feat: instruments com.twitter.util-stats

instrumentation/twitter-util-stats-23.11/javaagent/build.gradle.kts

@@ -0,0 +1,52 @@
+plugins {
+  id("otel.javaagent-instrumentation")
+  id("otel.scala-conventions")
+}
+
+muzzle {
+  pass {
+    group.set("com.twitter")
+    module.set("util-stats_2.12")
+    versions.set("[23.11.0,]")
+  }
+
+  pass {
+    group.set("com.twitter")
+    module.set("util-stats_2.13")
+    versions.set("[23.11.0,]")
+  }
+}
+
+val twitterUtilVersion = "23.11.0"
+val scalaVersion = "2.13.10"
+
+val scalaMinor = Regex("""^([0-9]+\.[0-9]+)\.?.*$""").find(scalaVersion)!!.run {
+  val (minorVersion) = this.destructured
+  minorVersion
+}
+
+val scalified = fun(pack: String): String {
+  return "${pack}_$scalaMinor"
+}
+
+dependencies {
+  bootstrap(project(":instrumentation:executors:bootstrap"))
+
+  compileOnly("com.google.auto.value:auto-value-annotations")
+  annotationProcessor("com.google.auto.value:auto-value")
+
+  library("${scalified("com.twitter:util-stats")}:$twitterUtilVersion")
+
+  testImplementation("${scalified("com.twitter:finagle-http")}:$twitterUtilVersion")
+  // get all the metric services loaded
+  testImplementation("${scalified("com.twitter:finagle-stats")}:$twitterUtilVersion")
+
+  // should wire netty contexts
+//  testInstrumentation(project(":instrumentation:netty:netty-4.1:javaagent"))
+}
+
+tasks {
+  test {
+    jvmArgs("-Dotel.instrumentation.twitter-util-stats.stats-receiver.mode=additive")
+  }
+}

instrumentation/twitter-util-stats-23.11/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/twitterutilstats/v23_11/LoadedStatsReceiverInstrumentation.java

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+package io.opentelemetry.javaagent.instrumentation.twitterutilstats.v23_11;
+
+import static net.bytebuddy.matcher.ElementMatchers.isTypeInitializer;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+
+import com.twitter.finagle.stats.BroadcastStatsReceiver;
+import com.twitter.finagle.stats.StatsReceiver;
+import io.opentelemetry.javaagent.bootstrap.internal.AgentInstrumentationConfig;
+import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
+import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+import net.bytebuddy.asm.Advice;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.matcher.ElementMatcher;
+
+public class LoadedStatsReceiverInstrumentation implements TypeInstrumentation {
+  @Override
+  public ElementMatcher<TypeDescription> typeMatcher() {
+    // $ => we want the scala object, not the class
+    return named("com.twitter.finagle.stats.LoadedStatsReceiver$");
+  }
+
+  @Override
+  public void transform(TypeTransformer transformer) {
+    // perform this on the class initializer bc LoadedStatsReceiver::self is a var, not a val;
+    // we don't want to wrap this every time, and we need to respect behavior when someone sets it
+    transformer.applyAdviceToMethod(
+        isTypeInitializer(), LoadedStatsReceiverInstrumentation.class.getName() + "$ClinitAdvice");
+  }
+
+  @SuppressWarnings("unused")
+  public static class ClinitAdvice {
+
+    @Advice.OnMethodExit(suppress = Throwable.class)
+    public static void methodEnter(
+        @Advice.FieldValue(value = "self", readOnly = false) StatsReceiver self) {
+      String mode =
+          AgentInstrumentationConfig.get()
+              .getString("otel.instrumentation.twitter-util-stats.metrics.mode", "additive");
+      List<StatsReceiver> sr;
+      if (Objects.equals(mode, "additive")) {
+        sr = Arrays.asList(new OtelStatsReceiverProxy(), self);
+
+      } else {
+        sr = Collections.singletonList(new OtelStatsReceiverProxy());
+      }
+      // emulate the original invocation to avoid downstream side effects;
+      // iow make no assumptions about how BroadcastStatsReceiver behaves
+      self =
+          BroadcastStatsReceiver.apply(
+              scala.jdk.CollectionConverters.ListHasAsScala(sr).asScala().toSeq());
+    }
+  }
+}