/* * Copyright 2000-2001 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ /* @test * @summary Test file mapping with FileChannel */ import java.io.*; import java.nio.MappedByteBuffer; import java.nio.channels.*; import java.nio.channels.FileChannel; import java.util.Random; /** * Testing FileChannel's mapping capabilities. */ public class MapTest { private static PrintStream err = System.err; private static Random generator = new Random(); private static int CHARS_PER_LINE = File.separatorChar == '/' ? 5 : 6; private static File blah; public static void main(String[] args) throws Exception { blah = File.createTempFile("blah", null); blah.deleteOnExit(); initTestFile(blah); err.println("Test file " + blah + " initialized"); testZero(); err.println("Zero size: OK"); testRead(); err.println("Read: OK"); testWrite(); err.println("Write: OK"); testHighOffset(); err.println("High offset: OK"); } /** * Creates file blah: * 0000 * 0001 * 0002 * 0003 * . * . * . * 3999 * * Blah extends beyond a single page of memory so that the * ability to index into a file of multiple pages is tested. */ private static void initTestFile(File blah) throws Exception { FileOutputStream fos = new FileOutputStream(blah); BufferedWriter awriter = new BufferedWriter(new OutputStreamWriter(fos, "8859_1")); for(int i=0; i<4000; i++) { String number = new Integer(i).toString(); for (int h=0; h<4-number.length(); h++) awriter.write("0"); awriter.write(""+i); awriter.newLine(); } awriter.flush(); awriter.close(); } /** * Tests zero size file mapping */ private static void testZero() throws Exception { FileInputStream fis = new FileInputStream(blah); FileChannel c = fis.getChannel(); MappedByteBuffer b = c.map(FileChannel.MapMode.READ_ONLY, 0, 0); c.close(); fis.close(); } /** * Maps blah file with a random offset and checks to see if read * from the ByteBuffer gets the right line number */ private static void testRead() throws Exception { StringBuffer sb = new StringBuffer(); sb.setLength(4); for (int x=0; x<1000; x++) { FileInputStream fis = new FileInputStream(blah); FileChannel c = fis.getChannel(); long offset = generator.nextInt(10000); long expectedResult = offset / CHARS_PER_LINE; offset = expectedResult * CHARS_PER_LINE; MappedByteBuffer b = c.map(FileChannel.MapMode.READ_ONLY, offset, 100); for (int i=0; i<4; i++) { byte aByte = b.get(i); sb.setCharAt(i, (char)aByte); } int result = Integer.parseInt(sb.toString()); if (result != expectedResult) { err.println("I expected "+expectedResult); err.println("I got "+result); throw new Exception("Read test failed"); } c.close(); fis.close(); } } /** * Maps blah file with a random offset and checks to see if data * written out to the file can be read back in */ private static void testWrite() throws Exception { StringBuffer sb = new StringBuffer(); sb.setLength(4); for (int x=0; x<1000; x++) { RandomAccessFile raf = new RandomAccessFile(blah, "rw"); FileChannel c = raf.getChannel(); long offset = generator.nextInt(1000); MappedByteBuffer b = c.map(FileChannel.MapMode.READ_WRITE, offset, 100); for (int i=0; i<4; i++) { b.put(i, (byte)('0' + i)); } for (int i=0; i<4; i++) { byte aByte = b.get(i); sb.setCharAt(i, (char)aByte); } if (!sb.toString().equals("0123")) throw new Exception("Write test failed"); c.close(); raf.close(); } } private static void testHighOffset() throws Exception { StringBuffer sb = new StringBuffer(); sb.setLength(4); for (int x=0; x<1000; x++) { RandomAccessFile raf = new RandomAccessFile(blah, "rw"); FileChannel fc = raf.getChannel(); long offset = 66000; MappedByteBuffer b = fc.map(FileChannel.MapMode.READ_WRITE, offset, 100); fc.close(); raf.close(); } } }