File	Doc	Category	Size	Date	Package
BATBlock.java	API Doc	Apache Poi 3.0.1	7608	Mon Jan 01 12:39:36 GMT 2007	org.apache.poi.poifs.storage

BATBlock

• java.lang.Object
  • org.apache.poi.poifs.storage.BigBlock

Fields Summary
private static final int	_entries_per_block
private static final int	_entries_per_xbat_block
private static final int	_xbat_chain_offset
private static final byte	_default_value
private IntegerField[]	_fields
private byte[]	_data

Constructors Summary
private BATBlock() Create a single instance initialized with default values _data = new byte[ POIFSConstants.BIG_BLOCK_SIZE ]; Arrays.fill(_data, _default_value); _fields = new IntegerField[ _entries_per_block ]; int offset = 0; for (int j = 0; j < _entries_per_block; j++) { _fields[ j ] = new IntegerField(offset); offset += LittleEndianConsts.INT_SIZE; }
private BATBlock(int[] entries, int start_index, int end_index) Create a single instance initialized (perhaps partially) with entries param entries the array of block allocation table entries param start_index the index of the first entry to be written to the block param end_index the index, plus one, of the last entry to be written to the block (writing is for all index k, start_index <= k < end_index) this(); for (int k = start_index; k < end_index; k++) { _fields[ k - start_index ].set(entries[ k ], _data); }

Methods Summary
public static int	calculateStorageRequirements(int entryCount) Calculate how many BATBlocks are needed to hold a specified number of BAT entries. param entryCount the number of entries return the number of BATBlocks needed return (entryCount + _entries_per_block - 1) / _entries_per_block;
public static int	calculateXBATStorageRequirements(int entryCount) Calculate how many XBATBlocks are needed to hold a specified number of BAT entries. param entryCount the number of entries return the number of XBATBlocks needed return (entryCount + _entries_per_xbat_block - 1) / _entries_per_xbat_block;
public static org.apache.poi.poifs.storage.BATBlock[]	createBATBlocks(int[] entries) Create an array of BATBlocks from an array of int block allocation table entries param entries the array of int entries return the newly created array of BATBlocks int block_count = calculateStorageRequirements(entries.length); BATBlock[] blocks = new BATBlock[ block_count ]; int index = 0; int remaining = entries.length; for (int j = 0; j < entries.length; j += _entries_per_block) { blocks[ index++ ] = new BATBlock(entries, j, (remaining > _entries_per_block) ? j + _entries_per_block : entries.length); remaining -= _entries_per_block; } return blocks;
public static org.apache.poi.poifs.storage.BATBlock[]	createXBATBlocks(int[] entries, int startBlock) Create an array of XBATBlocks from an array of int block allocation table entries param entries the array of int entries param startBlock the start block of the array of XBAT blocks return the newly created array of BATBlocks int block_count = calculateXBATStorageRequirements(entries.length); BATBlock[] blocks = new BATBlock[ block_count ]; int index = 0; int remaining = entries.length; if (block_count != 0) { for (int j = 0; j < entries.length; j += _entries_per_xbat_block) { blocks[ index++ ] = new BATBlock(entries, j, (remaining > _entries_per_xbat_block) ? j + _entries_per_xbat_block : entries.length); remaining -= _entries_per_xbat_block; } for (index = 0; index < blocks.length - 1; index++) { blocks[ index ].setXBATChain(startBlock + index + 1); } blocks[ index ].setXBATChain(POIFSConstants.END_OF_CHAIN); } return blocks;
public static final int	entriesPerBlock() return number of entries per block return _entries_per_block;
public static final int	entriesPerXBATBlock() return number of entries per XBAT block return _entries_per_xbat_block;
public static final int	getXBATChainOffset() return offset of chain index of XBAT block return _xbat_chain_offset;
private void	setXBATChain(int chainIndex) _fields[ _entries_per_xbat_block ].set(chainIndex, _data);
void	writeData(java.io.OutputStream stream) Write the block's data to an OutputStream param stream the OutputStream to which the stored data should be written exception IOException on problems writing to the specified stream doWriteData(stream, _data);