ThreadLocalCacheManager.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.cache.thread.local;

import com.liferay.portal.kernel.transaction.NewTransactionLifecycleListener;
import com.liferay.portal.kernel.transaction.TransactionAttribute;
import com.liferay.portal.kernel.transaction.TransactionLifecycleListener;
import com.liferay.portal.kernel.transaction.TransactionStatus;
import com.liferay.portal.kernel.util.InitialThreadLocal;

import java.io.Serializable;

import java.util.HashMap;
import java.util.Map;

/**
 * @author Shuyang Zhou
 */
public class ThreadLocalCacheManager {

	public static final TransactionLifecycleListener
		TRANSACTION_LIFECYCLE_LISTENER = new NewTransactionLifecycleListener() {

			@Override
			protected void doCommitted(
				TransactionAttribute transactionAttribute,
				TransactionStatus transactionStatus) {

				if (!transactionAttribute.isReadOnly()) {
					enable(Lifecycle.REQUEST);
				}
			}

			@Override
			protected void doCreated(
				TransactionAttribute transactionAttribute,
				TransactionStatus transactionStatus) {

				if (!transactionAttribute.isReadOnly()) {
					disable(Lifecycle.REQUEST);
				}
			}

			@Override
			protected void doRollbacked(
				TransactionAttribute transactionAttribute,
				TransactionStatus transactionStatus, Throwable throwable) {

				if (!transactionAttribute.isReadOnly()) {
					enable(Lifecycle.REQUEST);
				}
			}

		};

	public static void clearAll(Lifecycle lifecycle) {
		ThreadLocalCaches threadLocalCaches = _getThreadLocalCaches(lifecycle);

		if (threadLocalCaches != null) {
			Map<Object, ThreadLocalCache<?>> threadLocalCacheMaps =
				threadLocalCaches._threadLocalCacheMap;

			threadLocalCacheMaps.clear();
		}
	}

	public static void destroy() {
		_requestThreadLocalCaches.remove();

		_eternalThreadLocalCaches.remove();
	}

	public static void disable(Lifecycle lifecycle) {
		ThreadLocalCaches threadLocalCaches = _getThreadLocalCaches(lifecycle);

		if (threadLocalCaches != null) {
			threadLocalCaches._disabled = true;

			Map<Object, ThreadLocalCache<?>> threadLocalCacheMaps =
				threadLocalCaches._threadLocalCacheMap;

			threadLocalCacheMaps.clear();
		}
	}

	public static void enable(Lifecycle lifecycle) {
		ThreadLocalCaches threadLocalCaches = _getThreadLocalCaches(lifecycle);

		if (threadLocalCaches != null) {
			threadLocalCaches._disabled = false;
		}
	}

	public static <T> ThreadLocalCache<T> getThreadLocalCache(
		Lifecycle lifecycle, Object name) {

		ThreadLocalCaches threadLocalCaches = _getThreadLocalCaches(lifecycle);

		if ((threadLocalCaches == null) || threadLocalCaches._disabled) {
			return (ThreadLocalCache<T>)_emptyThreadLocalCache;
		}

		Map<Object, ThreadLocalCache<?>> threadLocalCacheMap =
			threadLocalCaches._threadLocalCacheMap;

		ThreadLocalCache<?> threadLocalCache = threadLocalCacheMap.get(name);

		if (threadLocalCache == null) {
			threadLocalCache = new ThreadLocalCache<>(name, lifecycle);

			threadLocalCacheMap.put(name, threadLocalCache);
		}

		return (ThreadLocalCache<T>)threadLocalCache;
	}

	public static <T> ThreadLocalCache<T> getThreadLocalCache(
		Lifecycle lifecycle, Serializable name) {

		return getThreadLocalCache(lifecycle, (Object)name);
	}

	private static ThreadLocalCaches _getThreadLocalCaches(
		Lifecycle lifecycle) {

		if (lifecycle == Lifecycle.REQUEST) {
			return _requestThreadLocalCaches.get();
		}

		if (lifecycle == Lifecycle.ETERNAL) {
			return _eternalThreadLocalCaches.get();
		}

		return null;
	}

	private static final EmptyThreadLocalCahce<?> _emptyThreadLocalCache =
		new EmptyThreadLocalCahce<>();

	private static final ThreadLocal<ThreadLocalCaches>
		_eternalThreadLocalCaches = new InitialThreadLocal<ThreadLocalCaches>(
			ThreadLocalCacheManager.class + "._eternalThreadLocalCaches",
			() -> null) {

			@Override
			protected ThreadLocalCaches initialValue() {
				return new ThreadLocalCaches();
			}

		};

	private static final ThreadLocal<ThreadLocalCaches>
		_requestThreadLocalCaches = new InitialThreadLocal<ThreadLocalCaches>(
			ThreadLocalCacheManager.class + "._requestThreadLocalCaches",
			() -> null) {

			@Override
			protected ThreadLocalCaches initialValue() {
				return new ThreadLocalCaches();
			}

		};

	private static class EmptyThreadLocalCahce<T> extends ThreadLocalCache<T> {

		@Override
		public T get(String key) {
			return null;
		}

		@Override
		public void put(String key, T obj) {
		}

		@Override
		public void remove(String key) {
		}

		@Override
		public void removeAll() {
		}

		@Override
		public String toString() {
			return EmptyThreadLocalCahce.class.getName();
		}

		private EmptyThreadLocalCahce() {
			super(null, null);
		}

	}

	private static class ThreadLocalCaches {

		private boolean _disabled;
		private final Map<Object, ThreadLocalCache<?>> _threadLocalCacheMap =
			new HashMap<>();

	}

}