[feature] 增加一个随机图片接口

cmd/api/main.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"git.vtb.link/eoefans/internal/app"
+	"git.vtb.link/eoefans/internal/app/api/service"
 	"git.vtb.link/eoefans/internal/launcher"
 	"git.vtb.link/eoefans/internal/pkg/database"
 	"git.vtb.link/eoefans/internal/pkg/httpserver"
@@ -23,7 +24,7 @@ func newAPI() fx.Option {
 	)
 }
 
-func lc(lifecycle fx.Lifecycle, ginServer *httpserver.Server) {
+func lc(lifecycle fx.Lifecycle, ginServer *httpserver.Server, randPicsCache *service.RandomPicsCache) {
 	lifecycle.Append(fx.Hook{
 		OnStart: func(ctx context.Context) error {
 			return ginServer.Start()
@@ -32,4 +33,9 @@ func lc(lifecycle fx.Lifecycle, ginServer *httpserver.Server) {
 			return ginServer.Stop()
 		},
 	})
+	lifecycle.Append(fx.Hook{
+		OnStart: func(ctx context.Context) error {
+			return randPicsCache.Run()
+		},
+	})
 }

internal/app/api/handler/bilbil_picture.go

@@ -41,3 +41,14 @@ func BilibiliRecommendPics(s *service.BilbilPicture) func(ctx *gin.Context) {
 		}
 	}
 }
+
+func BilibiliRandomPic(s *service.BilbilPicture) func(ctx *gin.Context) {
+	return func(ctx *gin.Context) {
+		if resp, err := s.Random(ctx); err != nil {
+			_ = ctx.Error(err)
+			return
+		} else {
+			ctx.JSON(http.StatusOK, help.SuccessJson(resp))
+		}
+	}
+}

internal/app/api/idl/bilibili_picture.go

@@ -65,6 +65,10 @@ type BilibiliPicturesRecommendResp struct {
 	Page  int `json:"page"`
 	Total int `json:"total"`
 }
+
+type BilibiliPictureRandomResp struct {
+	BilibiliDynamicPicture
+}
 type BilibiliDynamicDTO struct {
 	DynamicID uint64                  `json:"dynamic_id"`
 	Pictures  BilibiliDynamicPictures `json:"pictures"`
@@ -90,4 +94,5 @@ type BilibiliPictureRepository interface {
 	FindAllByPubDate(from, to time.Time, page, size int64) (list []*BilibiliDynamic, err error)
 	Latest(page, size, topicID int) (list []*BilibiliDynamic, err error)
 	Recommend(from, to time.Time, page, size, topicID int) (list []*BilibiliDynamic, err error)
+	Random(rand float64) (list []*BilibiliDynamic, err error)
 }

internal/app/api/router/router.go

@@ -33,6 +33,7 @@ func InitRouters(
 		{
 			picApi.GET("/latest", handler.BilibiliLatestPics(picService))
 			picApi.GET("/recommend", handler.BilibiliRecommendPics(picService))
+			picApi.GET("/random", handler.BilibiliRandomPic(picService))
 		}
 		// Auth相关
 		authApi := r.Group("/v1/auth")

internal/app/api/service/bilbil_picture.go

@@ -2,17 +2,88 @@ package service
 
 import (
 	"context"
+	"errors"
+	"math/rand"
+	"sync"
 	"time"
 
 	"git.vtb.link/eoefans/internal/app/api/idl"
 	"git.vtb.link/eoefans/internal/repository"
+	"go.uber.org/zap"
 	"gorm.io/gorm"
 )
 
 const (
 	picRecommendDefaultSize = 20
 )
 
