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// Copyright 2018 The gVisor 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 jenkins
import (
"bytes"
"encoding/binary"
"hash"
"hash/fnv"
"math"
"testing"
)
func TestGolden32(t *testing.T) {
var golden32 = []struct {
out []byte
in string
}{
{[]byte{0x00, 0x00, 0x00, 0x00}, ""},
{[]byte{0xca, 0x2e, 0x94, 0x42}, "a"},
{[]byte{0x45, 0xe6, 0x1e, 0x58}, "ab"},
{[]byte{0xed, 0x13, 0x1f, 0x5b}, "abc"},
}
hash := New32()
for _, g := range golden32 {
hash.Reset()
done, error := hash.Write([]byte(g.in))
if error != nil {
t.Fatalf("write error: %s", error)
}
if done != len(g.in) {
t.Fatalf("wrote only %d out of %d bytes", done, len(g.in))
}
if actual := hash.Sum(nil); !bytes.Equal(g.out, actual) {
t.Errorf("hash(%q) = 0x%x want 0x%x", g.in, actual, g.out)
}
}
}
func TestIntegrity32(t *testing.T) {
data := []byte{'1', '2', 3, 4, 5}
h := New32()
h.Write(data)
sum := h.Sum(nil)
if size := h.Size(); size != len(sum) {
t.Fatalf("Size()=%d but len(Sum())=%d", size, len(sum))
}
if a := h.Sum(nil); !bytes.Equal(sum, a) {
t.Fatalf("first Sum()=0x%x, second Sum()=0x%x", sum, a)
}
h.Reset()
h.Write(data)
if a := h.Sum(nil); !bytes.Equal(sum, a) {
t.Fatalf("Sum()=0x%x, but after Reset() Sum()=0x%x", sum, a)
}
h.Reset()
h.Write(data[:2])
h.Write(data[2:])
if a := h.Sum(nil); !bytes.Equal(sum, a) {
t.Fatalf("Sum()=0x%x, but with partial writes, Sum()=0x%x", sum, a)
}
sum32 := h.(hash.Hash32).Sum32()
if sum32 != binary.BigEndian.Uint32(sum) {
t.Fatalf("Sum()=0x%x, but Sum32()=0x%x", sum, sum32)
}
}
func BenchmarkJenkins32KB(b *testing.B) {
h := New32()
b.SetBytes(1024)
data := make([]byte, 1024)
for i := range data {
data[i] = byte(i)
}
in := make([]byte, 0, h.Size())
b.ResetTimer()
for i := 0; i < b.N; i++ {
h.Reset()
h.Write(data)
h.Sum(in)
}
}
func BenchmarkFnv32(b *testing.B) {
arr := make([]int64, 1000)
for i := 0; i < b.N; i++ {
var payload [8]byte
binary.BigEndian.PutUint32(payload[:4], uint32(i))
binary.BigEndian.PutUint32(payload[4:], uint32(i))
h := fnv.New32()
h.Write(payload[:])
idx := int(h.Sum32()) % len(arr)
arr[idx]++
}
b.StopTimer()
c := 0
if b.N > 1000000 {
for i := 0; i < len(arr)-1; i++ {
if math.Abs(float64(arr[i]-arr[i+1]))/float64(arr[i]) > float64(0.1) {
if c == 0 {
b.Logf("i %d val[i] %d val[i+1] %d b.N %b\n", i, arr[i], arr[i+1], b.N)
}
c++
}
}
if c > 0 {
b.Logf("Unbalanced buckets: %d", c)
}
}
}
func BenchmarkSum32(b *testing.B) {
arr := make([]int64, 1000)
for i := 0; i < b.N; i++ {
var payload [8]byte
binary.BigEndian.PutUint32(payload[:4], uint32(i))
binary.BigEndian.PutUint32(payload[4:], uint32(i))
h := Sum32(0)
h.Write(payload[:])
idx := int(h.Sum32()) % len(arr)
arr[idx]++
}
b.StopTimer()
if b.N > 1000000 {
for i := 0; i < len(arr)-1; i++ {
if math.Abs(float64(arr[i]-arr[i+1]))/float64(arr[i]) > float64(0.1) {
b.Logf("val[%3d]=%8d\tval[%3d]=%8d\tb.N=%b\n", i, arr[i], i+1, arr[i+1], b.N)
break
}
}
}
}
func BenchmarkNew32(b *testing.B) {
arr := make([]int64, 1000)
for i := 0; i < b.N; i++ {
var payload [8]byte
binary.BigEndian.PutUint32(payload[:4], uint32(i))
binary.BigEndian.PutUint32(payload[4:], uint32(i))
h := New32()
h.Write(payload[:])
idx := int(h.Sum32()) % len(arr)
arr[idx]++
}
b.StopTimer()
if b.N > 1000000 {
for i := 0; i < len(arr)-1; i++ {
if math.Abs(float64(arr[i]-arr[i+1]))/float64(arr[i]) > float64(0.1) {
b.Logf("val[%3d]=%8d\tval[%3d]=%8d\tb.N=%b\n", i, arr[i], i+1, arr[i+1], b.N)
break
}
}
}
}