28 lines
827 B
Go
28 lines
827 B
Go
package cuckoo
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import (
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"hash/maphash"
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)
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// A Hash function maps any data to a fixed-length value (in this case, a
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// [uint64]).
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//
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// It is used by the [Table] to evenly distribute values
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// amongst its slots. A good hash function is uniform, [chaotic], and
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// deterministic. [Table] uses [NewDefaultHash] by default, which is built on
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// [maphash.Comparable].
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//
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// [chaotic]: https://en.wikipedia.org/wiki/Avalanche_effect
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type Hash[K any] = func(key K) (digest uint64)
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// NewDefaultHash returns a new [Hash] which uses [maphash.Comparable].
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//
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// Each hash has a random seed, so calling this function again will return a new
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// hash. Do not use this for testing.
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func NewDefaultHash[K comparable]() Hash[K] {
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seed := maphash.MakeSeed()
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return func(key K) (digest uint64) {
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return maphash.Comparable(seed, key)
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}
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}
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