syncthing/vendor/github.com/rcrowley/go-metrics/sample_test.go
Jakob Borg 65aaa607ab Use Go 1.5 vendoring instead of Godeps
Change made by:

- running "gvt fetch" on each of the packages mentioned in
  Godeps/Godeps.json
- `rm -rf Godeps`
- tweaking the build scripts to not mention Godeps
- tweaking the build scripts to test `./lib/...`, `./cmd/...` explicitly
  (to avoid testing vendor)
- tweaking the build scripts to not juggle GOPATH for Godeps and instead
  set GO15VENDOREXPERIMENT.

This also results in some updated packages at the same time I bet.

Building with Go 1.3 and 1.4 still *works* but won't use our vendored
dependencies - the user needs to have the actual packages in their
GOPATH then, which they'll get with a normal "go get". Building with Go
1.6+ will get our vendored dependencies by default even when not using
our build script, which is nice.

By doing this we gain some freedom in that we can pick and choose
manually what to include in vendor, as it's not based on just dependency
analysis of our own code. This is also a risk as we might pick up
dependencies we are unaware of, as the build may work locally with those
packages present in GOPATH. On the other hand the build server will
detect this as it has no packages in it's GOPATH beyond what is included
in the repo.

Recommended tool to manage dependencies is github.com/FiloSottile/gvt.
2016-03-05 21:21:24 +01:00

