hash环构建

pkg/hash-ring/define.go

@@ -1,12 +1,63 @@
 package hashring
 
+import (
+	"sort"
+)
+
 type RingInterface interface {
 	// 获取一个 远程连接用的目标
-	GetTarget(key string) (*target, error)
+	GetTarget(key string) (*Target, error)
 
 	// 获取下一个目标
-	NextTarget(*target) (*target, error)
+	NextTarget(*Target) (*Target, error)
 
 	// 获取上一个目标
-	PreTarget(*target) (*target, error)
+	PreTarget(*Target) (*Target, error)
+}
+
+/**
+获取一个 远程连接用的目标
+*/
+func GetTarget(key string) string {
+	var clusterHash map[int]string = createClusterHashRing()
+	/*
+	   对集群key值从小到大排序
+	*/
+	var sortHash []int
+	for hash := range clusterHash {
+		sortHash = append(sortHash, hash)
+	}
+	/**
+	  放入一个值
+	*/
+	var keys = key
+	var hashKey int = int(getHash(keys))
+	/**
+	  建立映射关系
+	*/
+	var hashValue = make(map[int]string)
+	for value := range clusterHash {
+		hashValue[value-hashKey] = clusterHash[value]
+	}
+	var hashMap []int
+	for k := range hashValue {
+		hashMap = append(hashMap, k)
+	}
+	sort.Ints(hashMap)
+	var ip string
+	var flag int = 0
+	for hash := range hashMap {
+		if hashMap[hash] > 0 {
+			ip = hashValue[hashMap[hash]]
+			return ip
+		}
+		flag++
+	}
+	/**
+	若找不到离最近的环，则返回第一个环
+	*/
+	if flag == len(hashMap) {
+		ip = clusterHash[sortHash[0]]
+	}
+	return ip
 }

pkg/hash-ring/load.go

@@ -1,9 +1,52 @@
 package hashring
 
-type target struct {
+type Target struct {
+	address []string
 }
 
-func (t *target) GetAddrString() string {
+func (t *Target) GetAddrString() []string {
 	// TODO 获取负载机器地址
-	return ""
+	return t.address
+}
+
+func addAddrString(addrss []string) *Target {
+	return &Target{
+		address: addrss,
+	}
+}
+
+/**
+构建hash环
+*/
+func createClusterHashRing() map[int]string {
+	var servers = [...]string{"192.168.0.0:111", "192.168.0.1:111",
+		"192.168.0.2:111", "192.168.0.3:111", "192.168.0.4:111"}
+	var clusterHash map[int]string
+	clusterHash = make(map[int]string)
+	for i := 0; i < len(servers); i++ {
+		var hash = int(getHash(servers[i]))
+		clusterHash[hash] = servers[i]
+	}
+	return clusterHash
+}
+
+/**
+使用FNV1_32_HASH算法计算服务器的Hash值
+*/
+func getHash(key string) int32 {
+	var p int32 = 16777619
+	var hash int32 = -2128831035
+	for i := 0; i < len(key); i++ {
+		hash = (hash ^ int32(key[i])) * p
+	}
+	hash += hash << 13
+	hash ^= hash >> 7
+	hash += hash << 3
+	hash ^= hash >> 17
+	hash += hash << 5
+	if hash < 0 {
+		return -hash
+	} else {
+		return hash
+	}
 }