Add ExceptionEventData which wraps events that contain exceptions

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/SdkSpan.java

@@ -7,7 +7,6 @@
 
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.api.internal.GuardedBy;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
@@ -22,9 +21,7 @@
 import io.opentelemetry.sdk.trace.data.LinkData;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.data.StatusData;
-import io.opentelemetry.semconv.trace.attributes.SemanticAttributes;
-import java.io.PrintWriter;
-import java.io.StringWriter;
+import io.opentelemetry.sdk.trace.internal.data.ExceptionEventData;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -401,23 +398,8 @@ public ReadWriteSpan recordException(Throwable exception, Attributes additionalA
     if (additionalAttributes == null) {
       additionalAttributes = Attributes.empty();
     }
-    long timestampNanos = clock.now();
 
-    AttributesBuilder attributes = Attributes.builder();
-    attributes.put(SemanticAttributes.EXCEPTION_TYPE, exception.getClass().getCanonicalName());
-    if (exception.getMessage() != null) {
-      attributes.put(SemanticAttributes.EXCEPTION_MESSAGE, exception.getMessage());
-    }
-    StringWriter writer = new StringWriter();
-    exception.printStackTrace(new PrintWriter(writer));
-    attributes.put(SemanticAttributes.EXCEPTION_STACKTRACE, writer.toString());
-    attributes.putAll(additionalAttributes);
-
-    addEvent(
-        SemanticAttributes.EXCEPTION_EVENT_NAME,
-        attributes.build(),
-        timestampNanos,
-        TimeUnit.NANOSECONDS);
+    addTimedEvent(ExceptionEventData.create(clock.now(), exception, additionalAttributes));
     return this;
   }
 

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/data/EventData.java

@@ -9,7 +9,7 @@
 import io.opentelemetry.sdk.trace.SpanLimits;
 import javax.annotation.concurrent.Immutable;
 
-/** Data representation of a event. */
+/** Data representation of an event. */
 @Immutable
 public interface EventData {
 

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/internal/data/ExceptionEventData.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.trace.internal.data;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.sdk.trace.data.EventData;
+
+/**
+ * Data representation of an event for a recorded exception.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public interface ExceptionEventData extends EventData {
+
+  /**
+   * Returns a new immutable {@link ExceptionEventData}.
+   *
+   * @param epochNanos epoch timestamp in nanos of the {@link ExceptionEventData}.
+   * @param exception the {@link Throwable exception} of the {@code Event}.
+   * @param additionalAttributes the additional attributes of the {@link ExceptionEventData}.
+   * @return a new immutable {@link ExceptionEventData}
+   */
+  static ExceptionEventData create(
+      long epochNanos, Throwable exception, Attributes additionalAttributes) {
+    return ImmutableExceptionEventData.create(epochNanos, exception, additionalAttributes);
+  }
+
+  /**
+   * Return the {@link Throwable exception} of the {@link ExceptionEventData}.
+   *
+   * @return the {@link Throwable exception} of the {@link ExceptionEventData}
+   */
+  Throwable getException();
+
+  /**
+   * Return the additional {@link Attributes attributes} of the {@link ExceptionEventData}.
+   *
+   * @return the additional {@link Attributes attributes} of the {@link ExceptionEventData}
+   */
+  Attributes getAdditionalAttributes();
+}

