org.apache.directory.api.ldap.model.csn
Class Csn

java.lang.Object
  org.apache.directory.api.ldap.model.csn.Csn

All Implemented Interfaces:

Comparable<Csn>

public class Csn
extends Object
implements Comparable<Csn>

Represents 'Change Sequence Number' in LDUP specification. A CSN is a composition of a timestamp, a replica ID and a operation sequence number. It's described in http://tools.ietf.org/html/draft-ietf-ldup-model-09. The CSN syntax is :

             ::=  #  #  # 
       ::= A GMT based time, YYYYmmddHHMMSS.uuuuuuZ
     ::= [000000-ffffff] 
       ::= [000-fff]
  ::= [000000-ffffff]
 

It distinguishes a change made on an object on a server, and if two operations take place during the same timeStamp, the operation sequence number makes those operations distinct.

Author:

Apache Directory Project

Constructor Summary

Csn(long timestamp, int changeCount, int replicaId, int operationNumber)
Creates a new instance.

Csn(String value)
Creates a new instance of SimpleCSN from a String.

Method Summary

int	compareTo(Csn csn) Compares this object with the specified object for order.
boolean	equals(Object o) Indicates whether some other object is "equal to" this one
byte[]	getBytes() Get the CSN as a byte array.
int	getChangeCount()
int	getOperationNumber()
int	getReplicaId()
long	getTimestamp()
int	hashCode() Returns a hash code value for the object.
static boolean	isValid(String value) Check if the given String is a valid CSN.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Csn

public Csn(long timestamp,
           int changeCount,
           int replicaId,
           int operationNumber)

Creates a new instance. This method should be used only for deserializing a CSN

Parameters:

timestamp - GMT timestamp of modification

changeCount - The operation increment

replicaId - Replica ID where modification occurred ([-_A-Za-z0-9]{1,16})

operationNumber - Operation number in a modification operation

Csn

public Csn(String value)
    throws InvalidCSNException

Creates a new instance of SimpleCSN from a String. The string format must be : <timestamp> # <changeCount> # <replica ID> # <operation number>

Parameters:

value - The String containing the CSN

Throws:

InvalidCSNException - if the value doesn't contain a valid CSN

Method Detail

isValid

public static boolean isValid(String value)

Check if the given String is a valid CSN.

Parameters:

value - The String to check

Returns:

true if the String is a valid CSN

getBytes

public byte[] getBytes()

Get the CSN as a byte array. The data are stored as : bytes 1 to 8 : timestamp, big-endian bytes 9 to 12 : change count, big endian bytes 13 to ... : ReplicaId

Returns:

A copy of the byte array representing theCSN

getTimestamp

public long getTimestamp()

Returns:

The timestamp

getChangeCount

public int getChangeCount()

Returns:

The changeCount

getReplicaId

public int getReplicaId()

Returns:

The replicaId

getOperationNumber

public int getOperationNumber()

Returns:

The operation number

toString

public String toString()

Overrides:

toString in class Object

Returns:

The CSN as a String

hashCode

public int hashCode()

Returns a hash code value for the object.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

equals

public boolean equals(Object o)

Indicates whether some other object is "equal to" this one

Overrides:

equals in class Object

Parameters:

o - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

compareTo

public int compareTo(Csn csn)

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Specified by:

compareTo in interface Comparable<Csn>

Parameters:

csn - the Object to be compared.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.