feat: add ability to override clock

Author: fractalwrench

android-agent/api/android-agent.api

@@ -42,10 +42,12 @@ public final class io/opentelemetry/android/agent/dsl/HttpExportConfiguration {
 public final class io/opentelemetry/android/agent/dsl/OpenTelemetryConfiguration {
 	public fun <init> ()V
 	public final fun diskBuffering (Lkotlin/jvm/functions/Function1;)V
+	public final fun getClock ()Lio/opentelemetry/sdk/common/Clock;
 	public final fun globalAttributes (Lkotlin/jvm/functions/Function0;)V
 	public final fun httpExport (Lkotlin/jvm/functions/Function1;)V
 	public final fun instrumentations (Lkotlin/jvm/functions/Function1;)V
 	public final fun session (Lkotlin/jvm/functions/Function1;)V
+	public final fun setClock (Lio/opentelemetry/sdk/common/Clock;)V
 }
 
 public final class io/opentelemetry/android/agent/dsl/SessionConfiguration {

android-agent/src/main/kotlin/io/opentelemetry/android/agent/OpenTelemetryRumInitializer.kt

@@ -20,6 +20,7 @@ import io.opentelemetry.android.session.SessionProvider
 import io.opentelemetry.exporter.otlp.http.logs.OtlpHttpLogRecordExporter
 import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter
 import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter
+import io.opentelemetry.sdk.common.Clock
 
 @OptIn(Incubating::class)
 object OpenTelemetryRumInitializer {
@@ -61,7 +62,8 @@ object OpenTelemetryRumInitializer {
         val metricsEndpoint = cfg.exportConfig.metricsEndpoint()
         return RumBuilder
             .builder(ctx, cfg.rumConfig)
-            .setSessionProvider(createSessionProvider(ctx, sessionConfig))
+            .setSessionProvider(createSessionProvider(ctx, sessionConfig, cfg.clock))
+            .setClock(cfg.clock)
             .addSpanExporterCustomizer {
                 OtlpHttpSpanExporter
                     .builder()
@@ -95,9 +97,10 @@ object OpenTelemetryRumInitializer {
     private fun createSessionProvider(
         context: Context,
         sessionConfig: SessionConfig,
+        clock: Clock,
     ): SessionProvider {
-        val timeoutHandler = SessionIdTimeoutHandler(sessionConfig)
+        val timeoutHandler = SessionIdTimeoutHandler(sessionConfig, clock)
         Services.get(context).appLifecycle.registerListener(timeoutHandler)
-        return SessionManager.create(timeoutHandler, sessionConfig)
+        return SessionManager.create(timeoutHandler, sessionConfig, clock)
     }
 }

android-agent/src/main/kotlin/io/opentelemetry/android/agent/dsl/OpenTelemetryConfiguration.kt

@@ -10,6 +10,7 @@ import io.opentelemetry.android.agent.dsl.instrumentation.InstrumentationConfigu
 import io.opentelemetry.android.config.OtelRumConfig
 import io.opentelemetry.android.features.diskbuffering.DiskBufferingConfig
 import io.opentelemetry.api.common.Attributes
+import io.opentelemetry.sdk.common.Clock
 
 /**
  * Type-safe config DSL that controls how OpenTelemetry should behave.
@@ -28,6 +29,11 @@ class OpenTelemetryConfiguration internal constructor(
         diskBuffering {}
     }
 
+    /**
+     * Configures the [Clock] used for capturing telemetry.
+     */
+    var clock: Clock = Clock.getDefault()
+
     /**
      * Configures how OpenTelemetry should export telemetry over HTTP.
      */

android-agent/src/main/kotlin/io/opentelemetry/android/agent/session/SessionIdTimeoutHandler.kt

@@ -36,8 +36,8 @@ internal class SessionIdTimeoutHandler(
 
     // for testing
     @OptIn(Incubating::class)
-    internal constructor(sessionConfig: SessionConfig) : this(
-        Clock.getDefault(),
+    internal constructor(sessionConfig: SessionConfig, clock: Clock) : this(
+        clock,
         sessionConfig.backgroundInactivityTimeout,
     )
 

android-agent/src/main/kotlin/io/opentelemetry/android/agent/session/SessionManager.kt

