001/* MemoryCacheImageInputStream.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.BufferedInputStream; 042import java.io.IOException; 043import java.io.InputStream; 044 045/** 046 * @author Michael Koch (konqueror@gmx.de) 047 */ 048public 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}