Add Redis-based distributed lock with Lua script for atomicity

biz/dal/mysql/shop.go

@@ -101,9 +101,10 @@ func queryByID2(ctx context.Context, id int64) (*shop.Shop, error) {
 	if err == nil {
 		return result, nil
 	}
-
+	lock := redis.NewLock(ctx, lockKey, key, 10)
 	// 2. 缓存未命中，尝试获取锁
-	isLocked := redis.TryLock(ctx, lockKey)
+	isLocked := lock.TryLock()
+	defer lock.UnLock(key)
 	if !isLocked {
 		// 锁获取失败，等待后重试
 		time.Sleep(50 * time.Millisecond)
@@ -113,7 +114,6 @@ func queryByID2(ctx context.Context, id int64) (*shop.Shop, error) {
 	// 2.2 获取锁成功，再次检查缓存
 	result, err = redis.GetShopFromCache(ctx, key)
 	if err == nil {
-		redis.UnLock(ctx, lockKey)
 		return result, nil
 	}
 
@@ -122,22 +122,17 @@ func queryByID2(ctx context.Context, id int64) (*shop.Shop, error) {
 	if err := DB.First(&shop, id).Error; err != nil {
 		if err == gorm.ErrRecordNotFound {
 			redis.RedisClient.Set(ctx, key, "", constants.CACHE_NULL_TTL).Err()
-			redis.UnLock(ctx, lockKey)
 			return nil, err
 		}
-		redis.UnLock(ctx, lockKey)
 		return nil, err
 	}
 
 	// 4. 数据库中存在，缓存数据
 	shopJson, err := json.Marshal(shop)
 	if err != nil {
-		redis.UnLock(ctx, lockKey)
 		return nil, err
 	}
 	redis.RedisClient.Set(ctx, key, string(shopJson), constants.CACHE_SHOP_TTL).Err()
-
-	redis.UnLock(ctx, lockKey)
 	return &shop, nil
 }
 

biz/dal/mysql/voucher.go

@@ -3,7 +3,6 @@ package mysql
 import (
 	"context"
 	"errors"
-	"fmt"
 	"gorm.io/gorm"
 	"xzdp/biz/model/voucher"
 )
@@ -29,7 +28,6 @@ func QueryVoucherByID(ctx context.Context, id int64) (*voucher.SeckillVoucher, e
 func QueryVoucherOrderByVoucherID(ctx context.Context, userId int64, id int64) error {
 	var voucherOrder voucher.VoucherOrder
 	err = DB.WithContext(ctx).Where("voucher_id = ? and user_id=?", id, userId).Limit(1).Find(&voucherOrder).Error
-	fmt.Printf("voucherOrder: %v\n", voucherOrder)
 	if err != nil {
 		if !errors.Is(err, gorm.ErrRecordNotFound) {
 			return errors.New("重复下单")

biz/dal/redis/init.go

@@ -59,10 +59,11 @@ func SetStringLogical(ctx context.Context, key string, value interface{}, durati
 
 func GetStringLogical(ctx context.Context, key string, duration time.Duration, dbFallback ArgsFunc, args ...interface{}) (string, error) {
 	redisJson, err := RedisClient.Get(ctx, key).Result()
+	lock := NewLock(ctx, constants.LOCK_KEY+key, "lock", duration)
 	if redisJson == "" || errors.Is(err, redis.Nil) {
-		if TryLock(ctx, constants.LOCK_KEY+key) {
+		if lock.TryLock() {
 			go func() {
-				defer UnLock(ctx, constants.LOCK_KEY+key)
+				defer lock.UnLock("lock")
 				data, err := dbFallback(args...)
 				if err != nil {
 					return
@@ -81,9 +82,9 @@ func GetStringLogical(ctx context.Context, key string, duration time.Duration, d
 		if redisData.ExpiredTime.After(time.Now()) {
 			return redisData.Data, nil
 		} else {
-			if TryLock(ctx, constants.LOCK_KEY+key) {
+			if lock.TryLock() {
 				go func() {
-					defer UnLock(ctx, constants.LOCK_KEY+key)
+					defer lock.UnLock("lock")
 					data, err := dbFallback(args...)
 					if err != nil {
 						return

biz/dal/redis/lock.go

@@ -6,15 +6,38 @@ import (
 	"time"
 )
 
-func TryLock(ctx context.Context, key string) bool {
-	success, err := RedisClient.SetNX(ctx, key, "1", 10*time.Second).Result()
+type Lock struct {
+	Ctx    context.Context
+	Key    string
+	Value  string
+	Expire time.Duration
+}
+
+func NewLock(ctx context.Context, key string, value string, expire time.Duration) *Lock {
+	return &Lock{
+		Ctx:    ctx,
+		Key:    key,
+		Value:  value,
+		Expire: expire,
+	}
+}
+
+func (l *Lock) TryLock() bool {
+	// value 应当全局唯一
+	success, err := RedisClient.SetNX(l.Ctx, l.Key, l.Value, l.Expire*time.Second).Result()
 	if err != nil {
 		log.Printf("Error acquiring lock: %v", err)
 		return false
 	}
 	return success
 }
 
-func UnLock(ctx context.Context, key string) {
-	RedisClient.Del(ctx, key)
+func (l *Lock) UnLock(value string) {
+	luaScript := `
+        if redis.call("get", KEYS[1]) == ARGV[1] then
+            return redis.call("del", KEYS[1])
+        end
+		return 0
+    `
+	RedisClient.Eval(l.Ctx, luaScript, []string{l.Key}, value)
 }

biz/middleware/interceptor/refresh_token.go

@@ -14,7 +14,7 @@ import (
 
 func CheckToken(ctx context.Context, c *app.RequestContext) {
 	hlog.CtxInfof(ctx, "check token interceptor:%+v", conf.GetEnv())
-	if conf.GetEnv() == "dev" {
+	if conf.GetEnv() != "online" {
 		userdto := model.UserDTO{
 			ID:       2,
 			NickName: "法外狂徒张三",

biz/service/voucher/seckill_voucher.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"github.com/cloudwego/hertz/pkg/app"
+	"strconv"
 	"sync"
 	"time"
 	"xzdp/biz/dal/mysql"
@@ -49,8 +50,16 @@ func (h *SeckillVoucherService) Run(req *int64) (resp *int64, err error) {
 	if voucher.GetStock() <= 0 {
 		return nil, errors.New("已抢空")
 	}
-	mu.Lock()
-	defer mu.Unlock()
+	user := utils.GetUser(h.Context)
+	uuid, _ := utils.RandomUUID()
+	sec := time.Now().Unix()
+	lockValue := uuid + strconv.FormatInt(sec, 10) //由于value的全局唯一性，这里用uuid+时间戳，如需要更高精度应考虑雪花算法活其他方法生成
+	lock := redis.NewLock(h.Context, user.NickName, lockValue, 10)
+	ok := lock.TryLock()
+	if !ok {
+		return nil, errors.New("重复下单")
+	}
+	defer lock.UnLock(lockValue)
 	return h.createOrder(*req)
 }