| /* |
| * ==================================================================== |
| * 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.hc.client5.http.impl.cache; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.ScheduledFuture; |
| import java.util.concurrent.ScheduledThreadPoolExecutor; |
| |
| import org.apache.hc.client5.http.cache.HeaderConstants; |
| import org.apache.hc.client5.http.schedule.ConcurrentCountMap; |
| import org.apache.hc.client5.http.schedule.SchedulingStrategy; |
| import org.apache.hc.core5.http.Header; |
| import org.apache.hc.core5.http.HttpResponse; |
| import org.apache.hc.core5.util.Args; |
| import org.apache.hc.core5.util.TimeValue; |
| import org.apache.hc.core5.util.Timeout; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Abstract cache re-validation class. |
| */ |
| class CacheRevalidatorBase implements Closeable { |
| |
| interface ScheduledExecutor { |
| |
| Future<?> schedule(Runnable command, TimeValue timeValue) throws RejectedExecutionException; |
| |
| void shutdown(); |
| |
| void awaitTermination(final Timeout timeout) throws InterruptedException; |
| |
| } |
| |
| public static ScheduledExecutor wrap(final ScheduledExecutorService executorService) { |
| |
| return new ScheduledExecutor() { |
| |
| @Override |
| public ScheduledFuture<?> schedule(final Runnable command, final TimeValue timeValue) throws RejectedExecutionException { |
| Args.notNull(command, "Runnable"); |
| Args.notNull(timeValue, "Time value"); |
| return executorService.schedule(command, timeValue.getDuration(), timeValue.getTimeUnit()); |
| } |
| |
| @Override |
| public void shutdown() { |
| executorService.shutdown(); |
| } |
| |
| @Override |
| public void awaitTermination(final Timeout timeout) throws InterruptedException { |
| Args.notNull(timeout, "Timeout"); |
| executorService.awaitTermination(timeout.getDuration(), timeout.getTimeUnit()); |
| } |
| |
| }; |
| |
| } |
| |
| private final ScheduledExecutor scheduledExecutor; |
| private final SchedulingStrategy schedulingStrategy; |
| private final Set<String> pendingRequest; |
| private final ConcurrentCountMap<String> failureCache; |
| |
| private static final Logger LOG = LoggerFactory.getLogger(CacheRevalidatorBase.class); |
| |
| /** |
| * Create CacheValidator which will make ache revalidation requests |
| * using the supplied {@link SchedulingStrategy} and {@link ScheduledExecutor}. |
| */ |
| public CacheRevalidatorBase( |
| final ScheduledExecutor scheduledExecutor, |
| final SchedulingStrategy schedulingStrategy) { |
| this.scheduledExecutor = scheduledExecutor; |
| this.schedulingStrategy = schedulingStrategy; |
| this.pendingRequest = new HashSet<>(); |
| this.failureCache = new ConcurrentCountMap<>(); |
| } |
| |
| /** |
| * Create CacheValidator which will make ache revalidation requests |
| * using the supplied {@link SchedulingStrategy} and {@link ScheduledThreadPoolExecutor}. |
| */ |
| public CacheRevalidatorBase( |
| final ScheduledThreadPoolExecutor scheduledThreadPoolExecutor, |
| final SchedulingStrategy schedulingStrategy) { |
| this(wrap(scheduledThreadPoolExecutor), schedulingStrategy); |
| } |
| |
| /** |
| * Schedules an asynchronous re-validation |
| */ |
| void scheduleRevalidation(final String cacheKey, final Runnable command) { |
| synchronized (pendingRequest) { |
| if (!pendingRequest.contains(cacheKey)) { |
| final int consecutiveFailedAttempts = failureCache.getCount(cacheKey); |
| final TimeValue executionTime = schedulingStrategy.schedule(consecutiveFailedAttempts); |
| try { |
| scheduledExecutor.schedule(command, executionTime); |
| pendingRequest.add(cacheKey); |
| } catch (final RejectedExecutionException ex) { |
| LOG.debug("Revalidation of cache entry with key {} could not be scheduled", cacheKey, ex); |
| } |
| } |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| scheduledExecutor.shutdown(); |
| } |
| |
| public void awaitTermination(final Timeout timeout) throws InterruptedException { |
| Args.notNull(timeout, "Timeout"); |
| scheduledExecutor.awaitTermination(timeout); |
| } |
| |
| void jobSuccessful(final String identifier) { |
| failureCache.resetCount(identifier); |
| synchronized (pendingRequest) { |
| pendingRequest.remove(identifier); |
| } |
| } |
| |
| void jobFailed(final String identifier) { |
| failureCache.increaseCount(identifier); |
| synchronized (pendingRequest) { |
| pendingRequest.remove(identifier); |
| } |
| } |
| |
| Set<String> getScheduledIdentifiers() { |
| synchronized (pendingRequest) { |
| return new HashSet<>(pendingRequest); |
| } |
| } |
| |
| /** |
| * Determines if the given response is generated from a stale cache entry. |
| * @param httpResponse the response to be checked |
| * @return whether the response is stale or not |
| */ |
| boolean isStale(final HttpResponse httpResponse) { |
| for (final Iterator<Header> it = httpResponse.headerIterator(HeaderConstants.WARNING); it.hasNext(); ) { |
| /* |
| * warn-codes |
| * 110 = Response is stale |
| * 111 = Revalidation failed |
| */ |
| final Header warning = it.next(); |
| final String warningValue = warning.getValue(); |
| if (warningValue.startsWith("110") || warningValue.startsWith("111")) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| } |