/// <summary>
/// Stops the journaler; derived classes may override this method to perform
/// additional logic when stopping. The registration key controls the journaler's
/// registration with the underlying IEventListener. At the time of the call
/// the registration is suspended (journaler is no longer receiving LWES events).
/// It is the responsibility of the derived class to either call the base-class
/// PerformStop method or cancel the registration key. The journaler will hold
/// the registration key indefinitely if it is not canceled.
/// </summary>
/// <param name="registrationKey"></param>
/// <returns></returns>
protected virtual bool PerformStop(ISinkRegistrationKey registrationKey)
{
if (registrationKey == null) throw new ArgumentNullException("registrationKey");
registrationKey.Cancel();
return true;
}
/// <summary>
/// Starts the journaler; derived classes may override this method to perform
/// additional logic when starting. The registration key controls the journaler's
/// registration with the underlying IEventListener. At the time of the call
/// the registration is suspended (journaler is not yet receiving LWES events).
/// It is the responsibility of the derived class to either call the base-class
/// PerformStart method or activate the registration key. LWES events will not
/// flow to the journaler until the key has been activated.
/// </summary>
/// <param name="registrationKey"></param>
/// <returns></returns>
protected virtual bool PerformStart(ISinkRegistrationKey registrationKey)
{
if (registrationKey == null) throw new ArgumentNullException("registrationKey");
return registrationKey.Activate();
}
/// <summary>
/// Starts the journaler.
/// </summary>
public void Start()
{
if (_status.SetStateIfLessThan(JournalerState.Starting, JournalerState.Initialized))
{
try
{
_registrationKey = _listener.RegisterDataReceiverSink(this);
// Let the subclass decide if the start succeeded.
if (PerformStart(_registrationKey) && _registrationKey.Activate())
{
_status.TryTransition(JournalerState.Active, JournalerState.Starting);
}
}
catch (Exception e)
{
this.TraceData(TraceEventType.Error, Resources.Error_UnexpectedErrorStartngJournaler, e);
_status.TryTransition(JournalerState.Initialized, JournalerState.Starting);
}
}
}
/// <summary>
/// Stops the journaler.
/// </summary>
public void Stop()
{
if (_status.SetStateIfLessThan(JournalerState.Stopping, JournalerState.Active))
{
try
{
_registrationKey.Suspend();
// Let the subclass decide if the stop succeeded.
if (PerformStop(_registrationKey))
{
_registrationKey = null;
_status.TryTransition(JournalerState.Stopped, JournalerState.Stopping);
}
}
catch (Exception e)
{
this.TraceData(TraceEventType.Error, Resources.Error_UnexpectedErrorStoppingJournaler, e);
_status.TryTransition(JournalerState.Active, JournalerState.Stopping);
}
}
}
bool IDataReceiverSink.HandleData(ISinkRegistrationKey key, EndPoint remoteEP, byte[] data, int offset, int count)
{
return PerformHandleData(remoteEP, data, offset, count);
}
