Java tutorial
/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.controller.yang.parser.util; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Date; import java.util.List; import java.util.Map; import java.util.Set; import org.opendaylight.controller.yang.model.api.Module; import org.opendaylight.controller.yang.model.api.ModuleImport; import org.opendaylight.controller.yang.model.api.SchemaContext; import org.opendaylight.controller.yang.parser.builder.impl.ModuleBuilder; import org.opendaylight.controller.yang.parser.impl.YangParserListenerImpl; import org.opendaylight.controller.yang.parser.util.TopologicalSort.Node; import org.opendaylight.controller.yang.parser.util.TopologicalSort.NodeImpl; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Function; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Sets; /** * Creates a module dependency graph from provided {@link ModuleBuilder}s and * provides a {@link #sort()} method. It is topological sort and returns modules * in order in which they should be processed (e.g. if A imports B, sort returns * {B, A}). */ public final class ModuleDependencySort { private static final Date DEFAULT_REVISION = new Date(0); private static final Logger logger = LoggerFactory.getLogger(ModuleDependencySort.class); /** * Topological sort of module builder dependency graph. * * @return Sorted list of Module builders. Modules can be further processed * in returned order. */ public static List<ModuleBuilder> sort(ModuleBuilder... builders) { List<Node> sorted = sortInternal(Arrays.asList(builders)); // Cast to ModuleBuilder from Node and return return Lists.transform(sorted, new Function<Node, ModuleBuilder>() { @Override public ModuleBuilder apply(Node input) { return (ModuleBuilder) ((ModuleNodeImpl) input).getReference(); } }); } public static List<ModuleBuilder> sortWithContext(SchemaContext context, ModuleBuilder... builders) { List<Object> modules = new ArrayList<Object>(); Collections.addAll(modules, builders); modules.addAll(context.getModules()); List<Node> sorted = sortInternal(modules); // Cast to ModuleBuilder from Node if possible and return return Lists.transform(sorted, new Function<Node, ModuleBuilder>() { @Override public ModuleBuilder apply(Node input) { if (((ModuleNodeImpl) input).getReference() instanceof ModuleBuilder) { return (ModuleBuilder) ((ModuleNodeImpl) input).getReference(); } else { return null; } } }); } /** * Topological sort of module dependency graph. * * @return Sorted list of Modules. Modules can be further processed in * returned order. */ public static List<Module> sort(Module... modules) { List<Node> sorted = sortInternal(Arrays.asList(modules)); // Cast to Module from Node and return return Lists.transform(sorted, new Function<Node, Module>() { @Override public Module apply(Node input) { return (Module) ((ModuleNodeImpl) input).getReference(); } }); } private static List<Node> sortInternal(List<?> modules) { Map<String, Map<Date, ModuleNodeImpl>> moduleGraph = createModuleGraph(modules); Set<Node> nodes = Sets.newHashSet(); for (Map<Date, ModuleNodeImpl> map : moduleGraph.values()) { for (ModuleNodeImpl node : map.values()) { nodes.add(node); } } return TopologicalSort.sort(nodes); } @VisibleForTesting static Map<String, Map<Date, ModuleNodeImpl>> createModuleGraph(List<?> builders) { Map<String, Map<Date, ModuleNodeImpl>> moduleGraph = Maps.newHashMap(); processModules(moduleGraph, builders); processDependencies(moduleGraph, builders); return moduleGraph; } /** * Extract module:revision from module builders */ private static void processDependencies(Map<String, Map<Date, ModuleNodeImpl>> moduleGraph, List<?