Implement tracing API

.github/workflows/ci.yml

@@ -94,11 +94,11 @@ jobs:
 
       - name: Make target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
-        run: mkdir -p testkit/metrics/jvm/target java/metrics/target testkit/common/jvm/target core/tracing/.jvm/target core/tracing/.js/target target core/common/.jvm/target .js/target site/target core/metrics/.jvm/target core/all/.js/target java/all/target java/common/target core/metrics/.js/target core/all/.jvm/target .jvm/target .native/target core/common/.js/target testkit/all/jvm/target project/target
+        run: mkdir -p testkit/metrics/jvm/target java/metrics/target testkit/common/jvm/target core/tracing/.jvm/target core/tracing/.js/target target core/common/.jvm/target .js/target site/target core/metrics/.jvm/target core/all/.js/target java/all/target java/common/target java/tracing/target core/metrics/.js/target core/all/.jvm/target .jvm/target .native/target core/common/.js/target testkit/all/jvm/target project/target
 
       - name: Compress target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')
-        run: tar cf targets.tar testkit/metrics/jvm/target java/metrics/target testkit/common/jvm/target core/tracing/.jvm/target core/tracing/.js/target target core/common/.jvm/target .js/target site/target core/metrics/.jvm/target core/all/.js/target java/all/target java/common/target core/metrics/.js/target core/all/.jvm/target .jvm/target .native/target core/common/.js/target testkit/all/jvm/target project/target
+        run: tar cf targets.tar testkit/metrics/jvm/target java/metrics/target testkit/common/jvm/target core/tracing/.jvm/target core/tracing/.js/target target core/common/.jvm/target .js/target site/target core/metrics/.jvm/target core/all/.js/target java/all/target java/common/target java/tracing/target core/metrics/.js/target core/all/.jvm/target .jvm/target .native/target core/common/.js/target testkit/all/jvm/target project/target
 
       - name: Upload target directories
         if: github.event_name != 'pull_request' && (startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main')

build.sbt

@@ -23,6 +23,7 @@ ThisBuild / scalaVersion := Scala213 // the default Scala
 
 val CatsVersion = "2.8.0"
 val CatsEffectVersion = "3.3.14"
+val FS2Version = "3.3.0"
 val MUnitVersion = "0.7.29"
 val MUnitCatsEffectVersion = "1.0.7"
 val OpenTelemetryVersion = "1.19.0"
@@ -35,6 +36,13 @@ lazy val scalaReflectDependency = Def.settings(
   }
 )
 
+lazy val munitDependencies = Def.settings(
+  libraryDependencies ++= Seq(
+    "org.scalameta" %%% "munit" % MUnitVersion % Test,
+    "org.typelevel" %%% "munit-cats-effect-3" % MUnitCatsEffectVersion % Test
+  )
+)
+
 lazy val root = tlCrossRootProject
   .aggregate(
     `core-common`,
@@ -46,6 +54,7 @@ lazy val root = tlCrossRootProject
     testkit,
     `java-common`,
     `java-metrics`,
+    `java-tracing`,
     java
   )
   .settings(name := "otel4s")
@@ -66,12 +75,11 @@ lazy val `core-metrics` = crossProject(JVMPlatform, JSPlatform)
   .in(file("core/metrics"))
   .dependsOn(`core-common`)
   .settings(scalaReflectDependency)
+  .settings(munitDependencies)
   .settings(
     name := "otel4s-core-metrics",
     libraryDependencies ++= Seq(
       "org.typelevel" %%% "cats-effect-kernel" % CatsEffectVersion,
-      "org.scalameta" %%% "munit" % MUnitVersion % Test,
-      "org.typelevel" %%% "munit-cats-effect-3" % MUnitCatsEffectVersion % Test,
       "org.typelevel" %%% "cats-effect-testkit" % CatsEffectVersion % Test
     )
   )
@@ -81,14 +89,13 @@ lazy val `core-tracing` = crossProject(JVMPlatform, JSPlatform)
   .in(file("core/tracing"))
   .dependsOn(`core-common`)
   .settings(scalaReflectDependency)
+  .settings(munitDependencies)
   .settings(
     name := "otel4s-core-tracing",
     libraryDependencies ++= Seq(
       "org.typelevel" %%% "cats-effect-kernel" % CatsEffectVersion,
       "org.scodec" %%% "scodec-bits" % ScodecVersion,
-      "org.scalameta" %%% "munit" % MUnitVersion % Test,
-      "org.typelevel" %%% "munit-cats-effect-3" % MUnitCatsEffectVersion % Test,
-      "org.typelevel" %%% "cats-effect-testkit" % CatsEffectVersion % Test
+      "org.scalameta" %%% "munit" % MUnitVersion % Test
     )
   )
 
