Replace Function<X, X> with UnaryOperator<X> in unstable modules

instrumentation/cassandra/cassandra-4.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/cassandra/v4_0/CompletionStageFunction.java

@@ -6,9 +6,9 @@
 package io.opentelemetry.javaagent.instrumentation.cassandra.v4_0;
 
 import com.datastax.oss.driver.api.core.CqlSession;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 
-public class CompletionStageFunction implements Function<Object, Object> {
+public class CompletionStageFunction implements UnaryOperator<Object> {
 
   @Override
   public Object apply(Object session) {

instrumentation/cassandra/cassandra-4.4/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/cassandra/v4_4/CompletionStageFunction.java

@@ -6,9 +6,9 @@
 package io.opentelemetry.javaagent.instrumentation.cassandra.v4_4;
 
 import com.datastax.oss.driver.api.core.CqlSession;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 
-public class CompletionStageFunction implements Function<Object, Object> {
+public class CompletionStageFunction implements UnaryOperator<Object> {
 
   @Override
   public Object apply(Object session) {

instrumentation/elasticsearch/elasticsearch-rest-7.0/library/src/main/java/io/opentelemetry/instrumentation/elasticsearch/rest/v7_0/RestClientWrapper.java

@@ -14,8 +14,8 @@
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.util.List;
-import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.function.UnaryOperator;
 import net.bytebuddy.ByteBuddy;
 import net.bytebuddy.description.modifier.Visibility;
 import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
@@ -32,7 +32,7 @@ class RestClientWrapper {
   private static final Class<?> proxyClass = createProxyClass();
   private static final Field targetField = getTargetField(proxyClass);
   private static final Field instrumenterSupplierField = getInstrumenterSupplierField(proxyClass);
-  private static final Function<RestClient, RestClient> proxyFactory = getProxyFactory(proxyClass);
+  private static final UnaryOperator<RestClient> proxyFactory = getProxyFactory(proxyClass);
 
   private static Class<?> createProxyClass() {
     return new ByteBuddy()
@@ -139,7 +139,7 @@ private static Instrumenter<ElasticsearchRestRequest, Response> getInstrumenter(
     return supplier != null ? supplier.get() : null;
   }
 
-  private static Function<RestClient, RestClient> getProxyFactory(Class<?> clazz) {
+  private static UnaryOperator<RestClient> getProxyFactory(Class<?> clazz) {
     for (Constructor<?> constructor : clazz.getDeclaredConstructors()) {
       Class<?>[] parameterTypes = constructor.getParameterTypes();
       if (parameterTypes.length >= 3

instrumentation/jmx-metrics/library/src/main/java/io/opentelemetry/instrumentation/jmx/engine/UnitConverter.java

@@ -8,7 +8,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
 
 /**
@@ -24,7 +24,7 @@ class UnitConverter {
     registerConversion("ns", "s", value -> value.doubleValue() / TimeUnit.SECONDS.toNanos(1));
   }
 
-  private final Function<Number, Number> convertingFunction;
+  private final UnaryOperator<Number> convertingFunction;
 
   /**
    * Get an instance of converter that is able to convert a value from a given source to a target
@@ -66,7 +66,7 @@ public static UnitConverter getInstance(@Nullable String sourceUnit, String targ
    */
   // visible for testing
   static void registerConversion(
-      String sourceUnit, String targetUnit, Function<Number, Number> convertingFunction) {
+      String sourceUnit, String targetUnit, UnaryOperator<Number> convertingFunction) {
     if (sourceUnit.isEmpty()) {
       throw new IllegalArgumentException("Non empty sourceUnit must be provided");
     }
@@ -92,7 +92,7 @@ private static String buildConverterKey(String sourceUnit, String targetUnit) {
    *
    * @param convertingFunction an algorithm applied when converting value
    */
-  UnitConverter(Function<Number, Number> convertingFunction) {
+  UnitConverter(UnaryOperator<Number> convertingFunction) {
     this.convertingFunction = convertingFunction;
   }
 

instrumentation/opentelemetry-api/opentelemetry-api-1.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/opentelemetryapi/context/InstrumentationApiContextBridging.java

