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/Scala 2.13 Library

Package scala.util.hashing

package hashing

Source
package.scala
Linear Supertypes
AnyRef, Any

Type Members

final class ByteswapHashing[T] extends Hashing[T]

trait Hashing[T] extends Serializable

Hashing is a trait whose instances each represent a strategy for hashing instances of a type.

Hashing's companion object defines a default hashing strategy for all objects - it calls their ## method.

Note: when using a custom Hashing, make sure to use it with the Equiv such that if any two objects are equal, then their hash codes must be equal.

Annotations
@implicitNotFound("No implicit Hashing defined for ${T}.")
Since

2.10

Value Members

def byteswap32(v: Int): Int

def byteswap64(v: Long): Long

object ByteswapHashing extends java.io.Serializable

object Hashing extends java.io.Serializable

object MurmurHash3 extends MurmurHash3

An implementation of Austin Appleby's MurmurHash 3 algorithm (MurmurHash3_x86_32). This object contains methods that hash values of various types as well as means to construct Hashing objects.

This algorithm is designed to generate well-distributed non-cryptographic hashes. It is designed to hash data in 32 bit chunks (ints).

The mix method needs to be called at each step to update the intermediate hash value. For the last chunk to incorporate into the hash mixLast may be used instead, which is slightly faster. Finally finalizeHash needs to be called to compute the final hash value.

This is based on the earlier MurmurHash3 code by Rex Kerr, but the MurmurHash3 algorithm was since changed by its creator Austin Appleby to remedy some weaknesses and improve performance. This represents the latest and supposedly final version of the algorithm (revision 136).

See also

https://github.com/aappleby/smhasher

© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/util/hashing/index.html