poi/src/java/org/apache/poi/poifs/filesystem/POIFSDocument.java

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  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. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache POI" must not be used to endorse or promote products
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 * 5. Products derived from this software may not be called "Apache",
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 *
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 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.poi.poifs.filesystem;

import java.io.*;

import java.util.*;

import org.apache.poi.poifs.common.PoiFSConstants;
import org.apache.poi.poifs.dev.POIFSViewable;
import org.apache.poi.poifs.property.DocumentProperty;
import org.apache.poi.poifs.property.Property;
import org.apache.poi.poifs.storage.BlockWritable;
import org.apache.poi.poifs.storage.ListManagedBlock;
import org.apache.poi.poifs.storage.DocumentBlock;
import org.apache.poi.poifs.storage.RawDataBlock;
import org.apache.poi.poifs.storage.SmallDocumentBlock;
import org.apache.poi.util.HexDump;

/**
 * This class manages a document in the POIFS filesystem.
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public class POIFSDocument
    implements BATManaged, BlockWritable, POIFSViewable
{
    private DocumentProperty _property;
    private int              _size;

    // one of these stores will be valid
    private SmallBlockStore  _small_store;
    private BigBlockStore    _big_store;

    /**
     * Constructor from large blocks
     *
     * @param name the name of the POIFSDocument
     * @param blocks the big blocks making up the POIFSDocument
     * @param length the actual length of the POIFSDocument
     *
     * @exception IOException
     */

    public POIFSDocument(final String name, final RawDataBlock [] blocks,
                         final int length)
        throws IOException
    {
        _size        = length;
        _big_store   = new BigBlockStore(blocks);
        _property    = new DocumentProperty(name, _size);
        _small_store = new SmallBlockStore(new BlockWritable[ 0 ]);
        _property.setDocument(this);
    }

    /**
     * Constructor from small blocks
     *
     * @param name the name of the POIFSDocument
     * @param blocks the small blocks making up the POIFSDocument
     * @param length the actual length of the POIFSDocument
     */

    public POIFSDocument(final String name,
                         final SmallDocumentBlock [] blocks, final int length)
    {
        _size = length;
        try
        {
            _big_store = new BigBlockStore(new RawDataBlock[ 0 ]);
        }
        catch (IOException ignored)
        {

            // can't happen with that constructor
        }
        _property    = new DocumentProperty(name, _size);
        _small_store = new SmallBlockStore(blocks);
        _property.setDocument(this);
    }

    /**
     * Constructor from small blocks
     *
     * @param name the name of the POIFSDocument
     * @param blocks the small blocks making up the POIFSDocument
     * @param length the actual length of the POIFSDocument
     *
     * @exception IOException
     */

    public POIFSDocument(final String name, final ListManagedBlock [] blocks,
                         final int length)
        throws IOException
    {
        _size     = length;
        _property = new DocumentProperty(name, _size);
        _property.setDocument(this);
        if (Property.isSmall(_size))
        {
            _big_store   = new BigBlockStore(new RawDataBlock[ 0 ]);
            _small_store = new SmallBlockStore(blocks);
        }
        else
        {
            _big_store   = new BigBlockStore(blocks);
            _small_store = new SmallBlockStore(new BlockWritable[ 0 ]);
        }
    }

    /**
     * Constructor
     *
     * @param name the name of the POIFSDocument
     * @param stream the InputStream we read data from
     *
     * @exception IOException thrown on read errors
     */

    public POIFSDocument(final String name, final InputStream stream)
        throws IOException
    {
        List blocks = new ArrayList();

        _size = 0;
        while (true)
        {
            DocumentBlock block     = new DocumentBlock(stream);
            int           blockSize = block.size();

            if (blockSize > 0)
            {
                blocks.add(block);
                _size += blockSize;
            }
            if (block.partiallyRead())
            {
                break;
            }
        }
        DocumentBlock[] bigBlocks =
            ( DocumentBlock [] ) blocks.toArray(new DocumentBlock[ 0 ]);

        _big_store = new BigBlockStore(bigBlocks);
        _property  = new DocumentProperty(name, _size);
        _property.setDocument(this);
        if (_property.shouldUseSmallBlocks())
        {
            _small_store =
                new SmallBlockStore(SmallDocumentBlock.convert(bigBlocks,
                    _size));
            _big_store   = new BigBlockStore(new DocumentBlock[ 0 ]);
        }
        else
        {
            _small_store = new SmallBlockStore(new BlockWritable[ 0 ]);
        }
    }

    /**
     * Constructor
     *
     * @param name the name of the POIFSDocument
     * @param size the length of the POIFSDocument
     * @param path the path of the POIFSDocument
     * @param writer the writer who will eventually write the document
     *               contents
     *
     * @exception IOException thrown on read errors
     */

    public POIFSDocument(final String name, final int size,
                         final POIFSDocumentPath path,
                         final POIFSWriterListener writer)
        throws IOException
    {
        _size     = size;
        _property = new DocumentProperty(name, _size);
        _property.setDocument(this);
        if (_property.shouldUseSmallBlocks())
        {
            _small_store = new SmallBlockStore(path, name, size, writer);
            _big_store   = new BigBlockStore(new Object[ 0 ]);
        }
        else
        {
            _small_store = new SmallBlockStore(new BlockWritable[ 0 ]);
            _big_store   = new BigBlockStore(path, name, size, writer);
        }
    }

