feat:为ListByFollowing方法添加上redis缓存

internal/feed/entity.go

@@ -35,8 +35,8 @@ type ListLikesCountRequest struct {
 }
 
 type LikesCountCursor struct {
-	LikesCount  int64
-	ID          uint
+	LikesCount int64
+	ID         uint
 }
 
 type ListLikesCountResponse struct {
@@ -47,7 +47,8 @@ type ListLikesCountResponse struct {
 }
 
 type ListByFollowingRequest struct {
-	Limit int `json:"limit"`
+	Limit      int   `json:"limit"`
+	LatestTime int64 `json:"latest_time"`
 }
 
 type ListByFollowingResponse struct {

internal/feed/handler.go

@@ -101,7 +101,11 @@ func (f *FeedHandler) ListByFollowing(c *gin.Context) {
 	if err != nil {
 		viewerAccountID = 0
 	}
-	feedItems, err := f.service.ListByFollowing(c.Request.Context(), req.Limit, viewerAccountID)
+	var latestTime time.Time
+	if req.LatestTime > 0 {
+		latestTime = time.Unix(req.LatestTime, 0)
+	}
+	feedItems, err := f.service.ListByFollowing(c.Request.Context(), req.Limit, latestTime, viewerAccountID)
 	if err != nil {
 		c.JSON(500, gin.H{"error": err.Error()})
 		return

internal/feed/repo.go

@@ -49,7 +49,7 @@ func (repo *FeedRepository) ListLikesCountWithCursor(ctx context.Context, limit
 	return videos, nil
 }
 
-func (repo *FeedRepository) ListByFollowing(ctx context.Context, limit int, viewerAccountID uint) ([]*video.Video, error) {
+func (repo *FeedRepository) ListByFollowing(ctx context.Context, limit int, viewerAccountID uint, latestBefore time.Time) ([]*video.Video, error) {
 	var videos []*video.Video
 	query := repo.db.WithContext(ctx).Model(&video.Video{}).
 		Order("create_time DESC")
@@ -60,6 +60,9 @@ func (repo *FeedRepository) ListByFollowing(ctx context.Context, limit int, view
 			Where("follower_id = ?", viewerAccountID)
 		query = query.Where("author_id IN (?)", followingSubQuery)
 	}
+	if !latestBefore.IsZero() {
+		query = query.Where("create_time < ?", latestBefore)
+	}
 	if err := query.Limit(limit).Find(&videos).Error; err != nil {
 		return nil, err
 	}

internal/feed/service.go

@@ -96,8 +96,27 @@ func (f *FeedService) ListLikesCount(ctx context.Context, limit int, cursor *Lik
 	return resp, nil
 }
 
-func (f *FeedService) ListByFollowing(ctx context.Context, limit int, viewerAccountID uint) (ListByFollowingResponse, error) {
-	videos, err := f.repo.ListByFollowing(ctx, limit, viewerAccountID)
+func (f *FeedService) ListByFollowing(ctx context.Context, limit int, latestBefore time.Time, viewerAccountID uint) (ListByFollowingResponse, error) {
+	var cacheKey string
+	if viewerAccountID != 0 && f.cache != nil {
+		before := int64(0)
+		if !latestBefore.IsZero() {
+			before = latestBefore.Unix()
+		}
+		cacheKey = fmt.Sprintf("feed:listByFollowing:limit=%d:accountID=%d:before=%d", limit, viewerAccountID, before)
+		cacheCtx, cancel := context.WithTimeout(ctx, 50*time.Millisecond)
+		defer cancel()
+
+		b, err := f.cache.GetBytes(cacheCtx, cacheKey)
+		if err == nil {
+			var cached ListByFollowingResponse
+			if err := json.Unmarshal(b, &cached); err == nil {
+				return cached, nil
+			}
+		}
+	}
+
+	videos, err := f.repo.ListByFollowing(ctx, limit, viewerAccountID, latestBefore)
 	if err != nil {
 		return ListByFollowingResponse{}, err
 	}
@@ -117,6 +136,13 @@ func (f *FeedService) ListByFollowing(ctx context.Context, limit int, viewerAcco
 		NextTime:  nextTime,
 		HasMore:   hasMore,
 	}
+	if cacheKey != "" {
+		if b, err := json.Marshal(resp); err == nil {
+			cacheCtx, cancel := context.WithTimeout(ctx, 50*time.Millisecond)
+			defer cancel()
+			_ = f.cache.SetBytes(cacheCtx, cacheKey, b, f.cacheTTL)
+		}
+	}
 	return resp, nil
 }