Add an option to the SDK builder to specify an initial TraceConfig (#2192)

* Add an option to set the initial TraceConfig when building an SDK, and a TracerSdkProvider.

* add the missing javadoc

Author: jkwatson

sdk/all/src/main/java/io/opentelemetry/sdk/OpenTelemetrySdk.java

@@ -22,6 +22,7 @@
 import io.opentelemetry.sdk.trace.SpanProcessor;
 import io.opentelemetry.sdk.trace.TracerSdkManagement;
 import io.opentelemetry.sdk.trace.TracerSdkProvider;
+import io.opentelemetry.sdk.trace.config.TraceConfig;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -114,6 +115,7 @@ public static class Builder extends DefaultOpenTelemetry.Builder {
     private Resource resource;
     private final List<SpanProcessor> spanProcessors = new ArrayList<>();
     private IdGenerator idGenerator;
+    private TraceConfig traceConfig;
 
     /**
      * Sets the {@link TracerSdkProvider} to use. This can be used to configure tracing settings by
@@ -212,6 +214,18 @@ public Builder setIdGenerator(IdGenerator idGenerator) {
       return this;
     }
 
+    /**
+     * Set the {@link TraceConfig} that will be initially set on the Tracing SDK.
+     *
+     * <p>Using {@link #setTracerProvider(TracerProvider)} will override this setting.
+     *
+     * @return this
+     */
+    public Builder setTraceConfig(TraceConfig traceConfig) {
+      this.traceConfig = traceConfig;
+      return this;
+    }
+
     /**
      * Returns a new {@link OpenTelemetrySdk} built with the configuration of this {@link Builder}.
      */
@@ -253,6 +267,9 @@ private TracerSdkProvider buildTracerProvider() {
       if (idGenerator != null) {
         tracerProviderBuilder.setIdGenerator(idGenerator);
       }
+      if (traceConfig != null) {
+        tracerProviderBuilder.setTraceConfig(traceConfig);
+      }
       return tracerProviderBuilder.build();
     }
 

sdk/all/src/test/java/io/opentelemetry/sdk/OpenTelemetrySdkTest.java

@@ -27,6 +27,7 @@
 import io.opentelemetry.sdk.trace.IdGenerator;
 import io.opentelemetry.sdk.trace.SpanProcessor;
 import io.opentelemetry.sdk.trace.TracerSdkProvider;
+import io.opentelemetry.sdk.trace.config.TraceConfig;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
@@ -116,11 +117,13 @@ void building() {
   void testConfiguration_tracerSettings() {
     Resource resource = Resource.create(Attributes.builder().put("cat", "meow").build());
     IdGenerator idGenerator = mock(IdGenerator.class);
+    TraceConfig traceConfig = mock(TraceConfig.class);
     OpenTelemetrySdk openTelemetry =
         OpenTelemetrySdk.builder()
             .setClock(clock)
             .setResource(resource)
             .setIdGenerator(idGenerator)
+            .setTraceConfig(traceConfig)
             .build();
     TracerProvider unobfuscatedTracerProvider =
         ((ObfuscatedTracerProvider) openTelemetry.getTracerProvider()).unobfuscate();
@@ -132,7 +135,8 @@ void testConfiguration_tracerSettings() {
         .extracting("sharedState")
         .hasFieldOrPropertyWithValue("clock", clock)
         .hasFieldOrPropertyWithValue("resource", resource)
-        .hasFieldOrPropertyWithValue("idGenerator", idGenerator);
+        .hasFieldOrPropertyWithValue("idGenerator", idGenerator)
+        .hasFieldOrPropertyWithValue("activeTraceConfig", traceConfig);
 
     assertThat(openTelemetry.getMeterProvider()).isInstanceOf(MeterSdkProvider.class);
     // Since MeterProvider is in a different package, the only alternative to this reflective

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

@@ -42,8 +42,9 @@ public static Builder builder() {
     return new Builder();
   }
 
