perf: introduce nodes

cluster.go

@@ -210,12 +210,12 @@ func (c *clusterClient) _refresh() (err error) {
 	for master, g := range groups {
 		conns[master] = connrole{conn: c.connFn(master, c.opt)}
 		if c.rOpt != nil {
-			for _, addr := range g.nodes[1:] {
-				conns[addr] = connrole{conn: c.connFn(addr, c.rOpt)}
+			for _, nodeInfo := range g.nodes[1:] {
+				conns[nodeInfo.Addr] = connrole{conn: c.connFn(nodeInfo.Addr, c.rOpt)}
 			}
 		} else {
-			for _, addr := range g.nodes[1:] {
-				conns[addr] = connrole{conn: c.connFn(addr, c.opt)}
+			for _, nodeInfo := range g.nodes[1:] {
+				conns[nodeInfo.Addr] = connrole{conn: c.connFn(nodeInfo.Addr, c.opt)}
 			}
 		}
 	}
@@ -250,7 +250,7 @@ func (c *clusterClient) _refresh() (err error) {
 			nodesCount := len(g.nodes)
 			for _, slot := range g.slots {
 				for i := slot[0]; i <= slot[1]; i++ {
-					pslots[i] = conns[g.nodes[1+util.FastRand(nodesCount-1)]].conn
+					pslots[i] = conns[g.nodes[1+util.FastRand(nodesCount-1)].Addr].conn
 				}
 			}
 		case c.rOpt != nil:
@@ -259,18 +259,13 @@ func (c *clusterClient) _refresh() (err error) {
 			}
 			if len(g.nodes) > 1 {
 				n := len(g.nodes) - 1
-				replicas := make([]ReplicaInfo, 0, n)
-				for _, addr := range g.nodes[1:] {
-					replicas = append(replicas, ReplicaInfo{Addr: addr})
-				}
-
 				for _, slot := range g.slots {
 					for i := slot[0]; i <= slot[1]; i++ {
 						pslots[i] = conns[master].conn
 
-						rIndex := c.opt.ReplicaSelector(uint16(i), replicas)
+						rIndex := c.opt.ReplicaSelector(uint16(i), g.nodes[1:])
 						if rIndex >= 0 && rIndex < n {
-							rslots[i] = conns[g.nodes[1+rIndex]].conn
+							rslots[i] = conns[g.nodes[1+rIndex].Addr].conn
 						} else {
 							rslots[i] = conns[master].conn
 						}
@@ -325,8 +320,10 @@ func (c *clusterClient) nodes() []string {
 	return nodes
 }
 
+type nodes []ReplicaInfo
+
 type group struct {
-	nodes []string
+	nodes nodes
 	slots [][2]int64
 }
 
@@ -352,10 +349,10 @@ func parseSlots(slots RedisMessage, defaultAddr string) map[string]group {
 		g, ok := groups[master]
 		if !ok {
 			g.slots = make([][2]int64, 0)
-			g.nodes = make([]string, 0, len(v.values)-2)
+			g.nodes = make(nodes, 0, len(v.values)-2)
 			for i := 2; i < len(v.values); i++ {
 				if dst := parseEndpoint(defaultAddr, v.values[i].values[0].string, v.values[i].values[1].integer); dst != "" {
-					g.nodes = append(g.nodes, dst)
+					g.nodes = append(g.nodes, ReplicaInfo{Addr: dst})
 				}
 			}
 		}
@@ -373,16 +370,16 @@ func parseShards(shards RedisMessage, defaultAddr string, tls bool) map[string]g
 		m := -1
 		shard, _ := v.AsMap()
 		slots := shard["slots"].values
-		nodes := shard["nodes"].values
+		_nodes := shard["nodes"].values
 		g := group{
-			nodes: make([]string, 0, len(nodes)),
+			nodes: make(nodes, 0, len(_nodes)),
 			slots: make([][2]int64, len(slots)/2),
 		}
 		for i := range g.slots {
 			g.slots[i][0], _ = slots[i*2].AsInt64()
 			g.slots[i][1], _ = slots[i*2+1].AsInt64()
 		}
-		for _, n := range nodes {
+		for _, n := range _nodes {
 			dict, _ := n.AsMap()
 			if dict["health"].string != "online" {
 				continue
@@ -395,12 +392,12 @@ func parseShards(shards RedisMessage, defaultAddr string, tls bool) map[string]g
 				if dict["role"].string == "master" {
 					m = len(g.nodes)
 				}
-				g.nodes = append(g.nodes, dst)
+				g.nodes = append(g.nodes, ReplicaInfo{Addr: dst})
 			}
 		}
 		if m >= 0 {
 			g.nodes[0], g.nodes[m] = g.nodes[m], g.nodes[0]
-			groups[g.nodes[0]] = g
+			groups[g.nodes[0].Addr] = g
 		}
 	}
 	return groups
@@ -1106,15 +1103,15 @@ func (c *clusterClient) Dedicate() (DedicatedClient, func()) {
 
