first commit

backend/imagemanager.go

@@ -0,0 +1,36 @@
+package backend
+
+import (
+	"image"
+
+	"github.com/bluele/gcache"
+	subsonic "github.com/dweymouth/go-subsonic"
+)
+
+type ImageManager struct {
+	s              *subsonic.Client
+	thumbnailCache gcache.Cache
+}
+
+func NewImageManager(s *subsonic.Client) *ImageManager {
+	cache := gcache.New(100).LRU().Build()
+	return &ImageManager{
+		s:              s,
+		thumbnailCache: cache,
+	}
+}
+
+func (i *ImageManager) GetAlbumThumbnail(albumID string) (image.Image, error) {
+	if i.thumbnailCache.Has(albumID) {
+		if img, err := i.thumbnailCache.Get(albumID); err == nil {
+			return img.(image.Image), nil
+		}
+	}
+	// TODO: on disc cache
+	img, err := i.s.GetCoverArt(albumID, map[string]string{"size": "250"})
+	if err != nil {
+		return nil, err
+	}
+	i.thumbnailCache.Set(albumID, img)
+	return img, nil
+}