icu.easyj.core.util.CycleDependencyHandler Maven / Gradle / Ivy

/*
 * Copyright 2021 the original author or authors.
 *
 * Licensed 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 icu.easyj.core.util;

import java.util.HashSet;
import java.util.Set;
import java.util.function.Function;

/**
 * 循环依赖处理器
 *
 * @author wangliang181230
 */
public abstract class CycleDependencyHandler {

	private static final ThreadLocal> OBJECT_SET_LOCAL = new ThreadLocal<>();

	public static  String wrap(O obj, Function function) {
		boolean isStarting = isStarting();
		try {
			if (!isStarting) {
				start();
			} else {
				if (containsObject(obj)) {
					return toRefString(obj);
				}
			}

			// add object
			addObject(obj);

			// do function
			return function.apply(obj);
		} finally {
			if (!isStarting) {
				end();
			}
		}
	}

	public static String toRefString(Object obj) {
		return "(ref " + obj.getClass().getSimpleName() + ")";
	}

	private static boolean isStarting() {
		return OBJECT_SET_LOCAL.get() != null;
	}

	private static void start() {
		OBJECT_SET_LOCAL.set(new HashSet<>(4));
	}

	private static void end() {
		OBJECT_SET_LOCAL.remove();
	}

	private static void addObject(Object obj) {
		if (obj == null) {
			return;
		}

		// get object set
		Set