feat: tracer, logger, etc are regular emitters now

src/lib/logger.ml

@@ -4,34 +4,14 @@
     {{:https://opentelemetry.io/docs/reference/specification/overview/#log-signal}
      the spec} *)
 
-open Common_
+open Opentelemetry_emitter
 
-(** A logger object *)
-class type t = object
-  method is_enabled : Log_record.severity -> bool
+type t = Log_record.t Emitter.t
 
-  method emit : Log_record.t list -> unit
-end
+let dummy () : t = Emitter.dummy ()
 
-(** Dummy logger, always disabled *)
-let dummy : t =
-  object
-    method is_enabled _ = false
+let enabled = Emitter.enabled
 
-    method emit _ = ()
-  end
+let emit = Emitter.emit
 
-class simple (exp : #Exporter.t) : t =
-  object
-    method is_enabled _ = true
-
-    method emit logs = if logs <> [] then exp#send_logs logs
-  end
-
-let emit ?service_name:_ ?attrs:_ (l : Log_record.t list) : unit =
-  match Exporter.Main_exporter.get () with
-  | None -> ()
-  | Some e -> e#send_logs l
-[@@deprecated "use an explicit Logger"]
-
-let k_logger : t Context.key = Context.new_key ()
+let of_exporter (exp : Exporter.t) : t = exp.emit_logs

src/lib/metrics_callbacks.ml

@@ -6,7 +6,7 @@ let create () : t = { cbs = Alist.make () }
 
 let[@inline] add_metrics_cb (self : t) f = Alist.add self.cbs f
 
-let add_to_exporter (exp : #Exporter.t) (self : t) =
+let add_to_exporter (exp : Exporter.t) (self : t) =
   let on_tick () =
     (* collect all metrics *)
     let res = ref [] in

src/lib/metrics_callbacks.mli

@@ -16,7 +16,7 @@ val add_metrics_cb : t -> (unit -> Metrics.t list) -> unit
     metrics. It might be called regularly by the backend, in particular (but not
     only) when {!Exporter.tick} is called. *)
 
-val add_to_exporter : #Exporter.t -> t -> unit
+val add_to_exporter : Exporter.t -> t -> unit
 (** Make sure we export metrics at every [tick] of the exporter *)
 
 module Main_set : sig

src/lib/metrics_emitter.ml

@@ -1,32 +1,19 @@
-open Common_
+open Opentelemetry_emitter
 
-class type t = object
-  method is_enabled : unit -> bool
+type t = Metrics.t Emitter.t
 
-  method emit : Metrics.t list -> unit
-end
+let dummy () : t = Emitter.dummy ()
 
-class dummy : t =
-  object
-    method is_enabled () = false
+let enabled = Emitter.enabled
 
-    method emit _ = ()
-  end
+let emit = Emitter.emit
 
-class simple (exp : #Exporter.t) : t =
-  object
-    method is_enabled () = true
-
-    method emit l = if l <> [] then exp#send_metrics l
-  end
+let of_exporter (exp : Exporter.t) : t = exp.emit_metrics
 
 (** Emit some metrics to the collector (sync). This blocks until the backend has
-    pushed the metrics into some internal queue, or discarded them.
-
-    {b NOTE} be careful not to call this inside a Gc alarm, as it can cause
-    deadlocks. *)
+    pushed the metrics into some internal queue, or discarded them. *)
 let emit ?attrs:_ (l : Metrics.t list) : unit =
   match Exporter.Main_exporter.get () with
   | None -> ()
-  | Some exp -> exp#send_metrics l
+  | Some exp -> Exporter.send_metrics exp l
 [@@deprecated "use an explicit Metrics_emitter.t"]

src/lib/opentelemetry.ml

@@ -75,6 +75,7 @@ module Logs = Logger [@@deprecated "use Logger"]
 
 (** {2 Utils} *)
 
+module Any_signal = Any_signal
 module Trace_context = Trace_context
 module Gc_metrics = Gc_metrics
 

src/lib/tracer.ml

@@ -6,44 +6,36 @@
 
 open Common_
 open Proto.Trace
+open Opentelemetry_emitter
 
 type span = Span.t
 
+type t = Span.t Emitter.t
 (** A tracer.
 
     https://opentelemetry.io/docs/specs/otel/trace/api/#tracer *)
-class type t = object
-  method is_enabled : unit -> bool
-
-  method emit : span list -> unit
-end
 
 (** Dummy tracer, always disabled *)
-let dummy : t =
-  object
-    method is_enabled () = false
-
-    method emit _ = ()
-  end
-
-(** A simple exporter that directly calls the exporter. *)
-class simple (exp : #Exporter.t) : t =
-  object
-    method is_enabled () = true
-
-    method emit spans = if spans <> [] then Exporter.send_trace exp spans
-  end
+let dummy () : t = Emitter.dummy ()
 
 (** A tracer that uses {!Exporter.Main_exporter} *)
 let simple_main_exporter : t =
-  object
-    method is_enabled () = Exporter.Main_exporter.present ()
-
-    method emit spans =
+  let enabled () = Exporter.Main_exporter.present () in
+  let closed () = not (enabled ()) in
+  let flush_and_close () = () in
+  let tick ~now:_ =
+    match Exporter.Main_exporter.get () with
+    | None -> ()
+    | Some exp -> Exporter.tick exp
+  in
+  let emit spans =
+    if spans <> [] then (
       match Exporter.Main_exporter.get () with
       | None -> ()
-      | Some exp -> exp#send_trace spans
-  end
+      | Some exp -> Exporter.send_trace exp spans
+    )
+  in
+  { Emitter.enabled; closed; emit; tick; flush_and_close }
 
 (** Directly emit to the main exporter.
 
@@ -53,7 +45,7 @@ let (emit [@deprecated "use an explicit tracer"]) =
  fun ?service_name:_ ?attrs:_ (spans : span list) : unit ->
   match Exporter.Main_exporter.get () with
   | None -> ()
-  | Some exp -> exp#send_trace spans
+  | Some exp -> Exporter.send_trace exp spans
 
 let (add_event [@deprecated "use Span.add_event"]) = Span.add_event
 
@@ -107,7 +99,7 @@ let with_thunk_and_finally ?(tracer = simple_main_exporter)
         in
         Span.set_status span status));
 
-    tracer#emit [ span ]
+    Emitter.emit tracer [ span ]
   in
   let thunk () = Ambient_span.with_ambient span (fun () -> cb span) in
   thunk, finally