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EE4J Compatible Implementation for Jakarta Faces API
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/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.faces.application.resource;
import static com.sun.faces.util.Util.notNull;
import static java.util.logging.Level.FINE;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;
import com.sun.faces.config.WebConfiguration;
import com.sun.faces.config.WebConfiguration.WebContextInitParameter;
import com.sun.faces.util.FacesLogger;
import com.sun.faces.util.MultiKeyConcurrentHashMap;
import jakarta.servlet.ServletContext;
/**
*
* This is the caching mechanism for caching ResourceInfo instances to offset the cost of looking up the resource.
*
*
*
* This cache uses a background thread to check for modifications to the underlying webapp or JAR files containing
* resources. This check is periodic, configurable via context init param
* com.sun.faces.resourceUpdateCheckPeriod. Through this config option, the cache can also be made static
* or completely disabled. If the value of of this option is 0, then no check will be made making the cache
* static. If value of this option is less than 0, then no caching will be perfomed. Otherwise, the value
* of the option will be the number of minutes between modification checks.
*
*/
public class ResourceCache {
private static final Logger LOGGER = FacesLogger.RESOURCE.getLogger();
/**
* The ResourceInfo cache.
*/
private MultiKeyConcurrentHashMap resourceCache;
/**
* Resource check period in minutes.
*/
private long checkPeriod;
// ------------------------------------------------------------ Constructors
/**
* Constructs a new ResourceCache.
*/
public ResourceCache() {
this(WebConfiguration.getInstance());
}
private ResourceCache(WebConfiguration config) {
this(getCheckPeriod(config));
if (LOGGER.isLoggable(FINE)) {
ServletContext sc = config.getServletContext();
LOGGER.log(FINE, "ResourceCache constructed for {0}. Check period is {1} minutes.",
new Object[] { getServletContextIdentifier(sc), checkPeriod });
}
}
// this one is for unit tests
ResourceCache(long period) {
checkPeriod = period != -1 ? period * 1000L * 60L : -1;
resourceCache = new MultiKeyConcurrentHashMap<>(30);
}
// ---------------------------------------------------------- Public Methods
/**
* Add the {@link ResourceInfo} to the internal cache.
*
* @param info resource metadata
*
* @param contracts the contracts
* @return previous value associated with specified key, or null if there was no mapping for key
*/
public ResourceInfo add(ResourceInfo info, List contracts) {
notNull("info", info);
if (LOGGER.isLoggable(FINE)) {
LOGGER.log(FINE, "Caching ResourceInfo: {0}", info.toString());
}
ResourceInfoCheckPeriodProxy proxy = resourceCache.putIfAbsent(info.name, info.libraryName, info.localePrefix, new ArrayList(contracts),
new ResourceInfoCheckPeriodProxy(info, checkPeriod));
return proxy != null ? proxy.getResourceInfo() : null;
}
/**
* @param name the resource name
* @param libraryName the library name
* @param localePrefix the locale prefix
* @param contracts the contracts
* @return the {@link ResourceInfo} associated with key if any.
*/
public ResourceInfo get(String name, String libraryName, String localePrefix, List contracts) {
notNull("name", name);
ResourceInfoCheckPeriodProxy proxy = resourceCache.get(name, libraryName, localePrefix, contracts);
if (proxy != null && proxy.needsRefreshed()) {
resourceCache.remove(name, libraryName, localePrefix, contracts);
return null;
}
return proxy != null ? proxy.getResourceInfo() : null;
}
/**
*
* Empty the cache.
*
*/
public void clear() {
resourceCache.clear();
LOGGER.log(FINE, "Cache Cleared");
}
// --------------------------------------------------------- Private Methods
private static Long getCheckPeriod(WebConfiguration webConfig) {
String val = webConfig.getOptionValue(WebContextInitParameter.ResourceUpdateCheckPeriod);
try {
return Long.parseLong(val);
} catch (NumberFormatException nfe) {
return Long.parseLong(WebContextInitParameter.ResourceUpdateCheckPeriod.getDefaultValue());
}
}
private static String getServletContextIdentifier(ServletContext context) {
return context.getContextPath();
}
// ---------------------------------------------------------- Nested Classes
private static final class ResourceInfoCheckPeriodProxy {
private final ResourceInfo resourceInfo;
private Long checkTime;
// -------------------------------------------------------- Constructors
public ResourceInfoCheckPeriodProxy(ResourceInfo resourceInfo, long checkPeriod) {
this.resourceInfo = resourceInfo;
if (checkPeriod != -1L && !(resourceInfo.getHelper() instanceof ClasspathResourceHelper)) {
checkTime = System.currentTimeMillis() + checkPeriod;
}
}
private boolean needsRefreshed() {
return checkTime != null && checkTime < System.currentTimeMillis();
}
private ResourceInfo getResourceInfo() {
return resourceInfo;
}
} // END ResourceInfoCheckPeriodProxy
}