org.apache.parquet.column.page.PageReadStore 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;
import java.util.PrimitiveIterator;
import org.apache.parquet.column.ColumnDescriptor;
/**
* contains all the readers for all the columns of the corresponding row group
*
* TODO: rename to RowGroup?
*/
public interface PageReadStore {
/**
*
* @param descriptor
* the descriptor of the column
* @return the page reader for that column
*/
PageReader getPageReader(ColumnDescriptor descriptor);
/**
*
* @return the total number of rows in that row group
*/
long getRowCount();
/**
* @return the optional of the long representing the row index offset of this row group or an empty optional if the
* related data is not available
*/
default Optional getRowIndexOffset() {
return Optional.empty();
}
/**
* Returns the indexes of the rows to be read/built if the related data is available. All the rows which index is not
* returned shall be skipped.
*
* @return the optional of the incremental iterator of the row indexes or an empty optional if the related data is not
* available
*/
default Optional getRowIndexes() {
return Optional.empty();
}
}