001/* FileCacheImageOutputStream.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.File; 042import java.io.IOException; 043import java.io.OutputStream; 044import java.io.RandomAccessFile; 045 046/** 047 * @author Michael Koch (konqueror@gmx.de) 048 */ 049public 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}