ristretto-test.go

package main

import (
	"fmt"
	"math/rand"
	"net/http"
	"runtime"
	"strings"
	"time"

	"github.com/dgraph-io/ristretto"

	_ "net/http/pprof"
)

const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

func key() string {
	b := make([]byte, 2)
	for i := 0; i < len(b); i++ {
		b[i] = charset[rand.Intn(len(charset))]
	}
	return string(b)
}

type Value struct {
	key string
	val string
}

func main() {
	runtime.MemProfileRate = 1

	cache, err := ristretto.NewCache(&ristretto.Config{
		NumCounters: 10000000,
		MaxCost:     1024 * 1024 * 50,
		BufferItems: 64,
		Metrics:     false,
	})
	if err != nil {
		panic(err)
	}

	for i := 0; i < 4; i++ {
		go func() {
			for {
				time.Sleep(time.Duration(rand.Intn(10)) * time.Millisecond)

				k := key()
				v, ok := cache.Get(k)
				if ok && v != nil {
					vv := v.(*Value)
					if vv.key != k {
						panic(fmt.Sprintf("%q and %q collide\n", vv.key, k))
					}
				}
			}
		}()
	}

	go func() {
		for {
			time.Sleep(time.Duration(rand.Intn(10)) * time.Millisecond)

			k := key()
			val := ""

			if rand.Intn(100) < 10 {
				val = "test"
			} else {
				val = strings.Repeat("a", 1024*128)
			}

			v := &Value{
				key: k,
				val: val,
			}

			cache.Set(k, v, int64(len(v.key)+len(v.val)+8*7))
		}
	}()

	go func() {
		panic(http.ListenAndServe("localhost:6060", nil))
	}()

	for {
		time.Sleep(time.Second)

		var m runtime.MemStats
		runtime.GC()
		runtime.ReadMemStats(&m)

		fmt.Printf("%.2f MiB\n", float64(m.Alloc)/1024/1024)
	}
}