LargeFileAvailable.java revision 6073:cea72c2bf071
1/* 2 * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24/* 25 * @test 26 * @bug 6402006 7030573 27 * @summary Test if available returns correct value when reading 28 * a large file. 29 */ 30 31import java.io.*; 32import java.nio.ByteBuffer; 33import java.nio.channels.*; 34import java.nio.file.Files; 35import static java.nio.file.StandardOpenOption.*; 36 37public class LargeFileAvailable { 38 public static void main(String args[]) throws Exception { 39 // Create a temporary file in the current directory. 40 // Use it to check if we have 7G available for 41 // a large sparse file test. As a fallback use whatever 42 // space is available, so the test can proceed. 43 File file = File.createTempFile("largefile", null, new File(".")); 44 long spaceavailable = file.getUsableSpace(); 45 long filesize = Math.min(spaceavailable, 7405576182L); 46 if (spaceavailable == 0L) { 47 // A full disk is considered fatal. 48 throw new RuntimeException("No space available for temp file."); 49 } 50 51 createLargeFile(filesize, file); 52 53 try (FileInputStream fis = new FileInputStream(file)) { 54 if (file.length() != filesize) { 55 throw new RuntimeException("unexpected file size = " 56 + file.length()); 57 } 58 59 long bigSkip = Math.min(filesize/2, 3110608882L); 60 long remaining = filesize; 61 remaining -= skipBytes(fis, bigSkip, remaining); 62 remaining -= skipBytes(fis, 10L, remaining); 63 remaining -= skipBytes(fis, bigSkip, remaining); 64 if (fis.available() != (int) remaining) { 65 throw new RuntimeException("available() returns " 66 + fis.available() + " but expected " + remaining); 67 } 68 } finally { 69 file.delete(); 70 } 71 } 72 73 // Skip toSkip number of bytes and expect that the available() method 74 // returns avail number of bytes. 75 private static long skipBytes(InputStream is, long toSkip, long avail) 76 throws IOException { 77 long skip = is.skip(toSkip); 78 if (skip != toSkip) { 79 throw new RuntimeException("skip() returns " + skip 80 + " but expected " + toSkip); 81 } 82 long remaining = avail - skip; 83 int expected = remaining >= Integer.MAX_VALUE 84 ? Integer.MAX_VALUE 85 : (int) remaining; 86 87 System.out.println("Skipped " + skip + " bytes " 88 + " available() returns " + expected + 89 " remaining=" + remaining); 90 if (is.available() != expected) { 91 throw new RuntimeException("available() returns " 92 + is.available() + " but expected " + expected); 93 } 94 return skip; 95 } 96 97 private static void createLargeFile(long filesize, 98 File file) throws Exception { 99 // Recreate a large file as a sparse file if possible 100 Files.delete(file.toPath()); 101 102 try (FileChannel fc = 103 FileChannel.open(file.toPath(), 104 CREATE_NEW, WRITE, SPARSE)) { 105 ByteBuffer bb = ByteBuffer.allocate(1).put((byte)1); 106 bb.rewind(); 107 int rc = fc.write(bb, filesize - 1); 108 109 if (rc != 1) { 110 throw new RuntimeException("Failed to write 1 byte" 111 + " to the large file"); 112 } 113 } 114 return; 115 } 116} 117