Hi All, To emphasize the still experimental nature of 1.6.0, I made a new release changing suffix from RC to alpha. This will give us more wiggle room. More below. On 24/04/2010 3:55 PM, Joern Huxhorn wrote:
One of my goals in slf4j-n was to reduce the number of methods in the Logger interface. This was seemingly a bad idea since it would have a performance impact, in the case where a message isn't actually logged, as Ralph reported.
Because of this, it would be very wise to keep all the methods that are already present in the Logger interface and simply add debug(Message) debug(Message, Throwable) debug(Marker, Message) debug(Marker, Message, Throwable) [same for other levels plus generic log(Level, ...)-methods]
The designer in me doesn't like the "bloated" (in the sense that some methods could be dropped without losing functionality) interface, but the realist in me accepts that performance is more important than aesthetics ;)
Can't we coalesce debug(Message), debug(Message, Throwable), debug(Marker, Message) and debug(Marker, Message, Throwable) into a single variant? Here is an idea: try { ... } catch(Throwable t) { Message m = new Message("hello{}").addParam("word").add(marker).add(t); logger.error(m); } This approach incurs the cost of creating and building the Message object regardless of whether the request will be logged or not. I suspect that the bulk of the cost is due to the object creation incurred by new Message(...) and not due to the addition of extra data incurred in calling addParam() and the other add() methods. Thus, performance-wise we are in the same position as the original Message proposal but now we can get rid of all the overloaded variants dealing with Marker and throwable.
The big advantage, on the other hand, would be that the interfaces would indeed stay compile-time compatible.
I only dropped this requirement since I assumed that the original slf4j-api was absolutely frozen (and I still think that it would be a good idea to keep it that way...).
slf4j-api and slf4j-n-api were meant to exist side by side, with the former ensuring backwards-compatibility with Java 1.4 and slf4j-n-api for explicit opt-in to new functionality by changing the imports of Logger and LoggerFactory.
If the preconditions of a frozen slf4j-api and Java 1.4 compatibility have been dropped, there's no use for a separate slf4j-n-api and we can simply extend the current Logger interface with the previously mentioned methods.
If the Logger interface was frozen, then slf4j-n-api was the only possibility to evolve the API.
Cheers, Joern.