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fnv.go
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fnv.go
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// Modified from github.com/prometheus/common/model/fnv.go
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package client
// Inline and byte-free variant of hash/fnv's fnv64a.
const (
offset64 = 14695981039346656037
prime64 = 1099511628211
offset32 = 2166136261
prime32 = 16777619
)
// hashNew initializes a new fnv64a hash value.
func hashNew() uint64 {
return offset64
}
// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
// Note this is the same algorithm as Go stdlib `sum64a.Write()`
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
}
// HashNew32 initializies a new fnv32 hash value.
func HashNew32() uint32 {
return offset32
}
// HashAdd32 adds a string to a fnv32 hash value, returning the updated hash.
// Note this is the same algorithm as Go stdlib `sum32.Write()`
func HashAdd32(h uint32, s string) uint32 {
for i := 0; i < len(s); i++ {
h *= prime32
h ^= uint32(s[i])
}
return h
}
// HashAddByte32 adds a byte to a fnv32 hash value, returning the updated hash.
func HashAddByte32(h uint32, b byte) uint32 {
h *= prime32
h ^= uint32(b)
return h
}