Function jumpHash

pkg/cache/memcached_client_selector.go:90–101

jumpHash consistently chooses a hash bucket number in the range [0, numBuckets) for the given key. numBuckets must be >= 1. Copied from github.com/dgryski/go-jump/blob/master/jump.go

(key uint64, numBuckets int)

//
// Copied from github.com/dgryski/go-jump/blob/master/jump.go
func jumpHash(key uint64, numBuckets int) int32 {
	var b int64 = -1
	var j int64

	for j < int64(numBuckets) {
		b = j
		key = key*2862933555777941757 + 1
		j = int64(float64(b+1) * (float64(int64(1)<<31) / float64((key>>33)+1)))
	}

	return int32(b)
}

// PickServer returns the server address that a given item
// should be shared onto.