gauges

getkyo · Oct 16, 2023 · 975eaf4 · 975eaf4
1 parent 4c6eb76
commit 975eaf4
Show file tree

Hide file tree

Showing 4 changed files with 76 additions and 0 deletions.
diff --git a/kyo-core/shared/src/main/scala/kyo/stats/MetricReceiver.scala b/kyo-core/shared/src/main/scala/kyo/stats/MetricReceiver.scala
@@ -22,6 +22,14 @@ trait MetricReceiver {
       unit: String,
       a: Attributes
   ): Histogram
+
+  def gauge(
+      scope: List[String],
+      name: String,
+      description: String,
+      unit: String,
+      a: Attributes
+  )(f: => Double): Gauge
 }
 
 object MetricReceiver {
@@ -54,10 +62,20 @@ object MetricReceiver {
           a: Attributes
       ) =
         Histogram.noop
+
+      def gauge(
+          scope: List[String],
+          name: String,
+          description: String,
+          unit: String,
+          a: Attributes
+      )(f: => Double) =
+        Gauge.noop
     }
 
   def all(receivers: List[MetricReceiver]): MetricReceiver =
     new MetricReceiver {
+
       def counter(
           scope: List[String],
           name: String,
@@ -66,6 +84,7 @@ object MetricReceiver {
           a: Attributes
       ) =
         Counter.all(receivers.map(_.counter(scope, name, description, unit, a)))
+
       def histogram(
           scope: List[String],
           name: String,
@@ -74,5 +93,14 @@ object MetricReceiver {
           a: Attributes
       ) =
         Histogram.all(receivers.map(_.histogram(scope, name, description, unit, a)))
+
+      def gauge(
+          scope: List[String],
+          name: String,
+          description: String,
+          unit: String,
+          a: Attributes
+      )(f: => Double) =
+        Gauge.all(receivers.map(_.gauge(scope, name, description, unit, a)(f)))
     }
 }
diff --git a/kyo-core/shared/src/main/scala/kyo/stats/Stats.scala b/kyo-core/shared/src/main/scala/kyo/stats/Stats.scala
@@ -7,6 +7,7 @@ import kyo.stats.metrics._
 import kyo.stats.traces._
 
 trait Stats {
+
   def scope(name: String): Stats
 
   def initCounter(
@@ -84,5 +85,7 @@ object Stats {
           attributes: Attributes
       )(v: => T > S): T > (IOs with S) =
         Traces.span(path.reverse, name, attributes)(v)
+
+      override def toString = s"Stats(scope = ${path})"
     }
 }
diff --git a/kyo-core/shared/src/main/scala/kyo/stats/metrics.scala b/kyo-core/shared/src/main/scala/kyo/stats/metrics.scala
@@ -26,6 +26,15 @@ object metrics {
         a: Attributes = Attributes.empty
     ): Histogram =
       MetricReceiver.get.histogram(scope, name, description, unit, a)
+
+    def initGauge(
+        scope: List[String],
+        name: String,
+        description: String = "",
+        unit: String = "",
+        a: Attributes = Attributes.empty
+    )(f: => Double): Gauge =
+      MetricReceiver.get.gauge(scope, name, description, unit, a)(f)
   }
 
   trait Counter {
@@ -77,4 +86,20 @@ object metrics {
         def attributes(b: Attributes)         = all(l.map(_.attributes(b)))
       }
   }
+
+  trait Gauge {
+    def close: Unit > IOs
+  }
+
+  object Gauge {
+    val noop: Gauge =
+      new Gauge {
+        def close = ()
+      }
+
+    def all(l: List[Gauge]): Gauge =
+      new Gauge {
+        def close = Choices.traverseUnit(l)(_.close)
+      }
+  }
 }
diff --git a/kyo-stats-otel/src/main/scala/kyo/stats/otel/OTelMetricReceiver.scala b/kyo-stats-otel/src/main/scala/kyo/stats/otel/OTelMetricReceiver.scala
@@ -58,4 +58,24 @@ class OTelMetricReceiver extends MetricReceiver {
         histogram(scope, name, description, unit, a.add(b))
     }
 
+  def gauge(
+      scope: List[String],
+      name: String,
+      description: String,
+      unit: String,
+      a: Attributes
+  )(f: => Double) =
+    new Gauge {
+
+      val impl =
+        otel.getMeter(scope.mkString("_"))
+          .gaugeBuilder(name)
+          .setDescription(description)
+          .setUnit(unit)
+          .buildWithCallback(m => m.record(f))
+
+      def close =
+        IOs(impl.close())
+    }
+
 }