| /* |
| * ==================================================================== |
| * 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.IOException; |
| |
| import org.apache.hc.client5.http.cache.HeaderConstants; |
| import org.apache.hc.client5.http.cache.HttpCacheEntry; |
| import org.apache.hc.client5.http.sync.ExecChain; |
| import org.apache.hc.core5.http.ClassicHttpRequest; |
| import org.apache.hc.core5.http.ClassicHttpResponse; |
| import org.apache.hc.core5.http.Header; |
| import org.apache.hc.core5.http.HttpException; |
| import org.apache.hc.core5.http.HttpHost; |
| import org.apache.hc.core5.http.HttpResponse; |
| import org.apache.logging.log4j.LogManager; |
| import org.apache.logging.log4j.Logger; |
| |
| /** |
| * Class used to represent an asynchronous revalidation event, such as with |
| * "stale-while-revalidate" |
| */ |
| public class AsynchronousValidationRequest implements Runnable { |
| private final AsynchronousValidator parent; |
| private final CachingExec cachingExec; |
| private final HttpHost target; |
| private final ClassicHttpRequest request; |
| private final ExecChain.Scope scope; |
| private final ExecChain chain; |
| private final HttpCacheEntry cacheEntry; |
| private final String identifier; |
| private final int consecutiveFailedAttempts; |
| |
| private final Logger log = LogManager.getLogger(getClass()); |
| |
| /** |
| * Used internally by {@link AsynchronousValidator} to schedule a |
| */ |
| AsynchronousValidationRequest( |
| final AsynchronousValidator parent, |
| final CachingExec cachingExec, |
| final HttpHost target, |
| final ClassicHttpRequest request, |
| final ExecChain.Scope scope, |
| final ExecChain chain, |
| final HttpCacheEntry cacheEntry, |
| final String identifier, |
| final int consecutiveFailedAttempts) { |
| this.parent = parent; |
| this.cachingExec = cachingExec; |
| this.target = target; |
| this.request = request; |
| this.scope = scope; |
| this.chain = chain; |
| this.cacheEntry = cacheEntry; |
| this.identifier = identifier; |
| this.consecutiveFailedAttempts = consecutiveFailedAttempts; |
| } |
| |
| @Override |
| public void run() { |
| try { |
| if (revalidateCacheEntry()) { |
| parent.jobSuccessful(identifier); |
| } else { |
| parent.jobFailed(identifier); |
| } |
| } finally { |
| parent.markComplete(identifier); |
| } |
| } |
| |
| /** |
| * Revalidate the cache entry and return if the operation was successful. |
| * Success means a connection to the server was established and replay did |
| * not indicate a server error. |
| * @return {@code true} if the cache entry was successfully validated; |
| * otherwise {@code false} |
| */ |
| private boolean revalidateCacheEntry() { |
| try { |
| try (ClassicHttpResponse httpResponse = cachingExec.revalidateCacheEntry(target, request, scope, chain, cacheEntry)) { |
| final int statusCode = httpResponse.getCode(); |
| return isNotServerError(statusCode) && isNotStale(httpResponse); |
| } |
| } catch (final IOException ioe) { |
| log.debug("Asynchronous revalidation failed due to I/O error", ioe); |
| return false; |
| } catch (final HttpException pe) { |
| log.error("HTTP protocol exception during asynchronous revalidation", pe); |
| return false; |
| } catch (final RuntimeException re) { |
| log.error("RuntimeException thrown during asynchronous revalidation: " + re); |
| return false; |
| } |
| } |
| |
| /** |
| * Return whether the status code indicates a server error or not. |
| * @param statusCode the status code to be checked |
| * @return if the status code indicates a server error or not |
| */ |
| private boolean isNotServerError(final int statusCode) { |
| return statusCode < 500; |
| } |
| |
| /** |
| * Try to detect if the returned response is generated from a stale cache entry. |
| * @param httpResponse the response to be checked |
| * @return whether the response is stale or not |
| */ |
| private boolean isNotStale(final HttpResponse httpResponse) { |
| final Header[] warnings = httpResponse.getHeaders(HeaderConstants.WARNING); |
| if (warnings != null) |
| { |
| for (final Header warning : warnings) |
| { |
| /** |
| * warn-codes |
| * 110 = Response is stale |
| * 111 = Revalidation failed |
| */ |
| final String warningValue = warning.getValue(); |
| if (warningValue.startsWith("110") || warningValue.startsWith("111")) |
| { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| public String getIdentifier() { |
| return identifier; |
| } |
| |
| /** |
| * The number of consecutively failed revalidation attempts. |
| * @return the number of consecutively failed revalidation attempts. |
| */ |
| public int getConsecutiveFailedAttempts() { |
| return consecutiveFailedAttempts; |
| } |
| |
| } |