43 lines
891 B
Go
43 lines
891 B
Go
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// Copyright (C) 2023 Storj Labs, Inc.
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// See LICENSE for copying information.
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package nodeselection
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import mathrand "math/rand"
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// RandomOrder as an iterator of a pseudo-random permutation set.
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type RandomOrder struct {
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count uint64
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at uint64
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prime uint64
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len uint64
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}
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// NewRandomOrder creates new iterator, returns number between [0,n) in pseudo-random order.
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func NewRandomOrder(n int) RandomOrder {
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if n == 0 {
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return RandomOrder{
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count: 0,
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}
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}
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return RandomOrder{
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count: uint64(n),
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at: uint64(mathrand.Intn(n)),
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prime: primes[mathrand.Intn(len(primes))],
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len: uint64(n),
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}
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}
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// Next generates the next number.
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func (r *RandomOrder) Next() bool {
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if r.count == 0 {
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return false
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}
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r.at = (r.at + r.prime) % r.len
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r.count--
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return true
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}
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// At returns the current number in the permutations.
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func (r *RandomOrder) At() uint64 { return r.at }
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