001 /* MemoryCacheImageInputStream.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.BufferedInputStream;
042 import java.io.BufferedReader;
043 import java.io.IOException;
044 import java.io.InputStream;
045 import java.io.InputStreamReader;
046
047 /**
048 * @author Michael Koch (konqueror@gmx.de)
049 */
050 public class MemoryCacheImageInputStream extends ImageInputStreamImpl
051 {
052 private InputStream stream;
053 private BufferedInputStream buffer;
054
055 private int READLIMIT = 2048;
056
057 public MemoryCacheImageInputStream(InputStream stream)
058 {
059 this.stream = stream;
060 buffer = new BufferedInputStream(stream);
061 buffer.mark(READLIMIT);
062 }
063
064 public void close()
065 throws IOException
066 {
067 super.close();
068 stream.close();
069 }
070
071 public void flushBefore(long position)
072 throws IOException
073 {
074 long prevFlushedPosition = getFlushedPosition();
075 super.flushBefore(position);
076 buffer.reset();
077 buffer.skip(getFlushedPosition() - prevFlushedPosition);
078 buffer.mark(READLIMIT);
079 }
080
081 public boolean isCached()
082 {
083 return true;
084 }
085
086 public boolean isCachedFile()
087 {
088 return false;
089 }
090
091 public boolean isCachedMemory()
092 {
093 return true;
094 }
095
096 public int read()
097 throws IOException
098 {
099 setBitOffset(0);
100 int retval = buffer.read();
101
102 if (retval != -1)
103 streamPos++;
104
105 return retval;
106 }
107
108 public int read(byte[] data, int offset, int len)
109 throws IOException
110 {
111 setBitOffset(0);
112 int retval = buffer.read(data, offset, len);
113
114 if (retval != -1)
115 {
116 streamPos += retval;
117 }
118
119 return retval;
120 }
121
122 public void seek(long position)
123 throws IOException
124 {
125 super.seek(position);
126 buffer.reset();
127 buffer.skip(position - getFlushedPosition());
128 }
129 }