ojluni/src/main/java/com/sun/imageio/plugins/jpeg/MarkerSegment.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2001, 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 com.sun.imageio.plugins.jpeg;

 import javax.imageio.metadata.IIOInvalidTreeException;
 import javax.imageio.metadata.IIOMetadataNode;
 import javax.imageio.stream.ImageOutputStream;

 import java.io.IOException;

 import org.w3c.dom.Node;
 import org.w3c.dom.NamedNodeMap;

 /**
  * All metadata is stored in MarkerSegments.  Marker segments
  * that we know about are stored in subclasses of this
  * basic class, which used for unrecognized APPn marker
  * segments.  XXX break out UnknownMarkerSegment as a subclass
  * and make this abstract, avoiding unused data field.
  */
 class MarkerSegment implements Cloneable {
     protected static final int LENGTH_SIZE = 2; // length is 2 bytes
     int tag;      // See JPEG.java
     int length;    /* Sometimes needed by subclasses; doesn't include
                       itself.  Meaningful only if constructed from a stream */
     byte [] data = null;  // Raw segment data, used for unrecognized segments
     boolean unknown = false; // Set to true if the tag is not recognized

     /**
      * Constructor for creating <code>MarkerSegment</code>s by reading
      * from an <code>ImageInputStream</code>.
      */
     MarkerSegment(JPEGBuffer buffer) throws IOException {

         buffer.loadBuf(3);  // tag plus length
         tag = buffer.buf[buffer.bufPtr++] & 0xff;
         length = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
         length |= buffer.buf[buffer.bufPtr++] & 0xff;
         length -= 2;  // JPEG length includes itself, we don't
         buffer.bufAvail -= 3;
         // Now that we know the true length, ensure that we've got it,
         // or at least a bufferful if length is too big.
         buffer.loadBuf(length);
     }

     /**
      * Constructor used when creating segments other than by
      * reading them from a stream.
      */
     MarkerSegment(int tag) {
         this.tag = tag;
         length = 0;
     }

     /**
      * Construct a MarkerSegment from an "unknown" DOM Node.
      */
     MarkerSegment(Node node) throws IIOInvalidTreeException {
         // The type of node should have been verified already.
         // get the attribute and assign it to the tag
         tag = getAttributeValue(node,
                                 null,
                                 "MarkerTag",
                                 0, 255,
                                 true);
         length = 0;
         // get the user object and clone it to the data
         if (node instanceof IIOMetadataNode) {
             IIOMetadataNode iioNode = (IIOMetadataNode) node;
             try {
                 data = (byte []) iioNode.getUserObject();
             } catch (Exception e) {
                 IIOInvalidTreeException newGuy =
                     new IIOInvalidTreeException
                     ("Can't get User Object", node);
                 newGuy.initCause(e);
                 throw newGuy;
             }
         } else {
             throw new IIOInvalidTreeException
                 ("Node must have User Object", node);
         }
     }

     /**
      * Deep copy of data array.
      */
     protected Object clone() {
         MarkerSegment newGuy = null;
         try {
             newGuy = (MarkerSegment) super.clone();
         } catch (CloneNotSupportedException e) {} // won't happen
         if (this.data != null) {
             newGuy.data = (byte[]) data.clone();
         }
         return newGuy;
     }

     /**
      * We have determined that we don't know the type, so load
      * the data using the length parameter.
      */
     void loadData(JPEGBuffer buffer) throws IOException {
         data = new byte[length];
         buffer.readData(data);
     }

     IIOMetadataNode getNativeNode() {
         IIOMetadataNode node = new IIOMetadataNode("unknown");
         node.setAttribute("MarkerTag", Integer.toString(tag));
         node.setUserObject(data);

         return node;
     }

     static int getAttributeValue(Node node,
                                  NamedNodeMap attrs,
                                  String name,
                                  int min,
                                  int max,
                                  boolean required)
         throws IIOInvalidTreeException {
         if (attrs == null) {
             attrs = node.getAttributes();
         }
         String valueString = attrs.getNamedItem(name).getNodeValue();
         int value = -1;
         if (valueString == null) {
             if (required) {
                 throw new IIOInvalidTreeException
                     (name + " attribute not found", node);
             }
         } else {
               value = Integer.parseInt(valueString);
               if ((value < min) || (value > max)) {
                   throw new IIOInvalidTreeException
                       (name + " attribute out of range", node);
               }
         }
         return value;
     }

