Mihai Parparita f49b9f75b8 util/clientmetric: allow client metric values to be provided by a function ... Adds NewGaugeFunc and NewCounterFunc (inspired by expvar.Func) which change the current value to be reported by a function. This allows some client metric values to be computed on-demand during uploading (at most every 15 seconds), instead of being continuously updated. clientmetric uploading had a bunch of micro-optimizations for memory access (#3331) which are not possible with this approach. However, any performance hit from function-based metrics is contained to those metrics only, and we expect to have very few. Also adds a DisableDeltas() option for client metrics, so that absolute values are always reported. This makes server-side processing of some metrics easier to reason about. Updates tailscale/corp#9230 Signed-off-by: Mihai Parparita <mihai@tailscale.com>		2023-04-05 17:21:16 -07:00
..
clientmetric_test.go	util/clientmetric: allow client metric values to be provided by a function	2023-04-05 17:21:16 -07:00
clientmetric.go	util/clientmetric: allow client metric values to be provided by a function	2023-04-05 17:21:16 -07:00