Minimize public surface area of OpenTracingShim

opentracing-shim/src/main/java/io/opentelemetry/opentracingshim/OpenTracingShim.java

@@ -5,10 +5,9 @@
 
 package io.opentelemetry.opentracingshim;
 
-import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.api.OpenTelemetry;
-import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.api.trace.TracerProvider;
+import io.opentelemetry.context.propagation.TextMapPropagator;
 
 /**
  * Factory for creating an OpenTracing {@link io.opentracing.Tracer} that is implemented using the
@@ -18,66 +17,33 @@ public final class OpenTracingShim {
   private OpenTracingShim() {}
 
   /**
-   * Creates a {@code io.opentracing.Tracer} shim out of {@code
-   * GlobalOpenTelemetry.getTracerProvider()} and {@code GlobalOpenTelemetry.getPropagators()}.
-   *
-   * @return a {@code io.opentracing.Tracer}.
-   */
-  public static io.opentracing.Tracer createTracerShim() {
-    return createTracerShim(getTracer(GlobalOpenTelemetry.getTracerProvider()));
-  }
-
-  /**
-   * Creates a {@code io.opentracing.Tracer} shim using provided Tracer instance and {@code
-   * GlobalOpenTelemetry.getPropagators()}.
-   *
-   * @return a {@code io.opentracing.Tracer}.
-   */
-  public static io.opentracing.Tracer createTracerShim(Tracer tracer) {
-    return createTracerShim(tracer, OpenTracingPropagators.builder().build());
-  }
-
-  /**
-   * Creates a {@code io.opentracing.Tracer} shim using provided Tracer instance and {@code
-   * OpenTracingPropagators} instance.
-   *
-   * @return a {@code io.opentracing.Tracer}.
-   * @since 1.1.0
-   */
-  public static io.opentracing.Tracer createTracerShim(
-      Tracer tracer, OpenTracingPropagators propagators) {
-    return new TracerShim(tracer, propagators);
-  }
-
-  /**
-   * Creates a {@code io.opentracing.Tracer} shim using the provided OpenTelemetry instance.
+   * Creates a {@code io.opentracing.Tracer} shim using the provided {@link OpenTelemetry} instance.
+   * Uses the {@link TracerProvider} and {@link TextMapPropagator} associated with the {@link
+   * OpenTelemetry} instance.
    *
    * @param openTelemetry the {@code OpenTelemetry} instance used to create this shim.
    * @return a {@code io.opentracing.Tracer}.
    */
   public static io.opentracing.Tracer createTracerShim(OpenTelemetry openTelemetry) {
-    return createTracerShim(
-        getTracer(openTelemetry.getTracerProvider()),
-        OpenTracingPropagators.builder()
-            .setTextMap(openTelemetry.getPropagators().getTextMapPropagator())
-            .setHttpHeaders(openTelemetry.getPropagators().getTextMapPropagator())
-            .build());
+    TextMapPropagator propagator = openTelemetry.getPropagators().getTextMapPropagator();
+    return createTracerShim(openTelemetry.getTracerProvider(), propagator, propagator);
   }
 
   /**
    * Creates a {@code io.opentracing.Tracer} shim using the provided {@code TracerProvider} and
    * {@code TextMapPropagator} instance.
    *
    * @param provider the {@code TracerProvider} instance used to create this shim.
-   * @param propagators the {@code OpenTracingPropagators} instance used to create this shim.
+   * @param textMapPropagator the propagator used for {@link
+   *     io.opentracing.propagation.Format.Builtin#TEXT_MAP} format.
+   * @param httpPropagator the propagator used for {@link
+   *     io.opentracing.propagation.Format.Builtin#HTTP_HEADERS} format.
    * @return a {@code io.opentracing.Tracer}.
    */
   public static io.opentracing.Tracer createTracerShim(
-      TracerProvider provider, OpenTracingPropagators propagators) {
-    return createTracerShim(getTracer(provider), propagators);
-  }
-
-  private static Tracer getTracer(TracerProvider tracerProvider) {
-    return tracerProvider.get("opentracing-shim");
+      TracerProvider provider,
+      TextMapPropagator textMapPropagator,
+      TextMapPropagator httpPropagator) {
+    return new TracerShim(provider.get("opentracing-shim"), textMapPropagator, httpPropagator);
   }
 }

opentracing-shim/src/main/java/io/opentelemetry/opentracingshim/Propagation.java

@@ -20,15 +20,12 @@ final class Propagation {
   private static final TextMapSetter SETTER_INSTANCE = new TextMapSetter();
   private static final TextMapGetter GETTER_INSTANCE = new TextMapGetter();
 
-  private final OpenTracingPropagators propagators;
+  private final TextMapPropagator textMapPropagator;
+  private final TextMapPropagator httpPropagator;
 
-  Propagation(OpenTracingPropagators propagators) {
-    this.propagators = propagators;
-  }
-
-  // Visible for testing
-  OpenTracingPropagators propagators() {
-    return propagators;
+  Propagation(TextMapPropagator textMapPropagator, TextMapPropagator httpPropagator) {
+    this.textMapPropagator = textMapPropagator;
+    this.httpPropagator = httpPropagator;
   }
 
   <C> void injectTextMap(SpanContextShim contextShim, Format<C> format, TextMapInject carrier) {
@@ -56,11 +53,12 @@ <C> SpanContextShim extractTextMap(Format<C> format, TextMapExtract carrier) {
     return new SpanContextShim(span.getSpanContext(), baggage);
   }
 
-  private <C> TextMapPropagator getPropagator(Format<C> format) {
+  // Visible for testing
+  <C> TextMapPropagator getPropagator(Format<C> format) {
     if (format == Format.Builtin.HTTP_HEADERS) {
-      return propagators.httpHeadersPropagator();
+      return httpPropagator;
     }
-    return propagators.textMapPropagator();
+    return textMapPropagator;
   }
 
   static final class TextMapSetter

opentracing-shim/src/main/java/io/opentelemetry/opentracingshim/TracerShim.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.opentracingshim;
 
+import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentracing.Scope;
 import io.opentracing.ScopeManager;
 import io.opentracing.Span;
@@ -26,9 +27,11 @@ final class TracerShim implements Tracer {
   private volatile boolean isClosed;
 
   TracerShim(
-      io.opentelemetry.api.trace.Tracer tracer, OpenTracingPropagators openTracingPropagators) {
+      io.opentelemetry.api.trace.Tracer tracer,
+      TextMapPropagator textMapPropagator,
+      TextMapPropagator httpPropagator) {
     this.tracer = tracer;
-    this.propagation = new Propagation(openTracingPropagators);
+    this.propagation = new Propagation(textMapPropagator, httpPropagator);
     this.scopeManagerShim = new ScopeManagerShim();
   }