connector/catalog/NamespaceChange.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.sql.connector.catalog;
0019
0020 import org.apache.spark.annotation.Evolving;
0021
0022 /**
0023  * NamespaceChange subclasses represent requested changes to a namespace. These are passed to
0024  * {@link SupportsNamespaces#alterNamespace}. For example,
0025  * <pre>
0026  *   import NamespaceChange._
0027  *   val catalog = Catalogs.load(name)
0028  *   catalog.alterNamespace(ident,
0029  *       setProperty("prop", "value"),
0030  *       removeProperty("other_prop")
0031  *     )
0032  * </pre>
0033  *
0034  * @since 3.0.0
0035  */
0036 @Evolving
0037 public interface NamespaceChange {
0038   /**
0039    * Create a NamespaceChange for setting a namespace property.
0040    * <p>
0041    * If the property already exists, it will be replaced with the new value.
0042    *
0043    * @param property the property name
0044    * @param value the new property value
0045    * @return a NamespaceChange for the addition
0046    */
0047   static NamespaceChange setProperty(String property, String value) {
0048     return new SetProperty(property, value);
0049   }
0050
0051   /**
0052    * Create a NamespaceChange for removing a namespace property.
0053    * <p>
0054    * If the property does not exist, the change will succeed.
0055    *
0056    * @param property the property name
0057    * @return a NamespaceChange for the addition
0058    */
0059   static NamespaceChange removeProperty(String property) {
0060     return new RemoveProperty(property);
0061   }
0062
0063   /**
0064    * A NamespaceChange to set a namespace property.
0065    * <p>
0066    * If the property already exists, it must be replaced with the new value.
0067    */
0068   final class SetProperty implements NamespaceChange {
0069     private final String property;
0070     private final String value;
0071
0072     private SetProperty(String property, String value) {
0073       this.property = property;
0074       this.value = value;
0075     }
0076
0077     public String property() {
0078       return property;
0079     }
0080
0081     public String value() {
0082       return value;
0083     }
0084   }
0085
0086   /**
0087    * A NamespaceChange to remove a namespace property.
0088    * <p>
0089    * If the property does not exist, the change should succeed.
0090    */
0091   final class RemoveProperty implements NamespaceChange {
0092     private final String property;
0093
0094     private RemoveProperty(String property) {
0095       this.property = property;
0096     }
0097
0098     public String property() {
0099       return property;
0100     }
0101   }
0102 }