Hi Joern, On 24/04/2010 1:55 AM, Joern Huxhorn wrote:
Hi Ceki,
On 23.04.2010, at 16:18, Ceki Gülcü <ceki@qos.ch> wrote:
On 23/04/2010 2:14 PM, Joern Huxhorn wrote:
Didn't you change LocationAwareLogger and doesn't that mean that it's not compatible with the current Logback anymore? Or is this only relevant for wrappers like jcl-over-slf4j and you changed all of them already?
Right, LocationAwareLogger affects compatibility with logback but so does MessageFormatter changes, actually the latter in a deeper way as it is no longer possible to compute the formatted message lazily in LoggingEvent. I must be computed eagerly in LoggingEvent's constructor.
Are you aware that my ParameterizedMessage supports both #70 and lazy initialization?
Yes, but ParameterizedMessage has to be passed as a Message to a logger of type org.slf4j.n.Logger. More below.
This is possible since the placeholders are only counted during creation. The actual formatting/placeholder replacement is only performed when the formatted message is requested. The formatted message is kept so it won't be regenerated in case of further calls. It could also be enhanced to perform the toString of the arguments at a later time. The Message interface could be extended by an prepareForDeferredProcessing() method for that purpose.
I agree with Ralph that this would be a good time to extend the Logger interface with Message-aware methods since 1.6 will be incompatible anyway.
Initially, I also thought that 1.6.0 was a good time to integrate your changes. Changing the Logger interface breaks compatibility with client code using SLF4J. Breaking compatibility at this level is different than breaking compatibility within SLF4J internals. For example, as long as the end-user places slf4j-api-1.6.0.jar and an appropriate 1.6.0 binding on the class path, things will work fine without needing to compile client code or dependencies. However, if the logger interface was changed, then *all* client code (including all dependencies using SLF4J) would need to be recompiled. There is no comparison in the impact of changing SLF4J internals and changing client-facing interfaces such as org.slf4j.Logger. -- Ceki