loci.poi.poifs.storage

Class SmallDocumentBlock

java.lang.Object

loci.poi.poifs.storage.SmallDocumentBlock

All Implemented Interfaces:

BlockWritable, ListManagedBlock

public class SmallDocumentBlock
extends Object
implements BlockWritable, ListManagedBlock

Storage for documents that are too small to use regular DocumentBlocks for their data

Author:

Marc Johnson (mjohnson at apache dot org)

Field Summary

Fields

Modifier and Type	Field and Description
private static int	_block_size
private int	_blocks_per_big_block
private byte[]	_data
private static byte	_default_fill

Constructor Summary

Constructors

Modifier	Constructor and Description
private	SmallDocumentBlock(byte[] data, int index, int size)
private	SmallDocumentBlock(int size)

Method Summary

Methods

Modifier and Type	Method and Description
static int	calcSize(int size) Calculate the storage size of a set of SmallDocumentBlocks
static SmallDocumentBlock[]	convert(BlockWritable[] store, int size) Factory for creating SmallDocumentBlocks from DocumentBlocks
static SmallDocumentBlock[]	convert(byte[] array, int size) convert a single long array into an array of SmallDocumentBlock instances
private static int	convertToBlockCount(int size)
static List	extract(ListManagedBlock[] blocks, int size) create a list of SmallDocumentBlock's from raw data
static int	fill(List blocks, int size) fill out a List of SmallDocumentBlocks so that it fully occupies a set of big blocks
int	getBigBlockSize()
byte[]	getData() Get the data from the block
private static SmallDocumentBlock	makeEmptySmallDocumentBlock(int size)
static void	read(BlockWritable[] blocks, byte[] buffer, int offset) read data from an array of SmallDocumentBlocks
void	writeBlocks(OutputStream stream) Write the storage to an OutputStream

Methods inherited from class java.lang.Object

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

Field Detail

_data

private byte[] _data

_default_fill

private static final byte _default_fill

See Also:

Constant Field Values

_block_size

private static final int _block_size

See Also:

Constant Field Values

_blocks_per_big_block

private int _blocks_per_big_block

Constructor Detail

SmallDocumentBlock

private SmallDocumentBlock(byte[] data,
                  int index,
                  int size)

SmallDocumentBlock

private SmallDocumentBlock(int size)

Method Detail

getBigBlockSize

public int getBigBlockSize()

convert

public static SmallDocumentBlock[] convert(byte[] array,
                           int size)

convert a single long array into an array of SmallDocumentBlock instances

Parameters:

array - the byte array to be converted

size - the intended size of the array (which may be smaller)

Returns:

an array of SmallDocumentBlock instances, filled from the array

fill

public static int fill(List blocks,
       int size)

fill out a List of SmallDocumentBlocks so that it fully occupies a set of big blocks

Parameters:

blocks - the List to be filled out

Returns:

number of big blocks the list encompasses

convert

public static SmallDocumentBlock[] convert(BlockWritable[] store,
                           int size)
                                    throws IOException,
                                           ArrayIndexOutOfBoundsException

Factory for creating SmallDocumentBlocks from DocumentBlocks

Parameters:

store - the original DocumentBlocks

size - the total document size

Returns:

an array of new SmallDocumentBlocks instances

Throws:

IOException - on errors reading from the DocumentBlocks

ArrayIndexOutOfBoundsException - if, somehow, the store contains less data than size indicates

extract

public static List extract(ListManagedBlock[] blocks,
           int size)
                    throws IOException

create a list of SmallDocumentBlock's from raw data

Parameters:

blocks - the raw data containing the SmallDocumentBlock data

Returns:

a List of SmallDocumentBlock's extracted from the input

Throws:

IOException

read

public static void read(BlockWritable[] blocks,
        byte[] buffer,
        int offset)

read data from an array of SmallDocumentBlocks

Parameters:

blocks - the blocks to read from

buffer - the buffer to write the data into

offset - the offset into the array of blocks to read from

calcSize

public static int calcSize(int size)

Calculate the storage size of a set of SmallDocumentBlocks

Parameters:

size - number of SmallDocumentBlocks

Returns:

total size

makeEmptySmallDocumentBlock

private static SmallDocumentBlock makeEmptySmallDocumentBlock(int size)

convertToBlockCount

private static int convertToBlockCount(int size)

writeBlocks

public void writeBlocks(OutputStream stream)
                 throws IOException

Write the storage to an OutputStream

Specified by:

writeBlocks in interface BlockWritable

Parameters:

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

Throws:

IOException - on problems writing to the specified stream

getData

public byte[] getData()
               throws IOException

Get the data from the block

Specified by:

getData in interface ListManagedBlock

Returns:

the block's data as a byte array

Throws:

IOException - if there is no data