    /**
     * return the array of SmallDocumentBlocks used
     *
     * @return array of SmallDocumentBlocks; may be empty, cannot be null
     */

    public BlockWritable [] getSmallBlocks()
    {
        return _small_store.getBlocks();
    }

    /**
     * @return size of the document
     */

    public int getSize()
    {
        return _size;
    }

    /**
     * read data from the internal stores
     *
     * @param buffer the buffer to write to
     * @param offset the offset into our storage to read from
     */

    void read(final byte [] buffer, final int offset)
    {
        if (_property.shouldUseSmallBlocks())
        {
            SmallDocumentBlock.read(_small_store.getBlocks(), buffer, offset);
        }
        else
        {
            DocumentBlock.read(_big_store.getBlocks(), buffer, offset);
        }
    }

    /**
     * Get the DocumentProperty
     *
     * @return the instance's DocumentProperty
     */

    DocumentProperty getDocumentProperty()
    {
        return _property;
    }

    /* ********** START implementation of BlockWritable ********** */

    /**
     * Write the storage to an OutputStream
     *
     * @param stream the OutputStream to which the stored data should
     *               be written
     *
     * @exception IOException on problems writing to the specified
     *            stream
     */

    public void writeBlocks(final OutputStream stream)
        throws IOException
    {
        _big_store.writeBlocks(stream);
    }

    /* **********  END  implementation of BlockWritable ********** */
    /* ********** START implementation of BATManaged ********** */

    /**
     * Return the number of BigBlock's this instance uses
     *
     * @return count of BigBlock instances
     */

    public int countBlocks()
    {
        return _big_store.countBlocks();
    }

    /**
     * Set the start block for this instance
     *
     * @param index index into the array of blocks making up the
     *        filesystem
     */

    public void setStartBlock(final int index)
    {
        _property.setStartBlock(index);
    }

    /* **********  END  implementation of BATManaged ********** */
    /* ********** START begin implementation of POIFSViewable ********** */

    /**
     * Get an array of objects, some of which may implement
     * POIFSViewable
     *
     * @return an array of Object; may not be null, but may be empty
     */

    public Object [] getViewableArray()
    {
        Object[] results = new Object[ 1 ];
        String   result;

        try
        {
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            BlockWritable[]       blocks = null;

            if (_big_store.isValid())
            {
                blocks = _big_store.getBlocks();
            }
            else if (_small_store.isValid())
            {
                blocks = _small_store.getBlocks();
            }
            if (blocks != null)
            {
                for (int k = 0; k < blocks.length; k++)
                {
                    blocks[ k ].writeBlocks(output);
                }
                byte[] data = output.toByteArray();

                if (data.length > _property.getSize())
                {
                    byte[] tmp = new byte[ _property.getSize() ];

                    System.arraycopy(data, 0, tmp, 0, tmp.length);
                    data = tmp;
                }
                output = new ByteArrayOutputStream();
                HexDump.dump(data, 0, output, 0);
                result = output.toString();
            }
            else
            {
                result = "<NO DATA>";
            }
        }
        catch (IOException e)
        {
            result = e.getMessage();
        }
        results[ 0 ] = result;
        return results;
    }

    /**
     * Get an Iterator of objects, some of which may implement
     * POIFSViewable
     *
     * @return an Iterator; may not be null, but may have an empty
     * back end store
     */

    public Iterator getViewableIterator()
    {
        return Collections.EMPTY_LIST.iterator();
    }

    /**
     * Give viewers a hint as to whether to call getViewableArray or
     * getViewableIterator
     *
     * @return true if a viewer should call getViewableArray, false if
     *         a viewer should call getViewableIterator
     */

    public boolean preferArray()
    {
        return true;
    }

    /**
     * Provides a short description of the object, to be used when a
     * POIFSViewable object has not provided its contents.
     *
     * @return short description
     */

    public String getShortDescription()
    {
        StringBuffer buffer = new StringBuffer();

        buffer.append("Document: \"").append(_property.getName())
            .append("\"");
        buffer.append(" size = ").append(getSize());
        return buffer.toString();
    }

    /* **********  END  begin implementation of POIFSViewable ********** */
    private class SmallBlockStore
    {
        private SmallDocumentBlock[] smallBlocks;
        private POIFSDocumentPath    path;
        private String               name;
        private int                  size;
        private POIFSWriterListener  writer;

        /**
         * Constructor
         *
         * @param blocks blocks to construct the store from
         */

