org.apache.storm.assignments.LocalAssignmentsBackendFactory.java Source code

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Here is the source code for org.apache.storm.assignments.LocalAssignmentsBackendFactory.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.storm.assignments;

import com.google.common.base.Preconditions;
import org.apache.storm.Config;
import org.apache.storm.utils.ConfigUtils;
import org.apache.storm.utils.ReflectionUtils;

import java.util.Map;

/**
 * Factory class for creating local assignments.
 */
public class LocalAssignmentsBackendFactory {

    public static ILocalAssignmentsBackend getBackend(Map<String, Object> conf) {
        if (conf.get(Config.NIMBUS_LOCAL_ASSIGNMENTS_BACKEND_CLASS) != null) {
            Object targetObj = ReflectionUtils
                    .newInstance((String) conf.get(Config.NIMBUS_LOCAL_ASSIGNMENTS_BACKEND_CLASS));
            Preconditions.checkState(targetObj instanceof ILocalAssignmentsBackend,
                    "{} must implements ILocalAssignmentsBackend", Config.NIMBUS_LOCAL_ASSIGNMENTS_BACKEND_CLASS);
            ((ILocalAssignmentsBackend) targetObj).prepare(conf);
            return (ILocalAssignmentsBackend) targetObj;
        }

        return getDefault();
    }

    public static ILocalAssignmentsBackend getDefault() {
        ILocalAssignmentsBackend backend = new InMemoryAssignmentBackend();
        backend.prepare(ConfigUtils.readStormConfig());
        return backend;
    }
}