com.datastax.oss.dsbulk.codecs.api.util

Enum TimeUUIDGenerator

java.lang.Object

java.lang.Enum<TimeUUIDGenerator>

com.datastax.oss.dsbulk.codecs.api.util.TimeUUIDGenerator

All Implemented Interfaces:

Serializable, Comparable<TimeUUIDGenerator>

public enum TimeUUIDGenerator
extends Enum<TimeUUIDGenerator>

This class is loosely inspired by Cassandra's UUIDGen class and by the DataStax Java driver's UUIDs class.

See Also:

UUIDGen.java, UUIDs.java, RFC 4122

Enum Constant Summary

Enum Constants

Enum Constant and Description
FIXED Generates version 1 UUIDs using a fixed local clock sequence and node ID.
MAX Generates the biggest possible type 1 UUID having the provided Instant.
MIN Generates the smallest possible type 1 UUID having the provided Instant.
RANDOM Generates version 1 UUIDs using a random number in lieu of the local clock sequence and node ID.

Field Summary

Fields

Modifier and Type	Field and Description
static long	EPOCH_OFFSET The timestamp is a 60-bit value.

Method Summary

Modifier and Type	Method and Description
static Instant	fromUUIDTimestamp(long timestamp)
abstract UUID	generate(Instant instant) Generates a version 1 time-based UUID from the provided Instant.
static long	toUUIDTimestamp(Instant instant)
static TimeUUIDGenerator	valueOf(String name) Returns the enum constant of this type with the specified name.
static TimeUUIDGenerator[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

FIXED

public static final TimeUUIDGenerator FIXED

Generates version 1 UUIDs using a fixed local clock sequence and node ID.

Note that this strategy is generally only safe to use if you can guarantee that the provided timestamps are unique across calls (otherwise the generated UUIDs won't be unique across calls).

RANDOM

public static final TimeUUIDGenerator RANDOM

Generates version 1 UUIDs using a random number in lieu of the local clock sequence and node ID.

If you can guarantee that the instant argument is unique (for this JVM instance) for every call, then you should prefer FIXED, MIN or MAX which are faster. If you can't guarantee this however, this strategy will ensure the generated UUIDs are still unique (across calls) through randomization.

MIN

public static final TimeUUIDGenerator MIN

Generates the smallest possible type 1 UUID having the provided Instant.

Note that this strategy is generally only safe to use if you can guarantee that the provided timestamps are unique across calls (otherwise the generated UUIDs won't be unique across calls).

MAX

public static final TimeUUIDGenerator MAX

Generates the biggest possible type 1 UUID having the provided Instant.

Note that this strategy is generally only safe to use if you can guarantee that the provided timestamps are unique across calls (otherwise the generated UUIDs won't be unique across calls).

Field Detail

EPOCH_OFFSET

public static final long EPOCH_OFFSET

The timestamp is a 60-bit value. For UUID version 1, this is represented by Coordinated Universal Time (UTC) as a count of 100- nanosecond intervals since 00:00:00.00, 15 October 1582 (the date of Gregorian reform to the Christian calendar).

See Also:

Constant Field Values

Method Detail

values

public static TimeUUIDGenerator[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (TimeUUIDGenerator c : TimeUUIDGenerator.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static TimeUUIDGenerator valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

generate

public abstract UUID generate(Instant instant)

Generates a version 1 time-based UUID from the provided Instant.

Parameters:

instant - the instant to use.

Returns:

a version 1 time-based UUID.

toUUIDTimestamp

public static long toUUIDTimestamp(Instant instant)

fromUUIDTimestamp

public static Instant fromUUIDTimestamp(long timestamp)