go-metrics/sample_test.go

package metrics

import (
	"testing"
)

// <https://github.com/codahale/metrics/blob/development/metrics-core/src/test/java/com/yammer/metrics/stats/tests/ExponentiallyDecayingSampleTest.java>

func TestExpDecaySample10(t *testing.T) {
	s := NewExpDecaySample(100, 0.99)
	for i := 0; i < 10; i++ { s.Update(int64(i)) }
	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) {
	s := NewExpDecaySample(1000, 0.01)
	for i := 0; i < 100; i++ { s.Update(int64(i)) }
	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) {
	s := NewExpDecaySample(100, 0.99)
	for i := 0; i < 1000; i++ { s.Update(int64(i)) }
	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 TestUniformSample(t *testing.T) {
	s := NewUniformSample(100)
	for i := 0; i < 1000; i++ { s.Update(int64(i)) }
	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)
		}
	}
}