From e12f50c7d11f569d329590b9589048889c96a383 Mon Sep 17 00:00:00 2001
From: Jason Plumb <jplumb@splunk.com>
Date: Wed, 18 Oct 2023 15:25:18 -0700
Subject: [PATCH] Allow events to be emitted with timestamp

---
 .../api/events/DefaultEventEmitter.java       |  3 +++
 .../api/events/EventEmitter.java              | 11 +++++++++
 .../internal/SdkEventEmitterProvider.java     |  7 +++++-
 .../internal/SdkEventEmitterProviderTest.java | 23 +++++++++++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/api/events/src/main/java/io/opentelemetry/api/events/DefaultEventEmitter.java b/api/events/src/main/java/io/opentelemetry/api/events/DefaultEventEmitter.java
index 2be4164d010..9bebdc148f3 100644
--- a/api/events/src/main/java/io/opentelemetry/api/events/DefaultEventEmitter.java
+++ b/api/events/src/main/java/io/opentelemetry/api/events/DefaultEventEmitter.java
@@ -17,6 +17,9 @@ static EventEmitter getInstance() {
     return INSTANCE;
   }
 
+  @Override
+  public void emit(long epochNanos, String eventName, Attributes attributes) {}
+
   @Override
   public void emit(String eventName, Attributes attributes) {}
 }
diff --git a/api/events/src/main/java/io/opentelemetry/api/events/EventEmitter.java b/api/events/src/main/java/io/opentelemetry/api/events/EventEmitter.java
index 69df8407f43..457b5915740 100644
--- a/api/events/src/main/java/io/opentelemetry/api/events/EventEmitter.java
+++ b/api/events/src/main/java/io/opentelemetry/api/events/EventEmitter.java
@@ -32,6 +32,17 @@
 @ThreadSafe
 public interface EventEmitter {
 
+  /**
+   * Emit an event.
+   *
+   * @param epochNanos The time at which the event happened, in epoch nanoseconds.
+   * @param eventName the event name, which acts as a classifier for events. Within a particular
+   *     event domain, event name defines a particular class or type of event.
+   * @param attributes attributes associated with the event
+   */
+  @SuppressWarnings("InconsistentOverloads")
+  void emit(long epochNanos, String eventName, Attributes attributes);
+
   /**
    * Emit an event.
    *
diff --git a/sdk/logs/src/main/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProvider.java b/sdk/logs/src/main/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProvider.java
index 18d1e434824..db1070b9816 100644
--- a/sdk/logs/src/main/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProvider.java
+++ b/sdk/logs/src/main/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProvider.java
@@ -113,9 +113,14 @@ private SdkEventEmitter(Clock clock, Logger delegateLogger, String eventDomain)
 
     @Override
     public void emit(String eventName, Attributes attributes) {
+      emit(clock.now(), eventName, attributes);
+    }
+
+    @Override
+    public void emit(long epochNanos, String eventName, Attributes attributes) {
       delegateLogger
           .logRecordBuilder()
-          .setTimestamp(clock.now(), TimeUnit.NANOSECONDS)
+          .setTimestamp(epochNanos, TimeUnit.NANOSECONDS)
           .setAllAttributes(attributes)
           .setAttribute(EVENT_DOMAIN, eventDomain)
           .setAttribute(EVENT_NAME, eventName)
diff --git a/sdk/logs/src/test/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProviderTest.java b/sdk/logs/src/test/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProviderTest.java
index 964c67e64c1..a086c8d7909 100644
--- a/sdk/logs/src/test/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProviderTest.java
+++ b/sdk/logs/src/test/java/io/opentelemetry/sdk/logs/internal/SdkEventEmitterProviderTest.java
@@ -5,16 +5,19 @@
 
 package io.opentelemetry.sdk.logs.internal;
 
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.events.EventEmitter;
 import io.opentelemetry.sdk.common.Clock;
 import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
 import io.opentelemetry.sdk.logs.ReadWriteLogRecord;
 import io.opentelemetry.sdk.logs.SdkLoggerProvider;
 import io.opentelemetry.sdk.resources.Resource;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.jupiter.api.Test;
 
@@ -91,4 +94,24 @@ void emit_NoDomain() {
                 .put("event.name", "event-name")
                 .build());
   }
+
+  @Test
+  void emit_withTimestamp() {
+    long yesterday = System.nanoTime() - TimeUnit.DAYS.toNanos(1);
+    Attributes attributes = Attributes.of(stringKey("foo"), "bar");
+
+    EventEmitter emitter = eventEmitterProvider.eventEmitterBuilder("test-scope").build();
+
+    emitter.emit(yesterday, "testing", attributes);
+
+    assertThat(seenLog.get().toLogRecordData())
+        .hasResource(RESOURCE)
+        .hasInstrumentationScope(InstrumentationScopeInfo.create("test-scope"))
+        .hasTimestamp(yesterday)
+        .hasAttributes(
+            attributes.toBuilder()
+                .put("event.domain", "unknown")
+                .put("event.name", "testing")
+                .build());
+  }
 }