bl/common/utils/sqrt_test.go

package utils

import (
	"fmt"
	"math"
	"testing"

	"github.com/badu/bus"
)

func Test_fastSqrt(t *testing.T) {
	// 测试用例
	testCases := []float64{2, 4, 10, 16, 25, 100, 1000, 0.5, 0.01, 1e-20}

	fmt.Println("测试卡马克快速平方根算法与标准库的对比：")
	fmt.Println("数值\t快速算法结果\t标准库结果\t绝对误差")
	fmt.Println("--------------------------------------------------------------")

	for _, x := range testCases {
		fastResult := fastSqrt(x)
		stdResult := math.Sqrt(x)
		error := math.Abs(fastResult - stdResult)

		fmt.Printf("%.10g\t%.10g\t\t%.10g\t\t%.2e\n",
			x, fastResult, stdResult, error)
	}

	// 测试整数版本
	fmt.Println("\n测试整数快速平方根算法：")
	fmt.Println("数值\t快速算法结果\t标准库转换结果")
	fmt.Println("--------------------------------------")

	for _, x := range []int{2, 4, 10, 16, 25, 100, 1000} {
		fastResult := fastSqrtInt(x)
		stdResult := int(math.Sqrt(float64(x)))

		fmt.Printf("%d\t%d\t\t%d\n", x, fastResult, stdResult)
	}
}
func BenchmarkMathSqrt(b *testing.B) {
	testValues := []float64{2, 4, 10, 16, 25, 100, 1000, 0.5, 0.01, 1e-20}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for _, x := range testValues {
			_ = math.Sqrt(x)
		}
	}
}

func BenchmarkFastSqrt(b *testing.B) {
	testValues := []float64{2, 4, 10, 16, 25, 100, 1000, 0.5, 0.01, 1e-20}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for _, x := range testValues {
			_ = fastSqrt(x)
		}
	}
}

func BenchmarkFastSqrtCarmack(b *testing.B) {
	testValues := []float64{2, 4, 10, 16, 25, 100, 1000, 0.5, 0.01, 1e-20}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for _, x := range testValues {
			_ = fastSqrtCarmack(x)
		}
	}
}

func BenchmarkMathSqrtInt(b *testing.B) {
	testValues := []int{2, 4, 10, 16, 25, 100, 1000, 10000, 100000}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for _, x := range testValues {
			_ = int(math.Sqrt(float64(x)))
		}
	}
}

func BenchmarkFastSqrtInt(b *testing.B) {
	testValues := []int{2, 4, 10, 16, 25, 100, 1000, 10000, 100000}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		for _, x := range testValues {
			_ = fastSqrtInt(x)
		}
	}
}

func Test_fastSqr1(b *testing.T) {
	// scenario : we have a large number of subscribers.
	// we publish an event and while doing that,
	// we register another one on a different goroutine

	topic := bus.NewTopic[*Uint32AsyncEvent]()
	for i := 0; i < 4096; i++ {
		topic.Sub(func(v *Uint32AsyncEvent) {
			print(v.u)
		})
	}

	topic.Pub(&Uint32AsyncEvent{u: 1})
	// finishPubWait := make(chan struct{})
	// finishSubWait := make(chan struct{})
	// start := make(chan struct{})

	// go func() {
	// 	<-start
	// 	topic.PubAsync(&Uint32AsyncEvent{u: 1})
	// 	defer close(finishPubWait)
	// }()

	// newSubCalled := false

	// go func() {
	// 	<-start
	// 	topic.Sub(func(v *Uint32AsyncEvent) {
	// 		newSubCalled = true
	// 	})
	// 	close(finishSubWait)
	// }()

	// close(start) // start both goroutines

	// <-finishPubWait // wait for pub to finish

	// <-finishSubWait // wait for sub to finish

	// if newSubCalled {
	// 	print("new subscriber called")
	// }

}

// Various event types
const EventA = 0x01

type Uint32AsyncEvent struct {
	u uint32
}

// Event type for testing purposes
type Event struct {
	Data  string
	type1 uint32
}

// Type returns the event type
func (ev Event) Type() uint32 {
	return ev.type1
}

// newEventA creates a new instance of an event
func newEventA(data string) Event {
	return Event{Data: data, type1: EventA}
}

// Various event types
const EventB1 = 0x02

func newEventB(data string) Event {
	return Event{Data: data, type1: EventB1}
}