001/* FileCacheImageOutputStream.java --
002   Copyright (C) 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.imageio.stream;
040
041import java.io.File;
042import java.io.IOException;
043import java.io.OutputStream;
044import java.io.RandomAccessFile;
045
046/**
047 * @author Michael Koch (konqueror@gmx.de)
048 */
049public class FileCacheImageOutputStream extends ImageOutputStreamImpl
050{
051  private OutputStream stream;
052  private File cacheFile;
053  private RandomAccessFile cache;
054  private long maxPos;
055
056  public FileCacheImageOutputStream(OutputStream s, File cacheDir)
057    throws IOException
058  {
059    stream = s;
060    cacheFile = File.createTempFile("imageio", ".tmp", cacheDir);
061    cache = new RandomAccessFile(cacheFile, "rw");
062    maxPos = 0;
063  }
064
065  public void close()
066    throws IOException
067  {
068    maxPos = cache.length();
069    seek(maxPos);
070    flushBefore(maxPos);
071    super.close();
072    cache.close();
073    cacheFile.delete();
074    stream.flush();
075    stream = null;
076  }
077
078  public boolean isCached()
079  {
080    return true;
081  }
082
083  public boolean isCachedFile()
084  {
085    return true;
086  }
087  
088  public boolean isCachedMemory()
089  {
090    return false;
091  }
092  
093  public int read()
094    throws IOException
095  {
096    bitOffset = 0;
097    int val = cache.read();
098    if (val != -1)
099      streamPos++;
100    return val;
101  }
102
103  public int read(byte[] data, int offset, int len)
104    throws IOException
105  {
106    bitOffset = 0;
107    int num = cache.read(data, offset, len);
108    if (num != -1)
109      streamPos += num;
110    return num;
111  }
112
113  public void write(byte[] data, int offset, int len)
114    throws IOException
115  {
116    flushBits();
117    cache.write(data, offset, len);
118    streamPos += len;
119    maxPos = Math.max(streamPos, maxPos);
120  }
121
122  public void write(int value)
123    throws IOException
124  {
125    flushBits();
126    cache.write(value);
127    streamPos++;
128    maxPos = Math.max(streamPos, maxPos);
129  }
130
131  public long length()
132  {
133    long l;
134    try
135      {
136        l = cache.length();
137      }
138    catch (IOException ex)
139      {
140        l = -1;
141      }
142    return l;
143  }
144
145  public void seek(long pos)
146    throws IOException
147  {
148    checkClosed();
149    if (pos < flushedPos)
150      throw new IndexOutOfBoundsException();
151    cache.seek(pos);
152    streamPos = cache.getFilePointer();
153    maxPos = Math.max(streamPos, maxPos);
154    bitOffset = 0;
155  }
156
157  public void flushBefore(long pos)
158    throws IOException
159  {
160    long oldPos = flushedPos;
161    super.flushBefore(pos);
162    long flushed = flushedPos - oldPos;
163    if (flushed > 0)
164      {
165        int len = 512;
166        byte[] buf = new byte[len];
167        cache.seek(oldPos);
168        while (flushed > 0)
169          {
170            int l = (int) Math.min(flushed, len);
171            cache.readFully(buf, 0, l);
172            stream.write(buf, 0, l);
173            flushed -= l;
174          }
175        stream.flush();
176      }
177  }
178}