@@ -17,7 +17,7 @@ import kotlin.random.Random
 import kotlin.time.Duration
 
 internal class SessionManager(
-    private val clock: Clock = Clock.getDefault(),
+    private val clock: Clock,
     private val sessionStorage: SessionStorage = InMemorySessionStorage(),
     private val timeoutHandler: SessionIdTimeoutHandler,
     private val idGenerator: SessionIdGenerator = DefaultSessionIdGenerator(Random.Default),
@@ -85,10 +85,12 @@ internal class SessionManager(
         fun create(
             timeoutHandler: SessionIdTimeoutHandler,
             sessionConfig: SessionConfig,
+            clock: Clock,
         ): SessionManager =
             SessionManager(
                 timeoutHandler = timeoutHandler,
                 maxSessionLifetime = sessionConfig.maxLifetime,
+                clock = clock,
             )
     }
 }

android-agent/src/test/kotlin/io/opentelemetry/android/agent/dsl/ClockConfigTest.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.agent.dsl
+
+import io.opentelemetry.sdk.common.Clock
+import org.junit.Assert.assertSame
+import org.junit.Test
+
+class ClockConfigTest {
+    @Test
+    fun testDefaults() {
+        val otelConfig = OpenTelemetryConfiguration()
+        assertSame(Clock.getDefault(), otelConfig.clock)
+    }
+
+    @Test
+    fun testOverride() {
+        val fakeClock =
+            object : Clock {
+                override fun now(): Long = 0
+
+                override fun nanoTime(): Long = 0
+            }
+        val otelConfig =
+            OpenTelemetryConfiguration().apply {
+                clock = fakeClock
+            }
+        assertSame(fakeClock, otelConfig.clock)
+    }
+}

android-agent/src/test/kotlin/io/opentelemetry/android/agent/session/SessionManagerTest.kt

@@ -16,6 +16,7 @@ import io.mockk.verify
 import io.mockk.verifyOrder
 import io.opentelemetry.android.session.Session
 import io.opentelemetry.android.session.SessionObserver
+import io.opentelemetry.sdk.common.Clock
 import io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat
 import io.opentelemetry.sdk.testing.time.TestClock
 import org.junit.jupiter.api.BeforeEach
@@ -160,6 +161,7 @@ internal class SessionManagerTest {
             SessionManager(
                 timeoutHandler = timeoutHandler,
                 maxSessionLifetime = MAX_SESSION_LIFETIME.hours,
+                clock = Clock.getDefault(),
             )
 
         // When - access session ID twice, should be same

core/api/core.api

@@ -24,6 +24,7 @@ public final class io/opentelemetry/android/OpenTelemetryRumBuilder {
 	public final fun addTracerProviderCustomizer (Ljava/util/function/BiFunction;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;
 	public final fun build ()Lio/opentelemetry/android/OpenTelemetryRum;
 	public final fun mergeResource (Lio/opentelemetry/sdk/resources/Resource;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;
+	public final fun setClock (Lio/opentelemetry/sdk/common/Clock;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;
 	public final fun setExportScheduleHandler (Lio/opentelemetry/android/features/diskbuffering/scheduler/ExportScheduleHandler;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;
 	public final fun setResource (Lio/opentelemetry/sdk/resources/Resource;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;
 	public final fun setSessionProvider (Lio/opentelemetry/android/session/SessionProvider;)Lio/opentelemetry/android/OpenTelemetryRumBuilder;

core/src/main/java/io/opentelemetry/android/OpenTelemetryRumBuilder.kt

@@ -47,6 +47,7 @@ import io.opentelemetry.exporter.logging.LoggingMetricExporter
 import io.opentelemetry.exporter.logging.LoggingSpanExporter
 import io.opentelemetry.exporter.logging.SystemOutLogRecordExporter
 import io.opentelemetry.sdk.OpenTelemetrySdk
+import io.opentelemetry.sdk.common.Clock
 import io.opentelemetry.sdk.logs.LogRecordProcessor
 import io.opentelemetry.sdk.logs.SdkLoggerProvider
 import io.opentelemetry.sdk.logs.SdkLoggerProviderBuilder
@@ -91,6 +92,7 @@ class OpenTelemetryRumBuilder internal constructor(
         ): OpenTelemetryRumBuilder = OpenTelemetryRumBuilder(context, config)
     }
 
