public static string Format()

in src/Elastic.OpenTelemetry.Core/Diagnostics/LogFormatter.cs [13:58]
34 lines of code
6 McCabe index (conditional complexity)

	public static string Format<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
	{
		var managedThreadId = Environment.CurrentManagedThreadId;
		var dateTime = DateTime.UtcNow;
		string? spanId = null;
		var activity = Activity.Current;
		switch (state)
		{
			case LogState s:
				managedThreadId = s.ManagedThreadId;
				dateTime = s.DateTime;
				activity = s.Activity;
				spanId = s.SpanId;
				break;
		}

		var builder = StringBuilderCache.Acquire();

		// Force exceptions to be written as errors
		if (exception is not null)
			logLevel = LogLevel.Error;

		WriteLogPrefix(managedThreadId, dateTime, logLevel, builder, spanId ?? activity?.SpanId.ToHexString() ?? string.Empty);
		var message = formatter(state, exception);
		builder.Append(message);

		if (eventId != default)
			if (!string.IsNullOrEmpty(eventId.Name))
				builder.Append(" {{EventId: " + eventId.Id + ", EventName: " + eventId.Name + "}}");
			else
				builder.Append(" {{EventId: " + eventId.Id + "}}");

		if (activity is not null)
		{
			// Accessing activity.Id here will cause the Id to be initialized
			// before the sampler runs in case where the activity is created using legacy way
			// i.e. new Activity("Operation name"). This will result in Id not reflecting the
			// correct sampling flags
			// https://github.com/dotnet/runtime/issues/61857

			var activityId = $"00-{activity.TraceId.ToHexString()}-{activity.SpanId.ToHexString()}-{(activity.ActivityTraceFlags.HasFlag(ActivityTraceFlags.Recorded) ? "01" : "00")}";
			builder.Append($" <{activityId}>");
		}
		var fullLogLine = StringBuilderCache.GetStringAndRelease(builder);
		return fullLogLine;
	}