@@ -12,7 +12,7 @@
 import java.lang.invoke.MethodType;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
 
 final class InstrumentationApiContextBridging {
@@ -199,13 +199,13 @@ final class InstrumentationApiContextBridging {
     }
   }
 
-  private static Function<Object, Object> httpRouteStateConvert(
+  private static UnaryOperator<Object> httpRouteStateConvert(
       MethodHandle create,
       MethodHandle getMethod,
       MethodHandle getRoute,
       MethodHandle getUpdatedBySourceOrder,
       MethodHandle getSpan,
-      Function<Object, Object> convertSpan) {
+      UnaryOperator<Object> convertSpan) {
     return httpRouteHolder -> {
       try {
         String method = (String) getMethod.invoke(httpRouteHolder);

instrumentation/reactor/reactor-3.1/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/reactor/v3_1/ContextPropagationOperatorInstrumentationTest.java

@@ -19,6 +19,7 @@
 import java.lang.invoke.MethodHandles;
 import java.time.Duration;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -194,7 +195,7 @@ void storeContextForcesItToBecomeCurrent() {
   }
 
   private static class StoreOpenTelemetryContext
-      implements Function<reactor.util.context.Context, reactor.util.context.Context> {
+      implements UnaryOperator<reactor.util.context.Context> {
 
     private final Span span;
 

instrumentation/reactor/reactor-3.1/library/src/main/java/io/opentelemetry/instrumentation/reactor/v3_1/ContextPropagationOperator.java

@@ -32,6 +32,7 @@
 import java.lang.invoke.MethodHandles;
 import java.util.function.BiFunction;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
@@ -175,7 +176,7 @@ public void registerOnEachOperator() {
     }
   }
 
-  private static void registerScheduleHook(String key, Function<Runnable, Runnable> function) {
+  private static void registerScheduleHook(String key, UnaryOperator<Runnable> function) {
     if (SCHEDULERS_HOOK_METHOD == null) {
       return;
     }
@@ -252,7 +253,7 @@ private static <T extends Throwable> T sneakyThrow(Throwable t) throws T {
   }
 
   private static class StoreOpenTelemetryContext
-      implements Function<reactor.util.context.Context, reactor.util.context.Context> {
+      implements UnaryOperator<reactor.util.context.Context> {
 
     private final Context tracingContext;
 

instrumentation/reactor/reactor-3.1/library/src/test/java/io/opentelemetry/instrumentation/reactor/v3_1/ReactorCoreTest.java

@@ -25,6 +25,7 @@
 import java.time.Duration;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -131,7 +132,7 @@ void fluxInNonBlockingPublisherAssembly() {
                 (Flux<Integer>)
                     FLUX_CONTEXT_WRITE_METHOD.invoke(
                         interim,
-                        (Function<reactor.util.context.Context, reactor.util.context.Context>)
+                        (UnaryOperator<reactor.util.context.Context>)
                             ctx -> {
                               Context parent =
                                   ContextPropagationOperator.getOpenTelemetryContext(
@@ -389,7 +390,7 @@ void doesNotOverrideInnerCurrentSpansWithThereIsOuterCurrent() {
             (Flux<Object>)
                 FLUX_CONTEXT_WRITE_METHOD.invoke(
                     interim,
-                    (Function<reactor.util.context.Context, reactor.util.context.Context>)
+                    (UnaryOperator<reactor.util.context.Context>)
                         context -> {
                           // subscribers that know that their subscription can happen
                           // ahead of time and in the 'wrong' context, has to clean up 'wrong'
@@ -565,7 +566,7 @@ private <T> Mono<T> monoSpan(Mono<T> mono, String spanName) {
       return (Mono<T>)
           MONO_CONTEXT_WRITE_METHOD.invoke(
               interim,
-              (Function<reactor.util.context.Context, reactor.util.context.Context>)
+              (UnaryOperator<reactor.util.context.Context>)
                   ctx -> {
                     Context parent =
                         ContextPropagationOperator.getOpenTelemetryContext(ctx, Context.current());

instrumentation/resources/library/src/main/java/io/opentelemetry/instrumentation/resources/internal/MainJarPathFinder.java