+    private var clock: Clock = Clock.getDefault()
     private val tracerProviderCustomizers: MutableList<BiFunction<SdkTracerProviderBuilder, Context, SdkTracerProviderBuilder>> =
         mutableListOf()
     private val meterProviderCustomizers: MutableList<BiFunction<SdkMeterProviderBuilder, Context, SdkMeterProviderBuilder>> =
@@ -281,6 +283,14 @@ class OpenTelemetryRumBuilder internal constructor(
         return this
     }
 
+    /**
+     * Sets a custom [Clock] implementation.
+     */
+    fun setClock(clock: Clock): OpenTelemetryRumBuilder {
+        this.clock = clock
+        return this
+    }
+
     /**
      * Creates a new instance of [OpenTelemetryRum] with the settings of this [OpenTelemetryRum].
      *
@@ -306,15 +316,21 @@ class OpenTelemetryRumBuilder internal constructor(
                         sessionProvider,
                         context,
                         bufferDelegatingSpanExporter,
+                        clock,
                     ),
                 ).setLoggerProvider(
                     buildLoggerProvider(
                         sessionProvider,
                         context,
                         bufferDelegatingLogExporter,
+                        clock,
                     ),
                 ).setMeterProvider(
-                    buildMeterProvider(context, bufferDelegatingMetricExporter),
+                    buildMeterProvider(
+                        context,
+                        bufferDelegatingMetricExporter,
+                        clock,
+                    ),
                 ).setPropagators(buildFinalPropagators())
                 .build()
 
@@ -325,7 +341,7 @@ class OpenTelemetryRumBuilder internal constructor(
         )
 
         val delegate =
-            SdkPreconfiguredRumBuilder(context, sdk, sessionProvider, config)
+            SdkPreconfiguredRumBuilder(context, sdk, sessionProvider, config, clock)
                 .setShutdownHook {
                     exportScheduleHandler?.disable()
                     services.close()
@@ -501,11 +517,13 @@ class OpenTelemetryRumBuilder internal constructor(
         sessionProvider: SessionProvider,
         context: Context,
         spanExporter: SpanExporter,
+        clock: Clock,
     ): SdkTracerProvider {
         var tracerProviderBuilder =
             SdkTracerProvider
                 .builder()
                 .setResource(resource)
+                .setClock(clock)
                 .addSpanProcessor(SessionIdSpanAppender(sessionProvider))
 
         val batchSpanProcessor = BatchSpanProcessor.builder(spanExporter).build()
@@ -521,11 +539,13 @@ class OpenTelemetryRumBuilder internal constructor(
         sessionProvider: SessionProvider,
         context: Context,
         logsExporter: LogRecordExporter,
+        clock: Clock,
     ): SdkLoggerProvider {
         var loggerProviderBuilder =
             SdkLoggerProvider
                 .builder()
                 .setResource(resource)
+                .setClock(clock)
                 .addLogRecordProcessor(SessionIdLogRecordAppender(sessionProvider))
                 .addLogRecordProcessor(
                     GlobalAttributesLogRecordAppender(
@@ -559,10 +579,15 @@ class OpenTelemetryRumBuilder internal constructor(
     private fun buildMeterProvider(
         context: Context,
         metricExporter: MetricExporter,
+        clock: Clock,
     ): SdkMeterProvider {
         val reader: MetricReader = PeriodicMetricReader.create(metricExporter)
         var meterProviderBuilder =
-            SdkMeterProvider.builder().registerMetricReader(reader).setResource(resource)
+            SdkMeterProvider
+                .builder()
+                .registerMetricReader(reader)
+                .setResource(resource)
+                .setClock(clock)
         for (customizer in meterProviderCustomizers) {
             meterProviderBuilder = customizer.apply(meterProviderBuilder, context)
         }

core/src/main/java/io/opentelemetry/android/RumBuilder.kt

@@ -9,6 +9,7 @@ import android.content.Context
 import io.opentelemetry.android.config.OtelRumConfig
 import io.opentelemetry.android.session.SessionProvider
 import io.opentelemetry.sdk.OpenTelemetrySdk
+import io.opentelemetry.sdk.common.Clock
 
 object RumBuilder {
     /**
@@ -55,6 +56,7 @@ object RumBuilder {
             openTelemetrySdk,
             sessionProvider,
             config,
+            Clock.getDefault(),
         )
 
     /**