org.apache.parquet.column.page.DataPage 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.column.page;
import java.util.Optional;
/**
* one data page in a chunk
*/
abstract public class DataPage extends Page {
private final int valueCount;
private final long firstRowIndex;
DataPage(int compressedSize, int uncompressedSize, int valueCount) {
this(compressedSize, uncompressedSize, valueCount, -1);
}
DataPage(int compressedSize, int uncompressedSize, int valueCount, long firstRowIndex) {
super(compressedSize, uncompressedSize);
this.valueCount = valueCount;
this.firstRowIndex = firstRowIndex;
}
/**
* @return the number of values in that page
*/
public int getValueCount() {
return valueCount;
}
/**
* @return the index of the first row in this page if the related data is available (the optional column-index
* contains this value)
*/
public Optional getFirstRowIndex() {
return firstRowIndex < 0 ? Optional.empty() : Optional.of(firstRowIndex);
}
/**
* @return the number of rows in this page if the related data is available (in case of pageV1 the optional
* column-index contains this value)
*/
public abstract Optional getIndexRowCount();
public abstract T accept(Visitor visitor);
public static interface Visitor {
T visit(DataPageV1 dataPageV1);
T visit(DataPageV2 dataPageV2);
}
}