NLog.Layouts.SimpleLayout.GetFormattedMessage C# (CSharp) Method

        protected override string GetFormattedMessage(LogEventInfo logEvent)
        {
            if (IsFixedText)
            {
                return this.fixedText;
            }

            string cachedValue;

            if (logEvent.TryGetCachedLayoutValue(this, out cachedValue))
            {
                return cachedValue;
            }

            int initialSize = this.maxRenderedLength;
            if (initialSize > MaxInitialRenderBufferLength)
            {
                initialSize = MaxInitialRenderBufferLength;
            }

            var builder = new StringBuilder(initialSize);

            //Memory profiling pointed out that using a foreach-loop was allocating
            //an Enumerator. Switching to a for-loop avoids the memory allocation.
            for (int i = 0; i < this.Renderers.Count; i++)
            {
                LayoutRenderer renderer = this.Renderers[i];
                try
                {
                    renderer.Render(builder, logEvent);
                }
                catch (Exception exception)
                {
                    //also check IsErrorEnabled, otherwise 'MustBeRethrown' writes it to Error

                    //check for performance
                    if (InternalLogger.IsWarnEnabled || InternalLogger.IsErrorEnabled)
                    {
                        InternalLogger.Warn(exception, "Exception in '{0}.Append()'", renderer.GetType().FullName);
                    }

                    if (exception.MustBeRethrown())
                    {
                        throw;
                    }
                }
            }

            if (builder.Length > this.maxRenderedLength)
            {
                this.maxRenderedLength = builder.Length;
            }

            string value = builder.ToString();
            logEvent.AddCachedLayoutValue(this, value);
            return value;
        }