net.tomp2p.replication

Class Synchronization

java.lang.Object

net.tomp2p.replication.Synchronization

public final class Synchronization
extends Object

Synchronization class is responsible for efficient and optimal synchronization of data resources between responsible peer and replica peers. If one of replicas goes offline, the responsible peer transfers the value completely to the new replica peer. In case the values at responsible peer and replica peer are the same, then no data is transmitted. If the values are different, then only differences are sent to the replica peer.

Author:

Maxat Pernebayev, Thomas Bocek

Field Summary

Fields

Modifier and Type	Field and Description
static int	SIZE

Constructor Summary

Constructors

Constructor and Description
Synchronization()

Method Summary

Methods

Modifier and Type	Method and Description
static int	byteArrayToInt(byte[] b)
static ArrayList<Checksum>	decodeChecksumList(byte[] bytes)
static Number160	decodeHash(byte[] bytes)
static ArrayList<Instruction>	decodeInstructionList(byte[] bytes)
static byte[]	encodeChecksumList(ArrayList<Checksum> checksums)
static byte[]	encodeInstructionList(ArrayList<Instruction> instructions, Number160 number160)
static ArrayList<Checksum>	getChecksums(byte[] value, int blockSize) It returns an array of weak and strong checksums for the value.
static ArrayList<Instruction>	getInstructions(ArrayList<Instruction> result, int diff, int offset, int a, int b, byte[] newValue, ArrayList<Checksum> checksums, int blockSize)
static ArrayList<Instruction>	getInstructions(byte[] newValue, ArrayList<Checksum> checksums, int blockSize) It returns the sequence of instructions each of which contains either reference to a block or literal data.
static byte[]	getReconstructedValue(byte[] oldValue, ArrayList<Instruction> instructions, int blockSize) It reconstructs the copy of responsible peer's value using instructions and the replica's value.
static byte[]	intToByteArray(int value)

Methods inherited from class java.lang.Object

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

Field Detail

SIZE

public static final int SIZE

See Also:

Constant Field Values

Constructor Detail

Synchronization

public Synchronization()

Method Detail

getChecksums

public static ArrayList<Checksum> getChecksums(byte[] value,
                               int blockSize)

It returns an array of weak and strong checksums for the value.

Parameters:

value - The value

size - The offset size

Returns:

The array of checksums

Throws:

NoSuchAlgorithmException

getInstructions

public static ArrayList<Instruction> getInstructions(byte[] newValue,
                                     ArrayList<Checksum> checksums,
                                     int blockSize)

It returns the sequence of instructions each of which contains either reference to a block or literal data.

Parameters:

newValue - The value at responsible peer

checksums - The array of checksums

size - The offset size

Returns:

The sequence of instructions

Throws:

NoSuchAlgorithmException

getInstructions

public static ArrayList<Instruction> getInstructions(ArrayList<Instruction> result,
                                     int diff,
                                     int offset,
                                     int a,
                                     int b,
                                     byte[] newValue,
                                     ArrayList<Checksum> checksums,
                                     int blockSize)

getReconstructedValue

public static byte[] getReconstructedValue(byte[] oldValue,
                           ArrayList<Instruction> instructions,
                           int blockSize)

It reconstructs the copy of responsible peer's value using instructions and the replica's value.

Parameters:

oldValue - The value at replica

instructions - The sequence of instructions

blockSize - The offset size

Returns:

The value which is identical to the responsible peer's value

intToByteArray

public static byte[] intToByteArray(int value)

byteArrayToInt

public static int byteArrayToInt(byte[] b)

encodeChecksumList

public static byte[] encodeChecksumList(ArrayList<Checksum> checksums)

decodeChecksumList

public static ArrayList<Checksum> decodeChecksumList(byte[] bytes)

encodeInstructionList

public static byte[] encodeInstructionList(ArrayList<Instruction> instructions,
                           Number160 number160)

decodeInstructionList

public static ArrayList<Instruction> decodeInstructionList(byte[] bytes)

decodeHash

public static Number160 decodeHash(byte[] bytes)