/* * Copyright (c) 2000, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package javax.imageio.stream;import java.io.File;import java.io.InputStream;import java.io.IOException;import java.io.RandomAccessFile;import com.sun.imageio.stream.StreamCloser;import com.sun.imageio.stream.StreamFinalizer;import sun.java2d.Disposer;import sun.java2d.DisposerRecord;/** * An implementation of <code>ImageInputStream</code> that gets its * input from a regular <code>InputStream</code>. A file is used to * cache previously read data. * */public class FileCacheImageInputStream extends ImageInputStreamImpl { private InputStream stream; private File cacheFile; private RandomAccessFile cache; private static final int BUFFER_LENGTH = 1024; private byte[] buf = new byte[BUFFER_LENGTH]; private long length = 0L; private boolean foundEOF = false; /** The referent to be registered with the Disposer. */ private final Object disposerReferent; /** The DisposerRecord that closes the underlying cache. */ private final DisposerRecord disposerRecord; /** The CloseAction that closes the stream in * the StreamCloser's shutdown hook */ private final StreamCloser.CloseAction closeAction; /** * Constructs a <code>FileCacheImageInputStream</code> that will read * from a given <code>InputStream</code>. * * <p> A temporary file is used as a cache. If * <code>cacheDir</code>is non-<code>null</code> and is a * directory, the file will be created there. If it is * <code>null</code>, the system-dependent default temporary-file * directory will be used (see the documentation for * <code>File.createTempFile</code> for details). * * @param stream an <code>InputStream</code> to read from. * @param cacheDir a <code>File</code> indicating where the * cache file should be created, or <code>null</code> to use the * system directory. * * @exception IllegalArgumentException if <code>stream</code> is * <code>null</code>. * @exception IllegalArgumentException if <code>cacheDir</code> is * non-<code>null</code> but is not a directory. * @exception IOException if a cache file cannot be created. */ public FileCacheImageInputStream(InputStream stream, File cacheDir) throws IOException { if (stream == null) { throw new IllegalArgumentException("stream == null!"); } if ((cacheDir != null) && !(cacheDir.isDirectory())) { throw new IllegalArgumentException("Not a directory!"); } this.stream = stream; this.cacheFile = File.createTempFile("imageio", ".tmp", cacheDir); this.cache = new RandomAccessFile(cacheFile, "rw"); this.closeAction = StreamCloser.createCloseAction(this); StreamCloser.addToQueue(closeAction); disposerRecord = new StreamDisposerRecord(cacheFile, cache); if (getClass() == FileCacheImageInputStream.class) { disposerReferent = new Object(); Disposer.addRecord(disposerReferent, disposerRecord); } else { disposerReferent = new StreamFinalizer(this); } } /** * Ensures that at least <code>pos</code> bytes are cached, * or the end of the source is reached. The return value * is equal to the smaller of <code>pos</code> and the * length of the source file. */ private long readUntil(long pos) throws IOException { // We've already got enough data cached if (pos < length) { return pos; } // pos >= length but length isn't getting any bigger, so return it if (foundEOF) { return length; } long len = pos - length; cache.seek(length); while (len > 0) { // Copy a buffer's worth of data from the source to the cache // BUFFER_LENGTH will always fit into an int so this is safe int nbytes = stream.read(buf, 0, (int)Math.min(len, (long)BUFFER_LENGTH)); if (nbytes == -1) { foundEOF = true; return length; } cache.write(buf, 0, nbytes); len -= nbytes; length += nbytes; } return pos; } public int read() throws IOException { checkClosed(); bitOffset = 0; long next = streamPos + 1; long pos = readUntil(next); if (pos >= next) { cache.seek(streamPos++); return cache.read(); } else { return -1; } } public int read(byte[] b, int off, int len) throws IOException { checkClosed(); if (b == null) { throw new NullPointerException("b == null!"); } // Fix 4430357 - if off + len < 0, overflow occurred if (off < 0 || len < 0 || off + len > b.length || off + len < 0) { throw new IndexOutOfBoundsException ("off < 0 || len < 0 || off+len > b.length || off+len < 0!"); } bitOffset = 0; if (len == 0) { return 0; } long pos = readUntil(streamPos + len); // len will always fit into an int so this is safe len = (int)Math.min((long)len, pos - streamPos); if (len > 0) { cache.seek(streamPos); cache.readFully(b, off, len); streamPos += len; return len; } else { return -1; } } /** * Returns <code>true</code> since this * <code>ImageInputStream</code> caches data in order to allow * seeking backwards. * * @return <code>true</code>. * * @see #isCachedMemory * @see #isCachedFile */ public boolean isCached() { return true; } /** * Returns <code>true</code> since this * <code>ImageInputStream</code> maintains a file cache. * * @return <code>true</code>. * * @see #isCached * @see #isCachedMemory */ public boolean isCachedFile() { return true; } /** * Returns <code>false</code> since this * <code>ImageInputStream</code> does not maintain a main memory * cache. * * @return <code>false</code>. * * @see #isCached * @see #isCachedFile */ public boolean isCachedMemory() { return false; } /** * Closes this <code>FileCacheImageInputStream</code>, closing * and removing the cache file. The source <code>InputStream</code> * is not closed. * * @exception IOException if an error occurs. */ public void close() throws IOException { super.close(); disposerRecord.dispose(); // this will close/delete the cache file stream = null; cache = null; cacheFile = null; StreamCloser.removeFromQueue(closeAction); } /** * {@inheritDoc} */ protected void finalize() throws Throwable { // Empty finalizer: for performance reasons we instead use the // Disposer mechanism for ensuring that the underlying // RandomAccessFile is closed/deleted prior to garbage collection } private static class StreamDisposerRecord implements DisposerRecord { private File cacheFile; private RandomAccessFile cache; public StreamDisposerRecord(File cacheFile, RandomAccessFile cache) { this.cacheFile = cacheFile; this.cache = cache; } public synchronized void dispose() { if (cache != null) { try { cache.close(); } catch (IOException e) { } finally { cache = null; } } if (cacheFile != null) { cacheFile.delete(); cacheFile = null; } // Note: Explicit removal of the stream from the StreamCloser // queue is not mandatory in this case, as it will be removed // automatically by GC shortly after this method is called. } }}
/*
* Copyright (c) 2000, 2007, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javax.imageio.stream;
import java.io.File;
import java.io.InputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import com.sun.imageio.stream.StreamCloser;
import com.sun.imageio.stream.StreamFinalizer;
import sun.java2d.Disposer;
import sun.java2d.DisposerRecord;
/**
* An implementation of <code>ImageInputStream</code> that gets its
* input from a regular <code>InputStream</code>. A file is used to
* cache previously read data.
*
*/
public class FileCacheImageInputStream extends ImageInputStreamImpl {
private InputStream stream;
private File cacheFile;
private RandomAccessFile cache;
private static final int BUFFER_LENGTH = 1024;
private byte[] buf = new byte[BUFFER_LENGTH];
private long length = 0L;
private boolean foundEOF = false;
/** The referent to be registered with the Disposer. */
private final Object disposerReferent;
/** The DisposerRecord that closes the underlying cache. */
private final DisposerRecord disposerRecord;
/** The CloseAction that closes the stream in
* the StreamCloser's shutdown hook */
private final StreamCloser.CloseAction closeAction;
/**
* Constructs a <code>FileCacheImageInputStream</code> that will read
* from a given <code>InputStream</code>.
*
* <p> A temporary file is used as a cache. If
* <code>cacheDir</code>is non-<code>null</code> and is a
* directory, the file will be created there. If it is
* <code>null</code>, the system-dependent default temporary-file
* directory will be used (see the documentation for
* <code>File.createTempFile</code> for details).
*
* @param stream an <code>InputStream</code> to read from.
* @param cacheDir a <code>File</code> indicating where the
* cache file should be created, or <code>null</code> to use the
* system directory.
*
* @exception IllegalArgumentException if <code>stream</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>cacheDir</code> is
* non-<code>null</code> but is not a directory.
* @exception IOException if a cache file cannot be created.
