org.apache.hudi.internal.schema.action.TableChangesHelper Maven / Gradle / Ivy
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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.hudi.internal.schema.action;
import org.apache.hudi.internal.schema.Types;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
/**
* Helper class to support Table schema changes.
*/
public class TableChangesHelper {
/**
* Apply add operation and column position change operation.
*
* @param fields origin column fields.
* @param adds column fields to be added.
* @param pchanges a wrapper class hold all the position change operations.
* @return column fields after adjusting the position.
*/
public static List applyAddChange2Fields(List fields, ArrayList adds, ArrayList pchanges) {
if (adds == null && pchanges == null) {
return fields;
}
LinkedList result = new LinkedList<>(fields);
// apply add columns
if (adds != null && !adds.isEmpty()) {
result.addAll(adds);
}
// apply position change
if (pchanges != null && !pchanges.isEmpty()) {
for (TableChange.ColumnPositionChange pchange : pchanges) {
Types.Field srcField = result.stream().filter(f -> f.fieldId() == pchange.getSrcId()).findFirst().get();
Types.Field dsrField = result.stream().filter(f -> f.fieldId() == pchange.getDsrId()).findFirst().orElse(null);
// we remove srcField first
result.remove(srcField);
switch (pchange.type()) {
case AFTER:
// add srcField after dsrField
result.add(result.indexOf(dsrField) + 1, srcField);
break;
case BEFORE:
// add srcField before dsrField
result.add(result.indexOf(dsrField), srcField);
break;
case FIRST:
result.addFirst(srcField);
break;
default:
// should not reach here
}
}
}
return result;
}
public static String getParentName(String fullColName) {
int offset = fullColName.lastIndexOf(".");
return offset > 0 ? fullColName.substring(0, offset) : "";
}
public static String getLeafName(String fullColName) {
int offset = fullColName.lastIndexOf(".");
return offset > 0 ? fullColName.substring(offset + 1) : fullColName;
}
}