org.apache.whirr.DynamicClusterControllerFactory.java Source code

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Here is the source code for org.apache.whirr.DynamicClusterControllerFactory.java

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/*
 * 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.whirr;

import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import com.google.common.collect.Sets;

/**
 * A Dynamic Controller Factory.
 * This Factory can be used inside dynamic environments and leverage their dynamic nature.
 */
public class DynamicClusterControllerFactory extends ClusterControllerFactory {

    private static final String BASIC_CONTROLLER = "basic";
    private final Map<String, ClusterController> clusterControllerMap = new ConcurrentHashMap<String, ClusterController>();

    /**
    * Create an instance of a {@link ClusterController} according to the given
    * name. If the name is <code>null</code> then the default {@link ClusterController}
    * is returned.
    */
    @Override
    public ClusterController create(String serviceName) {
        if (serviceName == null) {
            return clusterControllerMap.get(BASIC_CONTROLLER);
        } else
            return clusterControllerMap.get(serviceName);
    }

    /**
     * Return a collection of available {@link ClusterController} names.
     * @return the available service names
     */
    @Override
    public Set<String> availableServices() {
        Set<String> result = Sets.newLinkedHashSet();
        for (Map.Entry<String, ClusterController> entry : clusterControllerMap.entrySet()) {
            result.add(entry.getKey());
        }
        return result;
    }

    public void bind(ClusterController clusterController) {
        if (clusterController != null) {
            String name = null;
            try {
                name = clusterController.getName();
            } catch (UnsupportedOperationException ex) {
                name = BASIC_CONTROLLER;
            }
            clusterControllerMap.put(name, clusterController);
        }
    }

    public void unbind(ClusterController clusterController) {
        if (clusterController != null) {
            try {
                clusterControllerMap.remove(clusterController.getName());
            } catch (UnsupportedOperationException ex) {
                //Ignore
            }
        }
    }
}