On Sep 19, 2011, at 4:09 PM, ralph.goers @dslextreme.com wrote: > > > On Mon, Sep 19, 2011 at 1:07 PM, ralph.goers @dslextreme.com > <[email protected]> wrote: > > > On Mon, Sep 19, 2011 at 10:07 AM, John Vasileff <[email protected]> wrote: > > What do you think about an optional LazyRenderMessage interface (I'm sure > there is a better name for this) that could be used by Message types that > have expensive constructers? > > interface LazyRenderMessage { > void render(); > } > > The logger would call render() immediately after checking isEnabled for level > and marker. So, this should not affect serialization - the object will > either be fully constructed or discarded right away. > > This would allow ThreadDumpMessage Thread.getAllStackTraces() work to be > avoided unless logging will actually occur (or is likely to occur in the case > of complex filters). > > The benefit of course is that trace(THREAD_DUMP_MARKER, new > ThreadDumpMessage()) could be left in production code without if > isTraceEnabled(...) { ... }, and with very little overhead - creating a short > lived object that does nothing in the constructor is pretty cheap these days. > > This would also help for Message types like ParameterizedMessage to avoid > parseArguments(arguments) when they are created by application code. > > I see some merit in this idea. But you are right, it really needs a better > name. > > One other point, though, is that there should always be a constructor that > allows immediate rendering. I could easily see the ThreadDumpMessage being > used for other purposes and never being passed to a logger. For example, I > could create two ThreadDumpMessages at slightly different points in time and > then only print the differences between them. > > Ralph
Good point. new ThreadDumpMessage().render(); would work if documented in the javadocs for the constructor. But I would hate to make things too complicated to bail out those too lazy to check isEnabled. I don't have a strong opinion either way on whether this complicates things too much. Maybe those that need to call render() will also pick up on the fact, and those that don't, don't need to. Not sure. As far as naming goes - I suppose it would take some effort to come up with something worse! I have no good ideas. John
