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Author: sarahchen6

dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java

@@ -707,12 +707,13 @@ private CoreTracer(
             : HealthMetrics.NO_OP;
     healthMetrics.start();
 
+    // Start RUM injector health metrics
     rumInjectorHealthMetrics =
         config.isHealthMetricsEnabled() && config.isRumEnabled()
             ? new DefaultRumInjectorHealthMetrics(this.statsDClient)
             : RumInjectorHealthMetrics.NO_OP;
     rumInjectorHealthMetrics.start();
-    // Register health metrics telemetry collector with RumInjector
+    // Register rumInjectorHealthMetrics as the RumInjector's telemetry collector
     RumInjector.setTelemetryCollector((DefaultRumInjectorHealthMetrics) rumInjectorHealthMetrics);
 
     performanceMonitoring =

dd-trace-core/src/main/java/datadog/trace/core/monitor/DefaultRumInjectorHealthMetrics.java

@@ -12,7 +12,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-// Default implementation of RumInjectorHealthMetrics that reports metrics to StatsDClient
+// Default implementation of RumInjectorHealthMetrics that reports metrics via StatsDClient
+// This class implements the RumTelemetryCollector interface, which is used to collect telemetry
+// from the RumInjector in the internal-api module
 public class DefaultRumInjectorHealthMetrics extends RumInjectorHealthMetrics
     implements RumTelemetryCollector {
   private static final Logger log = LoggerFactory.getLogger(DefaultRumInjectorHealthMetrics.class);

dd-trace-core/src/main/java/datadog/trace/core/monitor/RumInjectorHealthMetrics.java

@@ -1,7 +1,6 @@
 package datadog.trace.core.monitor;
 
-// Abstract health metrics for RUM injector
-// This class defines the interface for monitoring RUM injection operations
+// Abstract health metrics class for RUM injector
 public abstract class RumInjectorHealthMetrics implements AutoCloseable {
   public static RumInjectorHealthMetrics NO_OP = new RumInjectorHealthMetrics() {};
 

internal-api/src/main/java/datadog/trace/api/rum/RumInjector.java

@@ -124,21 +124,25 @@ public byte[] getMarkerBytes(String encoding) {
     return this.markerCache.computeIfAbsent(encoding, MARKER_BYTES);
   }
 
+  // set the telemetry collector for the RumInjector
   public static void setTelemetryCollector(RumTelemetryCollector collector) {
     telemetryCollector = collector != null ? collector : RumTelemetryCollector.NO_OP;
   }
 
-  // report that the RUM injector succeeded in injecting the SDK in an HTTP response
+  // report to the telemetry collector that the RUM injector succeeded in injecting the SDK in an
+  // HTTP response
   public static void reportInjectionSucceed() {
     telemetryCollector.onInjectionSucceed();
   }
 
-  // report that the RUM injector failed to inject the SDK in an HTTP response
+  // report to the telemetry collector that the RUM injector failed to inject the SDK in an HTTP
+  // response
   public static void reportInjectionFailed() {
     telemetryCollector.onInjectionFailed();
   }
 
-  // report that the RUM injector skipped injecting the SDK in an HTTP response
+  // report to the telemetry collector that the RUM injector skipped injecting the SDK in an HTTP
+  // response
   public static void reportInjectionSkipped() {
     telemetryCollector.onInjectionSkipped();
   }

internal-api/src/main/java/datadog/trace/api/rum/RumTelemetryCollector.java

@@ -1,6 +1,7 @@
 package datadog.trace.api.rum;
 
-// Collect RUM injection telemetry
+// Collect RUM injection telemetry from the RumInjector
+// This is implemented by the DefaultRumInjectorHealthMetrics class in the dd-trace-core module
 public interface RumTelemetryCollector {
 
   RumTelemetryCollector NO_OP =