On Mon, Sep 19, 2011 at 1:07 PM, ralph.goers @dslextreme.com <
ralph.go...@dslextreme.com> wrote:
>
>
> On Mon, Sep 19, 2011 at 10:07 AM, John Vasileff <john.li...@gmail.com>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
