update exporters and emitter combinators in client

src/client/batch.ml

@@ -91,6 +91,7 @@ let[@inline] push' self elems = ignore (push self elems : [ `Dropped | `Ok ])
 open Opentelemetry_emitter
 
 let wrap_emitter (self : _ t) (e : _ Emitter.t) : _ Emitter.t =
+  let enabled () = e.enabled () in
   let closed () = e.closed () in
   let flush_and_close () =
     (* FIXME: we need to close the batch first, to prevent
@@ -118,7 +119,7 @@ let wrap_emitter (self : _ t) (e : _ Emitter.t) : _ Emitter.t =
   in
 
   let emit l =
-    if l <> [] then (
+    if l <> [] && e.enabled () then (
       push' self l;
 
       (* TODO: it'd be nice if we checked only for size here, not
@@ -129,4 +130,4 @@ let wrap_emitter (self : _ t) (e : _ Emitter.t) : _ Emitter.t =
     )
   in
 
-  { Emitter.closed; flush_and_close; tick; emit }
+  { Emitter.closed; enabled; flush_and_close; tick; emit }

src/client/debug_exporter.ml

@@ -1,36 +1,31 @@
 open Common_
+open Opentelemetry_emitter
 
 (** [debug exporter] behaves like [exporter], but will print signals on [stderr]
     before passing them to [exporter] *)
-class debug ?(out = Format.err_formatter) (exp : #OTEL.Exporter.t) :
-  OTEL.Exporter.t =
+let debug ?(out = Format.err_formatter) (exp : OTEL.Exporter.t) :
+    OTEL.Exporter.t =
   let open Proto in
-  object
-    method send_trace l =
-      Format.fprintf out "SPANS: %a@." (Format.pp_print_list Trace.pp_span) l;
-      exp#send_trace l
-
-    method send_metrics l =
-      Format.fprintf out "METRICS: %a@."
-        (Format.pp_print_list Metrics.pp_metric)
-        l;
-      exp#send_metrics l
-
-    method send_logs l =
-      Format.fprintf out "LOGS: %a@."
-        (Format.pp_print_list Logs.pp_log_record)
-        l;
-      exp#send_logs l
-
-    method tick () = exp#tick ()
-
-    method add_on_tick_callback cb = exp#add_on_tick_callback cb
-
-    method cleanup ~on_done () =
-      Format.fprintf out "CLEANUP@.";
-      exp#cleanup ~on_done ()
-  end
+  {
+    emit_spans =
+      Emitter.tap
+        (fun sp -> Format.fprintf out "SPAN: %a@." Trace.pp_span sp)
+        exp.emit_spans;
+    emit_logs =
+      Emitter.tap
+        (fun log -> Format.fprintf out "LOG: %a@." Proto.Logs.pp_log_record log)
+        exp.emit_logs;
+    emit_metrics =
+      Emitter.tap
+        (fun m -> Format.fprintf out "METRIC: %a@." Metrics.pp_metric m)
+        exp.emit_metrics;
+    on_tick = exp.on_tick;
+    cleanup =
+      (fun ~on_done () ->
+        Format.fprintf out "CLEANUP@.";
+        exp.cleanup ~on_done ());
+  }
 
 (** Exporter that simply debugs on [stderr] *)
 let debug_only : OTEL.Exporter.t =
-  new debug ~out:Format.err_formatter OTEL.Exporter.dummy
+  debug ~out:Format.err_formatter @@ OTEL.Exporter.dummy ()

src/client/sampler.ml

@@ -34,13 +34,16 @@ let accept (self : t) : bool =
 open Opentelemetry_emitter
 
 let wrap_emitter (self : t) (e : _ Emitter.t) : _ Emitter.t =
+  let enabled () = e.enabled () in
   let closed () = Emitter.closed e in
   let flush_and_close () = Emitter.flush_and_close e in
   let tick ~now = Emitter.tick e ~now in
 
   let emit l =
-    let accepted = List.filter (fun _x -> accept self) l in
-    if accepted <> [] then Emitter.emit e accepted
+    if l <> [] && e.enabled () then (
+      let accepted = List.filter (fun _x -> accept self) l in
+      if accepted <> [] then Emitter.emit e accepted
+    )
   in
 
-  { Emitter.closed; flush_and_close; tick; emit }
+  { Emitter.closed; enabled; flush_and_close; tick; emit }

src/client/stdout_exporter.ml

@@ -1,49 +0,0 @@
-(** A simple exporter that prints on stdout *)
-
-open Common_
-open Opentelemetry_util
-
-open struct
-  let pp_span out (sp : OTEL.Span.t) =
-    let open OTEL in
-    Format.fprintf out
-      "@[<2>SPAN@ trace_id: %a@ span_id: %a@ name: %S@ start: %a@ end: %a@]@."
-      Trace_id.pp
-      (Trace_id.of_bytes sp.trace_id)
-      Span_id.pp
-      (Span_id.of_bytes sp.span_id)
-      sp.name Timestamp_ns.pp_debug sp.start_time_unix_nano
-      Timestamp_ns.pp_debug sp.end_time_unix_nano
-
-  let pp_vlist mutex pp out l =
-    if l != [] then (
-      let@ () = Util_mutex.protect mutex in
-      Format.fprintf out "@[<v>";
-      List.iteri
-        (fun i x ->
-          if i > 0 then Format.fprintf out "@,";
-          pp out x)
-        l;
-      Format.fprintf out "@]@."
-    )
-end
-
-class stdout : OTEL.Exporter.t =
-  let open Opentelemetry_util in
-  let out = Format.std_formatter in
-  let mutex = Mutex.create () in
-
-  let tick_cbs = Cb_set.create () in
-  object
-    method send_trace l = pp_vlist mutex pp_span out l
-
-    method send_metrics l = pp_vlist mutex Proto.Metrics.pp_metric out l
-
-    method send_logs l = pp_vlist mutex Proto.Logs.pp_log_record out l
-
-    method tick () = Cb_set.trigger tick_cbs
-
-    method add_on_tick_callback cb = Cb_set.register tick_cbs cb
-
-    method cleanup ~on_done () = on_done ()
-  end