ipld-eth-server/vendor/github.com/prometheus/tsdb/test/hash_test.go
2019-12-02 13:24:46 -06:00

125 lines
2.6 KiB
Go

// Copyright 2017 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 test
import (
"crypto/rand"
"fmt"
"hash/crc32"
"testing"
"github.com/cespare/xxhash"
sip13 "github.com/dgryski/go-sip13"
)
type pair struct {
name, value string
}
var testInput = []pair{
{"job", "node"},
{"instance", "123.123.1.211:9090"},
{"path", "/api/v1/namespaces/<namespace>/deployments/<name>"},
{"method", "GET"},
{"namespace", "system"},
{"status", "500"},
}
func BenchmarkHash(b *testing.B) {
input := []byte{}
for _, v := range testInput {
input = append(input, v.name...)
input = append(input, '\xff')
input = append(input, v.value...)
input = append(input, '\xff')
}
var total uint64
var k0 uint64 = 0x0706050403020100
var k1 uint64 = 0x0f0e0d0c0b0a0908
for name, f := range map[string]func(b []byte) uint64{
"xxhash": xxhash.Sum64,
"fnv64": fnv64a,
"sip13": func(b []byte) uint64 { return sip13.Sum64(k0, k1, b) },
} {
b.Run(name, func(b *testing.B) {
b.SetBytes(int64(len(input)))
total = 0
for i := 0; i < b.N; i++ {
total += f(input)
}
})
}
}
// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
func fnv64a(b []byte) uint64 {
const (
offset64 = 14695981039346656037
prime64 = 1099511628211
)
h := uint64(offset64)
for x := range b {
h ^= uint64(x)
h *= prime64
}
return h
}
func BenchmarkCRC32_diff(b *testing.B) {
data := [][]byte{}
for i := 0; i < 1000; i++ {
b := make([]byte, 512)
rand.Read(b)
data = append(data, b)
}
ctab := crc32.MakeTable(crc32.Castagnoli)
total := uint32(0)
b.Run("direct", func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
total += crc32.Checksum(data[i%1000], ctab)
}
})
b.Run("hash-reuse", func(b *testing.B) {
b.ReportAllocs()
h := crc32.New(ctab)
for i := 0; i < b.N; i++ {
h.Reset()
h.Write(data[i%1000])
total += h.Sum32()
}
})
b.Run("hash-new", func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
h := crc32.New(ctab)
h.Write(data[i%1000])
total += h.Sum32()
}
})
fmt.Println(total)
}