架构师训练营第五周作业

package main
import (
	"fmt"
	"math"
	"github.com/OneOfOne/xxhash"
	"github.com/grd/statistics"
)
var (
	nodeCount    uint64 = 10
	hashRingSize uint64 = math.MaxUint32
)
func main() {
	nodeCountMap := make(map[uint64]int64)
	i := 0
	for i < 1000000 {
		nodeNum := getNodeNum(fmt.Sprintf("key%v", i))
		if _, exsit := nodeCountMap[nodeNum]; !exsit {
			nodeCountMap[nodeNum] = 1
		} else {
			nodeCountMap[nodeNum] = nodeCountMap[nodeNum] + 1
		}
		i = i+1
	}
	fmt.Printf("nodeCountMap:%v", nodeCountMap)
	var testNumArray []int64
	for _ , v:=range nodeCountMap{
		testNumArray = append(testNumArray,v)
	}
	data := statistics.Int64(testNumArray)
	variance := statistics.Variance(&data)
	fmt.Printf("标准差:%v", variance)
}
func getNodeNum(key string) uint64 {
	ringHash := hashCode(key) % hashRingSize
	nodeHash := ringHash % nodeCount
	return nodeHash
}
func hashCode(anyStr string) uint64 {
	h := xxhash.New64()
	h.Write([]byte(anyStr))
	return h.Sum64()
}