net.messagevortex.router.operation

Class AddRedundancy

java.lang.Object

net.messagevortex.router.operation.AbstractOperation

net.messagevortex.router.operation.AddRedundancy

All Implemented Interfaces:

Serializable, Operation

public class AddRedundancy
extends AbstractOperation
implements Serializable

This is the core of the redundancy add operation.

It builds redundant data blocksfrom the existing data blocks.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AddRedundancy.SimplePrng Wrapper for the java random number generator (not normative).

Field Summary

Fields

Modifier and Type	Field and Description
static long	serialVersionUID

Constructor Summary

Constructors

Constructor and Description
AddRedundancy(AddRedundancyOperation op)

Method Summary

Modifier and Type	Method and Description
boolean	canRun() Checks if all prerequisiting fields do exist or can be provided by a subsequent operation.
static byte[]	execute(byte[] in, int redundancy, int dataStripes, int gf) Execute the add redundancy operation on the provided data.
int[]	execute(int[] id) Executes the operation and sets at least the provided set of id.
int[]	getInputId() Gets all ids which are required to execute this operation.
int[]	getOutputId() Gets all ids which are written by this operation.
static byte[]	pad(int blocksize, int numberOfOutBlocks, byte[] data, Prng prng, int c1, int c2) padds a given payload block.
String	toString()
static byte[]	unpad(int blocksize, int numberOfOutBlocks, byte[] in, Prng prng) Removes padding from a byte array.

Methods inherited from class net.messagevortex.router.operation.AbstractOperation

getIdentity, getUsagePeriod, isInUsagePeriod, setInternalPayload, setUsagePeriod

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

public static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

AddRedundancy

public AddRedundancy(AddRedundancyOperation op)

Method Detail

canRun

public boolean canRun()

Description copied from interface: Operation

Checks if all prerequisiting fields do exist or can be provided by a subsequent operation.

Specified by:

canRun in interface Operation

Specified by:

canRun in class AbstractOperation

Returns:

true if all prerequisits can potentially be satisfied

getOutputId

public int[] getOutputId()

Description copied from interface: Operation

Gets all ids which are written by this operation.

Specified by:

getOutputId in interface Operation

Returns:

array representing all ids which will be potentially set by this operation

getInputId

public int[] getInputId()

Description copied from interface: Operation

Gets all ids which are required to execute this operation.

Specified by:

getInputId in interface Operation

Returns:

array representing all ids which will be potentially set by this operation

execute

public int[] execute(int[] id)

Description copied from interface: Operation

Executes the operation and sets at least the provided set of id.

This operation might trigger to execute prerequisiting operations.

Specified by:

execute in interface Operation

Specified by:

execute in class AbstractOperation

Parameters:

id - the namespace id to be set minimally

Returns:

array representing all ids which have been set

execute

public static byte[] execute(byte[] in,
                             int redundancy,
                             int dataStripes,
                             int gf)

Execute the add redundancy operation on the provided data.

Parameters:

in - data to add redundancy

redundancy - the number of redundancy blocks

dataStripes - the number of data stripes

gf - the size of the GF

Returns:

the data with added redundancy

pad

public static byte[] pad(int blocksize,
                         int numberOfOutBlocks,
                         byte[] data,
                         Prng prng,
                         int c1,
                         int c2)

padds a given payload block.

Parameters:

blocksize - the size of the blocks of the used encryption in the addRedundancy operation

numberOfOutBlocks - the number of resulting blocks in the addRedundancy operation

data - the data to be padded (payload block

prng - the Prng to be used for padding

c1 - the padding parameter c1 as specified in the padding spec

c2 - the padding parameter c2 as specified in the padding spec

Returns:

the padded data array

unpad

public static byte[] unpad(int blocksize,
                           int numberOfOutBlocks,
                           byte[] in,
                           Prng prng)
                    throws IOException

Removes padding from a byte array.

Parameters:

blocksize - encryption block size

numberOfOutBlocks - number of out streams in the RS function

in - the padded array

prng - the random number generator for the padding data

Returns:

the unpadded data stream

Throws:

IOException - if unpadding fails for any reason

toString

public String toString()

Overrides:

toString in class Object