Create hashtag package.

cluster.go

@@ -3,10 +3,11 @@ package redis
 import (
 	"log"
 	"math/rand"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
+
+	"gopkg.in/redis.v3/internal/hashtag"
 )
 
 // ClusterClient is a Redis Cluster client representing a pool of zero
@@ -34,7 +35,7 @@ type ClusterClient struct {
 func NewClusterClient(opt *ClusterOptions) *ClusterClient {
 	client := &ClusterClient{
 		addrs:   opt.Addrs,
-		slots:   make([][]string, hashSlots),
+		slots:   make([][]string, hashtag.SlotNumber),
 		clients: make(map[string]*Client),
 		opt:     opt,
 	}
@@ -47,7 +48,7 @@ func NewClusterClient(opt *ClusterOptions) *ClusterClient {
 // Watch creates new transaction and marks the keys to be watched
 // for conditional execution of a transaction.
 func (c *ClusterClient) Watch(keys ...string) (*Multi, error) {
-	addr := c.slotMasterAddr(hashSlot(keys[0]))
+	addr := c.slotMasterAddr(hashtag.Slot(keys[0]))
 	client, err := c.getClient(addr)
 	if err != nil {
 		return nil, err
@@ -138,7 +139,7 @@ func (c *ClusterClient) randomClient() (client *Client, err error) {
 func (c *ClusterClient) process(cmd Cmder) {
 	var ask bool
 
-	slot := hashSlot(cmd.clusterKey())
+	slot := hashtag.Slot(cmd.clusterKey())
 
 	addr := c.slotMasterAddr(slot)
 	client, err := c.getClient(addr)
@@ -215,7 +216,7 @@ func (c *ClusterClient) setSlots(slots []ClusterSlotInfo) {
 		seen[addr] = struct{}{}
 	}
 
-	for i := 0; i < hashSlots; i++ {
+	for i := 0; i < hashtag.SlotNumber; i++ {
 		c.slots[i] = c.slots[i][:0]
 	}
 	for _, info := range slots {
@@ -333,26 +334,3 @@ func (opt *ClusterOptions) clientOptions() *Options {
 		IdleTimeout: opt.IdleTimeout,
 	}
 }
-
-//------------------------------------------------------------------------------
-
-const hashSlots = 16384
-
-func hashKey(key string) string {
-	if s := strings.IndexByte(key, '{'); s > -1 {
-		if e := strings.IndexByte(key[s+1:], '}'); e > 0 {
-			return key[s+1 : s+e+1]
-		}
-	}
-	return key
-}
-
-// hashSlot returns a consistent slot number between 0 and 16383
-// for any given string key.
-func hashSlot(key string) int {
-	key = hashKey(key)
-	if key == "" {
-		return rand.Intn(hashSlots)
-	}
-	return int(crc16sum(key)) % hashSlots
-}

cluster_pipeline.go

@@ -1,5 +1,9 @@
 package redis
 
+import (
+	"gopkg.in/redis.v3/internal/hashtag"
+)
+
 // ClusterPipeline is not thread-safe.
 type ClusterPipeline struct {
 	commandable
@@ -48,7 +52,7 @@ func (pipe *ClusterPipeline) Exec() (cmds []Cmder, retErr error) {
 
 	cmdsMap := make(map[string][]Cmder)
 	for _, cmd := range cmds {
-		slot := hashSlot(cmd.clusterKey())
+		slot := hashtag.Slot(cmd.clusterKey())
 		addr := pipe.cluster.slotMasterAddr(slot)
 		cmdsMap[addr] = append(cmdsMap[addr], cmd)
 	}

cluster_test.go

@@ -16,6 +16,7 @@ import (
 	. "github.com/onsi/gomega"
 
 	"gopkg.in/redis.v3"
+	"gopkg.in/redis.v3/internal/hashtag"
 )
 
 type clusterScenario struct {
@@ -182,7 +183,7 @@ var _ = Describe("Cluster", func() {
 			rand.Seed(100)
 
 			for _, test := range tests {
-				Expect(redis.HashSlot(test.key)).To(Equal(test.slot), "for %s", test.key)
+				Expect(hashtag.Slot(test.key)).To(Equal(test.slot), "for %s", test.key)
 			}
 		})
 
