src/java.desktop/share/classes/javax/imageio/stream/FileCacheImageOutputStream.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2000, 2012, 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} that writes its
  * output to a regular {@code OutputStream}.  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} that will write
      * to a given {@code outputStream}.
      *
      * <p> A temporary file is used as a cache.  If
      * {@code cacheDir} is non-{@code null} and is a
      * directory, the file will be created there.  If it is
      * {@code null}, the system-dependent default temporary-file
      * directory will be used (see the documentation for
      * {@code File.createTempFile} for details).
      *
      * @param stream an {@code OutputStream} to write to.
      * @param cacheDir a {@code File} indicating where the
      * cache file should be created, or {@code null} to use the
      * system directory.
      *
      * @exception IllegalArgumentException if {@code stream}
      * is {@code null}.
      * @exception IllegalArgumentException if {@code cacheDir} is
      * non-{@code null} 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} 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} 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} since this
      * {@code ImageOutputStream} caches data in order to allow
      * seeking backwards.
      *
      * @return {@code true}.
      *
      * @see #isCachedMemory
      * @see #isCachedFile
      */
     public boolean isCached() {
         return true;
     }

     /**
      * Returns {@code true} since this
      * {@code ImageOutputStream} maintains a file cache.
      *
      * @return {@code true}.
      *
      * @see #isCached
      * @see #isCachedMemory
      */
     public boolean isCachedFile() {
         return true;
     }

     /**
      * Returns {@code false} since this
      * {@code ImageOutputStream} does not maintain a main memory
      * cache.
      *
      * @return {@code false}.
      *
      * @see #isCached
      * @see #isCachedFile
      */
     public boolean isCachedMemory() {
         return false;
     }

     /**
      * Closes this {@code FileCacheImageOutputStream}.  All
      * pending data is flushed to the output, and the cache file
      * is closed and removed.  The destination {@code OutputStream}
      * 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();
         }
     }
 }
	/*
	* Copyright (c) 2000, 2012, 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} that writes its
	* output to a regular {@code OutputStream}. 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} that will write
	* to a given {@code outputStream}.
	*
	* <p> A temporary file is used as a cache. If
	* {@code cacheDir} is non-{@code null} and is a
	* directory, the file will be created there. If it is
	* {@code null}, the system-dependent default temporary-file
	* directory will be used (see the documentation for
	* {@code File.createTempFile} for details).
	*
	* @param stream an {@code OutputStream} to write to.
	* @param cacheDir a {@code File} indicating where the
	* cache file should be created, or {@code null} to use the
	* system directory.
	*
	* @exception IllegalArgumentException if {@code stream}
	* is {@code null}.
	* @exception IllegalArgumentException if {@code cacheDir} is
	* non-{@code null} 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} 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} 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} since this
	* {@code ImageOutputStream} caches data in order to allow
	* seeking backwards.
	*
	* @return {@code true}.
	*
	* @see #isCachedMemory
	* @see #isCachedFile
	*/
	public boolean isCached() {
	return true;
	}

	/**
	* Returns {@code true} since this
	* {@code ImageOutputStream} maintains a file cache.
	*
	* @return {@code true}.
	*
	* @see #isCached
	* @see #isCachedMemory
	*/
	public boolean isCachedFile() {
	return true;
	}

	/**
	* Returns {@code false} since this
	* {@code ImageOutputStream} does not maintain a main memory
	* cache.
	*
	* @return {@code false}.
	*
	* @see #isCached
	* @see #isCachedFile
	*/
	public boolean isCachedMemory() {
	return false;
	}

	/**
	* Closes this {@code FileCacheImageOutputStream}. All
	* pending data is flushed to the output, and the cache file
	* is closed and removed. The destination {@code OutputStream}
	* 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();
	}
	}
	}