| /* |
| * 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 |
| * |
| * https://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.avro.reflect; |
| |
| import org.apache.avro.AvroRuntimeException; |
| |
| import java.lang.invoke.CallSite; |
| import java.lang.invoke.LambdaMetafactory; |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodType; |
| import java.lang.reflect.ParameterizedType; |
| import java.lang.reflect.Type; |
| import java.lang.reflect.TypeVariable; |
| import java.util.IdentityHashMap; |
| import java.util.Map; |
| import java.util.function.Function; |
| import java.util.function.Supplier; |
| |
| /** |
| * A few utility methods for using @link{java.misc.Unsafe}, mostly for private |
| * use. |
| * |
| * Use of Unsafe on Android is forbidden, as Android provides only a very |
| * limited functionality for this class compared to the JDK version. |
| * |
| * InterfaceAudience.Private |
| */ |
| public class ReflectionUtil { |
| |
| private ReflectionUtil() { |
| } |
| |
| private static FieldAccess fieldAccess; |
| static { |
| resetFieldAccess(); |
| } |
| |
| static void resetFieldAccess() { |
| // load only one implementation of FieldAccess |
| // so it is monomorphic and the JIT can inline |
| FieldAccess access = null; |
| try { |
| if (null == System.getProperty("avro.disable.unsafe")) { |
| FieldAccess unsafeAccess = load("org.apache.avro.reflect.FieldAccessUnsafe", FieldAccess.class); |
| if (validate(unsafeAccess)) { |
| access = unsafeAccess; |
| } |
| } |
| } catch (Throwable ignored) { |
| } |
| if (access == null) { |
| try { |
| FieldAccess reflectAccess = load("org.apache.avro.reflect.FieldAccessReflect", FieldAccess.class); |
| if (validate(reflectAccess)) { |
| access = reflectAccess; |
| } |
| } catch (Throwable oops) { |
| throw new AvroRuntimeException("Unable to load a functional FieldAccess class!"); |
| } |
| } |
| fieldAccess = access; |
| } |
| |
| private static <T> T load(String name, Class<T> type) throws Exception { |
| return ReflectionUtil.class.getClassLoader().loadClass(name).asSubclass(type).getDeclaredConstructor() |
| .newInstance(); |
| } |
| |
| public static FieldAccess getFieldAccess() { |
| return fieldAccess; |
| } |
| |
| private static boolean validate(FieldAccess access) throws Exception { |
| return new AccessorTestClass().validate(access); |
| } |
| |
| private static final class AccessorTestClass { |
| private boolean b = true; |
| protected byte by = 0xf; |
| public char c = 'c'; |
| short s = 123; |
| int i = 999; |
| long l = 12345L; |
| float f = 2.2f; |
| double d = 4.4d; |
| Object o = "foo"; |
| Integer i2 = 555; |
| |
| private boolean validate(FieldAccess access) throws Exception { |
| boolean valid = true; |
| valid &= validField(access, "b", b, false); |
| valid &= validField(access, "by", by, (byte) 0xaf); |
| valid &= validField(access, "c", c, 'C'); |
| valid &= validField(access, "s", s, (short) 321); |
| valid &= validField(access, "i", i, 111); |
| valid &= validField(access, "l", l, 54321L); |
| valid &= validField(access, "f", f, 0.2f); |
| valid &= validField(access, "d", d, 0.4d); |
| valid &= validField(access, "o", o, new Object()); |
| valid &= validField(access, "i2", i2, -555); |
| return valid; |
| } |
| |
| private boolean validField(FieldAccess access, String name, Object original, Object toSet) throws Exception { |
| FieldAccessor a = accessor(access, name); |
| boolean valid = original.equals(a.get(this)); |
| a.set(this, toSet); |
| valid &= !original.equals(a.get(this)); |
| return valid; |
| } |
| |
| private FieldAccessor accessor(FieldAccess access, String name) throws Exception { |
| return access.getAccessor(this.getClass().getDeclaredField(name)); |
| } |
| } |
| |
| /** |
| * For an interface, get a map of any {@link TypeVariable}s to their actual |
| * types. |
| * |
| * @param iface interface to resolve types for. |
| * @return a map of {@link TypeVariable}s to actual types. |
| */ |
| protected static Map<TypeVariable<?>, Type> resolveTypeVariables(Class<?> iface) { |
| return resolveTypeVariables(iface, new IdentityHashMap<>()); |
| } |
| |
| private static Map<TypeVariable<?>, Type> resolveTypeVariables(Class<?> iface, Map<TypeVariable<?>, Type> reuse) { |
| |
| for (Type type : iface.getGenericInterfaces()) { |
| if (type instanceof ParameterizedType) { |
| ParameterizedType parameterizedType = (ParameterizedType) type; |
| Type rawType = parameterizedType.getRawType(); |
| if (rawType instanceof Class<?>) { |
| Class<?> classType = (Class<?>) rawType; |
| TypeVariable<? extends Class<?>>[] typeParameters = classType.getTypeParameters(); |
| Type[] actualTypeArguments = parameterizedType.getActualTypeArguments(); |
| for (int i = 0; i < typeParameters.length; i++) { |
| reuse.putIfAbsent(typeParameters[i], reuse.getOrDefault(actualTypeArguments[i], actualTypeArguments[i])); |
| } |
| resolveTypeVariables(classType, reuse); |
| } |
| } |
| } |
| return reuse; |
| } |
| |
| private static <D> Supplier<D> getConstructorAsSupplier(Class<D> clazz) { |
| try { |
| MethodHandles.Lookup lookup = MethodHandles.lookup(); |
| MethodHandle constructorHandle = lookup.findConstructor(clazz, MethodType.methodType(void.class)); |
| |
| CallSite site = LambdaMetafactory.metafactory(lookup, "get", MethodType.methodType(Supplier.class), |
| constructorHandle.type().generic(), constructorHandle, constructorHandle.type()); |
| |
| return (Supplier<D>) site.getTarget().invokeExact(); |
| } catch (Throwable t) { |
| // if anything goes wrong, don't provide a Supplier |
| return null; |
| } |
| } |
| |
| private static <V, R> Supplier<R> getOneArgConstructorAsSupplier(Class<R> clazz, Class<V> argumentClass, V argument) { |
| Function<V, R> supplierFunction = getConstructorAsFunction(argumentClass, clazz); |
| if (supplierFunction != null) { |
| return () -> supplierFunction.apply(argument); |
| } else { |
| return null; |
| } |
| } |
| |
| public static <V, R> Function<V, R> getConstructorAsFunction(Class<V> parameterClass, Class<R> clazz) { |
| try { |
| MethodHandles.Lookup lookup = MethodHandles.lookup(); |
| MethodHandle constructorHandle = lookup.findConstructor(clazz, MethodType.methodType(void.class, parameterClass)); |
| |
| CallSite site = LambdaMetafactory.metafactory(lookup, "apply", MethodType.methodType(Function.class), |
| constructorHandle.type().generic(), constructorHandle, constructorHandle.type()); |
| |
| return (Function<V, R>) site.getTarget().invokeExact(); |
| } catch (Throwable t) { |
| // if something goes wrong, do not provide a Function instance |
| return null; |
| } |
| } |
| |
| } |