add album art caching

backend/imagemanager.go

@@ -1,36 +1,75 @@
 package backend
 
 import (
+	"fmt"
 	"image"
+	"image/jpeg"
+	"log"
+	"os"
+	"path/filepath"
 
+	"github.com/20after4/configdir"
 	"github.com/bluele/gcache"
 	subsonic "github.com/dweymouth/go-subsonic"
 )
 
 type ImageManager struct {
 	s              *subsonic.Client
+	cacheDir       string
 	thumbnailCache gcache.Cache
 }
 
-func NewImageManager(s *subsonic.Client) *ImageManager {
+func NewImageManager(s *subsonic.Client, cacheDir string) *ImageManager {
 	cache := gcache.New(100).LRU().Build()
+	if err := configdir.MakePath(cacheDir); err != nil {
+		log.Println("failed to create album cover cache dir")
+		cacheDir = ""
+	}
 	return &ImageManager{
 		s:              s,
+		cacheDir:       cacheDir,
 		thumbnailCache: cache,
 	}
 }
 
 func (i *ImageManager) GetAlbumThumbnail(albumID string) (image.Image, error) {
+	// in-memory cache
 	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"})
+
+	// on disc cache
+	path := filepath.Join(i.cacheDir, fmt.Sprintf("%s.jpg", albumID))
+	if i.cacheDir != "" {
+		if _, err := os.Stat(path); err == nil {
+			// serve image from on-disc cache
+			// TODO: image may have changed on server.
+			//    first, return cached image, then fetch fresh img from server in background
+			if f, err := os.Open(path); err == nil {
+				defer f.Close()
+				if img, _, err := image.Decode(f); err == nil {
+					i.thumbnailCache.Set(albumID, img)
+					return img, nil
+				}
+			}
+		}
+	}
+
+	// fetch from server
+	img, err := i.s.GetCoverArt(albumID, map[string]string{"size": "300"})
 	if err != nil {
 		return nil, err
 	}
+	if i.cacheDir != "" {
+		if f, err := os.Create(path); err == nil {
+			defer f.Close()
+			if err := jpeg.Encode(f, img, nil /*options*/); err != nil {
+				log.Printf("failed to cache image: %s", err.Error())
+			}
+		}
+	}
 	i.thumbnailCache.Set(albumID, img)
 	return img, nil
 }

go.mod

@@ -11,6 +11,7 @@ require (
 
 require (
 	fyne.io/systray v1.10.1-0.20220621085403-9a2652634e93 // indirect
+	github.com/20after4/configdir v0.1.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fredbi/uri v0.0.0-20181227131451-3dcfdacbaaf3 // indirect
 	github.com/fsnotify/fsnotify v1.5.4 // indirect

go.sum

@@ -39,6 +39,8 @@ cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 fyne.io/systray v1.10.1-0.20220621085403-9a2652634e93 h1:V2IC9t0Zj9Ur6qDbfhUuzVmIvXKFyxZXRJyigUvovs4=
 fyne.io/systray v1.10.1-0.20220621085403-9a2652634e93/go.mod h1:oM2AQqGJ1AMo4nNqZFYU8xYygSBZkW2hmdJ7n4yjedE=
+github.com/20after4/configdir v0.1.1 h1:ylL5dO+aGxBV4jDtG9Ej9hZfeE8Fw9jULQVq0N+ErJ8=
+github.com/20after4/configdir v0.1.1/go.mod h1:kZ7yOiD6MFUABqBI2/N62QA1wyEB8sGeI+mygme1pl4=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/toml v1.1.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=

main.go

@@ -6,51 +6,43 @@ import (
 	"gomuse/backend"
 	"gomuse/player"
 	"gomuse/ui"
+	"log"
 	"net/http"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/app"
 	"fyne.io/fyne/v2/container"
+	"github.com/20after4/configdir"
 	"github.com/dweymouth/go-subsonic"
 )
 
+const appname = "gomuse"
+
 func main() {
 	ctx, cancel := context.WithCancel(context.Background())
+	cachePath := configdir.LocalCache(appname)
+	log.Println(cachePath)
 
-	myApp := app.New()
-	myWindow := myApp.NewWindow("gomuse")
-
-	p := player.NewWithClientName("gomuse")
+	p := player.NewWithClientName(appname)
 	fmt.Println(p.Init())
 
 	s := &subsonic.Client{
 		Client:     &http.Client{},
 		BaseUrl:    "***REMOVED***",
 		User:       "drew",
-		ClientName: "gomuse",
+		ClientName: appname,
 	}
 
 	lm := backend.NewLibraryManager(s)
 	pm := backend.NewPlaybackManager(ctx, s, p)
-	im := backend.NewImageManager(s)
+	im := backend.NewImageManager(s, configdir.LocalCache(appname, "covers"))
 
 	if err := s.Authenticate("***REMOVED***"); err != nil {
 		fmt.Printf("error authenticating: %v\n", err)
 	}
 
-	/*
-		if len(os.Args) > 1 {
-			// search albums by args[1] and load first matching album
-			log.Printf("Searching for %q\n", os.Args[1])
-			if res, err := s.Search3(os.Args[1], map[string]string{}); err == nil {
-				if len(res.Album) > 0 {
-					log.Println("Got album search result")
-					album := res.Album[0]
-					pm.LoadAlbum(album.ID)
-				}
-			}
-		}
-	*/
+	myApp := app.New()
+	myWindow := myApp.NewWindow(appname)
 
 	b := ui.NewBottomPanel(p, pm, im)
 	ag := ui.NewAlbumGrid(lm.RecentlyAddedIter(), pm, im)

ui/albumcard.go

@@ -64,7 +64,7 @@ func NewAlbumCard() *AlbumCard {
 	a.title.Wrapping = fyne.TextTruncate
 	a.artist.Wrapping = fyne.TextTruncate
 	a.title.TextStyle = fyne.TextStyle{Bold: true}
-	a.Cover.im.SetMinSize(fyne.NewSize(225, 225))
+	a.Cover.im.SetMinSize(fyne.NewSize(200, 200))
 	a.Cover.im.FillMode = canvas.ImageFillContain
 
 	a.createContainer()