sql/src/main/java/org/apache/druid/sql/calcite/schema/NamedSchema.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.druid.sql.calcite.schema;

import org.apache.calcite.schema.Schema;

import javax.annotation.Nullable;

/**
 * This interface provides everything that is needed to register a {@link Schema} as a sub schema to the root schema
 * of Druid SQL. The {@link #getSchemaName()} will be used to access the provided {@link Schema} via SQL.
 */
public interface NamedSchema
{
  /**
   * @return The name that this schema should be registered to.
   */
  String getSchemaName();

  /**
   * For a given name of a table, function, etc of this schema, return the value most appropriate to use for
   * {@link org.apache.druid.server.security.Resource#getType()} for the resource, used during authorization. If this
   * method returns null then the resource does not need any authorization.
   */
  @Nullable
  default String getSchemaResourceType(String resourceName)
  {
    return null;
  }

  /**
   * @return The Schema that Calcite should use.
   */
  Schema getSchema();
}