support hscan in redis (#428)

core/stores/redis/redis.go

@@ -501,6 +501,20 @@ func (s *Redis) Hvals(key string) (val []string, err error) {
 	return
 }
 
+func (s *Redis) Hscan(key string, cursor uint64, match string, count int64) (keys []string, cur uint64, err error) {
+	err = s.brk.DoWithAcceptable(func() error {
+		conn, err := getRedis(s)
+		if err != nil {
+			return err
+		}
+
+		keys, cur, err = conn.HScan(key, cursor, match, count).Result()
+		return err
+	}, acceptable)
+
+	return
+}
+
 func (s *Redis) Incr(key string) (val int64, err error) {
 	err = s.brk.DoWithAcceptable(func() error {
 		conn, err := getRedis(s)

core/stores/redis/redis_test.go

@@ -3,6 +3,7 @@ package redis
 import (
 	"errors"
 	"io"
+	"strconv"
 	"testing"
 	"time"
 
@@ -158,6 +159,38 @@ func TestRedis_Hmset(t *testing.T) {
 	})
 }
 
+func TestRedis_Hscan(t *testing.T) {
+	runOnRedis(t, func(client *Redis) {
+		key := "hash:test"
+		fieldsAndValues := make(map[string]string)
+		for i := 0; i < 1550; i++ {
+			fieldsAndValues["filed_" + strconv.Itoa(i)] = randomStr(i)
+		}
+		err := client.Hmset(key, fieldsAndValues)
+		assert.Nil(t, err)
+
+		var cursor uint64 = 0
+		sum := 0
+		for {
+			_, _, err := NewRedis(client.Addr, "").Hscan(key, cursor, "*", 100)
+			assert.NotNil(t, err)
+			reMap, next, err := client.Hscan(key, cursor, "*", 100)
+			assert.Nil(t, err)
+			sum += len(reMap)
+			if next == 0 {
+				break
+			}
+			cursor = next
+		}
+
+		assert.Equal(t, sum, 3100)
+		_, err = NewRedis(client.Addr, "").Del(key)
+		assert.NotNil(t, err)
+		_, err = client.Del(key)
+		assert.Nil(t, err)
+	})
+}
+
 func TestRedis_Incr(t *testing.T) {
 	runOnRedis(t, func(client *Redis) {
 		_, err := NewRedis(client.Addr, "").Incr("a")