val create : unit -> t
create () is a fresh registry. This is mostly useful for testing.
val default : t
The default registry.
register t metric collector adds
metric to the set of metrics being collected. It will call
collector () to collect the values each time
collect is called.
register_lwt t metric collector is the same as
register t metrics collector but
Sample_set.t LabelSetMap.t Lwt.t.
val register_pre_collect : t -> ( unit -> unit ) -> unit
register_pre_collect t fn arranges for
fn () to be called at the start of each collection. This is useful if one expensive call provides information about multiple metrics.