ocaml-opentelemetry/src/core/metrics.ml
2026-01-20 00:15:22 -05:00

80 lines
3 KiB
OCaml

(** Metrics.
See
{{:https://opentelemetry.io/docs/reference/specification/overview/#metric-signal}
the spec} *)
open Common_
open Proto
open Proto.Metrics
type t = Metrics.metric
(** A single metric, measuring some time-varying quantity or statistical
distribution. It is composed of one or more data points that have precise
values and time stamps. Each distinct metric should have a distinct name. *)
let pp = Proto.Metrics.pp_metric
open struct
let _program_start = Timestamp_ns.now_unix_ns ()
end
(** Number data point, as a float *)
let float ?start_time_unix_nano ?(now = Timestamp_ns.now_unix_ns ())
?(attrs = []) (d : float) : number_data_point =
let attributes = attrs |> List.map Key_value.conv in
make_number_data_point ?start_time_unix_nano ~time_unix_nano:now ~attributes
~value:(As_double d) ()
(** Number data point, as an int *)
let int ?start_time_unix_nano ?(now = Timestamp_ns.now_unix_ns ()) ?(attrs = [])
(i : int) : number_data_point =
let attributes = attrs |> List.map Key_value.conv in
make_number_data_point ?start_time_unix_nano ~time_unix_nano:now ~attributes
~value:(As_int (Int64.of_int i))
()
(** Aggregation of a scalar metric, always with the current value *)
let gauge ~name ?description ?unit_ (l : number_data_point list) : t =
let data = Gauge (make_gauge ~data_points:l ()) in
make_metric ~name ?description ?unit_ ~data ()
type aggregation_temporality = Metrics.aggregation_temporality =
| Aggregation_temporality_unspecified
| Aggregation_temporality_delta
| Aggregation_temporality_cumulative
(** Sum of all reported measurements over a time interval *)
let sum ~name ?description ?unit_
?(aggregation_temporality = Aggregation_temporality_cumulative)
?is_monotonic (l : number_data_point list) : t =
let data =
Sum (make_sum ~data_points:l ?is_monotonic ~aggregation_temporality ())
in
make_metric ~name ?description ?unit_ ~data ()
(** Histogram data
@param count number of values in population (non negative)
@param sum sum of values in population (0 if count is 0)
@param bucket_counts
count value of histogram for each bucket. Sum of the counts must be equal
to [count]. length must be [1+length explicit_bounds]
@param explicit_bounds strictly increasing list of bounds for the buckets *)
let histogram_data_point ?start_time_unix_nano
?(now = Timestamp_ns.now_unix_ns ()) ?(attrs = []) ?(exemplars = [])
?(explicit_bounds = []) ?sum ~bucket_counts ~count () : histogram_data_point
=
let attributes = attrs |> List.map Key_value.conv in
make_histogram_data_point ?start_time_unix_nano ~time_unix_nano:now
~attributes ~exemplars ~bucket_counts ~explicit_bounds ~count ?sum ()
let histogram ~name ?description ?unit_ ?aggregation_temporality
(l : histogram_data_point list) : t =
let data =
Histogram (make_histogram ~data_points:l ?aggregation_temporality ())
in
make_metric ~name ?description ?unit_ ~data ()
(* TODO: exponential history *)
(* TODO: summary *)
(* TODO: exemplar *)