marcuslinke commented on code in PR #481: URL: https://github.com/apache/maven-build-cache-extension/pull/481#discussion_r3167857739
########## src/main/java/org/apache/maven/buildcache/HostnameResolver.java: ########## @@ -0,0 +1,88 @@ +/* + * 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. + */ +package org.apache.maven.buildcache; + +import java.net.InetAddress; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.TimeoutException; + +/** + * Resolves and caches the canonical host name of the local machine. + * <p> + * The lookup is performed asynchronously in a separate thread because + * {@code InetAddress.getLocalHost().getCanonicalHostName()} may block for a + * considerable amount of time in environments with slow or misconfigured name + * resolution (for example DNS or mDNS timeouts). + * <p> + * To avoid delaying application processing, the caller waits only up to + * {@value #TIMEOUT_MS} ms for the result. If the lookup does not complete in + * time or fails, the fallback value {@value #FALLBACK} is used instead. + * <p> + * The resolved value is cached after the first call to + * {@link #resolve()}. + */ +public final class HostnameResolver { + + private static final String FALLBACK = "unknown"; + private static final long TIMEOUT_MS = 1000; + private static String hostname; + + private HostnameResolver() { + // utility class + } + + public static String resolve() { + if (hostname == null) { + ExecutorService executor = Executors.newSingleThreadExecutor(); + try { + + Future<String> future = executor.submit(() -> { + try { + return InetAddress.getLocalHost().getCanonicalHostName(); + } catch (Exception e) { + return null; + } + }); + + String resolved; + try { + resolved = future.get(TIMEOUT_MS, TimeUnit.MILLISECONDS); + } catch (TimeoutException e) { + future.cancel(true); + resolved = FALLBACK; + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + resolved = FALLBACK; + } catch (ExecutionException e) { + resolved = FALLBACK; + } + + hostname = (resolved == null || resolved.trim().isEmpty()) ? FALLBACK : resolved.trim(); + } finally { + executor.shutdownNow(); + } + } + + return hostname; + } Review Comment: Injection into a static utility class is not possible. I added a basic test case but I don't see the need to make the resolution logic injectable here as the class is used for metadata retrieval only. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
