| /* |
| * ==================================================================== |
| * 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 |
| * |
| * http://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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| package org.apache.http.impl.client.cache; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Set; |
| import java.util.concurrent.ArrayBlockingQueue; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.ThreadPoolExecutor; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.http.HttpHost; |
| import org.apache.http.client.cache.HttpCacheContext; |
| import org.apache.http.client.cache.HttpCacheEntry; |
| import org.apache.http.client.methods.HttpRequestWrapper; |
| |
| /** |
| * Class used for asynchronous revalidations to be used when the "stale- |
| * while-revalidate" directive is present |
| */ |
| class AsynchronousAsyncValidator { |
| private final CachingHttpAsyncClient cachingAsyncClient; |
| private final ExecutorService executor; |
| private final Set<String> queued; |
| private final CacheKeyGenerator cacheKeyGenerator; |
| |
| private final Log log = LogFactory.getLog(getClass()); |
| |
| /** |
| * Create AsynchronousValidator which will make revalidation requests using |
| * the supplied {@link CachingHttpAsyncClient}, and a {@link ThreadPoolExecutor} |
| * generated according to the thread pool settings provided in the given |
| * {@link CacheConfig}. |
| * |
| * @param cachingClient |
| * used to execute asynchronous requests |
| * @param config |
| * specifies thread pool settings. See |
| * {@link CacheConfig#getAsynchronousWorkersMax()}, |
| * {@link CacheConfig#getAsynchronousWorkersCore()}, |
| * {@link CacheConfig#getAsynchronousWorkerIdleLifetimeSecs()}, |
| * and {@link CacheConfig#getRevalidationQueueSize()}. |
| */ |
| public AsynchronousAsyncValidator(final CachingHttpAsyncClient cachingClient, final CacheConfig config) { |
| this(cachingClient, new ThreadPoolExecutor(config.getAsynchronousWorkersCore(), |
| config.getAsynchronousWorkersMax(), config.getAsynchronousWorkerIdleLifetimeSecs(), |
| TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>( |
| config.getRevalidationQueueSize()))); |
| } |
| |
| /** |
| * Create AsynchronousValidator which will make revalidation requests using |
| * the supplied {@link CachingHttpAsyncClient} and {@link ExecutorService}. |
| * |
| * @param cachingClient |
| * used to execute asynchronous requests |
| * @param executor |
| * used to manage a thread pool of revalidation workers |
| */ |
| AsynchronousAsyncValidator(final CachingHttpAsyncClient cachingClient, final ExecutorService executor) { |
| this.cachingAsyncClient = cachingClient; |
| this.executor = executor; |
| this.queued = new HashSet<String>(); |
| this.cacheKeyGenerator = new CacheKeyGenerator(); |
| } |
| |
| /** |
| * Schedules an asynchronous revalidation |
| */ |
| public synchronized void revalidateCacheEntry(final HttpHost target, final HttpRequestWrapper request, |
| final HttpCacheContext clientContext, final HttpCacheEntry entry) { |
| // getVariantURI will fall back on getURI if no variants exist |
| final String uri = this.cacheKeyGenerator.getVariantURI(target, request, entry); |
| |
| if (!this.queued.contains(uri)) { |
| final AsynchronousAsyncValidationRequest asyncRevalidationRequest = new AsynchronousAsyncValidationRequest( |
| this, this.cachingAsyncClient, target, request, clientContext, entry, uri); |
| |
| try { |
| this.executor.execute(asyncRevalidationRequest); |
| this.queued.add(uri); |
| } catch (final RejectedExecutionException ree) { |
| this.log.debug("Revalidation for [" + uri + "] not scheduled: " + ree); |
| } |
| } |
| } |
| |
| /** |
| * Removes an identifier from the internal list of revalidation jobs in |
| * progress. This is meant to be called by |
| * {@link AsynchronousValidationRequest#run()} once the revalidation is |
| * complete, using the identifier passed in during constructions. |
| */ |
| synchronized void markComplete(final String identifier) { |
| this.queued.remove(identifier); |
| } |
| |
| Set<String> getScheduledIdentifiers() { |
| return Collections.unmodifiableSet(this.queued); |
| } |
| |
| ExecutorService getExecutor() { |
| return this.executor; |
| } |
| |
| } |