+type RandomPicKey string
+
+const (
+	overall RandomPicKey = "overall"
+)
+
+var (
+	errRandomPictureNotFound = errors.New("random picture was not found")
+)
+var (
+	randomPicsCache *RandomPicsCache = &RandomPicsCache{
+		syncMap: &sync.Map{},
+	}
+)
+
+type RandomPicsCache struct {
+	syncMap *sync.Map
+	success bool
+	db      *gorm.DB
+	log     *zap.Logger
+}
+
+func NewRandomPicsCache(db *gorm.DB, log *zap.Logger) *RandomPicsCache {
+	randomPicsCache.db = db
+	randomPicsCache.log = log
+	return randomPicsCache
+}
+
+func (c *RandomPicsCache) Run() error {
+	tk := time.NewTicker(5 * time.Second)
+	go func() {
+		c.flush()
+	}()
+	go func(_tk *time.Ticker) {
+		for {
+			select {
+			case <-_tk.C:
+				c.flush()
+			default:
+				continue
+			}
+		}
+	}(tk)
+	return nil
+}
+
+func (c *RandomPicsCache) flush() {
+	now := time.Now()
+	rand.Seed(now.UnixNano())
+	tx := c.db.WithContext(context.Background())
+	picRepository := repository.NewBilibiliPicture(tx)
+	list, err := picRepository.Random(rand.Float64())
+	if err != nil || len(list) == 0 {
+		c.success = false
+		c.log.Error("randomPicsCache flush error ", zap.Error(err), zap.Time("time", now), zap.Int("list", len(list)))
+		return
+	}
+	pictures := make(idl.BilibiliDynamicPictures, 0)
+	for i := range list {
+		for j := range list[i].Pictures {
+			pictures = append(pictures, list[i].Pictures[j])
+		}
+	}
+	c.syncMap.Store(overall, pictures)
+	c.success = true
+}
+
 type BilbilPicture struct {
 	db *gorm.DB
 }
@@ -63,3 +134,39 @@ func (service *BilbilPicture) Recommend(ctx context.Context, req idl.BilibiliPic
 	}
 	return &resp, nil
 }
+
+func (service *BilbilPicture) Random(ctx context.Context) (*idl.BilibiliPictureRandomResp, error) {
+	if randomPicsCache.success {
+		value, ok := randomPicsCache.syncMap.Load(overall)
+		if ok {
+			pictures, ok := value.(idl.BilibiliDynamicPictures)
+			if ok && len(pictures) != 0 {
+				idx := rand.Intn(len(pictures))
+				resp := &idl.BilibiliPictureRandomResp{}
+				resp.BilibiliDynamicPicture = pictures[idx]
+				return resp, nil
+			}
+		}
+	}
+	now := time.Now()
+	rand.Seed(now.UnixNano())
+	tx := service.db.WithContext(ctx)
+	picRepository := repository.NewBilibiliPicture(tx)
+	list, err := picRepository.Random(rand.Float64())
+	if err != nil {
+		return nil, err
+	}
+	if len(list) == 0 {
+		return nil, errRandomPictureNotFound
+	}
+	pictures := make(idl.BilibiliDynamicPictures, 0)
+	for i := range list {
+		for j := range list[i].Pictures {
+			pictures = append(pictures, list[i].Pictures[j])
+		}
+	}
+	idx := rand.Intn(len(pictures))
+	resp := &idl.BilibiliPictureRandomResp{}
+	resp.BilibiliDynamicPicture = pictures[idx]
+	return resp, nil
+}

internal/app/provide.go

@@ -37,5 +37,6 @@ func ServiceProvider() fx.Option {
 		service.NewAuth,
 		service.NewUser,
 		service.NewTool,
+		service.NewRandomPicsCache,
 	)
 }

internal/repository/bilibili_picture.go

@@ -1,6 +1,7 @@
 package repository
 
 import (
+	"math"
 	"time"
 
 	"git.vtb.link/eoefans/internal/app/api/idl"
@@ -90,3 +91,22 @@ func (impl *BilibiliPictureMysqlImpl) Recommend(from, to time.Time, page, size,
 	}
 	return list, nil
 }
+
+func (impl *BilibiliPictureMysqlImpl) Random(rand float64) (list []*idl.BilibiliDynamic, err error) {
+	conn := impl.tx.Table(idl.BilibiliDynamic{}.TableName())
+	type Pair struct {
+		MaxId float64
+		MinId float64
+	}
+	var pair Pair
+	err = conn.Select("max(id) as max_id,min(id) as min_id").Scan(&pair).Error
+	if err != nil {
+		return nil, err
+	}
+	offset := math.Floor((pair.MaxId - pair.MinId) * rand)
+	err = conn.Where("id >= ?", uint64(pair.MinId+offset)).Select("pictures").Limit(5).Find(&list).Error
+	if err != nil {
+		return nil, err
+	}
+	return list, nil
+}