*/
public FileCacheImageInputStream(InputStream stream, File cacheDir)
throws IOException {
if (stream == null) {
throw new IllegalArgumentException("stream == null!");
}
if ((cacheDir != null) && !(cacheDir.isDirectory())) {
throw new IllegalArgumentException("Not a directory!");
}
this.stream = stream;
this.cacheFile =
File.createTempFile("imageio", ".tmp", cacheDir);
this.cache = new RandomAccessFile(cacheFile, "rw");
this.closeAction = StreamCloser.createCloseAction(this);
StreamCloser.addToQueue(closeAction);
disposerRecord = new StreamDisposerRecord(cacheFile, cache);
if (getClass() == FileCacheImageInputStream.class) {
disposerReferent = new Object();
Disposer.addRecord(disposerReferent, disposerRecord);
} else {
disposerReferent = new StreamFinalizer(this);
}
}
/**
* Ensures that at least <code>pos</code> bytes are cached,
* or the end of the source is reached. The return value
* is equal to the smaller of <code>pos</code> and the
* length of the source file.
*/
private long readUntil(long pos) throws IOException {
// We've already got enough data cached
if (pos < length) {
return pos;
}
// pos >= length but length isn't getting any bigger, so return it
if (foundEOF) {
return length;
}
long len = pos - length;
cache.seek(length);
while (len > 0) {
// Copy a buffer's worth of data from the source to the cache
// BUFFER_LENGTH will always fit into an int so this is safe
int nbytes =
stream.read(buf, 0, (int)Math.min(len, (long)BUFFER_LENGTH));
if (nbytes == -1) {
foundEOF = true;
return length;
}
cache.write(buf, 0, nbytes);
len -= nbytes;
length += nbytes;
}
return pos;
}
public int read() throws IOException {
checkClosed();
bitOffset = 0;
long next = streamPos + 1;
long pos = readUntil(next);
if (pos >= next) {
cache.seek(streamPos++);
return cache.read();
} else {
return -1;
}
}
public int read(byte[] b, int off, int len) throws IOException {
checkClosed();
if (b == null) {
throw new NullPointerException("b == null!");
}
// Fix 4430357 - if off + len < 0, overflow occurred
if (off < 0 || len < 0 || off + len > b.length || off + len < 0) {
throw new IndexOutOfBoundsException
("off < 0 || len < 0 || off+len > b.length || off+len < 0!");
}
bitOffset = 0;
if (len == 0) {
return 0;
}
long pos = readUntil(streamPos + len);
// len will always fit into an int so this is safe
len = (int)Math.min((long)len, pos - streamPos);
if (len > 0) {
cache.seek(streamPos);
cache.readFully(b, off, len);
streamPos += len;
return len;
} else {
return -1;
}
}
/**
* Returns <code>true</code> since this
* <code>ImageInputStream</code> caches data in order to allow
* seeking backwards.
*
* @return <code>true</code>.
*
* @see #isCachedMemory
* @see #isCachedFile
*/
public boolean isCached() {
return true;
}
/**
* Returns <code>true</code> since this
* <code>ImageInputStream</code> maintains a file cache.
*
* @return <code>true</code>.
*
* @see #isCached
* @see #isCachedMemory
*/
public boolean isCachedFile() {
return true;
}
/**
* Returns <code>false</code> since this
* <code>ImageInputStream</code> does not maintain a main memory
* cache.
*
* @return <code>false</code>.
*
* @see #isCached
* @see #isCachedFile
*/
public boolean isCachedMemory() {
return false;
}
/**
* Closes this <code>FileCacheImageInputStream</code>, closing
* and removing the cache file. The source <code>InputStream</code>
* is not closed.
*
* @exception IOException if an error occurs.
*/
public void close() throws IOException {
super.close();
disposerRecord.dispose(); // this will close/delete the cache file
stream = null;
cache = null;
cacheFile = null;
StreamCloser.removeFromQueue(closeAction);
}
/**
* {@inheritDoc}
*/
protected void finalize() throws Throwable {
// Empty finalizer: for performance reasons we instead use the
// Disposer mechanism for ensuring that the underlying
// RandomAccessFile is closed/deleted prior to garbage collection
}
private static class StreamDisposerRecord implements DisposerRecord {
private File cacheFile;
private RandomAccessFile cache;
public StreamDisposerRecord(File cacheFile, RandomAccessFile cache) {
this.cacheFile = cacheFile;
this.cache = cache;
}
public synchronized void dispose() {
if (cache != null) {
try {
cache.close();
} catch (IOException e) {
} finally {
cache = null;
}
}
if (cacheFile != null) {
cacheFile.delete();
cacheFile = null;
}
// Note: Explicit removal of the stream from the StreamCloser
// queue is not mandatory in this case, as it will be removed
// automatically by GC shortly after this method is called.
}
}
}