> builders) { Map<String, Date> imported = Maps.newHashMap(); // Create edges in graph for (Object mb : builders) { String fromName = null; Date fromRevision = null; Set<ModuleImport> imports = null; if (mb instanceof Module) { fromName = ((Module) mb).getName(); fromRevision = ((Module) mb).getRevision(); imports = ((Module) mb).getImports(); } else if (mb instanceof ModuleBuilder) { fromName = ((ModuleBuilder) mb).getName(); fromRevision = ((ModuleBuilder) mb).getRevision(); imports = ((ModuleBuilder) mb).getModuleImports(); } // no need to check if other Type of object, check is performed in // process modules if (fromRevision == null) fromRevision = DEFAULT_REVISION; for (ModuleImport imprt : imports) { String toName = imprt.getModuleName(); Date toRevision = imprt.getRevision() == null ? DEFAULT_REVISION : imprt.getRevision(); ModuleNodeImpl from = moduleGraph.get(fromName).get(fromRevision); ModuleNodeImpl to = getModuleByNameAndRevision(moduleGraph, fromName, fromRevision, toName, toRevision); /* * Check imports: If module is imported twice with different * revisions then throw exception */ if (imported.get(toName) != null && !imported.get(toName).equals(toRevision)) { if (!imported.get(toName).equals(DEFAULT_REVISION) && !toRevision.equals(DEFAULT_REVISION)) { ex(String.format("Module:%s imported twice with different revisions:%s, %s", toName, formatRevDate(imported.get(toName)), formatRevDate(toRevision))); } } imported.put(toName, toRevision); from.addEdge(to); } } } /** * Get imported module by its name and revision from moduleGraph */ private static ModuleNodeImpl getModuleByNameAndRevision(Map<String, Map<Date, ModuleNodeImpl>> moduleGraph, String fromName, Date fromRevision, String toName, Date toRevision) { ModuleNodeImpl to = null; if (moduleGraph.get(toName) == null || !moduleGraph.get(toName).containsKey(toRevision)) { // If revision is not specified in import, but module exists // with different revisions, take first if (moduleGraph.get(toName) != null && !moduleGraph.get(toName).isEmpty() && toRevision.equals(DEFAULT_REVISION)) { to = moduleGraph.get(toName).values().iterator().next(); logger.warn(String.format( "Import:%s:%s by module:%s:%s does not specify revision, using:%s:%s for module dependency sort", toName, formatRevDate(toRevision), fromName, formatRevDate(fromRevision), to.getName(), formatRevDate(to.getRevision()))); } else ex(String.format("Not existing module imported:%s:%s by:%s:%s", toName, formatRevDate(toRevision), fromName, formatRevDate(fromRevision))); } else { to = moduleGraph.get(toName).get(toRevision); } return to; } private static void ex(String message) { throw new YangValidationException(message); } /** * Extract dependencies from module builders or modules to fill dependency * graph */ private static void processModules(Map<String, Map<Date, ModuleNodeImpl>> moduleGraph, List<?> builders) { // Process nodes for (Object mb : builders) { String name = null; Date rev = null; if (mb instanceof Module) { name = ((Module) mb).getName(); rev = ((Module) mb).getRevision(); } else if (mb instanceof ModuleBuilder) { name = ((ModuleBuilder) mb).getName(); rev = ((ModuleBuilder) mb).getRevision(); } else { throw new IllegalStateException( String.format("Unexpected type of node for sort, expected only:%s, %s, got:%s", Module.class, ModuleBuilder.class, mb.getClass())); } if (rev == null) rev = DEFAULT_REVISION; if (moduleGraph.get(name) == null) moduleGraph.put(name, Maps.<Date, ModuleNodeImpl>newHashMap()); if (moduleGraph.get(name).get(rev) != null) ex(String.format("Module:%s with revision:%s declared twice", name, formatRevDate(rev))); moduleGraph.get(name).put(rev, new ModuleNodeImpl(name, rev, mb)); } } private static String formatRevDate(Date rev) { return rev == DEFAULT_REVISION ? "default" : YangParserListenerImpl.simpleDateFormat.format(rev); } @VisibleForTesting static class ModuleNodeImpl extends NodeImpl { private final String name; private final Date revision; private final Object originalObject; public ModuleNodeImpl(String name, Date revision, Object builder) { this.name = name; this.revision = revision; this.originalObject = builder; } public String getName() { return name; } public Date getRevision() { return revision; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((name == null) ? 0 : name.hashCode()); result = prime * result + ((revision == null) ? 0 : revision.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; ModuleNodeImpl other = (ModuleNodeImpl) obj; if (name == null) { if (other.name != null) return false; } else if (!name.equals(other.name)) return false; if (revision == null) { if (other.revision != null) return false; } else if (!revision.equals(other.revision)) return false; return true; } @Override public String toString() { return "Module [name=" + name + ", revision=" + formatRevDate(revision) + "]"; } public Object getReference() { return originalObject; } } }