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).
- Source
- MurmurHash3.scala
- See also
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- MurmurHash3
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Type Members
- class ArrayHashing[T] extends Hashing[Array[T]]
Value Members
- def arrayHash[T](a: Array[T]): Int
- final def arrayHash[T](a: Array[T], seed: Int): Int
Compute the hash of an array.
Compute the hash of an array. Potential range hashes are recognized to produce a hash that is compatible with rangeHash.
- Definition Classes
- MurmurHash3
- def arrayHashing[T]: ArrayHashing[T]
- final val arraySeed: Int(1007110753)
- def bytesHash(data: Array[Byte]): Int
- final def bytesHash(data: Array[Byte], seed: Int): Int
Compute the hash of a byte array.
Compute the hash of a byte array. Faster than arrayHash, because it hashes 4 bytes at once. Note that the result is not compatible with arrayHash!
- Definition Classes
- MurmurHash3
- def bytesHashing: Hashing[Array[Byte]]
- final def finalizeHash(hash: Int, length: Int): Int
Finalize a hash to incorporate the length and make sure all bits avalanche.
Finalize a hash to incorporate the length and make sure all bits avalanche.
- Definition Classes
- MurmurHash3
- final def indexedSeqHash(a: collection.IndexedSeq[Any], seed: Int): Int
Compute the hash of an IndexedSeq.
Compute the hash of an IndexedSeq. Potential range hashes are recognized to produce a hash that is compatible with rangeHash.
- Definition Classes
- MurmurHash3
- final def listHash(xs: collection.immutable.List[_], seed: Int): Int
Compute the hash of a List.
Compute the hash of a List. Potential range hashes are recognized to produce a hash that is compatible with rangeHash.
- Definition Classes
- MurmurHash3
- def mapHash(xs: Map[_, _]): Int
- final val mapSeed: Int
- final def mix(hash: Int, data: Int): Int
Mix in a block of data into an intermediate hash value.
Mix in a block of data into an intermediate hash value.
- Definition Classes
- MurmurHash3
- final def mixLast(hash: Int, data: Int): Int
May optionally be used as the last mixing step.
May optionally be used as the last mixing step. Is a little bit faster than mix, as it does no further mixing of the resulting hash. For the last element this is not necessary as the hash is thoroughly mixed during finalization anyway.
- Definition Classes
- MurmurHash3
- def orderedHash(xs: IterableOnce[Any]): Int
- final def orderedHash(xs: IterableOnce[Any], seed: Int): Int
Compute a hash that depends on the order of its arguments.
Compute a hash that depends on the order of its arguments. Potential range hashes are recognized to produce a hash that is compatible with rangeHash.
- Definition Classes
- MurmurHash3
- def orderedHashing: Hashing[IterableOnce[Any]]
- def productHash(x: Product): Int
- final def productHash(x: Product, seed: Int, ignorePrefix: Boolean = false): Int
Compute the hash of a product
Compute the hash of a product
- Definition Classes
- MurmurHash3
- def productHashing: Hashing[Product]
- final val productSeed: Int(-889275714)
- def rangeHash(start: Int, step: Int, last: Int): Int
- final def rangeHash(start: Int, step: Int, last: Int, seed: Int): Int
Compute the hash of a Range with at least 2 elements.
Compute the hash of a Range with at least 2 elements. Ranges with fewer elements need to use seqHash instead. The
last
parameter must be the actual last element produced by a Range, not the nominalend
.- Definition Classes
- MurmurHash3
- def seqHash(xs: collection.Seq[_]): Int
To offer some potential for optimization.
- final val seqSeed: Int
- def setHash(xs: Set[_]): Int
- final val setSeed: Int
- def stringHash(x: String): Int
- final def stringHash(str: String, seed: Int): Int
Compute the hash of a string
Compute the hash of a string
- Definition Classes
- MurmurHash3
- def stringHashing: Hashing[String]
- final val stringSeed: Int(-137723950)
- final val symmetricSeed: Int(-1248659538)
- final val traversableSeed: Int(-415593707)
- def unorderedHash(xs: IterableOnce[Any]): Int
- final def unorderedHash(xs: IterableOnce[Any], seed: Int): Int
Compute a hash that is symmetric in its arguments - that is a hash where the order of appearance of elements does not matter.
Compute a hash that is symmetric in its arguments - that is a hash where the order of appearance of elements does not matter. This is useful for hashing sets, for example.
- Definition Classes
- MurmurHash3
- def unorderedHashing: Hashing[IterableOnce[Any]]
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