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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
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 * 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,
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package jdk.tools.jlink.internal;

import jdk.tools.jlink.plugin.PluginException;
import jdk.tools.jlink.plugin.ResourcePoolEntry;
import jdk.tools.jlink.plugin.ResourcePoolModule;
import jdk.tools.jlink.plugin.ResourcePoolModuleView;

import java.lang.module.ModuleDescriptor;
import java.lang.module.ModuleDescriptor.Requires.Modifier;

import java.nio.ByteBuffer;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.stream.Stream;

Helper class to sort modules in topological order
/** * Helper class to sort modules in topological order */
public final class ModuleSorter { private final Deque<ResourcePoolModule> nodes = new LinkedList<>(); private final Map<String, Set<ResourcePoolModule>> edges = new HashMap<>(); private final Deque<ResourcePoolModule> result = new LinkedList<>(); private final ResourcePoolModuleView moduleView; public ModuleSorter(ResourcePoolModuleView moduleView) { this.moduleView = moduleView; moduleView.modules().forEach(this::addModule); } private ModuleDescriptor readModuleDescriptor(ResourcePoolModule module) { String p = "/" + module.name() + "/module-info.class"; ResourcePoolEntry content = module.findEntry(p).orElseThrow(() -> new PluginException("module-info.class not found for " + module.name() + " module") ); ByteBuffer bb = ByteBuffer.wrap(content.contentBytes()); return ModuleDescriptor.read(bb); } private ModuleSorter addModule(ResourcePoolModule module) { addNode(module); readModuleDescriptor(module).requires().forEach(req -> { ResourcePoolModule dep = moduleView.findModule(req.name()).orElse(null); if (dep != null) { addNode(dep); edges.get(module.name()).add(dep); } else if (!req.modifiers().contains(Modifier.STATIC)) { throw new PluginException(req.name() + " not found"); } }); return this; } private void addNode(ResourcePoolModule module) { nodes.add(module); edges.computeIfAbsent(module.name(), _n -> new HashSet<>()); } private synchronized void build() { if (!result.isEmpty() || nodes.isEmpty()) return; Deque<ResourcePoolModule> visited = new LinkedList<>(); Deque<ResourcePoolModule> done = new LinkedList<>(); ResourcePoolModule node; while ((node = nodes.poll()) != null) { if (!visited.contains(node)) { visit(node, visited, done); } } } public Stream<ResourcePoolModule> sorted() { build(); return result.stream(); } private void visit(ResourcePoolModule node, Deque<ResourcePoolModule> visited, Deque<ResourcePoolModule> done) { if (visited.contains(node)) { if (!done.contains(node)) { throw new IllegalArgumentException("Cyclic detected: " + node + " " + edges.get(node.name())); } return; } visited.add(node); edges.get(node.name()) .forEach(x -> visit(x, visited, done)); done.add(node); result.addLast(node); } }