     /**
      * Writes the marker, tag, and length.  Note that length
      * should be verified by the caller as a correct JPEG
      * length, i.e it includes itself.
      */
     void writeTag(ImageOutputStream ios) throws IOException {
         ios.write(0xff);
         ios.write(tag);
         write2bytes(ios, length);
     }

     /**
      * Writes the data for this segment to the stream in
      * valid JPEG format.
      */
     void write(ImageOutputStream ios) throws IOException {
         length = 2 + ((data != null) ? data.length : 0);
         writeTag(ios);
         if (data != null) {
             ios.write(data);
         }
     }

     static void write2bytes(ImageOutputStream ios,
                             int value) throws IOException {
         ios.write((value >> 8) & 0xff);
         ios.write(value & 0xff);

     }

     void printTag(String prefix) {
         System.out.println(prefix + " marker segment - marker = 0x"
                            + Integer.toHexString(tag));
         System.out.println("length: " + length);
     }

     void print() {
         printTag("Unknown");
         if (length > 10) {
             System.out.print("First 5 bytes:");
             for (int i=0;i<5;i++) {
                 System.out.print(" Ox"
                                  + Integer.toHexString((int)data[i]));
             }
             System.out.print("\nLast 5 bytes:");
             for (int i=data.length-5;i<data.length;i++) {
                 System.out.print(" Ox"
                                  + Integer.toHexString((int)data[i]));
             }
         } else {
             System.out.print("Data:");
             for (int i=0;i<data.length;i++) {
                 System.out.print(" Ox"
                                  + Integer.toHexString((int)data[i]));
             }
         }
         System.out.println();
     }
 }
	/*
	* Copyright (c) 2001, 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 com.sun.imageio.plugins.jpeg;

	import javax.imageio.metadata.IIOInvalidTreeException;
	import javax.imageio.metadata.IIOMetadataNode;
	import javax.imageio.stream.ImageOutputStream;

	import java.io.IOException;

	import org.w3c.dom.Node;
	import org.w3c.dom.NamedNodeMap;

	/**
	* All metadata is stored in MarkerSegments. Marker segments
	* that we know about are stored in subclasses of this
	* basic class, which used for unrecognized APPn marker
	* segments. XXX break out UnknownMarkerSegment as a subclass
	* and make this abstract, avoiding unused data field.
	*/
	class MarkerSegment implements Cloneable {
	protected static final int LENGTH_SIZE = 2; // length is 2 bytes
	int tag; // See JPEG.java
	int length; /* Sometimes needed by subclasses; doesn't include
	itself. Meaningful only if constructed from a stream */
	byte [] data = null; // Raw segment data, used for unrecognized segments
	boolean unknown = false; // Set to true if the tag is not recognized

	/**
	* Constructor for creating <code>MarkerSegment</code>s by reading
	* from an <code>ImageInputStream</code>.
	*/
	MarkerSegment(JPEGBuffer buffer) throws IOException {

	buffer.loadBuf(3); // tag plus length
	tag = buffer.buf[buffer.bufPtr++] & 0xff;
	length = (buffer.buf[buffer.bufPtr++] & 0xff) << 8;
	length \|= buffer.buf[buffer.bufPtr++] & 0xff;
	length -= 2; // JPEG length includes itself, we don't
	buffer.bufAvail -= 3;
	// Now that we know the true length, ensure that we've got it,
	// or at least a bufferful if length is too big.
	buffer.loadBuf(length);
	}

	/**
	* Constructor used when creating segments other than by
	* reading them from a stream.
	*/
	MarkerSegment(int tag) {
	this.tag = tag;
	length = 0;
	}

