Ktor: support setting custom spanNameExtractor (#12842)

Closes #12842

Author: SIMULATAN

instrumentation/ktor/ktor-2-common/library/src/main/kotlin/io/opentelemetry/instrumentation/ktor/client/AbstractKtorClientTracingBuilder.kt

@@ -13,7 +13,9 @@ import io.opentelemetry.api.common.AttributesBuilder
 import io.opentelemetry.context.Context
 import io.opentelemetry.instrumentation.api.incubator.builder.internal.DefaultHttpClientInstrumenterBuilder
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor
+import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor
 import io.opentelemetry.instrumentation.ktor.internal.KtorBuilderUtil
+import java.util.function.Function
 
 abstract class AbstractKtorClientTracingBuilder(
   private val instrumentationName: String
@@ -169,4 +171,8 @@ abstract class AbstractKtorClientTracingBuilder(
   fun emitExperimentalHttpClientMetrics() {
     clientBuilder.setEmitExperimentalHttpClientMetrics(true)
   }
+
+  fun spanNameExtractor(spanNameExtractorTransformer: Function<SpanNameExtractor<in HttpRequestData>, out SpanNameExtractor<in HttpRequestData>>) {
+    clientBuilder.setSpanNameExtractor(spanNameExtractorTransformer)
+  }
 }

instrumentation/ktor/ktor-2-common/library/src/main/kotlin/io/opentelemetry/instrumentation/ktor/server/AbstractKtorServerTracingBuilder.kt

@@ -6,7 +6,6 @@
 package io.opentelemetry.instrumentation.ktor.server
 
 import io.ktor.http.*
-import io.ktor.server.application.*
 import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.opentelemetry.api.OpenTelemetry
@@ -16,9 +15,11 @@ import io.opentelemetry.context.Context
 import io.opentelemetry.instrumentation.api.incubator.builder.internal.DefaultHttpServerInstrumenterBuilder
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor
 import io.opentelemetry.instrumentation.api.instrumenter.SpanKindExtractor
+import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusBuilder
 import io.opentelemetry.instrumentation.api.instrumenter.SpanStatusExtractor
 import io.opentelemetry.instrumentation.ktor.internal.KtorBuilderUtil
+import java.util.function.Function
 
 abstract class AbstractKtorServerTracingBuilder(private val instrumentationName: String) {
   companion object {
@@ -86,6 +87,10 @@ abstract class AbstractKtorServerTracingBuilder(private val instrumentationName:
     }
   }
 
+  fun spanNameExtractor(spanNameExtractorTransformer: Function<SpanNameExtractor<in ApplicationRequest>, out SpanNameExtractor<in ApplicationRequest>>) {
+    serverBuilder.setSpanNameExtractor(spanNameExtractorTransformer)
+  }
+
   @Deprecated("Please use method `attributeExtractor`")
   fun addAttributeExtractor(extractor: AttributesExtractor<in ApplicationRequest, in ApplicationResponse>) {
     attributeExtractor {