364 lines
8.5 KiB
Go

package metrics
import (
"math/rand"
"runtime"
"testing"
"time"
)
// Benchmark{Compute,Copy}{1000,1000000} demonstrate that, even for relatively
// expensive computations like Variance, the cost of copying the Sample, as
// approximated by a make and copy, is much greater than the cost of the
// computation for small samples and only slightly less for large samples.
func BenchmarkCompute1000(b *testing.B) {
s := make([]int64, 1000)
for i := 0; i < len(s); i++ {
s[i] = int64(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
SampleVariance(s)
}
}
func BenchmarkCompute1000000(b *testing.B) {
s := make([]int64, 1000000)
for i := 0; i < len(s); i++ {
s[i] = int64(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
SampleVariance(s)
}
}
func BenchmarkCopy1000(b *testing.B) {
s := make([]int64, 1000)
for i := 0; i < len(s); i++ {
s[i] = int64(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
sCopy := make([]int64, len(s))
copy(sCopy, s)
}
}
func BenchmarkCopy1000000(b *testing.B) {
s := make([]int64, 1000000)
for i := 0; i < len(s); i++ {
s[i] = int64(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
sCopy := make([]int64, len(s))
copy(sCopy, s)
}
}
func BenchmarkExpDecaySample257(b *testing.B) {
benchmarkSample(b, NewExpDecaySample(257, 0.015))
}
func BenchmarkExpDecaySample514(b *testing.B) {
benchmarkSample(b, NewExpDecaySample(514, 0.015))
}
func BenchmarkExpDecaySample1028(b *testing.B) {
benchmarkSample(b, NewExpDecaySample(1028, 0.015))
}
func BenchmarkUniformSample257(b *testing.B) {
benchmarkSample(b, NewUniformSample(257))
}
func BenchmarkUniformSample514(b *testing.B) {
benchmarkSample(b, NewUniformSample(514))
}
func BenchmarkUniformSample1028(b *testing.B) {
benchmarkSample(b, NewUniformSample(1028))
}
func TestExpDecaySample10(t *testing.T) {
rand.Seed(1)
s := NewExpDecaySample(100, 0.99)
for i := 0; i < 10; i++ {
s.Update(int64(i))
}
if size := s.Count(); 10 != size {
t.Errorf("s.Count(): 10 != %v\n", size)
}
if size := s.Size(); 10 != size {
t.Errorf("s.Size(): 10 != %v\n", size)
}
if l := len(s.Values()); 10 != l {
t.Errorf("len(s.Values()): 10 != %v\n", l)
}
for _, v := range s.Values() {
if v > 10 || v < 0 {
t.Errorf("out of range [0, 10): %v\n", v)
}
}
}
func TestExpDecaySample100(t *testing.T) {
rand.Seed(1)
s := NewExpDecaySample(1000, 0.01)
for i := 0; i < 100; i++ {
s.Update(int64(i))
}
if size := s.Count(); 100 != size {
t.Errorf("s.Count(): 100 != %v\n", size)
}
if size := s.Size(); 100 != size {
t.Errorf("s.Size(): 100 != %v\n", size)
}
if l := len(s.Values()); 100 != l {
t.Errorf("len(s.Values()): 100 != %v\n", l)
}
for _, v := range s.Values() {
if v > 100 || v < 0 {
t.Errorf("out of range [0, 100): %v\n", v)
}
}
}
func TestExpDecaySample1000(t *testing.T) {
rand.Seed(1)
s := NewExpDecaySample(100, 0.99)
for i := 0; i < 1000; i++ {
s.Update(int64(i))
}
if size := s.Count(); 1000 != size {
t.Errorf("s.Count(): 1000 != %v\n", size)
}
if size := s.Size(); 100 != size {
t.Errorf("s.Size(): 100 != %v\n", size)
}
if l := len(s.Values()); 100 != l {
t.Errorf("len(s.Values()): 100 != %v\n", l)
}
for _, v := range s.Values() {
if v > 1000 || v < 0 {
t.Errorf("out of range [0, 1000): %v\n", v)
}
}
}
// This test makes sure that the sample's priority is not amplified by using
// nanosecond duration since start rather than second duration since start.
// The priority becomes +Inf quickly after starting if this is done,
// effectively freezing the set of samples until a rescale step happens.
func TestExpDecaySampleNanosecondRegression(t *testing.T) {
rand.Seed(1)
s := NewExpDecaySample(100, 0.99)
for i := 0; i < 100; i++ {
s.Update(10)
}
time.Sleep(1 * time.Millisecond)
for i := 0; i < 100; i++ {
s.Update(20)
}
v := s.Values()
avg := float64(0)
for i := 0; i < len(v); i++ {
avg += float64(v[i])
}
avg /= float64(len(v))
if avg > 16 || avg < 14 {
t.Errorf("out of range [14, 16]: %v\n", avg)
}
}
func TestExpDecaySampleRescale(t *testing.T) {
s := NewExpDecaySample(2, 0.001).(*ExpDecaySample)
s.update(time.Now(), 1)
s.update(time.Now().Add(time.Hour+time.Microsecond), 1)
for _, v := range s.values.Values() {
if v.k == 0.0 {
t.Fatal("v.k == 0.0")
}
