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 }