me.prettyprint.cassandra.utils

Class TimeUUIDUtils

java.lang.Object

me.prettyprint.cassandra.utils.TimeUUIDUtils

public final class TimeUUIDUtils
extends Object

Utilitary class to generate TimeUUID (type 1)

Author:

Patricio Echague (pechague@gmail.com)

Constructor Summary

Constructors

Constructor and Description
TimeUUIDUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static byte[]	asByteArray(UUID uuid) As byte array.
static ByteBuffer	asByteBuffer(UUID uuid) Coverts a java.util.UUID into a ByteBuffer.
static long	getTimeFromUUID(byte[] uuid) Retrieves the time as long based on the byte[] representation of a UUID.
static long	getTimeFromUUID(UUID uuid)
static UUID	getTimeUUID(ClockResolution clock) Gets a new time uuid using ClockResolution.createClock() as a time generator.
static UUID	getTimeUUID(long time) Gets a new time uuid based on time.
static UUID	getUniqueTimeUUIDinMillis() Gets a new and unique time uuid in milliseconds.
static UUID	toUUID(byte[] uuid) Returns an instance of uuid.
static UUID	uuid(byte[] uuid, int offset)
static UUID	uuid(ByteBuffer bb) Converts a ByteBuffer containing a UUID into a java.util.UUID

Methods inherited from class java.lang.Object

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

Constructor Detail

TimeUUIDUtils

public TimeUUIDUtils()

Method Detail

getUniqueTimeUUIDinMillis

public static UUID getUniqueTimeUUIDinMillis()

Gets a new and unique time uuid in milliseconds. It is useful to use in a TimeUUIDType sorted column family.

Returns:

the time uuid

getTimeUUID

public static UUID getTimeUUID(ClockResolution clock)

Gets a new time uuid using ClockResolution.createClock() as a time generator. It is useful to use in a TimeUUIDType sorted column family.

Parameters:

clock - a ClockResolution

Returns:

the time uuid

getTimeUUID

public static UUID getTimeUUID(long time)

Gets a new time uuid based on time. NOTE: this algorithm does not resolve duplicates. To avoid duplicates use getTimeUUID(ClockResolution clock) with an implementaion that provides unique timestamp resolution, like MicrosecondsSyncClockResolution It is useful to use in a TimeUUIDType sorted column family.

Parameters:

clock - a ClockResolution

Returns:

the time uuid

toUUID

public static UUID toUUID(byte[] uuid)

Returns an instance of uuid. Useful for when you read out of cassandra you are getting a byte[] that needs to be converted into a TimeUUID.

Parameters:

uuid - the uuid

Returns:

the java.util.uuid

getTimeFromUUID

public static long getTimeFromUUID(byte[] uuid)

Retrieves the time as long based on the byte[] representation of a UUID.

Parameters:

uuid - byte[] uuid representation

Returns:

a long representing the time

getTimeFromUUID

public static long getTimeFromUUID(UUID uuid)

asByteArray

public static byte[] asByteArray(UUID uuid)

As byte array. This method is often used in conjunction with @link #getTimeUUID()

Parameters:

uuid - the uuid

Returns:

the byte[]

asByteBuffer

public static ByteBuffer asByteBuffer(UUID uuid)

Coverts a java.util.UUID into a ByteBuffer.

Parameters:

uuid - a java.util.UUID

Returns:

a ByteBuffer representaion of the param UUID

uuid

public static UUID uuid(byte[] uuid,
        int offset)

uuid

public static UUID uuid(ByteBuffer bb)

Converts a ByteBuffer containing a UUID into a java.util.UUID

Parameters:

bb - a ByteBuffer containing a UUID

Returns:

a java.util.UUID