content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.calcite.linq4j.util;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.lang.invoke.MethodHandle;
  import java.lang.invoke.MethodHandles;
  import java.lang.invoke.MethodType;
  import java.lang.reflect.Proxy;
  import java.util.Locale;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Compatibility layer.
   *
   * <p>Allows to use advanced functionality if the latest JDK version is present.
   */
  public interface Compatible {
    Compatible INSTANCE = new Compatible.Factory().create();
  
    /** Tells whether the given class is a JDK 16+ record. */
    <T> boolean isRecord(Class<T> clazz);
  
    /** Creates an implementation of {@link Compatible} suitable for the current environment. */
    class Factory {
      private static final @Nullable MethodHandle IS_RECORD =
          tryGetIsRecordMethod(MethodHandles.lookup());
  
      Compatible create() {
        return (Compatible) Proxy.newProxyInstance(
            Compatible.class.getClassLoader(),
            new Class<?>[]{Compatible.class},
            (proxy, method, args) -> {
              if ("isRecord".equals(method.getName())) {
                return isRecord(requireNonNull(args[0], "args[0]"));
              }
              return null;
            });
      }
  
      private static boolean isRecord(Object clazz) {
        if (IS_RECORD == null) {
          return false;
        }
  
        try {
          return (boolean) IS_RECORD.invoke(clazz);
        } catch (Throwable e) {
          throw new RuntimeException(
              String.format(Locale.ROOT, "Failed to invoke %s on %s", IS_RECORD, clazz), e);
        }
      }
  
      private static @Nullable MethodHandle tryGetIsRecordMethod(MethodHandles.Lookup lookup) {
        try {
          MethodType methodType = MethodType.methodType(boolean.class);
          return lookup.findVirtual(Class.class, "isRecord", methodType);
        } catch (NoSuchMethodException | IllegalAccessException e) {
          return null;
        }
      }
    }
  }
  