PageReader.java

/* 
 * 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 parquet.column.page;

/**
 * Reader for a sequence a page from a given column chunk
 *
 * @author Julien Le Dem
 *
 */
public interface PageReader {

 /**
  * @return the dictionary page in that chunk or null if none
  */
  DictionaryPage readDictionaryPage();

  /**
   * @return the total number of values in the column chunk
   */
  long getTotalValueCount();

  /**
   * @return the next page in that chunk or null if after the last page
   */
  DataPage readPage();
}