}
}
func TestExpDecaySampleSnapshot(t *testing.T) {
now := time.Now()
rand.Seed(1)
s := NewExpDecaySample(100, 0.99)
for i := 1; i <= 10000; i++ {
s.(*ExpDecaySample).update(now.Add(time.Duration(i)), int64(i))
}
snapshot := s.Snapshot()
s.Update(1)
testExpDecaySampleStatistics(t, snapshot)
}
func TestExpDecaySampleStatistics(t *testing.T) {
now := time.Now()
rand.Seed(1)
s := NewExpDecaySample(100, 0.99)
for i := 1; i <= 10000; i++ {
s.(*ExpDecaySample).update(now.Add(time.Duration(i)), int64(i))
}
testExpDecaySampleStatistics(t, s)
}
func TestUniformSample(t *testing.T) {
rand.Seed(1)
s := NewUniformSample(100)
for i := 0; i < 1000; i++ {
s.Update(int64(i))
}
if size := s.Count(); 1000 != size {
t.Errorf("s.Count(): 1000 != %v\n", size)
}
if size := s.Size(); 100 != size {
t.Errorf("s.Size(): 100 != %v\n", size)
}
if l := len(s.Values()); 100 != l {
t.Errorf("len(s.Values()): 100 != %v\n", l)
}
for _, v := range s.Values() {
if v > 1000 || v < 0 {
t.Errorf("out of range [0, 100): %v\n", v)
}
}
}
func TestUniformSampleIncludesTail(t *testing.T) {
rand.Seed(1)
s := NewUniformSample(100)
max := 100
for i := 0; i < max; i++ {
s.Update(int64(i))
}
v := s.Values()
sum := 0
exp := (max - 1) * max / 2
for i := 0; i < len(v); i++ {
sum += int(v[i])
}
if exp != sum {
t.Errorf("sum: %v != %v\n", exp, sum)
}
}
func TestUniformSampleSnapshot(t *testing.T) {
s := NewUniformSample(100)
for i := 1; i <= 10000; i++ {
s.Update(int64(i))
}
snapshot := s.Snapshot()
s.Update(1)
testUniformSampleStatistics(t, snapshot)
}
func TestUniformSampleStatistics(t *testing.T) {
rand.Seed(1)
s := NewUniformSample(100)
for i := 1; i <= 10000; i++ {
s.Update(int64(i))
}
testUniformSampleStatistics(t, s)
}
func benchmarkSample(b *testing.B, s Sample) {
var memStats runtime.MemStats
runtime.ReadMemStats(&memStats)
pauseTotalNs := memStats.PauseTotalNs
b.ResetTimer()
for i := 0; i < b.N; i++ {
s.Update(1)
}
b.StopTimer()
runtime.GC()
runtime.ReadMemStats(&memStats)
b.Logf("GC cost: %d ns/op", int(memStats.PauseTotalNs-pauseTotalNs)/b.N)
}
func testExpDecaySampleStatistics(t *testing.T, s Sample) {
if count := s.Count(); 10000 != count {
t.Errorf("s.Count(): 10000 != %v\n", count)
}
if min := s.Min(); 107 != min {
t.Errorf("s.Min(): 107 != %v\n", min)
}
if max := s.Max(); 10000 != max {
t.Errorf("s.Max(): 10000 != %v\n", max)
}
if mean := s.Mean(); 4965.98 != mean {
t.Errorf("s.Mean(): 4965.98 != %v\n", mean)
}
if stdDev := s.StdDev(); 2959.825156930727 != stdDev {
t.Errorf("s.StdDev(): 2959.825156930727 != %v\n", stdDev)
}
ps := s.Percentiles([]float64{0.5, 0.75, 0.99})
if 4615 != ps[0] {
t.Errorf("median: 4615 != %v\n", ps[0])
}
if 7672 != ps[1] {
t.Errorf("75th percentile: 7672 != %v\n", ps[1])
}
if 9998.99 != ps[2] {
t.Errorf("99th percentile: 9998.99 != %v\n", ps[2])
}
}
func testUniformSampleStatistics(t *testing.T, s Sample) {
if count := s.Count(); 10000 != count {
t.Errorf("s.Count(): 10000 != %v\n", count)
}
if min := s.Min(); 37 != min {
t.Errorf("s.Min(): 37 != %v\n", min)
}
if max := s.Max(); 9989 != max {
t.Errorf("s.Max(): 9989 != %v\n", max)
}
if mean := s.Mean(); 4748.14 != mean {
t.Errorf("s.Mean(): 4748.14 != %v\n", mean)
}
if stdDev := s.StdDev(); 2826.684117548333 != stdDev {
t.Errorf("s.StdDev(): 2826.684117548333 != %v\n", stdDev)
}
ps := s.Percentiles([]float64{0.5, 0.75, 0.99})
if 4599 != ps[0] {
t.Errorf("median: 4599 != %v\n", ps[0])
}
if 7380.5 != ps[1] {
t.Errorf("75th percentile: 7380.5 != %v\n", ps[1])
}
if 9986.429999999998 != ps[2] {
t.Errorf("99th percentile: 9986.429999999998 != %v\n", ps[2])
}
}
// TestUniformSampleConcurrentUpdateCount would expose data race problems with
// concurrent Update and Count calls on Sample when test is called with -race
// argument
func TestUniformSampleConcurrentUpdateCount(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
s := NewUniformSample(100)
for i := 0; i < 100; i++ {
s.Update(int64(i))
}
quit := make(chan struct{})
go func() {
t := time.NewTicker(10 * time.Millisecond)
for {
select {
case <-t.C:
s.Update(rand.Int63())
case <-quit:
t.Stop()
return
}
}
}()
for i := 0; i < 1000; i++ {
s.Count()
time.Sleep(5 * time.Millisecond)
}
quit <- struct{}{}
}