net.openhft.chronicle.bytes.algo

Class XxHash

java.lang.Object

net.openhft.chronicle.bytes.algo.XxHash

All Implemented Interfaces:

ToLongFunction<BytesStore<?,?>>, BytesStoreHash<BytesStore<?,?>>

public class XxHash
extends Object
implements BytesStoreHash<BytesStore<?,?>>

This class implements the xxHash algorithm for hashing byte stores. xxHash is a non-cryptographic hash function known for its speed.

Migrated from Zero-Allocation-Hashing.

See Also:

BytesStoreHash, BytesStore

Field Summary

Fields

Modifier and Type	Field and Description
static XxHash	INSTANCE Singleton instance of XxHash with seed P4.

Constructor Summary

Constructors

Constructor and Description
XxHash(long seed) Constructs a new instance of XxHash with the specified seed.

Method Summary

Modifier and Type	Method and Description
long	applyAsLong(BytesStore<?,?> bytes) Calculates the hash code of the given byte store.
long	applyAsLong(BytesStore<?,?> bytes, long length) Computes a hash value for the given byte store with a specified length.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.openhft.chronicle.bytes.algo.BytesStoreHash

hash, hash, hash32, hash32

Field Detail

INSTANCE

public static final XxHash INSTANCE

Singleton instance of XxHash with seed P4.

Constructor Detail

XxHash

public XxHash(long seed)

Constructs a new instance of XxHash with the specified seed.

Parameters:

seed - the seed for hash computation.

Method Detail

applyAsLong

public long applyAsLong(BytesStore<?,?> bytes)

Calculates the hash code of the given byte store.

Specified by:

applyAsLong in interface ToLongFunction<BytesStore<?,?>>

Parameters:

bytes - the byte store to be hashed.

Returns:

the hash code.

Throws:

net.openhft.chronicle.core.io.ClosedIllegalStateException - If the resource has been released or closed.

net.openhft.chronicle.core.io.ThreadingIllegalStateException - If this resource was accessed by multiple threads in an unsafe way

applyAsLong

public long applyAsLong(BytesStore<?,?> bytes,
                        long length)
                 throws IllegalStateException,
                        BufferUnderflowException

Computes a hash value for the given byte store with a specified length.

Specified by:

applyAsLong in interface BytesStoreHash<BytesStore<?,?>>

Parameters:

bytes - the byte store.

length - the number of bytes to hash.

Returns:

the hash value.

Throws:

BufferUnderflowException - If there is not enough data.

net.openhft.chronicle.core.io.ClosedIllegalStateException - If the resource has been released or closed.

net.openhft.chronicle.core.io.ThreadingIllegalStateException - If this resource was accessed by multiple threads in an unsafe way

IllegalStateException