Add support for spanNameExtractor

Author: steverao

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/InstrumenterBuilder.java

@@ -56,7 +56,7 @@ public final class InstrumenterBuilder<REQUEST, RESPONSE> {
 
   final OpenTelemetry openTelemetry;
   final String instrumentationName;
-  final SpanNameExtractor<? super REQUEST> spanNameExtractor;
+  SpanNameExtractor<? super REQUEST> spanNameExtractor;
 
   final List<SpanLinksExtractor<? super REQUEST>> spanLinksExtractors = new ArrayList<>();
   final List<AttributesExtractor<? super REQUEST, ? super RESPONSE>> attributesExtractors =
@@ -316,6 +316,9 @@ private Instrumenter<REQUEST, RESPONSE> buildInstrumenter(
         if (customizer.getOperationMetrics() != null) {
           addOperationMetrics(customizer.getOperationMetrics());
         }
+        if (customizer.getSpanNameExtractor() != null) {
+          this.spanNameExtractor = customizer.getSpanNameExtractor();
+        }
       }
     }
     this.spanKindExtractor = spanKindExtractor;

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/internal/InstrumentationCustomizer.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.ContextCustomizer;
 import io.opentelemetry.instrumentation.api.instrumenter.OperationMetrics;
+import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import java.util.function.Predicate;
 
 /**
@@ -50,7 +51,8 @@ default OperationMetrics getOperationMetrics() {
    * @param <RESPONSE> the type of response object used by the instrumented library
    * @return an attributes extractor instance, or null if not applicable
    */
-  default <REQUEST, RESPONSE> AttributesExtractor<REQUEST, RESPONSE> getAttributesExtractor() {
+  default <REQUEST, RESPONSE>
+      AttributesExtractor<? super REQUEST, ? super RESPONSE> getAttributesExtractor() {
     return null;
   }
 
@@ -61,7 +63,18 @@ default <REQUEST, RESPONSE> AttributesExtractor<REQUEST, RESPONSE> getAttributes
    * @param <REQUEST> the type of request object used by the instrumented library
    * @return a context customizer instance, or null if not applicable
    */
-  default <REQUEST> ContextCustomizer<REQUEST> getContextCustomizer() {
+  default <REQUEST> ContextCustomizer<? super REQUEST> getContextCustomizer() {
+    return null;
+  }
+
+  /**
+   * Returns a new instance of a {@link SpanNameExtractor} that will customize the span name during
+   * request processing.
+   *
+   * @param <REQUEST> the type of request object used by the instrumented library
+   * @return a customized {@link SpanNameExtractor}, or null if not applicable
+   */
+  default <REQUEST> SpanNameExtractor<? super REQUEST> getSpanNameExtractor() {
     return null;
   }
 }

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/internal/InstrumentationCustomizerTest.java

@@ -10,6 +10,7 @@
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.ContextCustomizer;
 import io.opentelemetry.instrumentation.api.instrumenter.OperationMetrics;
+import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
 import java.util.function.Predicate;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -20,9 +21,10 @@
 @ExtendWith(MockitoExtension.class)
 class InstrumentationCustomizerTest {
 
-  @Mock private AttributesExtractor<Object, Object> attributesExtractor;
   @Mock private OperationMetrics operationMetrics;
+  @Mock private AttributesExtractor<Object, Object> attributesExtractor;
   @Mock private ContextCustomizer<Object> contextCustomizer;
+  @Mock private SpanNameExtractor<Object> spanNameExtractor;
 
   private InstrumentationCustomizer customizer;
 
@@ -31,32 +33,33 @@ class InstrumentationCustomizerTest {
   void setUp() {
     customizer =
         new InstrumentationCustomizer() {
-          @Override
-          public <REQUEST> ContextCustomizer<REQUEST> getContextCustomizer() {
-            return (ContextCustomizer<REQUEST>) contextCustomizer;
-          }
 
           @Override
           public Predicate<String> instrumentationNamePredicate() {
             return name -> name.startsWith("test.instrumentation");
           }
 
+          @Override
+          public OperationMetrics getOperationMetrics() {
+            return operationMetrics;
+          }
+
           @Override
           public <REQUEST, RESPONSE>
-              AttributesExtractor<REQUEST, RESPONSE> getAttributesExtractor() {
-            return (AttributesExtractor<REQUEST, RESPONSE>) attributesExtractor;
+              AttributesExtractor<? super REQUEST, ? super RESPONSE> getAttributesExtractor() {
+            return (AttributesExtractor<? super REQUEST, ? super RESPONSE>) attributesExtractor;
           }
 
           @Override
-          public OperationMetrics getOperationMetrics() {
-            return operationMetrics;
+          public <REQUEST> ContextCustomizer<? super REQUEST> getContextCustomizer() {
+            return (ContextCustomizer<? super REQUEST>) contextCustomizer;
           }
-        };
-  }
 
-  @Test
-  void testGetContextCustomizer() {
-    assertThat(customizer.getContextCustomizer()).isSameAs(contextCustomizer);
+          @Override
+          public <REQUEST> SpanNameExtractor<? super REQUEST> getSpanNameExtractor() {
+            return (SpanNameExtractor<? super REQUEST>) spanNameExtractor;
+          }
+        };
   }
 
   @Test
@@ -67,15 +70,26 @@ void testInstrumentationNamePredicate() {
         .isFalse();
   }
 
+  @Test
+  void testGetOperationMetrics() {
+    OperationMetrics metrics = customizer.getOperationMetrics();
+    assertThat(metrics).isSameAs(operationMetrics);
+  }
+
   @Test
   void testGetAttributesExtractor() {
     AttributesExtractor<Object, Object> extractor = customizer.getAttributesExtractor();
     assertThat(extractor).isSameAs(attributesExtractor);
   }
 
   @Test
-  void testGetOperationMetrics() {
-    OperationMetrics metrics = customizer.getOperationMetrics();
-    assertThat(metrics).isSameAs(operationMetrics);
+  void testGetContextCustomizer() {
+    assertThat(customizer.getContextCustomizer()).isSameAs(contextCustomizer);
+  }
+
+  @Test
+  void testGetSpanNameExtractor() {
+    SpanNameExtractor<Object> extractor = customizer.getSpanNameExtractor();
+    assertThat(extractor).isSameAs(spanNameExtractor);
   }
 }