StandardControllerServiceReference.java

/*
 * 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.
 */
package org.apache.nifi.controller.service;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.apache.nifi.controller.ConfiguredComponent;
import org.apache.nifi.controller.ProcessorNode;
import org.apache.nifi.controller.ReportingTaskNode;

public class StandardControllerServiceReference implements ControllerServiceReference {

    private final ControllerServiceNode referenced;
    private final Set<ConfiguredComponent> components;

    public StandardControllerServiceReference(final ControllerServiceNode referencedService,
            final Set<ConfiguredComponent> referencingComponents) {
        this.referenced = referencedService;
        this.components = new HashSet<>(referencingComponents);
    }

    @Override
    public ControllerServiceNode getReferencedComponent() {
        return referenced;
    }

    @Override
    public Set<ConfiguredComponent> getReferencingComponents() {
        return Collections.unmodifiableSet(components);
    }

    private boolean isRunning(final ConfiguredComponent component) {
        if (component instanceof ReportingTaskNode) {
            return ((ReportingTaskNode) component).isRunning();
        }

        if (component instanceof ProcessorNode) {
            return ((ProcessorNode) component).isRunning();
        }

        return false;
    }

    @Override
    public Set<ConfiguredComponent> getActiveReferences() {
        final Set<ConfiguredComponent> activeReferences = new HashSet<>();
        final Set<ControllerServiceNode> serviceNodes = new HashSet<>();

        for (final ConfiguredComponent component : components) {
            if (component instanceof ControllerServiceNode) {
                serviceNodes.add((ControllerServiceNode) component);

                if (((ControllerServiceNode) component).isActive()) {
                    activeReferences.add(component);
                }
            } else if (isRunning(component)) {
                activeReferences.add(component);
            }
        }

        activeReferences.addAll(getActiveIndirectReferences(serviceNodes));
        return activeReferences;
    }

    private Set<ConfiguredComponent> getActiveIndirectReferences(final Set<ControllerServiceNode> referencingServices) {
        if (referencingServices.isEmpty()) {
            return Collections.emptySet();
        }

        final Set<ConfiguredComponent> references = new HashSet<>();
        for (final ControllerServiceNode referencingService : referencingServices) {
            final Set<ControllerServiceNode> serviceNodes = new HashSet<>();
            final ControllerServiceReference ref = referencingService.getReferences();

            for (final ConfiguredComponent component : ref.getReferencingComponents()) {
                if (component instanceof ControllerServiceNode) {
                    serviceNodes.add((ControllerServiceNode) component);
                } else if (isRunning(component)) {
                    references.add(component);
                }
            }

            references.addAll(getActiveIndirectReferences(serviceNodes));
        }

        return references;
    }
}