| /* |
| * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.internal.module; |
| |
| import java.lang.module.ModuleDescriptor; |
| import java.lang.module.ModuleDescriptor.Provides; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.CopyOnWriteArrayList; |
| |
| import jdk.internal.loader.ClassLoaderValue; |
| |
| /** |
| * A <em>services catalog</em>. Each {@code ClassLoader} and {@code Layer} has |
| * an optional {@code ServicesCatalog} for modules that provide services. |
| * |
| * @apiNote This class will be replaced once the ServiceLoader is further |
| * specified |
| */ |
| public final class ServicesCatalog { |
| |
| /** |
| * Represents a service provider in the services catalog. |
| */ |
| public final class ServiceProvider { |
| private final Module module; |
| private final String providerName; |
| |
| public ServiceProvider(Module module, String providerName) { |
| this.module = module; |
| this.providerName = providerName; |
| } |
| |
| public Module module() { |
| return module; |
| } |
| |
| public String providerName() { |
| return providerName; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(module, providerName); |
| } |
| |
| @Override |
| public boolean equals(Object ob) { |
| if (!(ob instanceof ServiceProvider)) |
| return false; |
| ServiceProvider that = (ServiceProvider)ob; |
| return Objects.equals(this.module, that.module) |
| && Objects.equals(this.providerName, that.providerName); |
| } |
| } |
| |
| // service name -> list of providers |
| private final Map<String, List<ServiceProvider>> map = new ConcurrentHashMap<>(); |
| |
| private ServicesCatalog() { } |
| |
| /** |
| * Creates a ServicesCatalog that supports concurrent registration and |
| * and lookup |
| */ |
| public static ServicesCatalog create() { |
| return new ServicesCatalog(); |
| } |
| |
| /** |
| * Returns the list of service provides for the given service type |
| * name, creating it if needed. |
| */ |
| private List<ServiceProvider> providers(String service) { |
| // avoid computeIfAbsent here |
| List<ServiceProvider> list = map.get(service); |
| if (list == null) { |
| list = new CopyOnWriteArrayList<>(); |
| List<ServiceProvider> prev = map.putIfAbsent(service, list); |
| if (prev != null) |
| list = prev; // someone else got there |
| } |
| return list; |
| } |
| |
| /** |
| * Registers the providers in the given module in this services catalog. |
| */ |
| public void register(Module module) { |
| ModuleDescriptor descriptor = module.getDescriptor(); |
| for (Provides provides : descriptor.provides()) { |
| String service = provides.service(); |
| List<String> providerNames = provides.providers(); |
| int count = providerNames.size(); |
| if (count == 1) { |
| String pn = providerNames.get(0); |
| providers(service).add(new ServiceProvider(module, pn)); |
| } else { |
| List<ServiceProvider> list = new ArrayList<>(count); |
| for (String pn : providerNames) { |
| list.add(new ServiceProvider(module, pn)); |
| } |
| providers(service).addAll(list); |
| } |
| } |
| } |
| |
| /** |
| * Add a provider in the given module to this services catalog |
| * |
| * @apiNote This method is for use by java.lang.instrument |
| */ |
| public void addProvider(Module module, Class<?> service, Class<?> impl) { |
| List<ServiceProvider> list = providers(service.getName()); |
| list.add(new ServiceProvider(module, impl.getName())); |
| } |
| |
| /** |
| * Returns the (possibly empty) list of service providers that implement |
| * the given service type. |
| */ |
| public List<ServiceProvider> findServices(String service) { |
| return map.getOrDefault(service, Collections.emptyList()); |
| } |
| |
| /** |
| * Returns the ServicesCatalog for the given class loader or {@code null} |
| * if there is none. |
| */ |
| public static ServicesCatalog getServicesCatalogOrNull(ClassLoader loader) { |
| return CLV.get(loader); |
| } |
| |
| /** |
| * Returns the ServicesCatalog for the given class loader, creating it if |
| * needed. |
| */ |
| public static ServicesCatalog getServicesCatalog(ClassLoader loader) { |
| // CLV.computeIfAbsent(loader, (cl, clv) -> create()); |
| ServicesCatalog catalog = CLV.get(loader); |
| if (catalog == null) { |
| catalog = create(); |
| ServicesCatalog previous = CLV.putIfAbsent(loader, catalog); |
| if (previous != null) catalog = previous; |
| } |
| return catalog; |
| } |
| |
| // the ServicesCatalog registered to a class loader |
| private static final ClassLoaderValue<ServicesCatalog> CLV = new ClassLoaderValue<>(); |
| } |