aboutsummaryrefslogtreecommitdiff
path: root/vendor/github.com/prometheus/client_golang/prometheus/fnv.go
blob: e3b67df8ac0681fd73151e7e44c3ea8bed3bfb63 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
package prometheus

// Inline and byte-free variant of hash/fnv's fnv64a.

const (
	offset64 = 14695981039346656037
	prime64  = 1099511628211
)

// hashNew initializies a new fnv64a hash value.
func hashNew() uint64 {
	return offset64
}

// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
func hashAdd(h uint64, s string) uint64 {
	for i := 0; i < len(s); i++ {
		h ^= uint64(s[i])
		h *= prime64
	}
	return h
}

// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
func hashAddByte(h uint64, b byte) uint64 {
	h ^= uint64(b)
	h *= prime64
	return h
}