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/internal/data/ImmutableExceptionEventData.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.trace.internal.data;
+
+import com.google.auto.value.AutoValue;
+import com.google.auto.value.extension.memoized.Memoized;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.semconv.trace.attributes.SemanticAttributes;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import javax.annotation.concurrent.Immutable;
+
+/** An effectively immutable implementation of {@link ExceptionEventData}. */
+@AutoValue
+@Immutable
+abstract class ImmutableExceptionEventData implements ExceptionEventData {
+
+  /**
+   * Returns a new immutable {@code Event}.
+   *
+   * @param epochNanos epoch timestamp in nanos of the {@code Event}.
+   * @param exception the {@link Throwable exception} of the {@code Event}.
+   * @param additionalAttributes the additional {@link Attributes} of the {@code Event}.
+   * @return a new immutable {@code Event<T>}
+   */
+  static ExceptionEventData create(
+      long epochNanos, Throwable exception, Attributes additionalAttributes) {
+
+    return new AutoValue_ImmutableExceptionEventData(epochNanos, exception, additionalAttributes);
+  }
+
+  ImmutableExceptionEventData() {}
+
+  @Override
+  public final String getName() {
+    return SemanticAttributes.EXCEPTION_EVENT_NAME;
+  }
+
+  @Override
+  @Memoized
+  public Attributes getAttributes() {
+    Throwable exception = getException();
+    Attributes additionalAttributes = getAdditionalAttributes();
+    AttributesBuilder attributesBuilder = Attributes.builder();
+
+    attributesBuilder.put(
+        SemanticAttributes.EXCEPTION_TYPE, exception.getClass().getCanonicalName());
+    String message = exception.getMessage();
+    if (message != null) {
+      attributesBuilder.put(SemanticAttributes.EXCEPTION_MESSAGE, message);
+    }
+
+    StringWriter stringWriter = new StringWriter();
+    try (PrintWriter printWriter = new PrintWriter(stringWriter)) {
+      exception.printStackTrace(printWriter);
+    }
+    attributesBuilder.put(SemanticAttributes.EXCEPTION_STACKTRACE, stringWriter.toString());
+    attributesBuilder.putAll(additionalAttributes);
+
+    return attributesBuilder.build();
+  }
+
+  @Override
+  public final int getTotalAttributeCount() {
+    return getAttributes().size();
+  }
+}

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/internal/data/package-info.java

@@ -0,0 +1,15 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Interfaces and implementations that are internal to OpenTelemetry.
+ *
+ * <p>All the content under this package and its subpackages are considered not part of the public
+ * API, and must not be used by users of the OpenTelemetry library.
+ */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.sdk.trace.internal.data;
+
+import javax.annotation.ParametersAreNonnullByDefault;

sdk/trace/src/test/java/io/opentelemetry/sdk/trace/SdkSpanTest.java

@@ -35,6 +35,7 @@
 import io.opentelemetry.sdk.trace.data.LinkData;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.data.StatusData;
+import io.opentelemetry.sdk.trace.internal.data.ExceptionEventData;
 import io.opentelemetry.semconv.trace.attributes.SemanticAttributes;
 import java.io.PrintWriter;
 import java.io.StringWriter;
@@ -894,6 +895,14 @@ void recordException() {
                 .put(SemanticAttributes.EXCEPTION_MESSAGE, "there was an exception")
                 .put(SemanticAttributes.EXCEPTION_STACKTRACE, stacktrace)
                 .build());
+
+    assertThat(event)
+        .isInstanceOfSatisfying(
+            ExceptionEventData.class,
+            exceptionEvent -> {
+              assertThat(exceptionEvent.getException()).isSameAs(exception);
+              assertThat(exceptionEvent.getAdditionalAttributes()).isEqualTo(Attributes.empty());
+            });
   }
 
   @Test
@@ -958,6 +967,20 @@ void recordException_additionalAttributes() {
                 .put("exception.message", "this is a precedence attribute")
                 .put("exception.stacktrace", stacktrace)
                 .build());
+
+    assertThat(event)
+        .isInstanceOfSatisfying(
+            ExceptionEventData.class,
+            exceptionEvent -> {
+              assertThat(exceptionEvent.getException()).isSameAs(exception);
+              assertThat(exceptionEvent.getAdditionalAttributes())
+                  .isEqualTo(
+                      Attributes.of(
+                          stringKey("key1"),
+                          "this is an additional attribute",
+                          stringKey("exception.message"),
+                          "this is a precedence attribute"));
+            });
   }
 
   @Test