Package org.apache.directory.api.ldap.model.csn

Class 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 : 
     <CSN>            ::= <timestamp> # <changeCount> # <replicaId> # <modifierNumber>
 <timestamp>      ::= A GMT based time, YYYYmmddHHMMSS.uuuuuuZ
 <changeCount>    ::= [000000-ffffff] 
 <replicaId>      ::= [000-fff]
 <modifierNumber> ::= [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 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)
        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

      • Csn

        Csn​(byte[] value)
        Creates a new instance of SimpleCSN from the serialized data
        Parameters:
        value - The byte array which contains the serialized 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.