Package io.lettuce.core.cluster

Class SlotHash

java.lang.Object

io.lettuce.core.cluster.SlotHash

public class SlotHash
extends Object

Utility to calculate the slot from a key.

Since:

3.0

Author:

Mark Paluch

Field Summary

Fields

Modifier and Type	Field	Description
static int	SLOT_COUNT	Number of redis cluster slot hashes.
static byte	SUBKEY_END	Constant for a subkey end.
static byte	SUBKEY_START	Constant for a subkey start.

Method Summary

Modifier and Type	Method	Description
static int	getSlot(byte[] key)	Calculate the slot from the given key.
static int	getSlot(String key)	Calculate the slot from the given key.
static int	getSlot(ByteBuffer key)	Calculate the slot from the given key.
static <S extends Number,K> Map<K,S>	getSlots(Map<S,? extends Iterable<K>> partitioned)	Create mapping between the Key and hash slot.
static <K,V> Map<Integer,List<K>>	partition(RedisCodec<K,V> codec, Iterable<K> keys)	Partition keys by slot-hash.

Methods inherited from class java.lang.Object

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

Field Detail

SUBKEY_START

public static final byte SUBKEY_START

Constant for a subkey start.

See Also:

Constant Field Values

SUBKEY_END

public static final byte SUBKEY_END

Constant for a subkey end.

See Also:

Constant Field Values

SLOT_COUNT

public static final int SLOT_COUNT

Number of redis cluster slot hashes.

See Also:

Constant Field Values

Method Detail

getSlot

public static int getSlot(String key)

Calculate the slot from the given key.

Parameters:

key - the key

Returns:

slot

getSlot

public static int getSlot(byte[] key)

Calculate the slot from the given key.

Parameters:

key - the key

Returns:

slot

getSlot

public static int getSlot(ByteBuffer key)

Calculate the slot from the given key.

Parameters:

key - the key

Returns:

slot

partition

public static <K,V> Map<Integer,List<K>> partition(RedisCodec<K,V> codec,
                                                               Iterable<K> keys)

Partition keys by slot-hash. The resulting map honors order of the keys.

Type Parameters:

K - Key type.

V - Value type.

Parameters:

codec - codec to encode the key.

keys - iterable of keys.

Returns:

map between slot-hash and an ordered list of keys.

getSlots

public static <S extends Number,K> Map<K,S> getSlots(Map<S,? extends Iterable<K>> partitioned)

Create mapping between the Key and hash slot.

Type Parameters:

K - key type

S - slot-hash number type.

Parameters:

partitioned - map partitioned by slot-hash and keys.

Returns:

map of keys to their slot-hash.