@@ -9,14 +9,14 @@
 import java.nio.file.InvalidPathException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
+import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
 
 class MainJarPathFinder {
   private final Supplier<String[]> getProcessHandleArguments;
-  private final Function<String, String> getSystemProperty;
+  private final UnaryOperator<String> getSystemProperty;
   private final Predicate<Path> fileExists;
 
   public MainJarPathFinder() {
@@ -26,7 +26,7 @@ public MainJarPathFinder() {
   // visible for tests
   MainJarPathFinder(
       Supplier<String[]> getProcessHandleArguments,
-      Function<String, String> getSystemProperty,
+      UnaryOperator<String> getSystemProperty,
       Predicate<Path> fileExists) {
     this.getProcessHandleArguments = getProcessHandleArguments;
     this.getSystemProperty = getSystemProperty;

instrumentation/resources/library/src/test/java/io/opentelemetry/instrumentation/resources/internal/JarServiceNameResourceExtractorTest.java

@@ -12,8 +12,8 @@
 import io.opentelemetry.sdk.resources.Resource;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -29,7 +29,7 @@ class JarServiceNameResourceExtractorTest {
   @Test
   void extractResource_empty() {
     String[] processArgs = new String[0];
-    Function<String, String> getProperty = prop -> null;
+    UnaryOperator<String> getProperty = prop -> null;
     Predicate<Path> fileExists = JarServiceNameResourceExtractorTest::failPath;
     JarServiceNameResourceExtractor serviceNameProvider =
         getExtractor(processArgs, getProperty, fileExists);
@@ -40,7 +40,7 @@ void extractResource_empty() {
   }
 
   private static JarServiceNameResourceExtractor getExtractor(
-      String[] processArgs, Function<String, String> getProperty, Predicate<Path> fileExists) {
+      String[] processArgs, UnaryOperator<String> getProperty, Predicate<Path> fileExists) {
     return new JarServiceNameResourceExtractor(
         new MainJarPathFinder(() -> processArgs, getProperty, fileExists));
   }
@@ -100,7 +100,7 @@ static String[] getArgs(String jarName) {
   @ParameterizedTest
   @MethodSource("sunCommandLineArguments")
   void extractResource_sunCommandLine(String commandLine, Path jarPath) {
-    Function<String, String> getProperty =
+    UnaryOperator<String> getProperty =
         key -> "sun.java.command".equals(key) ? commandLine : null;
     Predicate<Path> fileExists = jarPath::equals;
 
@@ -116,7 +116,7 @@ void extractResource_sunCommandLine(String commandLine, Path jarPath) {
   // https://github.com/open-telemetry/opentelemetry-java-instrumentation/pull/7567
   @Test
   void extractResource_sunCommandLineProblematicArgs() {
-    Function<String, String> getProperty =
+    UnaryOperator<String> getProperty =
         key -> key.equals("sun.java.command") ? "one C:/two" : null;
     Predicate<Path> fileExists = path -> false;
 

javaagent-extension-api/src/main/java/io/opentelemetry/javaagent/extension/instrumentation/TypeTransformer.java

@@ -5,7 +5,7 @@
 
 package io.opentelemetry.javaagent.extension.instrumentation;
 
