1 /*
   2  * Copyright (c) 2002, 2017, 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 4507868
  27  * @summary Checks that ImageOutputStreamImpl.writeBits() advances the stream
  28  *          position and bit offset correctly. Also verifies that the
  29  *          MemoryCacheImageOutputStream.read() variants reset the bitOffset
  30  *          before the read actually occurs.
  31  */
  32 
  33 import java.io.ByteArrayOutputStream;
  34 import java.io.IOException;
  35 
  36 import javax.imageio.stream.ImageOutputStream;
  37 import javax.imageio.stream.MemoryCacheImageOutputStream;
  38 
  39 public class WriteBitsTest {
  40 
  41     private static void verify(ImageOutputStream ios,
  42                                long expstreampos, int expbitoffset)
  43         throws IOException, RuntimeException
  44     {
  45         long actstreampos = ios.getStreamPosition();
  46         int actbitoffset = ios.getBitOffset();
  47 
  48         if ((actstreampos != expstreampos) ||
  49             (actbitoffset != expbitoffset))
  50         {
  51             System.err.println("Expected stream position: " + expstreampos +
  52                                " Actual: " + actstreampos);
  53             System.err.println("Expected bit offset: " + expbitoffset +
  54                                " Actual: " + actbitoffset);
  55             throw new RuntimeException("Test failed.");
  56         }
  57     }
  58 
  59     public static void main(String argv[]) throws RuntimeException {
  60         ByteArrayOutputStream ostream = new ByteArrayOutputStream();
  61         MemoryCacheImageOutputStream mcios = new
  62             MemoryCacheImageOutputStream(ostream);
  63 
  64         try {
  65             // verify correct writeBits() functionality
  66             long streampos = 0;
  67             int bitoffset = 0;
  68 
  69             mcios.setBitOffset(bitoffset);
  70             verify(mcios, streampos, bitoffset);
  71 
  72             bitoffset = 3;
  73             mcios.setBitOffset(bitoffset);
  74             verify(mcios, streampos, bitoffset);
  75 
  76             for (int incr = 3; incr <= 15; incr += 12) {
  77                 for (int i = 0; i < 64; i += incr) {
  78                     mcios.writeBits(10, incr);
  79 
  80                     bitoffset += incr;
  81 
  82                     if (bitoffset > 7) {
  83                         int stroffset = bitoffset / 8;
  84                         bitoffset = bitoffset % 8;
  85                         streampos += stroffset;
  86                     }
  87 
  88                     verify(mcios, streampos, bitoffset);
  89                 }
  90             }
  91 
  92             // verify correct read(byte[], int, int) functionality
  93             byte[] bytearr = new byte[2];
  94             mcios.seek(2);
  95             mcios.setBitOffset(3);
  96             int numread = mcios.read(bytearr, 0, 2);
  97             if (numread != 2) {
  98                 throw new RuntimeException("Error in mcios.read([BII)I");
  99             }
 100             verify(mcios, 4, 0);
 101 
 102             // verify correct read() functionality
 103             mcios.setBitOffset(3);
 104             mcios.read();
 105             verify(mcios, 5, 0);
 106         } catch (IOException e) {
 107             throw new RuntimeException("Unexpected IOException: " + e);
 108         }
 109     }
 110 }