fuse: move to top level

fuse/snapshot.go

@@ -0,0 +1,109 @@
+package fuse
+
+import (
+	"os"
+	"sync"
+	"time"
+
+	"bazil.org/fuse"
+	"bazil.org/fuse/fs"
+
+	"github.com/restic/restic"
+	"github.com/restic/restic/backend"
+	"github.com/restic/restic/repository"
+
+	"golang.org/x/net/context"
+)
+
+type SnapshotWithId struct {
+	*restic.Snapshot
+	backend.ID
+}
+
+// These lines statically ensure that a *SnapshotsDir implement the given
+// interfaces; a misplaced refactoring of the implementation that breaks
+// the interface will be catched by the compiler
+var _ = fs.HandleReadDirAller(&SnapshotsDir{})
+var _ = fs.NodeStringLookuper(&SnapshotsDir{})
+
+type SnapshotsDir struct {
+	repo *repository.Repository
+
+	// knownSnapshots maps snapshot timestamp to the snapshot
+	sync.RWMutex
+	knownSnapshots map[string]SnapshotWithId
+}
+
+func NewSnapshotsDir(repo *repository.Repository) *SnapshotsDir {
+	return &SnapshotsDir{
+		repo:           repo,
+		knownSnapshots: make(map[string]SnapshotWithId),
+	}
+}
+
+func (sn *SnapshotsDir) Attr(ctx context.Context, attr *fuse.Attr) error {
+	attr.Inode = 0
+	attr.Mode = os.ModeDir | 0555
+	return nil
+}
+
+func (sn *SnapshotsDir) updateCache(ctx context.Context) error {
+	sn.Lock()
+	defer sn.Unlock()
+
+	for id := range sn.repo.List(backend.Snapshot, ctx.Done()) {
+		snapshot, err := restic.LoadSnapshot(sn.repo, id)
+		if err != nil {
+			return err
+		}
+		sn.knownSnapshots[snapshot.Time.Format(time.RFC3339)] = SnapshotWithId{snapshot, id}
+	}
+	return nil
+}
+
+func (sn *SnapshotsDir) get(name string) (snapshot SnapshotWithId, ok bool) {
+	sn.RLock()
+	snapshot, ok = sn.knownSnapshots[name]
+	sn.RUnlock()
+	return snapshot, ok
+}
+
+func (sn *SnapshotsDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
+	err := sn.updateCache(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	sn.RLock()
+	defer sn.RUnlock()
+
+	ret := make([]fuse.Dirent, 0)
+	for _, snapshot := range sn.knownSnapshots {
+		ret = append(ret, fuse.Dirent{
+			Inode: inodeFromBackendId(snapshot.ID),
+			Type:  fuse.DT_Dir,
+			Name:  snapshot.Time.Format(time.RFC3339),
+		})
+	}
+
+	return ret, nil
+}
+
+func (sn *SnapshotsDir) Lookup(ctx context.Context, name string) (fs.Node, error) {
+	snapshot, ok := sn.get(name)
+
+	if !ok {
+		// We don't know about it, update the cache
+		err := sn.updateCache(ctx)
+		if err != nil {
+			return nil, err
+		}
+		snapshot, ok = sn.get(name)
+		if !ok {
+			// We still don't know about it, this time it really doesn't exist
+			return nil, fuse.ENOENT
+		}
+	}
+
+	return newDirFromSnapshot(sn.repo, snapshot)
+}