Add caching to folders API #260

Signed-off-by: Michael Mayer <michael@liquidbytes.net>

internal/api/album.go

@@ -15,6 +15,7 @@ import (
 	"github.com/photoprism/photoprism/internal/event"
 	"github.com/photoprism/photoprism/internal/form"
 	"github.com/photoprism/photoprism/internal/query"
+	"github.com/photoprism/photoprism/internal/service"
 	"github.com/photoprism/photoprism/internal/thumb"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/rnd"
@@ -429,7 +430,7 @@ func AlbumThumbnail(router *gin.RouterGroup, conf *config.Config) {
 			return
 		}
 
-		gc := conf.Cache()
+		gc := service.Cache()
 		cacheKey := fmt.Sprintf("album-thumbnail:%s:%s", uuid, typeName)
 
 		if cacheData, ok := gc.Get(cacheKey); ok {

internal/api/folder.go

@@ -1,11 +1,14 @@
 package api
 
 import (
+	"fmt"
 	"net/http"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/entity"
+	"github.com/photoprism/photoprism/internal/service"
 )
 
 // GetFolders is a reusable request handler for directory listings (GET /api/v1/folders/*).
@@ -16,12 +19,26 @@ func GetFolders(router *gin.RouterGroup, conf *config.Config, root, pathName str
 			return
 		}
 
+		start := time.Now()
+		gc := service.Cache()
 		recursive := c.Query("recursive") != ""
 
+		cacheKey := fmt.Sprintf("folders:%s:%t", pathName, recursive)
+
+		if cacheData, ok := gc.Get(cacheKey); ok {
+			log.Debugf("folders: %s cache hit [%s]", cacheKey, time.Since(start))
+			c.JSON(http.StatusOK, cacheData.([]entity.Folder))
+			return
+		}
+
 		folders, err := entity.Folders(root, pathName, recursive)
 
 		if err != nil {
-			log.Errorf("folder: %s", err)
+			log.Errorf("folders: %s", err)
+		} else {
+			gc.Set(cacheKey, folders, time.Minute*5)
+
+			log.Debugf("folders: %s cached [%s]", cacheKey, time.Since(start))
 		}
 
 		c.JSON(http.StatusOK, folders)

internal/api/label.go

@@ -15,6 +15,7 @@ import (
 	"github.com/photoprism/photoprism/internal/event"
 	"github.com/photoprism/photoprism/internal/form"
 	"github.com/photoprism/photoprism/internal/query"
+	"github.com/photoprism/photoprism/internal/service"
 	"github.com/photoprism/photoprism/internal/thumb"
 	"github.com/photoprism/photoprism/pkg/fs"
 	"github.com/photoprism/photoprism/pkg/txt"
@@ -175,7 +176,7 @@ func LabelThumbnail(router *gin.RouterGroup, conf *config.Config) {
 			return
 		}
 
-		gc := conf.Cache()
+		gc := service.Cache()
 		cacheKey := fmt.Sprintf("label-thumbnail:%s:%s", labelUUID, typeName)
 
 		if cacheData, ok := gc.Get(cacheKey); ok {

internal/service/cache.go

@@ -0,0 +1,20 @@
+package service
+
+import (
+	"sync"
+	"time"
+
+	gc "github.com/patrickmn/go-cache"
+)
+
+var onceCache sync.Once
+
+func initCache() {
+	services.Cache = gc.New(336*time.Hour, 30*time.Minute)
+}
+
+func Cache() *gc.Cache {
+	onceCache.Do(initCache)
+
+	return services.Cache
+}

internal/service/service.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	gc "github.com/patrickmn/go-cache"
 	"github.com/photoprism/photoprism/internal/classify"
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/nsfw"
@@ -12,6 +13,7 @@ import (
 var conf *config.Config
 
 var services struct {
+	Cache    *gc.Cache
 	Classify *classify.TensorFlow
 	Convert  *photoprism.Convert
 	Import   *photoprism.Import