Examples with BlockAllocationTableWriter org.apache.poi.poifs.storage.BlockAllocationTableWriter used on opensource projects

Example 1 with BlockAllocationTableWriter

use of org.apache.poi.poifs.storage.BlockAllocationTableWriter in project poi by apache.

the class OPOIFSFileSystem method writeFilesystem.

/**
     * Write the filesystem out
     *
     * @param stream the OutputStream to which the filesystem will be
     *               written
     *
     * @exception IOException thrown on errors writing to the stream
     */
public void writeFilesystem(final OutputStream stream) throws IOException {
    // get the property table ready
    _property_table.preWrite();
    // create the small block store, and the SBAT
    SmallBlockTableWriter sbtw = new SmallBlockTableWriter(bigBlockSize, _documents, _property_table.getRoot());
    // create the block allocation table
    BlockAllocationTableWriter bat = new BlockAllocationTableWriter(bigBlockSize);
    // create a list of BATManaged objects: the documents plus the
    // property table and the small block table
    List<Object> bm_objects = new ArrayList<Object>();
    bm_objects.addAll(_documents);
    bm_objects.add(_property_table);
    bm_objects.add(sbtw);
    bm_objects.add(sbtw.getSBAT());
    // walk the list, allocating space for each and assigning each
    // a starting block number
    Iterator<Object> iter = bm_objects.iterator();
    while (iter.hasNext()) {
        BATManaged bmo = (BATManaged) iter.next();
        int block_count = bmo.countBlocks();
        if (block_count != 0) {
            bmo.setStartBlock(bat.allocateSpace(block_count));
        } else {
        // Either the BATManaged object is empty or its data
        // is composed of SmallBlocks; in either case,
        // allocating space in the BAT is inappropriate
        }
    }
    // allocate space for the block allocation table and take its
    // starting block
    int batStartBlock = bat.createBlocks();
    // get the extended block allocation table blocks
    HeaderBlockWriter header_block_writer = new HeaderBlockWriter(bigBlockSize);
    BATBlock[] xbat_blocks = header_block_writer.setBATBlocks(bat.countBlocks(), batStartBlock);
    // set the property table start block
    header_block_writer.setPropertyStart(_property_table.getStartBlock());
    // set the small block allocation table start block
    header_block_writer.setSBATStart(sbtw.getSBAT().getStartBlock());
    // set the small block allocation table block count
    header_block_writer.setSBATBlockCount(sbtw.getSBATBlockCount());
    // the header is now properly initialized. Make a list of
    // writers (the header block, followed by the documents, the
    // property table, the small block store, the small block
    // allocation table, the block allocation table, and the
    // extended block allocation table blocks)
    List<Object> writers = new ArrayList<Object>();
    writers.add(header_block_writer);
    writers.addAll(_documents);
    writers.add(_property_table);
    writers.add(sbtw);
    writers.add(sbtw.getSBAT());
    writers.add(bat);
    for (int j = 0; j < xbat_blocks.length; j++) {
        writers.add(xbat_blocks[j]);
    }
    // now, write everything out
    iter = writers.iterator();
    while (iter.hasNext()) {
        BlockWritable writer = (BlockWritable) iter.next();
        writer.writeBlocks(stream);
    }
}