@@ -150,20 +157,33 @@ lazy val `java-common` = project
 lazy val `java-metrics` = project
   .in(file("java/metrics"))
   .dependsOn(`java-common`, `core-metrics`.jvm, `testkit-metrics`.jvm)
+  .settings(munitDependencies)
   .settings(
     name := "otel4s-java-metrics",
     libraryDependencies ++= Seq(
-      "io.opentelemetry" % "opentelemetry-api" % OpenTelemetryVersion,
+      "io.opentelemetry" % "opentelemetry-sdk" % OpenTelemetryVersion % Test,
+      "io.opentelemetry" % "opentelemetry-sdk-testing" % OpenTelemetryVersion % Test
+    )
+  )
+
+lazy val `java-tracing` = project
+  .in(file("java/tracing"))
+  .dependsOn(`java-common`, `core-tracing`.jvm)
+  .settings(munitDependencies)
+  .settings(
+    name := "otel4s-java-tracing",
+    libraryDependencies ++= Seq(
+      "org.typelevel" %%% "cats-effect" % CatsEffectVersion,
       "io.opentelemetry" % "opentelemetry-sdk" % OpenTelemetryVersion % Test,
       "io.opentelemetry" % "opentelemetry-sdk-testing" % OpenTelemetryVersion % Test,
-      "org.scalameta" %% "munit" % MUnitVersion % Test,
-      "org.typelevel" %% "munit-cats-effect-3" % MUnitCatsEffectVersion % Test
+      "org.typelevel" %%% "cats-effect-testkit" % CatsEffectVersion % Test,
+      "co.fs2" %% "fs2-core" % FS2Version % Test
     )
   )
 
 lazy val java = project
   .in(file("java/all"))
-  .dependsOn(core.jvm, `java-metrics`)
+  .dependsOn(core.jvm, `java-metrics`, `java-tracing`)
   .settings(
     name := "otel4s-java"
   )

core/all/src/main/scala/org/typelevel/otel4s/Otel4s.scala

@@ -17,10 +17,15 @@
 package org.typelevel.otel4s
 
 import org.typelevel.otel4s.metrics.MeterProvider
+import org.typelevel.otel4s.trace.TracerProvider
 
 trait Otel4s[F[_]] {
 
   /** A registry for creating named meters.
     */
   def meterProvider: MeterProvider[F]
+
+  /** An entry point of the tracing API.
+    */
+  def tracerProvider: TracerProvider[F]
 }

