1 /* 2 * Copyright (c) 2010, 2011, 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 27 * @summary Test if available returns correct value when reading 28 * a large file. 29 */ 30 31 import java.io.*; 32 import java.nio.ByteBuffer; 33 import java.nio.channels.*; 34 import java.nio.file.Files; 35 import static java.nio.file.StandardOpenOption.*; 36 37 public class LargeFileAvailable { 38 private static final long FILESIZE = 7405576182L; 39 public static void main(String args[]) throws Exception { 40 File file = createLargeFile(FILESIZE); 41 try (FileInputStream fis = new FileInputStream(file)) { 42 if (file.length() != FILESIZE) { 43 throw new RuntimeException("unexpected file size = " + file.length()); 44 } 45 46 long bigSkip = 3110608882L; 47 long remaining = FILESIZE; 48 remaining -= skipBytes(fis, bigSkip, remaining); 49 remaining -= skipBytes(fis, 10L, remaining); 50 remaining -= skipBytes(fis, bigSkip, remaining); 51 if (fis.available() != (int) remaining) { 52 throw new RuntimeException("available() returns " + 53 fis.available() + 54 " but expected " + remaining); 55 } 56 } finally { 57 file.delete(); 58 } 59 } 60 61 // Skip toSkip number of bytes and expect that the available() method 62 // returns avail number of bytes. 63 private static long skipBytes(InputStream is, long toSkip, long avail) 64 throws IOException { 65 long skip = is.skip(toSkip); 66 if (skip != toSkip) { 67 throw new RuntimeException("skip() returns " + skip + 68 " but expected " + toSkip); 69 } 70 long remaining = avail - skip; 71 int expected = remaining >= Integer.MAX_VALUE 72 ? Integer.MAX_VALUE 73 : (int) remaining; 74 75 System.out.println("Skipped " + skip + " bytes " + 76 " available() returns " + expected + 77 " remaining=" + remaining); 78 if (is.available() != expected) { 79 throw new RuntimeException("available() returns " + 80 is.available() + " but expected " + expected); 81 } 82 return skip; 83 } 84 85 private static File createLargeFile(long filesize) throws Exception { 86 // Create a large file as a sparse file if possible 87 File largefile = File.createTempFile("largefile", null); 88 // re-create as a sparse file 89 Files.delete(largefile.toPath()); 90 try (FileChannel fc = 91 FileChannel.open(largefile.toPath(), 92 CREATE_NEW, WRITE, SPARSE)) { 93 ByteBuffer bb = ByteBuffer.allocate(1).put((byte)1); 94 bb.rewind(); 95 int rc = fc.write(bb, filesize-1); 96 if (rc != 1) { 97 throw new RuntimeException("Failed to write 1 byte to the large file"); 98 } 99 } 100 return largefile; 101 } 102 }