@@ -198,7 +199,7 @@ var _ = Describe("Cluster", func() {
 			}
 
 			for _, test := range tests {
-				Expect(redis.HashSlot(test.one)).To(Equal(redis.HashSlot(test.two)), "for %s <-> %s", test.one, test.two)
+				Expect(hashtag.Slot(test.one)).To(Equal(hashtag.Slot(test.two)), "for %s <-> %s", test.one, test.two)
 			}
 		})
 
@@ -232,7 +233,7 @@ var _ = Describe("Cluster", func() {
 		It("should CLUSTER KEYSLOT", func() {
 			hashSlot, err := cluster.primary().ClusterKeySlot("somekey").Result()
 			Expect(err).NotTo(HaveOccurred())
-			Expect(hashSlot).To(Equal(int64(11058)))
+			Expect(hashSlot).To(Equal(int64(hashtag.Slot("somekey"))))
 		})
 
 		It("should CLUSTER COUNT-FAILURE-REPORTS", func() {
@@ -315,7 +316,7 @@ var _ = Describe("Cluster", func() {
 		It("should follow redirects", func() {
 			Expect(client.Set("A", "VALUE", 0).Err()).NotTo(HaveOccurred())
 
-			slot := redis.HashSlot("A")
+			slot := hashtag.Slot("A")
 			Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
 
 			val, err := client.Get("A").Result()
@@ -328,7 +329,7 @@ var _ = Describe("Cluster", func() {
 		})
 
 		It("should perform multi-pipelines", func() {
-			slot := redis.HashSlot("A")
+			slot := hashtag.Slot("A")
 			Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
 
 			pipe := client.Pipeline()
@@ -361,7 +362,7 @@ var _ = Describe("Cluster", func() {
 				MaxRedirects: -1,
 			})
 
-			slot := redis.HashSlot("A")
+			slot := hashtag.Slot("A")
 			Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
 
 			err := client.Get("A").Err()

export_test.go

@@ -11,7 +11,3 @@ var NewConnDialer = newConnDialer
 func (cn *conn) SetNetConn(netcn net.Conn) {
 	cn.netcn = netcn
 }
-
-func HashSlot(key string) int {
-	return hashSlot(key)
-}

internal/hashtag/hashtag.go

@@ -1,4 +1,11 @@
-package redis
+package hashtag
+
+import (
+	"math/rand"
+	"strings"
+)
+
+const SlotNumber = 16384
 
 // CRC16 implementation according to CCITT standards.
 // Copyright 2001-2010 Georges Menie (www.menie.org)
@@ -39,6 +46,25 @@ var crc16tab = [256]uint16{
 	0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
 }
 
+func Key(key string) string {
+	if s := strings.IndexByte(key, '{'); s > -1 {
+		if e := strings.IndexByte(key[s+1:], '}'); e > 0 {
+			return key[s+1 : s+e+1]
+		}
+	}
+	return key
+}
+
+// hashSlot returns a consistent slot number between 0 and 16383
+// for any given string key.
+func Slot(key string) int {
+	key = Key(key)
+	if key == "" {
+		return rand.Intn(SlotNumber)
+	}
+	return int(crc16sum(key)) % SlotNumber
+}
+
 func crc16sum(key string) (crc uint16) {
 	for i := 0; i < len(key); i++ {
 		crc = (crc << 8) ^ crc16tab[(byte(crc>>8)^key[i])&0x00ff]

internal/hashtag/hashtag_test.go

@@ -1,4 +1,4 @@
-package redis
+package hashtag
 
 import (
 	. "github.com/onsi/ginkgo"

ring.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"gopkg.in/redis.v3/internal/consistenthash"
+	"gopkg.in/redis.v3/internal/hashtag"
 )
 
 var (
@@ -151,7 +152,7 @@ func (ring *Ring) getClient(key string) (*Client, error) {
 		return nil, errClosed
 	}
 
-	name := ring.hash.Get(hashKey(key))
+	name := ring.hash.Get(hashtag.Key(key))
 	if name == "" {
 		ring.mx.RUnlock()
 		return nil, errRingShardsDown
@@ -297,7 +298,7 @@ func (pipe *RingPipeline) Exec() (cmds []Cmder, retErr error) {
 
 	cmdsMap := make(map[string][]Cmder)
 	for _, cmd := range cmds {
-		name := pipe.ring.hash.Get(hashKey(cmd.clusterKey()))
+		name := pipe.ring.hash.Get(hashtag.Key(cmd.clusterKey()))
 		if name == "" {
 			cmd.setErr(errRingShardsDown)
 			if retErr == nil {