精简后的项目：仅保留 api/ui 源码、文档、构建依赖

api/dataloader/loaders.go

@@ -0,0 +1,48 @@
+package dataloader
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"gorm.io/gorm"
+)
+
+type contextKey string
+
+const loadersKey contextKey = "dataloaders"
+
+type Loaders struct {
+	MediaThumbnail      *MediaURLLoader
+	MediaHighres        *MediaURLLoader
+	MediaVideoWeb       *MediaURLLoader
+	UserFromAccessToken *UserLoader
+	UserMediaFavorite   *UserFavoritesLoader
+}
+
+func Middleware(db *gorm.DB) mux.MiddlewareFunc {
+	return mux.MiddlewareFunc(func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+			ctx := context.WithValue(r.Context(), loadersKey, &Loaders{
+				MediaThumbnail:      NewThumbnailMediaURLLoader(db),
+				MediaHighres:        NewHighresMediaURLLoader(db),
+				MediaVideoWeb:       NewVideoWebMediaURLLoader(db),
+				UserFromAccessToken: NewUserLoaderByToken(db),
+				UserMediaFavorite:   NewUserFavoriteLoader(db),
+			})
+
+			r = r.WithContext(ctx)
+
+			next.ServeHTTP(w, r)
+		})
+	})
+}
+
+func For(ctx context.Context) *Loaders {
+	loaders, ok := ctx.Value(loadersKey).(*Loaders)
+	if !ok {
+		return nil
+	}
+	return loaders
+}