001 /* FileCacheImageOutputStream.java --
002 Copyright (C) 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.imageio.stream;
040
041 import java.io.File;
042 import java.io.IOException;
043 import java.io.OutputStream;
044 import java.io.RandomAccessFile;
045
046 /**
047 * @author Michael Koch (konqueror@gmx.de)
048 */
049 public 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 }