 func (c *clusterClient) Nodes() map[string]Client {
 	c.mu.RLock()
-	nodes := make(map[string]Client, len(c.conns))
+	_nodes := make(map[string]Client, len(c.conns))
 	disableCache := c.opt != nil && c.opt.DisableCache
 	for addr, cc := range c.conns {
 		if !cc.hidden {
-			nodes[addr] = newSingleClientWithConn(cc.conn, c.cmd, c.retry, disableCache, c.retryHandler)
+			_nodes[addr] = newSingleClientWithConn(cc.conn, c.cmd, c.retry, disableCache, c.retryHandler)
 		}
 	}
 	c.mu.RUnlock()
-	return nodes
+	return _nodes
 }
 
 func (c *clusterClient) Close() {

cluster_test.go

@@ -5048,13 +5048,15 @@ func TestClusterShardsParsing(t *testing.T) {
 			t.Fatalf("unexpected result %v", result)
 		}
 		for _, val := range result {
-			nodes := val.nodes
-			sort.Strings(nodes)
-			if len(nodes) != 3 ||
-				nodes[0] != "127.0.1.1:1" ||
-				nodes[1] != "127.0.2.1:2" ||
-				nodes[2] != "127.0.3.1:3" {
-				t.Fatalf("unexpected nodes %v", nodes)
+			_nodes := val.nodes
+			sort.Slice(_nodes, func(i, j int) bool {
+				return _nodes[i].Addr < _nodes[j].Addr
+			})
+			if len(_nodes) != 3 ||
+				_nodes[0].Addr != "127.0.1.1:1" ||
+				_nodes[1].Addr != "127.0.2.1:2" ||
+				_nodes[2].Addr != "127.0.3.1:3" {
+				t.Fatalf("unexpected nodes %v", _nodes)
 			}
 		}
 
@@ -5063,13 +5065,15 @@ func TestClusterShardsParsing(t *testing.T) {
 			t.Fatalf("unexpected result %v", result)
 		}
 		for _, val := range result {
-			nodes := val.nodes
-			sort.Strings(nodes)
-			if len(nodes) != 3 ||
-				nodes[0] != "127.0.1.1:0" ||
-				nodes[1] != "127.0.2.1:0" ||
-				nodes[2] != "127.0.3.1:3" {
-				t.Fatalf("unexpected nodes %v", nodes)
+			_nodes := val.nodes
+			sort.Slice(_nodes, func(i, j int) bool {
+				return _nodes[i].Addr < _nodes[j].Addr
+			})
+			if len(_nodes) != 3 ||
+				_nodes[0].Addr != "127.0.1.1:0" ||
+				_nodes[1].Addr != "127.0.2.1:0" ||
+				_nodes[2].Addr != "127.0.3.1:3" {
+				t.Fatalf("unexpected nodes %v", _nodes)
 			}
 		}
 	})
@@ -5080,7 +5084,7 @@ func TestClusterShardsParsing(t *testing.T) {
 			t.Fatalf("unexpected result %v", result)
 		}
 		for master, group := range result {
-			if len(group.nodes) == 0 || group.nodes[0] != master {
+			if len(group.nodes) == 0 || group.nodes[0].Addr != master {
 				t.Fatalf("unexpected first node %v", group)
 			}
 		}

rueidis.go

@@ -215,7 +215,8 @@ type ClientOption struct {
 	// If the returned value is out of range, the primary node will be selected.
 	// If primary node does not have any replica, the primary node will be selected
 	// and function will not be called.
-	// currently only used for cluster client.
+	// Currently only used for cluster client.
+	// Each ReplicaInfo must not be modified.
 	// NOTE: This function can't be used with ReplicaOnly option.
 	// NOTE: This function must be used with SendToReplicas function.
 	ReplicaSelector func(slot uint16, replicas []ReplicaInfo) int