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