| /** |
| * 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.ambari.view.huetoambarimigration.utils; |
| |
| import org.apache.ambari.view.ViewContext; |
| import org.apache.hadoop.fs.FSDataInputStream; |
| |
| import java.io.IOException; |
| import java.nio.charset.Charset; |
| import java.util.Arrays; |
| |
| import static java.lang.Math.ceil; |
| |
| /** |
| * Pagination for HDFS file implementation |
| */ |
| public class FilePaginator { |
| private static int PAGE_SIZE = 1*1024*1024; // 1MB |
| |
| private String filePath; |
| private ViewContext context; |
| |
| /** |
| * Constructor |
| * @param filePath Path to file on HDFS |
| * @param context View Context instance |
| */ |
| public FilePaginator(String filePath, ViewContext context) { |
| this.filePath = filePath; |
| this.context = context; |
| } |
| |
| /** |
| * Set page size |
| * @param PAGE_SIZE size |
| */ |
| public static void setPageSize(int PAGE_SIZE) { |
| FilePaginator.PAGE_SIZE = PAGE_SIZE; |
| } |
| |
| /** |
| * Get page count |
| * @return page count |
| * @throws IOException |
| * @throws InterruptedException |
| */ |
| |
| /** |
| * Read one page of size PAGE_SIZE |
| * @param page page index |
| * @return data in UTF-8 |
| * @throws IOException |
| * @throws InterruptedException |
| */ |
| |
| } |