| /* |
| * 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.IOException; |
| import java.io.OutputStream; |
| import java.io.RandomAccessFile; |
| import java.nio.file.Files; |
| import com.sun.imageio.stream.StreamCloser; |
| |
| /** |
| * An implementation of <code>ImageOutputStream</code> that writes its |
| * output to a regular <code>OutputStream</code>. A file is used to |
| * cache data until it is flushed to the output stream. |
| * |
| */ |
| public class FileCacheImageOutputStream extends ImageOutputStreamImpl { |
| |
| private OutputStream stream; |
| |
| private File cacheFile; |
| |
| private RandomAccessFile cache; |
| |
| // Pos after last (rightmost) byte written |
| private long maxStreamPos = 0L; |
| |
| /** The CloseAction that closes the stream in |
| * the StreamCloser's shutdown hook */ |
| private final StreamCloser.CloseAction closeAction; |
| |
| /** |
| * Constructs a <code>FileCacheImageOutputStream</code> that will write |
| * to a given <code>outputStream</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>OutputStream</code> to write to. |
| * @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 FileCacheImageOutputStream(OutputStream 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; |
| if (cacheDir == null) |
| this.cacheFile = Files.createTempFile("imageio", ".tmp").toFile(); |
| else |
| this.cacheFile = Files.createTempFile(cacheDir.toPath(), "imageio", ".tmp") |
| .toFile(); |
| this.cache = new RandomAccessFile(cacheFile, "rw"); |
| |
| this.closeAction = StreamCloser.createCloseAction(this); |
| StreamCloser.addToQueue(closeAction); |
| } |
| |
| public int read() throws IOException { |
| checkClosed(); |
| bitOffset = 0; |
| int val = cache.read(); |
| if (val != -1) { |
| ++streamPos; |
| } |
| return val; |
| } |
| |
| public int read(byte[] b, int off, int len) throws IOException { |
| checkClosed(); |
| |
| if (b == null) { |
| throw new NullPointerException("b == null!"); |
| } |
| 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; |
| } |
| |
| int nbytes = cache.read(b, off, len); |
| if (nbytes != -1) { |
| streamPos += nbytes; |
| } |
| return nbytes; |
| } |
| |
| public void write(int b) throws IOException { |
| flushBits(); // this will call checkClosed() for us |
| cache.write(b); |
| ++streamPos; |
| maxStreamPos = Math.max(maxStreamPos, streamPos); |
| } |
| |
| public void write(byte[] b, int off, int len) throws IOException { |
| flushBits(); // this will call checkClosed() for us |
| cache.write(b, off, len); |
| streamPos += len; |
| maxStreamPos = Math.max(maxStreamPos, streamPos); |
| } |
| |
| public long length() { |
| try { |
| checkClosed(); |
| return cache.length(); |
| } catch (IOException e) { |
| return -1L; |
| } |
| } |
| |
| /** |
| * Sets the current stream position and resets the bit offset to |
| * 0. It is legal to seek past the end of the file; an |
| * <code>EOFException</code> will be thrown only if a read is |
| * performed. The file length will not be increased until a write |
| * is performed. |
| * |
| * @exception IndexOutOfBoundsException if <code>pos</code> is smaller |
| * than the flushed position. |
| * @exception IOException if any other I/O error occurs. |
| */ |
| public void seek(long pos) throws IOException { |
| checkClosed(); |
| |
| if (pos < flushedPos) { |
| throw new IndexOutOfBoundsException(); |
| } |
| |
| cache.seek(pos); |
| this.streamPos = cache.getFilePointer(); |
| maxStreamPos = Math.max(maxStreamPos, streamPos); |
| this.bitOffset = 0; |
| } |
| |
| /** |
| * Returns <code>true</code> since this |
| * <code>ImageOutputStream</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>ImageOutputStream</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>ImageOutputStream</code> does not maintain a main memory |
| * cache. |
| * |
| * @return <code>false</code>. |
| * |
| * @see #isCached |
| * @see #isCachedFile |
| */ |
| public boolean isCachedMemory() { |
| return false; |
| } |
| |
| /** |
| * Closes this <code>FileCacheImageOutputStream</code>. All |
| * pending data is flushed to the output, and the cache file |
| * is closed and removed. The destination <code>OutputStream</code> |
| * is not closed. |
| * |
| * @exception IOException if an error occurs. |
| */ |
| public void close() throws IOException { |
| maxStreamPos = cache.length(); |
| |
| seek(maxStreamPos); |
| flushBefore(maxStreamPos); |
| super.close(); |
| cache.close(); |
| cache = null; |
| cacheFile.delete(); |
| cacheFile = null; |
| stream.flush(); |
| stream = null; |
| StreamCloser.removeFromQueue(closeAction); |
| } |
| |
| public void flushBefore(long pos) throws IOException { |
| long oFlushedPos = flushedPos; |
| super.flushBefore(pos); // this will call checkClosed() for us |
| |
| long flushBytes = flushedPos - oFlushedPos; |
| if (flushBytes > 0) { |
| int bufLen = 512; |
| byte[] buf = new byte[bufLen]; |
| cache.seek(oFlushedPos); |
| while (flushBytes > 0) { |
| int len = (int)Math.min(flushBytes, bufLen); |
| cache.readFully(buf, 0, len); |
| stream.write(buf, 0, len); |
| flushBytes -= len; |
| } |
| stream.flush(); |
| } |
| } |
| } |