-  private TracerSdkProvider(Clock clock, IdGenerator idsGenerator, Resource resource) {
-    this.sharedState = new TracerSharedState(clock, idsGenerator, resource);
+  private TracerSdkProvider(
+      Clock clock, IdGenerator idsGenerator, Resource resource, TraceConfig traceConfig) {
+    this.sharedState = new TracerSharedState(clock, idsGenerator, resource, traceConfig);
     this.tracerSdkComponentRegistry = new TracerSdkComponentRegistry(sharedState);
   }
 
@@ -92,14 +93,15 @@ public CompletableResultCode forceFlush() {
   }
 
   /**
-   * Builder class for the TracerSdkFactory. Has fully functional default implementations of all
+   * Builder class for the TraceSdkProvider. Has fully functional default implementations of all
    * three required interfaces.
    */
   public static class Builder {
 
     private Clock clock = SystemClock.getInstance();
     private IdGenerator idsGenerator = IdGenerator.random();
     private Resource resource = Resource.getDefault();
+    private TraceConfig traceConfig = TraceConfig.getDefault();
 
     /**
      * Assign a {@link Clock}.
@@ -139,12 +141,23 @@ public Builder setResource(Resource resource) {
     }
 
     /**
-     * Create a new TracerSdkFactory instance.
+     * Assign an initial {@link TraceConfig} that should be used with this SDK.
      *
-     * @return An initialized TracerSdkFactory.
+     * @return this
+     */
+    public Builder setTraceConfig(TraceConfig traceConfig) {
+      this.traceConfig = traceConfig;
+      Objects.requireNonNull(traceConfig);
+      return this;
+    }
+
+    /**
+     * Create a new TraceSdkProvider instance.
+     *
+     * @return An initialized TraceSdkProvider.
      */
     public TracerSdkProvider build() {
-      return new TracerSdkProvider(clock, idsGenerator, resource);
+      return new TracerSdkProvider(clock, idsGenerator, resource, traceConfig);
     }
 
     private Builder() {}

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

@@ -22,17 +22,19 @@ final class TracerSharedState {
 
   // Reads and writes are atomic for reference variables. Use volatile to ensure that these
   // operations are visible on other CPUs as well.
-  private volatile TraceConfig activeTraceConfig = TraceConfig.getDefault();
+  private volatile TraceConfig activeTraceConfig;
   private volatile SpanProcessor activeSpanProcessor = NoopSpanProcessor.getInstance();
   private volatile boolean isStopped = false;
 
   @GuardedBy("lock")
   private final List<SpanProcessor> registeredSpanProcessors = new ArrayList<>();
 
-  TracerSharedState(Clock clock, IdGenerator idGenerator, Resource resource) {
+  TracerSharedState(
+      Clock clock, IdGenerator idGenerator, Resource resource, TraceConfig traceConfig) {
     this.clock = clock;
     this.idGenerator = idGenerator;
     this.resource = resource;
+    this.activeTraceConfig = traceConfig;
   }
 
   Clock getClock() {

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

@@ -48,10 +48,19 @@ void builder_HappyPath() {
                 .setClock(mock(Clock.class))
                 .setResource(mock(Resource.class))
                 .setIdGenerator(mock(IdGenerator.class))
+                .setTraceConfig(mock(TraceConfig.class))
                 .build())
         .isNotNull();
   }
 
+  @Test
+  void builder_NullTraceConfig() {
+    assertThrows(
+        NullPointerException.class,
+        () -> TracerSdkProvider.builder().setTraceConfig(null),
+        "traceConfig");
+  }
+
   @Test
   void builder_NullClock() {
     assertThrows(
@@ -107,6 +116,15 @@ void updateActiveTraceConfig() {
     assertThat(tracerFactory.getActiveTraceConfig()).isEqualTo(newConfig);
   }
 
+  @Test
+  void build_traceConfig() {
+    TraceConfig initialTraceConfig = mock(TraceConfig.class);
+    TracerSdkProvider tracerSdkProvider =
+        TracerSdkProvider.builder().setTraceConfig(initialTraceConfig).build();
+
+    assertThat(tracerSdkProvider.getActiveTraceConfig()).isSameAs(initialTraceConfig);
+  }
+
   @Test
   void shutdown() {
     tracerFactory.shutdown();