the expected maximum number of events in a single data taking run.
     *
     * \return                 weigth [s]
     */
    static double getWeight()
    {
      return 1.0e-7; // [s]
    }
  };


  /**
   * Function object for evaluation of DAQ objects.
   */
  static const JDAQEvaluator getDAQValue;
}

#endif