Extract a generic Resource decorator for exposing runtime children fr…

…om SingletonPolicyResource.

clustering/common/src/main/java/org/jboss/as/clustering/controller/ChildResourceProvider.java

@@ -0,0 +1,46 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2019, Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+
+package org.jboss.as.clustering.controller;
+
+import java.util.Set;
+
+import org.jboss.as.controller.registry.Resource;
+
+/**
+ * Provides child resources.
+ * @author Paul Ferraro
+ */
+public interface ChildResourceProvider {
+    /**
+     * Returns a child resource with the specified name.
+     * @param name a resource name
+     * @return a resource
+     */
+    Resource getChild(String name);
+
+    /**
+     * Returns the complete set of child resource names.
+     * @return a set of resource names
+     */
+    Set<String> getChildren();
+}

clustering/common/src/main/java/org/jboss/as/clustering/controller/ComplexResource.java

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+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2019, Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+
+package org.jboss.as.clustering.controller;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+import org.jboss.as.controller.PathAddress;
+import org.jboss.as.controller.PathElement;
+import org.jboss.as.controller.registry.DelegatingResource;
+import org.jboss.as.controller.registry.Resource;
+
+/**
+ * A generic {@link Resource} decorator augmented to support additional runtime children.
+ * @author Paul Ferraro
+ */
+public class ComplexResource extends DelegatingResource implements Function<String, ChildResourceProvider> {
+
+    private final Map<String, ChildResourceProvider> providers;
+    private final BiFunction<Resource, Map<String, ChildResourceProvider>, Resource> factory;
+
+    /**
+     * Constructs a new resource.
+     * @param resource the concrete resource
+     * @param providers a set of providers for specific child types
+     */
+    public ComplexResource(Resource resource, Map<String, ChildResourceProvider> providers) {
+        this(resource, providers, ComplexResource::new);
+    }
+
+    /**
+     * Constructs a new resource.
+     * @param resource the concrete resource
+     * @param providers a set of providers for specific child types
+     * @param factory a function used to clone this resource
+     */
+    protected ComplexResource(Resource resource, Map<String, ChildResourceProvider> providers, BiFunction<Resource, Map<String, ChildResourceProvider>, Resource> factory) {
+        super(resource);
+        this.providers = providers;
+        this.factory = factory;
+    }
+
+    @Override
+    public ChildResourceProvider apply(String childType) {
+        return this.providers.get(childType);
+    }
+
+    @Override
+    public Resource clone() {
+        return this.factory.apply(super.clone(), this.providers);
+    }
+
+    @Override
+    public Resource getChild(PathElement path) {
+        ChildResourceProvider provider = this.apply(path.getKey());
+        return (provider != null) ? provider.getChild(path.getValue()) : super.getChild(path);
+    }
+
+    @Override
+    public Set<Resource.ResourceEntry> getChildren(String childType) {
+        ChildResourceProvider provider = this.apply(childType);
+        if (provider != null) {
+            Set<String> names = provider.getChildren();
+            Set<Resource.ResourceEntry> entries = !names.isEmpty() ? new HashSet<>() : Collections.emptySet();
+            for (String name : names) {
+                Resource resource = provider.getChild(name);
+                entries.add(new SimpleResourceEntry(PathElement.pathElement(childType, name), resource));
+            }
+            return entries;
+        }
+        return super.getChildren(childType);
+    }
+
+    @Override
+    public Set<String> getChildrenNames(String childType) {
+        ChildResourceProvider provider = this.apply(childType);
+        return (provider != null) ? provider.getChildren() : super.getChildrenNames(childType);
+    }
+
+    @Override
+    public Set<String> getChildTypes() {
+        Set<String> childTypes = new HashSet<>(super.getChildTypes());
+        childTypes.addAll(this.providers.keySet());
+        return childTypes;
+    }
+
+    @Override
+    public boolean hasChild(PathElement path) {
+        ChildResourceProvider provider = this.apply(path.getKey());
+        return (provider != null) ? provider.getChild(path.getValue()) != null : super.hasChild(path);
+    }
+
+    @Override
+    public boolean hasChildren(String childType) {
+        ChildResourceProvider provider = this.apply(childType);
+        return (provider != null) ? !provider.getChildren().isEmpty() : super.hasChildren(childType);
+    }
+
+    @Override
+    public Resource navigate(PathAddress address) {
+        return (address.size() == 1) ? this.requireChild(address.getLastElement()) : super.navigate(address);
+    }
+
+    @Override
+    public Resource requireChild(PathElement path) {
+        Resource resource = this.getChild(path);
+        if (resource == null) {
+            throw new NoSuchResourceException(path);
+        }
+        return resource;
+    }
+
+    private static class SimpleResourceEntry extends DelegatingResource implements Resource.ResourceEntry {
+
+        private final PathElement path;
+
+        SimpleResourceEntry(PathElement path, Resource resource) {
+            super(resource);
+            this.path = path;
+        }
+
+        @Override
+        public String getName() {
+            return this.path.getValue();
+        }
+
+        @Override
+        public PathElement getPathElement() {
+            return this.path;
+        }
+
+        @Override
+        public int hashCode() {
+            return this.path.hashCode();
+        }
+
+        @Override
+        public boolean equals(Object object) {
+            if (!(object instanceof Resource.ResourceEntry)) return false;
+            return this.path.equals(((Resource.ResourceEntry) object).getPathElement());
+        }
+
+        @Override
+        public String toString() {
+            return this.path.toString();
+        }
+    }
+}

clustering/common/src/main/java/org/jboss/as/clustering/controller/SimpleChildResourceProvider.java

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+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2019, Red Hat, Inc., and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+
+package org.jboss.as.clustering.controller;
+
+import java.util.Set;
+import java.util.function.Supplier;
+
+import org.jboss.as.controller.registry.PlaceholderResource;
+import org.jboss.as.controller.registry.Resource;
+import org.wildfly.common.function.Functions;
+
+/**
+ * A simple {@link ChildResourceProvider} containing a predefined set of children.
+ * @author Paul Ferraro
+ */
+public class SimpleChildResourceProvider implements ChildResourceProvider {
+
+    private final Set<String> children;
+    private final Supplier<Resource> provider;
+
+    public SimpleChildResourceProvider(Set<String> children) {
+        this(children, Functions.constantSupplier(PlaceholderResource.INSTANCE));
+    }
+
+    public SimpleChildResourceProvider(Set<String> children, Supplier<Resource> provider) {
+        this.children = children;
+        this.provider = provider;
+    }
+
+    @Override
+    public Resource getChild(String name) {
+        return this.children.contains(name) ? this.provider.get() : null;
+    }
+
+    @Override
+    public Set<String> getChildren() {
+        return this.children;
+    }
+}