feat(middleware):为登录与互动接口增加限流中间件

backend/internal/middleware/ratelimit/ratelimit.go

@@ -0,0 +1,71 @@
+package ratelimit
+
+import (
+	rediscache "feedsystem_video_go/internal/middleware/redis"
+	jwt "feedsystem_video_go/internal/middleware/jwt"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+	"strconv"
+	"github.com/gin-gonic/gin"
+)
+
+type KeyFunc func(*gin.Context) (string, bool)
+
+func Limit(
+	cache *rediscache.Client,
+	keyPrefix string,
+	maxRequests int64,
+	window time.Duration,
+	keyFunc KeyFunc,
+) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if cache == nil || keyFunc == nil || maxRequests <= 0 || window <= 0 {
+			c.Next()
+			return
+		}
+		subject, ok := keyFunc(c)
+		if !ok {
+			c.Next()
+			return
+		}
+		key := buildKey(keyPrefix, subject)
+		count, err := cache.IncrementWithExpire(c.Request.Context(), key, window)
+		if err != nil {
+			c.Next()
+			return
+		}
+		if count > maxRequests {
+			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{
+				"error": "too many requests",
+			})
+			return
+		}
+		c.Next()
+	}
+}
+
+func buildKey(keyPrefix, subject string) string {
+	keyPrefix = strings.TrimSpace(keyPrefix)
+	if keyPrefix == "" {
+		keyPrefix = "default"
+	}
+	return fmt.Sprintf("feedsystem:ratelimit:%s:%s", keyPrefix, strings.TrimSpace(subject))
+}
+
+func KeyByIP(c *gin.Context) (string, bool) {
+	ip := strings.TrimSpace(c.ClientIP())
+	if ip == "" {
+		return "", false
+	}
+	return ip, true
+}
+
+func KeyByAccount(c *gin.Context) (string, bool) {
+	accountID, err := jwt.GetAccountID(c)
+	if err != nil || accountID == 0 {
+		return "", false
+	}
+	return strconv.FormatUint(uint64(accountID), 10), true
+}

backend/internal/middleware/redis/redis.go

@@ -77,3 +77,20 @@ func (c *Client) Unlock(ctx context.Context, key string, token string) error {
 	_, err := unlockScript.Run(ctx, c.rdb, []string{key}, token).Result()
 	return err
 }
+
+func (c *Client) IncrementWithExpire(ctx context.Context, key string, expire time.Duration) (int64, error) {
+	if c == nil || c.rdb == nil {
+		return 0, nil
+	}
+	count, err := c.rdb.Incr(ctx, key).Result()
+	if err != nil {
+		return 0, err
+	}
+	if count == 1 {
+		err = c.rdb.Expire(ctx, key, expire).Err()
+		if err != nil {
+			return 0, err
+		}
+	}
+	return count, nil
+}