protected override void Append()

in src/log4net/Appender/BufferingAppenderSkeleton.cs [456:529]
50 lines of code
18 McCabe index (conditional complexity)

		protected override void Append(LoggingEvent loggingEvent) 
		{
			// If the buffer size is set to 1 or less then the buffer will be
			// sent immediately because there is not enough space in the buffer
			// to buffer up more than 1 event. Therefore as a special case
			// we don't use the buffer at all.
			if (m_cb == null || m_bufferSize <= 1)
			{
				// Only send the event if we are in non lossy mode or the event is a triggering event
				if ((!m_lossy) || 
					(m_evaluator != null && m_evaluator.IsTriggeringEvent(loggingEvent)) || 
					(m_lossyEvaluator != null && m_lossyEvaluator.IsTriggeringEvent(loggingEvent)))
				{
					if (m_eventMustBeFixed)
					{
						// Derive class expects fixed events
						loggingEvent.Fix = this.Fix;
					}

					// Not buffering events, send immediately
					SendBuffer(new LoggingEvent[] { loggingEvent } );
				}
			}
			else
			{
				// Because we are caching the LoggingEvent beyond the
				// lifetime of the Append() method we must fix any
				// volatile data in the event.
				loggingEvent.Fix = this.Fix;

				// Add to the buffer, returns the event discarded from the buffer if there is no space remaining after the append
				LoggingEvent discardedLoggingEvent = m_cb.Append(loggingEvent);

				if (discardedLoggingEvent != null)
				{
					// Buffer is full and has had to discard an event
					if (!m_lossy)
					{
						// Not lossy, must send all events
						SendFromBuffer(discardedLoggingEvent, m_cb);
					}
					else
					{
						// Check if the discarded event should not be logged
						if (m_lossyEvaluator == null || !m_lossyEvaluator.IsTriggeringEvent(discardedLoggingEvent))
						{
							// Clear the discarded event as we should not forward it
							discardedLoggingEvent = null;
						}

						// Check if the event should trigger the whole buffer to be sent
						if (m_evaluator != null && m_evaluator.IsTriggeringEvent(loggingEvent))
						{
							SendFromBuffer(discardedLoggingEvent, m_cb);
						}
						else if (discardedLoggingEvent != null)
						{
							// Just send the discarded event
							SendBuffer(new LoggingEvent[] { discardedLoggingEvent } );
						}
					}
				}
				else
				{
					// Buffer is not yet full

					// Check if the event should trigger the whole buffer to be sent
					if (m_evaluator != null && m_evaluator.IsTriggeringEvent(loggingEvent))
					{
						SendFromBuffer(null, m_cb);
					}
				}
			}
		}