	/**
	* Construct a MarkerSegment from an "unknown" DOM Node.
	*/
	MarkerSegment(Node node) throws IIOInvalidTreeException {
	// The type of node should have been verified already.
	// get the attribute and assign it to the tag
	tag = getAttributeValue(node,
	null,
	"MarkerTag",
	0, 255,
	true);
	length = 0;
	// get the user object and clone it to the data
	if (node instanceof IIOMetadataNode) {
	IIOMetadataNode iioNode = (IIOMetadataNode) node;
	try {
	data = (byte []) iioNode.getUserObject();
	} catch (Exception e) {
	IIOInvalidTreeException newGuy =
	new IIOInvalidTreeException
	("Can't get User Object", node);
	newGuy.initCause(e);
	throw newGuy;
	}
	} else {
	throw new IIOInvalidTreeException
	("Node must have User Object", node);
	}
	}

	/**
	* Deep copy of data array.
	*/
	protected Object clone() {
	MarkerSegment newGuy = null;
	try {
	newGuy = (MarkerSegment) super.clone();
	} catch (CloneNotSupportedException e) {} // won't happen
	if (this.data != null) {
	newGuy.data = (byte[]) data.clone();
	}
	return newGuy;
	}

	/**
	* We have determined that we don't know the type, so load
	* the data using the length parameter.
	*/
	void loadData(JPEGBuffer buffer) throws IOException {
	data = new byte[length];
	buffer.readData(data);
	}

	IIOMetadataNode getNativeNode() {
	IIOMetadataNode node = new IIOMetadataNode("unknown");
	node.setAttribute("MarkerTag", Integer.toString(tag));
	node.setUserObject(data);

	return node;
	}

	static int getAttributeValue(Node node,
	NamedNodeMap attrs,
	String name,
	int min,
	int max,
	boolean required)
	throws IIOInvalidTreeException {
	if (attrs == null) {
	attrs = node.getAttributes();
	}
	String valueString = attrs.getNamedItem(name).getNodeValue();
	int value = -1;
	if (valueString == null) {
	if (required) {
	throw new IIOInvalidTreeException
	(name + " attribute not found", node);
	}
	} else {
	value = Integer.parseInt(valueString);
	if ((value < min) \|\| (value > max)) {
	throw new IIOInvalidTreeException
	(name + " attribute out of range", node);
	}
	}
	return value;
	}

	/**
	* Writes the marker, tag, and length. Note that length
	* should be verified by the caller as a correct JPEG
	* length, i.e it includes itself.
	*/
	void writeTag(ImageOutputStream ios) throws IOException {
	ios.write(0xff);
	ios.write(tag);
	write2bytes(ios, length);
	}

	/**
	* Writes the data for this segment to the stream in
	* valid JPEG format.
	*/
	void write(ImageOutputStream ios) throws IOException {
	length = 2 + ((data != null) ? data.length : 0);
	writeTag(ios);
	if (data != null) {
	ios.write(data);
	}
	}

	static void write2bytes(ImageOutputStream ios,
	int value) throws IOException {
	ios.write((value >> 8) & 0xff);
	ios.write(value & 0xff);

	}

	void printTag(String prefix) {
	System.out.println(prefix + " marker segment - marker = 0x"
	+ Integer.toHexString(tag));
	System.out.println("length: " + length);
	}

	void print() {
	printTag("Unknown");
	if (length > 10) {
	System.out.print("First 5 bytes:");
	for (int i=0;i<5;i++) {
	System.out.print(" Ox"
	+ Integer.toHexString((int)data[i]));
	}
	System.out.print("\nLast 5 bytes:");
	for (int i=data.length-5;i<data.length;i++) {
	System.out.print(" Ox"
	+ Integer.toHexString((int)data[i]));
	}
	} else {
	System.out.print("Data:");
	for (int i=0;i<data.length;i++) {
	System.out.print(" Ox"
	+ Integer.toHexString((int)data[i]));
	}
	}
	System.out.println();
	}
	}