prometheus/vendor/github.com/influxdata/influxdb/models/inline_fnv.go
2017-04-03 12:38:05 +02:00

33 lines
820 B
Go

package models // import "github.com/influxdata/influxdb/models"
// from stdlib hash/fnv/fnv.go
const (
prime64 = 1099511628211
offset64 = 14695981039346656037
)
// InlineFNV64a is an alloc-free port of the standard library's fnv64a.
// See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function.
type InlineFNV64a uint64
// NewInlineFNV64a returns a new instance of InlineFNV64a.
func NewInlineFNV64a() InlineFNV64a {
return offset64
}
// Write adds data to the running hash.
func (s *InlineFNV64a) Write(data []byte) (int, error) {
hash := uint64(*s)
for _, c := range data {
hash ^= uint64(c)
hash *= prime64
}
*s = InlineFNV64a(hash)
return len(data), nil
}
// Sum64 returns the uint64 of the current resulting hash.
func (s *InlineFNV64a) Sum64() uint64 {
return uint64(*s)
}