loci.poi.poifs.storage

Class BATBlock

java.lang.Object

loci.poi.poifs.storage.BigBlock

loci.poi.poifs.storage.BATBlock

All Implemented Interfaces:

BlockWritable

public class BATBlock
extends BigBlock

A block of block allocation table entries. BATBlocks are created only through a static factory method: createBATBlocks.

Author:

Marc Johnson (mjohnson at apache dot org)

Field Summary

Fields

Modifier and Type	Field and Description
private byte[]	_data
private static byte	_default_value
private int	_entries_per_block
private IntegerField[]	_fields
private int	_xbat_chain_offset
private int	blockSize

Constructor Summary

Constructors

Modifier	Constructor and Description
private	BATBlock(int blockSize) Create a single instance initialized with default values
private	BATBlock(int[] entries, int start_index, int end_index, int size) Create a single instance initialized (perhaps partially) with entries

Method Summary

Methods

Modifier and Type	Method and Description
static int	calculateStorageRequirements(int entryCount, int size) Calculate how many BATBlocks are needed to hold a specified number of BAT entries.
static int	calculateXBATStorageRequirements(int entryCount, int size) Calculate how many XBATBlocks are needed to hold a specified number of BAT entries.
static BATBlock[]	createBATBlocks(int[] entries, int size) Create an array of BATBlocks from an array of int block allocation table entries
static BATBlock[]	createXBATBlocks(int[] entries, int startBlock, int size) Create an array of XBATBlocks from an array of int block allocation table entries
static int	entriesPerBlock(int size)
static int	entriesPerXBATBlock(int size)
int	getBigBlockSize()
static int	getXBATChainOffset(int size)
private void	setXBATChain(int chainIndex)
(package private) void	writeData(OutputStream stream) Write the block's data to an OutputStream

Methods inherited from class loci.poi.poifs.storage.BigBlock

doWriteData, writeBlocks

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

_default_value

private static final byte _default_value

See Also:

Constant Field Values

_fields

private IntegerField[] _fields

_data

private byte[] _data

_entries_per_block

private int _entries_per_block

_xbat_chain_offset

private int _xbat_chain_offset

blockSize

private int blockSize

Constructor Detail

BATBlock

private BATBlock(int blockSize)

Create a single instance initialized with default values

BATBlock

private BATBlock(int[] entries,
        int start_index,
        int end_index,
        int size)

Create a single instance initialized (perhaps partially) with entries

Parameters:

entries - the array of block allocation table entries

start_index - the index of the first entry to be written to the block

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)

Method Detail

getBigBlockSize

public int getBigBlockSize()

Specified by:

getBigBlockSize in class BigBlock

createBATBlocks

public static BATBlock[] createBATBlocks(int[] entries,
                         int size)

Create an array of BATBlocks from an array of int block allocation table entries

Parameters:

entries - the array of int entries

Returns:

the newly created array of BATBlocks

createXBATBlocks

public static BATBlock[] createXBATBlocks(int[] entries,
                          int startBlock,
                          int size)

Create an array of XBATBlocks from an array of int block allocation table entries

Parameters:

entries - the array of int entries

startBlock - the start block of the array of XBAT blocks

Returns:

the newly created array of BATBlocks

calculateStorageRequirements

public static int calculateStorageRequirements(int entryCount,
                               int size)

Calculate how many BATBlocks are needed to hold a specified number of BAT entries.

Parameters:

entryCount - the number of entries

Returns:

the number of BATBlocks needed

calculateXBATStorageRequirements

public static int calculateXBATStorageRequirements(int entryCount,
                                   int size)

Calculate how many XBATBlocks are needed to hold a specified number of BAT entries.

Parameters:

entryCount - the number of entries

Returns:

the number of XBATBlocks needed

entriesPerBlock

public static final int entriesPerBlock(int size)

Returns:

number of entries per block

entriesPerXBATBlock

public static final int entriesPerXBATBlock(int size)

Returns:

number of entries per XBAT block

getXBATChainOffset

public static final int getXBATChainOffset(int size)

Returns:

offset of chain index of XBAT block

setXBATChain

private void setXBATChain(int chainIndex)

writeData

void writeData(OutputStream stream)
         throws IOException

Write the block's data to an OutputStream

Specified by:

writeData in class BigBlock

Parameters:

stream - the OutputStream to which the stored data should be written

Throws:

IOException - on problems writing to the specified stream