3-arity version of `metrics.timers/timer` is not implemented

[sebastianpoeplau]

The arity-3 version of metrics.timers/deftimer tries to call timer with 3 arguments, which is not implemented. I guess it should either be dropped or call timer-with-reservoir. On a related note, is there a reason why timer passes the title through metrics.core/metric-name while timer-with-reservoir doesn't?

[michaelklishin]

I doubt there is a reason.

Feel free to look into a pull request.

[sebastianpoeplau]

@michaelklishin I'm not sure if an arity-3 version of metrics.timers/timer makes sense: callers would create a new reservoir in vain on every call but the first. I think deftimer should rather delegate to metrics.timers/timer-with-reservoir in this case. Regarding naming, I can certainly add the call to metric-name in timer-with-reservoir, but that would not be a backwards-compatible change. Duplicating the function just for the sake of keeping naming consistent in deftimer doesn't seem elegant either, though. Do you have any preference?