com.semanticcms.core.servlet.SingleThreadCache Maven / Gradle / Ivy

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/*
 * semanticcms-core-servlet - Java API for modeling web page content and relationships in a Servlet environment.
 * Copyright (C) 2016, 2019, 2020, 2021  AO Industries, Inc.
 *     [email protected]
 *     7262 Bull Pen Cir
 *     Mobile, AL 36695
 *
 * This file is part of semanticcms-core-servlet.
 *
 * semanticcms-core-servlet 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 3 of the License, or
 * (at your option) any later version.
 *
 * semanticcms-core-servlet 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with semanticcms-core-servlet.  If not, see .
 */
package com.semanticcms.core.servlet;

import com.aoapps.collections.AoCollections;
import com.semanticcms.core.model.Page;
import com.semanticcms.core.model.PageRef;
import static com.semanticcms.core.servlet.Cache.VERIFY_CACHE_PARENT_CHILD_RELATIONSHIPS;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import javax.servlet.ServletException;

/**
 * A page cache that is not thread safe and should only be used within the
 * context of a single thread.
 */
class SingleThreadCache extends MapCache {

	private final Thread assertingThread;

	@SuppressWarnings("AssertWithSideEffects")
	SingleThreadCache() {
		super(
			new HashMap(),
			VERIFY_CACHE_PARENT_CHILD_RELATIONSHIPS ? new HashMap>() : null,
			VERIFY_CACHE_PARENT_CHILD_RELATIONSHIPS ? new HashMap>() : null,
			new HashMap()
		);
		Thread t = null;
		// Intentional side-effect from assert
		assert (t = Thread.currentThread()) != null;
		assertingThread = t;
	}

	@Override
	Page get(CaptureKey key) {
		assert assertingThread == Thread.currentThread();
		return super.get(key);
	}

	@Override
	void put(CaptureKey key, Page page) throws ServletException {
		assert assertingThread == Thread.currentThread();
		super.put(key, page);
	}

	@Override
	public  Map newMap() {
		assert assertingThread == Thread.currentThread();
		return new HashMap<>();
	}

	@Override
	public  Map newMap(int size) {
		assert assertingThread == Thread.currentThread();
		return AoCollections.newHashMap(size);
	}

	@Override
	public void setAttribute(String key, Object value) {
		assert assertingThread == Thread.currentThread();
		super.setAttribute(key, value);
	}

	@Override
	public Object getAttribute(String key) {
		assert assertingThread == Thread.currentThread();
		return super.getAttribute(key);
	}

	/**
	 * @param    An arbitrary exception type that may be thrown
	 */
	@Override
	// TODO: Ex extends Throwable
	public  V getAttribute(String key, Class clazz, Callable callable) throws Ex {
		assert assertingThread == Thread.currentThread();
		return super.getAttribute(key, clazz, callable);
	}

	@Override
	public void removeAttribute(String key) {
		assert assertingThread == Thread.currentThread();
		super.removeAttribute(key);
	}
}