core/tracing/src/main/scala-2/org/typelevel/otel4s/trace/SpanMacro.scala

@@ -0,0 +1,202 @@
+/*
+ * Copyright 2022 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.typelevel.otel4s
+package trace
+
+import scala.concurrent.duration.FiniteDuration
+
+private[otel4s] trait SpanMacro[F[_]] {
+  self: Span[F] =>
+
+  /** Adds an event to the span with the given attributes. The timestamp of the
+    * event will be the current time.
+    *
+    * @param name
+    *   the name of the event
+    *
+    * @param attributes
+    *   the set of attributes to associate with the event
+    */
+  def addEvent(name: String, attributes: Attribute[_]*): F[Unit] =
+    macro SpanMacro.addEvent
+
+  /** Adds an event to the span with the given attributes and timestamp.
+    *
+    * '''Note''': the timestamp should be based on `Clock[F].realTime`. Using
+    * `Clock[F].monotonic` may lead to an incorrect data.
+    *
+    * @param name
+    *   the name of the event
+    *
+    * @param timestamp
+    *   the explicit event timestamp since epoch
+    *
+    * @param attributes
+    *   the set of attributes to associate with the event
+    */
+  def addEvent(
+      name: String,
+      timestamp: FiniteDuration,
+      attributes: Attribute[_]*
+  ): F[Unit] =
+    macro SpanMacro.addEventWithTimestamp
+
+  /** Records information about the `Throwable` to the span.
+    *
+    * @param exception
+    *   the `Throwable` to record
+    *
+    * @param attributes
+    *   the set of attributes to associate with the value
+    */
+  def recordException(
+      exception: Throwable,
+      attributes: Attribute[_]*
+  ): F[Unit] =
+    macro SpanMacro.recordException
+
+  /** Sets an attribute to the span. If the span previously contained a mapping
+    * for the key, the old value is replaced by the specified value.
+    *
+    * @param attribute
+    *   the attribute to add to the span
+    */
+  def setAttribute[A](attribute: Attribute[A]): F[Unit] =
+    macro SpanMacro.setAttribute[A]
+
+  /** Sets attributes to the span. If the span previously contained a mapping
+    * for any of the keys, the old values are replaced by the specified values.
+    *
+    * @param attributes
+    *   the set of attributes to add to the span
+    */
+  def setAttributes(attributes: Attribute[_]*): F[Unit] =
+    macro SpanMacro.setAttributes
+
+  /** Sets the status to the span.
+    *
+    * Only the value of the last call will be recorded, and implementations are
+    * free to ignore previous calls.
+    *
+    * @param status
+    *   the [[Status]] to set
+    */
+  def setStatus(status: Status): F[Unit] =
+    macro SpanMacro.setStatus
+
+  /** Sets the status to the span.
+    *
+    * Only the value of the last call will be recorded, and implementations are
+    * free to ignore previous calls.
+    *
+    * @param status
+    *   the [[Status]] to set
+    *
+    * @param description
+    *   the description of the [[Status]]
+    */
+  def setStatus(status: Status, description: String): F[Unit] =
+    macro SpanMacro.setStatusWithDescription
+
+}
+
+object SpanMacro {
+  import scala.reflect.macros.blackbox
+
+  def addEvent(c: blackbox.Context)(
+      name: c.Expr[String],
+      attributes: c.Expr[Attribute[_]]*
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.addEvent($name, ..$attributes) else $meta.unit"
+  }
+
+  def addEventWithTimestamp(c: blackbox.Context)(
+      name: c.Expr[String],
+      timestamp: c.Expr[FiniteDuration],
+      attributes: c.Expr[Attribute[_]]*
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.addEvent($name, $timestamp, ..$attributes) else $meta.unit"
+  }
+
+  def recordException(c: blackbox.Context)(
+      exception: c.Expr[Throwable],
+      attributes: c.Expr[Attribute[_]]*
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.recordException($exception, ..$attributes) else $meta.unit"
+  }
+
+  def setAttribute[A](c: blackbox.Context)(
+      attribute: c.Expr[Attribute[A]]
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.setAttributes($attribute) else $meta.unit"
+  }
+
+  def setAttributes(c: blackbox.Context)(
+      attributes: c.Expr[Attribute[_]]*
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.setAttributes(..$attributes) else $meta.unit"
+  }
+
+  def setStatus(c: blackbox.Context)(
+      status: c.Expr[Status]
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.setStatus($status) else $meta.unit"
+  }
+
+  def setStatusWithDescription(c: blackbox.Context)(
+      status: c.Expr[Status],
+      description: c.Expr[String]
+  ): c.universe.Tree = {
+    import c.universe._
+
+    val backend = q"${c.prefix}.backend"
+    val meta = q"$backend.meta"
+
+    q"if ($meta.isEnabled) $backend.setStatus($status, $description) else $meta.unit"
+  }
+
+}