added preload status and cancel

pkg/fs/fs.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"io"
 	stdfs "io/fs"
+	"math"
 	"net/http"
 	"os"
 	"path"
@@ -28,6 +29,7 @@ type FS struct {
 	mdf     *os.File
 	jenc    *json.Encoder
 	mm      map[string]*Metadata
+	prem    map[string]func()
 	cancel  func()
 }
 
@@ -55,6 +57,7 @@ func NewFS(src, dst, metadata string, log logr.Logger) (fs *FS, err error) {
 		dst:     dst,
 		mdf:     mdf,
 		mm:      make(map[string]*Metadata),
+		prem:    make(map[string]func()),
 		jenc:    json.NewEncoder(mdf),
 	}
 	err = json.NewDecoder(mdf).Decode(&fs.mm)
@@ -79,7 +82,7 @@ func (fs *FS) initMetadata() {
 		}
 		if len(v.Chunks) == 0 {
 			log.V(2).Info("removing empty file", "file", k)
-			err := fs.removeDst(k)
+			err := fs.RemoveDst(k)
 			if err != nil {
 				log.Error(err, "error removing empty file", "file", k)
 				continue
@@ -110,7 +113,7 @@ func (fs *FS) StatWithOffline(name string) (fi stdfs.FileInfo, offline bool, err
 	return
 }
 
-func (fs *FS) removeDst(name string) error {
+func (fs *FS) RemoveDst(name string) error {
 	_, dp := fs.paths(name)
 	return os.Remove(dp)
 }
@@ -120,25 +123,33 @@ func (fs *FS) statDst(name string) (fi stdfs.FileInfo, err error) {
 	return os.Stat(dp)
 }
 
-func (fs *FS) Open(name string) (http.File, error) {
-	return fs.open(name)
-}
-
-func (fs *FS) OpenFile(name string) (*File, error) {
-	return fs.open(name)
+func (fs *FS) CancelPreload(name string) {
+	if cancel, ok := fs.prem[name]; ok {
+		cancel()
+	}
 }
 
 func (fs *FS) Preload(name string) {
-	f, err := fs.open(name)
+	file, err := fs.Open(name)
 	if err != nil {
 		return
 	}
+	f, ok := file.(*File)
+	if !ok {
+		return
+	}
+
 	if f.md.Preload() {
 		fs.log.WithValues("file", name).Error(errors.New("preload is running"), "error starting preload")
 		return
 	}
-	unlock := func() { f.md.UnlockPreload() }
-	go f.Preload(unlock)
+	ctx, cancel := context.WithCancel(context.Background())
+	fs.prem[name] = cancel
+	unlock := func() {
+		delete(fs.prem, name)
+		f.md.UnlockPreload()
+	}
+	go f.Preload(ctx, unlock)
 }
 
 func skipLog(name string) bool {
@@ -152,7 +163,7 @@ func (fs *FS) paths(name string) (sp string, dp string) {
 	return
 }
 
-func (fs *FS) open(name string) (f *File, err error) {
+func (fs *FS) Open(name string) (f http.File, err error) {
 	log := fs.log.WithValues("file", name)
 	sp, dp := fs.paths(name)
 	offline := false
@@ -186,7 +197,7 @@ func (fs *FS) open(name string) (f *File, err error) {
 			offline = true
 			log.V(2).Info("dir offline mode", "path", dp)
 		}
-		return &File{f: sf, offline: offline}, err
+		return &Dir{f: sf}, err
 	}
 	md := fs.metadata(name, sfi.Size())
 	return &File{
@@ -244,6 +255,15 @@ func (fs *FS) metadata(name string, size int64) (md *Metadata) {
 	return
 }
 
+func (fs *FS) CacheStatus(name string) int {
+	fs.mu.RLock()
+	defer fs.mu.RUnlock()
+	if md, ok := fs.mm[name]; ok {
+		return int(math.Round(float64(md.Chunks.Size()) / float64(md.Size) * 100))
+	}
+	return -1
+}
+
 func (fs *FS) flusher(ctx context.Context) {
 	for {
 		select {