michael-o commented on a change in pull request #68: URL: https://github.com/apache/maven-resolver/pull/68#discussion_r475245083
########## File path: maven-resolver-synccontext-redisson/src/main/java/org/eclipse/aether/synccontext/RedissonSyncContextFactory.java ########## @@ -0,0 +1,390 @@ +package org.eclipse.aether.synccontext; + +/* + * 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. + */ + +import java.io.File; +import java.io.IOException; +import java.io.InputStream; +import java.net.InetAddress; +import java.net.UnknownHostException; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; +import java.util.Iterator; +import java.util.LinkedHashMap; +import java.util.LinkedList; +import java.util.Map; +import java.util.TreeSet; + +import javax.annotation.PreDestroy; +import javax.annotation.Priority; +import javax.inject.Named; +import javax.inject.Singleton; + +import org.eclipse.aether.RepositorySystemSession; +import org.eclipse.aether.SyncContext; +import org.eclipse.aether.artifact.Artifact; +import org.eclipse.aether.impl.SyncContextFactory; +import org.eclipse.aether.metadata.Metadata; +import org.eclipse.aether.util.ChecksumUtils; +import org.eclipse.aether.util.ConfigUtils; +import org.redisson.Redisson; +import org.redisson.api.RLock; +import org.redisson.api.RReadWriteLock; +import org.redisson.api.RedissonClient; +import org.redisson.config.Config; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * A singleton factory to create synchronization contexts using Redisson's {@link RReadWriteLock}. + * It locks fine-grained with groupId, artifactId and version if required. + * <p> + * <strong>Note: This component is still considered to be experimental, use with caution!</strong> + * <h2>Configuration</h2> + * You can configure various aspects of this factory. + * + * <h3>Redisson Client</h3> + * To fully configure the Redisson client, this factory uses the following staggered approach: + * <ol> + * <li>If the property {@code aether.syncContext.redisson.configFile} is set and the file at that + * specific path does exist, load it otherwise an exception is thrown.</li> + * <li>If no configuration file path is provided, load default from + * <code>${maven.conf}/maven-resolver-redisson.yaml</code>, but ignore if it does not exist.</li> + * <li>If no configuration file is available at all, Redisson is configured with a single server pointing + * to {@code redis://localhost:6379} with client name {@code maven-resolver}.</li> + * </ol> + * Please note that an invalid confguration file results in an exception too. + * + * <h3>Discrimination</h3> + * You may freely use a single Redis instance to serve multiple Maven instances, on multiple hosts + * with shared or exclusive local repositories. Every sync context instance will generate a unique + * discriminator which identifies each host paired with the local repository currently accessed. + * The following staggered approach is used: + * <ol> + * <li>Determine hostname, if not possible use {@code localhost}.</li> + * <li>If the property {@code aether.syncContext.redisson.discriminator} is set, use it and skip + * the remaining steps.</li> + * <li>Concat hostname with the path of the local repository: <code>${hostname}:${maven.repo.local}</code>.</li> + * <li>Calculate the SHA-1 digest of this value. If that fails use the static digest of an empty string.</li> + * </ol> + * + * <h2>Key Composition</h2> + * Each lock is assigned a unique key in the configured Redis instance which has the following pattern: + * <code>maven:resolver:${discriminator}:${artifact|metadata}</code>. + * <ul> + * <li><code>${artifact}</code> will + * always resolve to <code>artifact:${groupId}:${artifactId}:${baseVersion}</code>.</li> + * <li><code>${metadata}</code> will resolve to one of <code>metadata:${groupId}:${artifactId}:${version}</code>, + * <code>metadata:${groupId}:${artifactId}</code>, <code>metadata:${groupId}</code>, + * <code>metadata:</code>.</li> + * </ul> + */ +@Named +@Priority( Integer.MAX_VALUE ) +@Singleton +public class RedissonSyncContextFactory + implements SyncContextFactory +{ + + private static final String DEFAULT_CONFIG_FILE_NAME = "maven-resolver-redisson.yaml"; + private static final String DEFAULT_REDIS_ADDRESS = "redis://localhost:6379"; + private static final String DEFAULT_CLIENT_NAME = "maven-resolver"; + private static final String DEFAULT_HOSTNAME = "localhost"; + private static final String DEFAULT_DISCRIMINATOR_DIGEST = "da39a3ee5e6b4b0d3255bfef95601890afd80709"; + + private static final String CONFIG_PROP_CONFIG_FILE = "aether.syncContext.redisson.configFile"; + + private static final Logger LOGGER = LoggerFactory.getLogger( RedissonSyncContextFactory.class ); + + // We are in a singleton so these should exist only once! + private RedissonClient redissonClient; + private String hostname; + + public RedissonSyncContextFactory() + { + // TODO These two log statements will go away + LOGGER.trace( "TCCL: {}", Thread.currentThread().getContextClassLoader() ); + LOGGER.trace( "CCL: {}", getClass().getClassLoader() ); + this.redissonClient = createRedissonClient(); + this.hostname = getHostname(); + } + + private RedissonClient createRedissonClient() + { + Path configFilePath = null; + + String configFile = ConfigUtils.getString( System.getProperties(), null, CONFIG_PROP_CONFIG_FILE ); + if ( configFile != null && !configFile.isEmpty() ) + { + configFilePath = Paths.get( configFile ); + if ( Files.notExists( configFilePath ) ) + { + throw new IllegalArgumentException( "The specified Redisson config file does not exist: " + + configFilePath ); + } + } + + if ( configFilePath == null ) + { + String mavenConf = ConfigUtils.getString( System.getProperties(), null, "maven.conf" ); + if ( mavenConf != null && !mavenConf.isEmpty() ) + { + configFilePath = Paths.get( mavenConf, DEFAULT_CONFIG_FILE_NAME ); + if ( Files.notExists( configFilePath ) ) + { + configFilePath = null; + } + } + } + + Config config = null; + + if ( configFilePath != null ) + { + LOGGER.trace( "Reading Redisson config file from '{}'", configFilePath ); + try ( InputStream is = Files.newInputStream( configFilePath ) ) + { + config = Config.fromYAML( is ); + } + catch ( IOException e ) + { + throw new IllegalStateException( "Failed to read Redisson config file: " + configFilePath, e ); + } + } + else + { + config = new Config(); + config.useSingleServer() + .setAddress( DEFAULT_REDIS_ADDRESS ) + .setClientName( DEFAULT_CLIENT_NAME ); + } + + RedissonClient redissonClient = Redisson.create( config ); + LOGGER.trace( "Created Redisson client with id '{}'", redissonClient.getId() ); + + return redissonClient; + } + + private String getHostname() + { + try + { + return InetAddress.getLocalHost().getHostName(); Review comment: Not here, you can provide YAML-based config. This one covers default config. So multiple servers are covered. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected]