        SmallBlockStore(final Object [] blocks)
        {
            smallBlocks = new SmallDocumentBlock[ blocks.length ];
            for (int j = 0; j < blocks.length; j++)
            {
                smallBlocks[ j ] = ( SmallDocumentBlock ) blocks[ j ];
            }
            this.path   = null;
            this.name   = null;
            this.size   = -1;
            this.writer = null;
        }

        /**
         * Constructor for a small block store that will be written
         * later
         *
         * @param path path of the document
         * @param name name of the document
         * @param size length of the document
         * @param writer the object that will eventually write the document
         */

        SmallBlockStore(final POIFSDocumentPath path, final String name,
                        final int size, final POIFSWriterListener writer)
        {
            smallBlocks = new SmallDocumentBlock[ 0 ];
            this.path   = path;
            this.name   = name;
            this.size   = size;
            this.writer = writer;
        }

        /**
         * @return true if this store is a valid source of data
         */

        boolean isValid()
        {
            return ((smallBlocks.length > 0) || (writer != null));
        }

        /**
         * @return the SmallDocumentBlocks
         */

        BlockWritable [] getBlocks()
        {
            if (isValid() && (writer != null))
            {
                ByteArrayOutputStream stream  =
                    new ByteArrayOutputStream(size);
                DocumentOutputStream  dstream =
                    new DocumentOutputStream(stream, size);

                writer.processPOIFSWriterEvent(new POIFSWriterEvent(dstream,
                        path, name, size));
                smallBlocks = SmallDocumentBlock.convert(stream.toByteArray(),
                                                         size);
            }
            return smallBlocks;
        }
    }   // end private class SmallBlockStore

    private class BigBlockStore
    {
        private DocumentBlock[]     bigBlocks;
        private POIFSDocumentPath   path;
        private String              name;
        private int                 size;
        private POIFSWriterListener writer;

        /**
         * Constructor
         *
         * @param blocks the blocks making up the store
         *
         * @exception IOException on I/O error
         */

        BigBlockStore(final Object [] blocks)
            throws IOException
        {
            bigBlocks = new DocumentBlock[ blocks.length ];
            for (int j = 0; j < blocks.length; j++)
            {
                if (blocks[ j ] instanceof DocumentBlock)
                {
                    bigBlocks[ j ] = ( DocumentBlock ) blocks[ j ];
                }
                else
                {
                    bigBlocks[ j ] =
                        new DocumentBlock(( RawDataBlock ) blocks[ j ]);
                }
            }
            this.path   = null;
            this.name   = null;
            this.size   = -1;
            this.writer = null;
        }

        /**
         * Constructor for a big block store that will be written
         * later
         *
         * @param path path of the document
         * @param name name of the document
         * @param size length of the document
         * @param writer the object that will eventually write the
         *               document
         */

        BigBlockStore(final POIFSDocumentPath path, final String name,
                      final int size, final POIFSWriterListener writer)
        {
            bigBlocks   = new DocumentBlock[ 0 ];
            this.path   = path;
            this.name   = name;
            this.size   = size;
            this.writer = writer;
        }

        /**
         * @return true if this store is a valid source of data
         */

        boolean isValid()
        {
            return ((bigBlocks.length > 0) || (writer != null));
        }

        /**
         * @return the DocumentBlocks
         */

        DocumentBlock [] getBlocks()
        {
            if (isValid() && (writer != null))
            {
                ByteArrayOutputStream stream  =
                    new ByteArrayOutputStream(size);
                DocumentOutputStream  dstream =
                    new DocumentOutputStream(stream, size);

                writer.processPOIFSWriterEvent(new POIFSWriterEvent(dstream,
                        path, name, size));
                bigBlocks = DocumentBlock.convert(stream.toByteArray(), size);
            }
            return bigBlocks;
        }

        /**
         * write the blocks to a stream
         *
         * @param stream the stream to which the data is to be written
         *
         * @exception IOException on error
         */

        void writeBlocks(OutputStream stream)
            throws IOException
        {
            if (isValid())
            {
                if (writer != null)
                {
                    DocumentOutputStream dstream =
                        new DocumentOutputStream(stream, size);

                    writer.processPOIFSWriterEvent(
                        new POIFSWriterEvent(dstream, path, name, size));
                    dstream.writeFiller(countBlocks()
                                        * PoiFSConstants
                                            .BIG_BLOCK_SIZE, DocumentBlock
                                            .getFillByte());
                }
                else
                {
                    for (int k = 0; k < bigBlocks.length; k++)
                    {
                        bigBlocks[ k ].writeBlocks(stream);
                    }
                }
            }
        }

        /**
         * @return number of big blocks making up this document
         */

        int countBlocks()
        {
            int rval = 0;

            if (isValid())
            {
                if (writer != null)
                {
                    rval = (size + PoiFSConstants.BIG_BLOCK_SIZE - 1)
                           / PoiFSConstants.BIG_BLOCK_SIZE;
                }
                else
                {
                    rval = bigBlocks.length;
                }
            }
            return rval;
        }
    }   // end private class BigBlockStore
}       // end class POIFSDocument