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import net.bytebuddy.agent.builder.AgentBuilder;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -25,7 +25,7 @@ public interface TypeTransformer {
    */
   default void applyAdviceToMethod(
       ElementMatcher<? super MethodDescription> methodMatcher, String adviceClassName) {
-    applyAdviceToMethod(methodMatcher, Function.identity(), adviceClassName);
+    applyAdviceToMethod(methodMatcher, UnaryOperator.identity(), adviceClassName);
   }
 
   /**
@@ -34,7 +34,7 @@ default void applyAdviceToMethod(
    */
   void applyAdviceToMethod(
       ElementMatcher<? super MethodDescription> methodMatcher,
-      Function<Advice.WithCustomMapping, Advice.WithCustomMapping> mappingCustomizer,
+      UnaryOperator<Advice.WithCustomMapping> mappingCustomizer,
       String adviceClassName);
 
   /**

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/instrumentation/TypeTransformerImpl.java

@@ -9,7 +9,7 @@
 import io.opentelemetry.javaagent.tooling.Utils;
 import io.opentelemetry.javaagent.tooling.bytebuddy.ExceptionHandlers;
 import io.opentelemetry.javaagent.tooling.instrumentation.indy.ForceDynamicallyTypedAssignReturnedFactory;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import net.bytebuddy.agent.builder.AgentBuilder;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -31,7 +31,7 @@ final class TypeTransformerImpl implements TypeTransformer {
   @Override
   public void applyAdviceToMethod(
       ElementMatcher<? super MethodDescription> methodMatcher,
-      Function<Advice.WithCustomMapping, Advice.WithCustomMapping> mappingCustomizer,
+      UnaryOperator<Advice.WithCustomMapping> mappingCustomizer,
       String adviceClassName) {
     agentBuilder =
         agentBuilder.transform(

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/instrumentation/indy/IndyTypeTransformerImpl.java

@@ -12,7 +12,7 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.function.BiFunction;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import net.bytebuddy.agent.builder.AgentBuilder;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -51,7 +51,7 @@ public IndyTypeTransformerImpl(
   @Override
   public void applyAdviceToMethod(
       ElementMatcher<? super MethodDescription> methodMatcher,
-      Function<Advice.WithCustomMapping, Advice.WithCustomMapping> mappingCustomizer,
+      UnaryOperator<Advice.WithCustomMapping> mappingCustomizer,
       String adviceClassName) {
     // default strategy used by AgentBuilder.Transformer.ForAdvice
     AgentBuilder.PoolStrategy poolStrategy = AgentBuilder.PoolStrategy.Default.FAST;

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/instrumentation/indy/InstrumentationModuleClassLoader.java

@@ -25,7 +25,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import net.bytebuddy.agent.builder.AgentBuilder;
@@ -184,7 +184,7 @@ private static Set<String> getModuleAdviceNames(InstrumentationModule module) {
           @Override
           public void applyAdviceToMethod(
               ElementMatcher<? super MethodDescription> methodMatcher,
-              Function<Advice.WithCustomMapping, Advice.WithCustomMapping> mappingCustomizer,
+              UnaryOperator<Advice.WithCustomMapping> mappingCustomizer,
               String adviceClassName) {
             adviceNames.add(adviceClassName);
           }

muzzle/src/main/java/io/opentelemetry/javaagent/tooling/muzzle/generation/AdviceClassNameCollector.java

@@ -8,7 +8,7 @@
 import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
 import java.util.HashSet;
 import java.util.Set;
-import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import net.bytebuddy.agent.builder.AgentBuilder;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -20,7 +20,7 @@ final class AdviceClassNameCollector implements TypeTransformer {
   @Override
   public void applyAdviceToMethod(
       ElementMatcher<? super MethodDescription> methodMatcher,
-      Function<Advice.WithCustomMapping, Advice.WithCustomMapping> mappingCustomizer,
+      UnaryOperator<Advice.WithCustomMapping> mappingCustomizer,
       String adviceClassName) {
     adviceClassNames.add(adviceClassName);
   }