feat: add a proper caching system to the transcoding functionality

engine/wire_providers.go

@@ -1,8 +1,14 @@
 package engine
 
 import (
+	"path/filepath"
+	"time"
+
+	"github.com/deluan/navidrome/conf"
+	"github.com/deluan/navidrome/consts"
 	"github.com/deluan/navidrome/engine/ffmpeg"
 	"github.com/google/wire"
+	"gopkg.in/djherbis/fscache.v0"
 )
 
 var Set = wire.NewSet(
@@ -17,4 +23,16 @@ var Set = wire.NewSet(
 	NewUsers,
 	NewMediaStreamer,
 	ffmpeg.New,
+	NewTranscodingCache,
 )
+
+func NewTranscodingCache() (fscache.Cache, error) {
+	lru := fscache.NewLRUHaunter(0, conf.Server.MaxTranscodingCacheSize, 30*time.Second)
+	h := fscache.NewLRUHaunterStrategy(lru)
+	cacheFolder := filepath.Join(conf.Server.DataFolder, consts.CacheDir)
+	fs, err := fscache.NewFs(cacheFolder, 0755)
+	if err != nil {
+		return nil, err
+	}
+	return fscache.NewCacheWithHaunter(fs, h)
+}