content: /*
   * 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.carbondata.core.metadata;
  
  import org.apache.carbondata.core.constants.CarbonCommonConstants;
  import org.apache.carbondata.core.util.CarbonProperties;
  
  /**
   * support converting database name to session-related name
   */
  public abstract class DatabaseLocationProvider {
  
    private static final DatabaseLocationProvider PROVIDER;
  
    static {
      final String providerClassName = CarbonProperties.getInstance()
          .getProperty(CarbonCommonConstants.DATABASE_LOCATION_PROVIDER);
      final DatabaseLocationProvider provider;
      if (providerClassName == null) {
        provider = null;
      } else {
        try {
          final Class providerClass =
              DatabaseLocationProvider.class.getClassLoader().loadClass(providerClassName);
          provider = (DatabaseLocationProvider) providerClass.newInstance();
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException exception) {
          throw new RuntimeException(
              "Fail to construct database location provider[" + providerClassName + "].", exception);
        }
      }
      PROVIDER = provider;
    }
  
    public static DatabaseLocationProvider get() {
      return PROVIDER == null ? Default.INSTANCE : PROVIDER;
    }
  
    public abstract String provide(String originalDatabaseName);
  
    private static final class Default extends DatabaseLocationProvider {
  
      static final Default INSTANCE = new Default();
  
      @Override
      public String provide(final String originalDatabaseName) {
        return originalDatabaseName;
      }
    }
  }
  