store placeholder span in root context

Author: adinauer

sentry-opentelemetry/sentry-opentelemetry-bootstrap/api/sentry-opentelemetry-bootstrap.api

@@ -171,6 +171,20 @@ public final class io/sentry/opentelemetry/SentryContextWrapper : io/opentelemet
 	public static fun wrap (Lio/opentelemetry/context/Context;)Lio/sentry/opentelemetry/SentryContextWrapper;
 }
 
+public final class io/sentry/opentelemetry/SentryOtelGlobalHubModeSpan : io/opentelemetry/api/trace/Span {
+	public fun <init> ()V
+	public fun addEvent (Ljava/lang/String;Lio/opentelemetry/api/common/Attributes;)Lio/opentelemetry/api/trace/Span;
+	public fun addEvent (Ljava/lang/String;Lio/opentelemetry/api/common/Attributes;JLjava/util/concurrent/TimeUnit;)Lio/opentelemetry/api/trace/Span;
+	public fun end ()V
+	public fun end (JLjava/util/concurrent/TimeUnit;)V
+	public fun getSpanContext ()Lio/opentelemetry/api/trace/SpanContext;
+	public fun isRecording ()Z
+	public fun recordException (Ljava/lang/Throwable;Lio/opentelemetry/api/common/Attributes;)Lio/opentelemetry/api/trace/Span;
+	public fun setAttribute (Lio/opentelemetry/api/common/AttributeKey;Ljava/lang/Object;)Lio/opentelemetry/api/trace/Span;
+	public fun setStatus (Lio/opentelemetry/api/trace/StatusCode;Ljava/lang/String;)Lio/opentelemetry/api/trace/Span;
+	public fun updateName (Ljava/lang/String;)Lio/opentelemetry/api/trace/Span;
+}
+
 public final class io/sentry/opentelemetry/SentryOtelKeys {
 	public static final field SENTRY_BAGGAGE_KEY Lio/opentelemetry/context/ContextKey;
 	public static final field SENTRY_SCOPES_KEY Lio/opentelemetry/context/ContextKey;

sentry-opentelemetry/sentry-opentelemetry-bootstrap/src/main/java/io/sentry/opentelemetry/SentryContextStorage.java

@@ -42,10 +42,11 @@ public Context current() {
 
   @Override
   public Context root() {
-    final @NotNull Context originalRoot = ContextStorage.super.root();
+    final @NotNull Context originalRoot = contextStorage.root();
 
     if (Sentry.isGlobalHubMode()) {
-      return SentryContextWrapper.wrap(originalRoot);
+      return new SentryOtelGlobalHubModeSpan()
+          .storeInContext(SentryContextWrapper.wrap(originalRoot));
     }
 
     return originalRoot;

sentry-opentelemetry/sentry-opentelemetry-bootstrap/src/main/java/io/sentry/opentelemetry/SentryContextWrapper.java

@@ -40,6 +40,9 @@ private <V> boolean shouldReturnRootSpanInstead(
     if (result == null) {
       return true;
     }
+    if (result instanceof SentryOtelGlobalHubModeSpan) {
+      return true;
+    }
     return result instanceof Span && !((Span) result).getSpanContext().isValid();
   }
 

sentry-opentelemetry/sentry-opentelemetry-bootstrap/src/main/java/io/sentry/opentelemetry/SentryOtelGlobalHubModeSpan.java

@@ -0,0 +1,78 @@
+package io.sentry.opentelemetry;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanContext;
+import io.opentelemetry.api.trace.StatusCode;
+import java.util.concurrent.TimeUnit;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+@ApiStatus.Experimental
+public final class SentryOtelGlobalHubModeSpan implements Span {
+
+  private @NotNull Span getOtelSpan() {
+    final @Nullable IOtelSpanWrapper lastKnownUnfinishedRootSpan =
+        SentryWeakSpanStorage.getInstance().getLastKnownUnfinishedRootSpan();
+    if (lastKnownUnfinishedRootSpan != null) {
+      final @Nullable Span openTelemetrySpan = lastKnownUnfinishedRootSpan.getOpenTelemetrySpan();
+      if (openTelemetrySpan != null) {
+        return openTelemetrySpan;
+      }
+    }
+
+    return Span.getInvalid();
+  }
+
+  @Override
+  public <T> Span setAttribute(AttributeKey<T> key, T value) {
+    return getOtelSpan().setAttribute(key, value);
+  }
+
+  @Override
+  public Span addEvent(String name, Attributes attributes) {
+    return getOtelSpan().addEvent(name, attributes);
+  }
+
+  @Override
+  public Span addEvent(String name, Attributes attributes, long timestamp, TimeUnit unit) {
+    return getOtelSpan().addEvent(name, attributes, timestamp, unit);
+  }
+
+  @Override
+  public Span setStatus(StatusCode statusCode, String description) {
+    return getOtelSpan().setStatus(statusCode, description);
+  }
+
+  @Override
+  public Span recordException(Throwable exception, Attributes additionalAttributes) {
+    return getOtelSpan().recordException(exception, additionalAttributes);
+  }
+
+  @Override
+  public Span updateName(String name) {
+    return getOtelSpan().updateName(name);
+  }
+
+  @Override
+  public void end() {
+    getOtelSpan().end();
+  }
+
+  @Override
+  public void end(long timestamp, TimeUnit unit) {
+    getOtelSpan().end(timestamp, unit);
+  }
+
+  @Override
+  public SpanContext getSpanContext() {
+    return getOtelSpan().getSpanContext();
+  }
+
+  @Override
+  public boolean isRecording() {
+    return getOtelSpan().isRecording();
+  }
+}

sentry-opentelemetry/sentry-opentelemetry-core/src/test/kotlin/SentryContextWrapperTest.kt

@@ -18,6 +18,7 @@ import kotlin.test.BeforeTest
 import kotlin.test.Test
 import kotlin.test.assertNull
 import kotlin.test.assertSame
+import kotlin.test.assertTrue
 
 class SentryContextWrapperTest {
 
@@ -35,15 +36,15 @@ class SentryContextWrapperTest {
     }
 
     @Test
-    fun `returns null if no transaction is available`() {
+    fun `returns global hub span if no transaction is available`() {
         Sentry.init {
             it.dsn = "https://key@sentry.io/proj"
             it.isGlobalHubMode = true
         }
 
         val c = SentryContextWrapper.wrap(Context.root())
         val returnedSpan = Span.fromContextOrNull(c)
-        assertNull(returnedSpan)
+        assertTrue(returnedSpan is SentryOtelGlobalHubModeSpan)
     }
 
     @Test