Initial import of release 2.2.REL-2.2@923

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@4 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 215 insertions, 0 deletions

diff --git a/src/main/java/org/pdfbox/filter/LZWDictionary.java b/src/main/java/org/pdfbox/filter/LZWDictionary.java
new file mode 100644
index 0000000..075dab8
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+++ b/src/main/java/org/pdfbox/filter/LZWDictionary.java
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+/**

+ * Copyright (c) 2003, www.pdfbox.org

+ * All rights reserved.

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions are met:

+ *

+ * 1. Redistributions of source code must retain the above copyright notice,

+ *    this list of conditions and the following disclaimer.

+ * 2. Redistributions in binary form must reproduce the above copyright notice,

+ *    this list of conditions and the following disclaimer in the documentation

+ *    and/or other materials provided with the distribution.

+ * 3. Neither the name of pdfbox; nor the names of its

+ *    contributors may be used to endorse or promote products derived from this

+ *    software without specific prior written permission.

+ *

+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+ * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY

+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON

+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+ *

+ * http://www.pdfbox.org

+ *

+ */

+package org.pdfbox.filter;

+

+import java.io.ByteArrayOutputStream;

+import java.io.IOException;

+

+import java.util.HashMap;

+import java.util.Map;

+

+/**

+ * This is the used for the LZWDecode filter.  This represents the dictionary mappings

+ * between codes and their values.

+ *

+ * @author Ben Litchfield (ben@csh.rit.edu)

+ * @version $Revision: 1.3 $

+ */

+class LZWDictionary

+{

+    private Map codeToData = new HashMap();

+    private LZWNode root = new LZWNode();

+

+    private ByteArrayOutputStream buffer = new ByteArrayOutputStream();

+    private long nextCode = 258;

+    private int codeSize = 9;

+

+    /**

+     * constructor.

+     */

+    public LZWDictionary()

+    {

+        for( long i=0; i<256; i++ )

+        {

+            LZWNode node = new LZWNode();

+            node.setCode( i );

+            root.setNode( (byte)i, node );

+            codeToData.put( new Long( i ), new byte[]{ (byte)i } );

+        }

+    }

+

+    /**

+     * This will get the value for the code.  It will return null if the code is not

+     * defined.

+     *

+     * @param code The key to the data.

+     *

+     * @return The data that is mapped to the code.

+     */

+    public byte[] getData( long code )

+    {

+        return (byte[])codeToData.get( new Long( code ) );

+    }

+

+    /**

+     * This will take a visit from a byte[].  This will create new code entries as

+     * necessary.

+     *

+     * @param data The byte to get a visit from.

+     *

+     * @throws IOException If there is an error visiting this data.

+     */

+    public void visit( byte[] data ) throws IOException

+    {

+        for( int i=0; i<data.length; i++ )

+        {

+            visit( data[i] );

+        }

+    }

+

+    /**

+     * This will take a visit from a byte.  This will create new code entries as

+     * necessary.

+     *

+     * @param data The byte to get a visit from.

+     *

+     * @throws IOException If there is an error visiting this data.

+     */

+    public void visit( byte data ) throws IOException

+    {

+        buffer.write( data );

+        byte[] curBuffer = buffer.toByteArray();

+        LZWNode previous = null;

+        LZWNode current = root;

+        boolean createNewCode = false;

+        for( int i=0; i<curBuffer.length && current != null; i++ )

+        {

+            previous = current;

+            current = current.getNode( curBuffer[i] );

+            if( current == null )

+            {

+                createNewCode = true;

+                current = new LZWNode();

+                previous.setNode( curBuffer[i], current );

+            }

+        }

+        if( createNewCode )

+        {

+            long code = nextCode++;

+            current.setCode( code );

+            codeToData.put( new Long( code ), curBuffer );

+

+            /**

+            System.out.print( "Adding " + code + "='" );

+            for( int i=0; i<curBuffer.length; i++ )

+            {

+                String hex = Integer.toHexString( ((curBuffer[i]+256)%256) );

+                if( hex.length() <=1 )

+                {

+                    hex = "0" + hex;

+                }

+                if( i != curBuffer.length -1 )

+                {

+                    hex += " ";

+                }

+                System.out.print( hex.toUpperCase() );

+            }

+            System.out.println( "'" );

+            **/

+            buffer.reset();

+            buffer.write( data );

+            resetCodeSize();

+        }

+    }

+

+    /**

+     * This will get the next code that will be created.

+     *

+     * @return The next code to be created.

+     */

+    public long getNextCode()

+    {

+        return nextCode;

+    }

+

+    /**

+     * This will get the size of the code in bits, 9, 10, or 11.

+     *

+     * @return The size of the code in bits.

+     */

+    public int getCodeSize()

+    {

+        return codeSize;

+    }

+

+    /**

+     * This will determine the code size.

+     */

+    private void resetCodeSize()

+    {

+        if( nextCode >= 2048 )

+        {

+            codeSize = 12;

+        }

+        else if( nextCode >= 1024 )

+        {

+            codeSize = 11;

+        }

+        else if( nextCode >= 512 )

+        {

+            codeSize = 10;

+        }

+        else

+        {

+            codeSize = 9;

+        }

+    }

+

+    /**

+     * This will crear the internal buffer that the dictionary uses.

+     */

+    public void clear()

+    {

+        buffer.reset();

+    }

+

+    /**

+     * This will folow the path to the data node.

+     *

+     * @param data The path to the node.

+     *

+     * @return The node that resides at that path.

+     */

+    public LZWNode getNode( byte[] data )

+    {

+        return root.getNode( data );

+    }

+}
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