org.apache.cassandra.utils
Class UUIDGen

java.lang.Object
  org.apache.cassandra.utils.UUIDGen

public class UUIDGen
extends java.lang.Object

The goods are here: www.ietf.org/rfc/rfc4122.txt.

Method Summary

static byte[]	decompose(java.util.UUID uuid) decomposes a uuid into raw bytes.
static long	getAdjustedTimestamp(java.util.UUID uuid) Returns a milliseconds-since-epoch value for a type-1 UUID.
static java.util.UUID	getTimeUUID() Creates a type 1 UUID (time-based UUID).
static byte[]	getTimeUUIDBytes() Returns a 16 byte representation of a type 1 UUID (a time-based UUID), based on the current system time.
static byte[]	getTimeUUIDBytes(long timeMillis) Converts a milliseconds-since-epoch timestamp into the 16 byte representation of a type 1 UUID (a time-based UUID).
static byte[]	getTimeUUIDBytes(long timeMillis, int nanos) Converts a 100-nanoseconds precision timestamp into the 16 byte representation of a type 1 UUID (a time-based UUID).
static java.util.UUID	getUUID(java.nio.ByteBuffer raw) creates a type 1 uuid from raw bytes.

Methods inherited from class java.lang.Object

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

Method Detail

getTimeUUID

public static java.util.UUID getTimeUUID()

Creates a type 1 UUID (time-based UUID).

Returns:

a UUID instance

getUUID

public static java.util.UUID getUUID(java.nio.ByteBuffer raw)

creates a type 1 uuid from raw bytes.

decompose

public static byte[] decompose(java.util.UUID uuid)

decomposes a uuid into raw bytes.

getTimeUUIDBytes

public static byte[] getTimeUUIDBytes()

Returns a 16 byte representation of a type 1 UUID (a time-based UUID), based on the current system time.

Returns:

a type 1 UUID represented as a byte[]

getTimeUUIDBytes

public static byte[] getTimeUUIDBytes(long timeMillis)

Converts a milliseconds-since-epoch timestamp into the 16 byte representation of a type 1 UUID (a time-based UUID).

Warning: This method is not guaranteed to return unique UUIDs; Multiple invocations using identical timestamps will result in identical UUIDs.

Parameters:

timeMillis -

Returns:

a type 1 UUID represented as a byte[]

getTimeUUIDBytes

public static byte[] getTimeUUIDBytes(long timeMillis,
                                      int nanos)

Converts a 100-nanoseconds precision timestamp into the 16 byte representation of a type 1 UUID (a time-based UUID). To specify a 100-nanoseconds precision timestamp, one should provide a milliseconds timestamp and a number 0 <= n < 10000 such that n*100 is the number of nanoseconds within that millisecond.

Warning: This method is not guaranteed to return unique UUIDs; Multiple invocations using identical timestamps will result in identical UUIDs.

Returns:

a type 1 UUID represented as a byte[]

getAdjustedTimestamp

public static long getAdjustedTimestamp(java.util.UUID uuid)

Returns a milliseconds-since-epoch value for a type-1 UUID.

Parameters:

uuid - a type-1 (time-based) UUID

Returns:

the number of milliseconds since the unix epoch

Throws:

java.lang.IllegalArgumentException - if the UUID is not version 1