| /* |
| * 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. |
| } |
| } |
| } |