org.apache.parquet.schema.ColumnOrder Maven / Gradle / Ivy
/*
* 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.parquet.schema;
import java.util.Objects;
/**
* Class representing the column order with all the related parameters.
*/
public class ColumnOrder {
/**
* The enum type of the column order.
*/
public enum ColumnOrderName {
/**
* Representing the case when the defined column order is undefined (e.g. the file is written by a later API and the
* current one does not support the related column order). No statistics will be written/read in this case.
*/
UNDEFINED,
/**
* Type defined order meaning that the comparison order of the elements are based on its type.
*/
TYPE_DEFINED_ORDER
}
private static final ColumnOrder UNDEFINED_COLUMN_ORDER = new ColumnOrder(ColumnOrderName.UNDEFINED);
private static final ColumnOrder TYPE_DEFINED_COLUMN_ORDER = new ColumnOrder(ColumnOrderName.TYPE_DEFINED_ORDER);
/**
* @return a {@link ColumnOrder} instance representing an undefined order
* @see ColumnOrderName#UNDEFINED
*/
public static ColumnOrder undefined() {
return UNDEFINED_COLUMN_ORDER;
}
/**
* @return a {@link ColumnOrder} instance representing a type defined order
* @see ColumnOrderName#TYPE_DEFINED_ORDER
*/
public static ColumnOrder typeDefined() {
return TYPE_DEFINED_COLUMN_ORDER;
}
private final ColumnOrderName columnOrderName;
private ColumnOrder(ColumnOrderName columnOrderName) {
this.columnOrderName = Objects.requireNonNull(columnOrderName, "columnOrderName cannot be null");
}
public ColumnOrderName getColumnOrderName() {
return columnOrderName;
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof ColumnOrder) {
return columnOrderName == ((ColumnOrder) obj).columnOrderName;
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
public int hashCode() {
return columnOrderName.hashCode();
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
return columnOrderName.toString();
}
}