src/main/java/org/apache/hadoop/chukwa/extraction/engine/datasource/DataSourceFactory.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.hadoop.chukwa.extraction.engine.datasource;


import java.util.HashMap;
import org.apache.hadoop.chukwa.extraction.engine.datasource.database.DatabaseDS;
import org.apache.hadoop.chukwa.extraction.engine.datasource.record.ChukwaRecordDataSource;

public class DataSourceFactory {
  private static Object lock = new Object();
  private static DataSourceFactory factory = null;
  private HashMap<String, DataSource> dataSources = new HashMap<String, DataSource>();

  private DataSourceFactory() {
    // TODO load from config Name + class + threadSafe?

    DataSource databaseDS = new DatabaseDS();
    dataSources.put("MRJob", databaseDS);
    dataSources.put("HodJob", databaseDS);
    dataSources.put("QueueInfo", databaseDS);

  }

  public static DataSourceFactory getInstance() {
    synchronized (lock) {
      if (factory == null) {
        factory = new DataSourceFactory();
      }
    }
    return factory;
  }

  public DataSource getDataSource(String datasourceName)
      throws DataSourceException {
    if (dataSources.containsKey(datasourceName)) {
      return dataSources.get(datasourceName);
    } else {
      DataSource hsdfsDS = new ChukwaRecordDataSource();
      dataSources.put(datasourceName, hsdfsDS);
      return hsdfsDS;
      // TODO proto only!
      // throw new DataSourceException("Unknown datasource");
    }
  }
}