mountlib: refactor before adding serve docker (#5415)

Co-authored-by: Ivan Andreev <ivandeex@gmail.com>

cmd/mountlib/rc.go

@@ -11,29 +11,33 @@ import (
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/rc"
 	"github.com/rclone/rclone/vfs"
-	"github.com/rclone/rclone/vfs/vfscommon"
 	"github.com/rclone/rclone/vfs/vfsflags"
 )
 
-// MountInfo defines the configuration for a mount
-type MountInfo struct {
-	unmountFn  UnmountFn
-	MountPoint string    `json:"MountPoint"`
-	MountedOn  time.Time `json:"MountedOn"`
-	Fs         string    `json:"Fs"`
-	MountOpt   *Options
-	VFSOpt     *vfscommon.Options
-}
-
 var (
 	// mutex to protect all the variables in this block
 	mountMu sync.Mutex
 	// Mount functions available
 	mountFns = map[string]MountFn{}
 	// Map of mounted path => MountInfo
-	liveMounts = map[string]MountInfo{}
+	liveMounts = map[string]*MountPoint{}
+	// Supported mount types
+	supportedMountTypes = []string{"mount", "cmount", "mount2"}
 )
 
+// ResolveMountMethod returns mount function by name
+func ResolveMountMethod(mountType string) (string, MountFn) {
+	if mountType != "" {
+		return mountType, mountFns[mountType]
+	}
+	for _, mountType := range supportedMountTypes {
+		if mountFns[mountType] != nil {
+			return mountType, mountFns[mountType]
+		}
+	}
+	return "", nil
+}
+
 // AddRc adds mount and unmount functionality to rc
 func AddRc(mountUtilName string, mountFunction MountFn) {
 	mountMu.Lock()
@@ -99,14 +103,12 @@ func mountRc(ctx context.Context, in rc.Params) (out rc.Params, err error) {
 	mountMu.Lock()
 	defer mountMu.Unlock()
 
-	if err != nil || mountType == "" {
-		if mountFns["mount"] != nil {
-			mountType = "mount"
-		} else if mountFns["cmount"] != nil {
-			mountType = "cmount"
-		} else if mountFns["mount2"] != nil {
-			mountType = "mount2"
-		}
+	if err != nil {
+		mountType = ""
+	}
+	mountType, mountFn := ResolveMountMethod(mountType)
+	if mountFn == nil {
+		return nil, errors.New("Mount Option specified is not registered, or is invalid")
 	}
 
 	// Get Fs.fs to be mounted from fs parameter in the params
@@ -115,28 +117,26 @@ func mountRc(ctx context.Context, in rc.Params) (out rc.Params, err error) {
 		return nil, err
 	}
 
-	if mountFns[mountType] != nil {
-		VFS := vfs.New(fdst, &vfsOpt)
-		_, unmountFn, err := mountFns[mountType](VFS, mountPoint, &mountOpt)
-
-		if err != nil {
-			log.Printf("mount FAILED: %v", err)
-			return nil, err
-		}
-		// Add mount to list if mount point was successfully created
-		liveMounts[mountPoint] = MountInfo{
-			unmountFn:  unmountFn,
-			MountedOn:  time.Now(),
-			Fs:         fdst.Name(),
-			MountPoint: mountPoint,
-			VFSOpt:     &vfsOpt,
-			MountOpt:   &mountOpt,
-		}
-
-		fs.Debugf(nil, "Mount for %s created at %s using %s", fdst.String(), mountPoint, mountType)
-		return nil, nil
+	VFS := vfs.New(fdst, &vfsOpt)
+	_, unmountFn, err := mountFn(VFS, mountPoint, &mountOpt)
+	if err != nil {
+		log.Printf("mount FAILED: %v", err)
+		return nil, err
 	}
-	return nil, errors.New("Mount Option specified is not registered, or is invalid")
+
+	// Add mount to list if mount point was successfully created
+	liveMounts[mountPoint] = &MountPoint{
+		MountPoint: mountPoint,
+		MountedOn:  time.Now(),
+		MountFn:    mountFn,
+		UnmountFn:  unmountFn,
+		MountOpt:   mountOpt,
+		VFSOpt:     vfsOpt,
+		Fs:         fdst,
+	}
+
+	fs.Debugf(nil, "Mount for %s created at %s using %s", fdst.String(), mountPoint, mountType)
+	return nil, nil
 }
 
 func init() {
@@ -169,10 +169,14 @@ func unMountRc(_ context.Context, in rc.Params) (out rc.Params, err error) {
 	}
 	mountMu.Lock()
 	defer mountMu.Unlock()
-	err = performUnMount(mountPoint)
-	if err != nil {
+	mountInfo, found := liveMounts[mountPoint]
+	if !found {
+		return nil, errors.New("mount not found")
+	}
+	if err = mountInfo.Unmount(); err != nil {
 		return nil, err
 	}
+	delete(liveMounts, mountPoint)
 	return nil, nil
 }
 
@@ -231,16 +235,34 @@ Eg
 	})
 }
 
-// listMountsRc returns a list of current mounts
+// MountInfo is a transitional structure for json marshaling
+type MountInfo struct {
+	Fs         string    `json:"Fs"`
+	MountPoint string    `json:"MountPoint"`
+	MountedOn  time.Time `json:"MountedOn"`
+}
+
+// listMountsRc returns a list of current mounts sorted by mount path
 func listMountsRc(_ context.Context, in rc.Params) (out rc.Params, err error) {
-	var mountTypes = []MountInfo{}
 	mountMu.Lock()
 	defer mountMu.Unlock()
-	for _, a := range liveMounts {
-		mountTypes = append(mountTypes, a)
+	var keys []string
+	for key := range liveMounts {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	mountPoints := []MountInfo{}
+	for _, k := range keys {
+		m := liveMounts[k]
+		info := MountInfo{
+			Fs:         m.Fs.Name(),
+			MountPoint: m.MountPoint,
+			MountedOn:  m.MountedOn,
+		}
+		mountPoints = append(mountPoints, info)
 	}
 	return rc.Params{
-		"mountPoints": mountTypes,
+		"mountPoints": mountPoints,
 	}, nil
 }
 
@@ -265,27 +287,12 @@ Eg
 func unmountAll(_ context.Context, in rc.Params) (out rc.Params, err error) {
 	mountMu.Lock()
 	defer mountMu.Unlock()
-	for key, mountInfo := range liveMounts {
-		err = performUnMount(mountInfo.MountPoint)
-		if err != nil {
-			fs.Debugf(nil, "Couldn't unmount : %s", key)
+	for mountPoint, mountInfo := range liveMounts {
+		if err = mountInfo.Unmount(); err != nil {
+			fs.Debugf(nil, "Couldn't unmount : %s", mountPoint)
 			return nil, err
 		}
+		delete(liveMounts, mountPoint)
 	}
 	return nil, nil
 }
-
-// performUnMount unmounts the specified mountPoint
-func performUnMount(mountPoint string) (err error) {
-	mountInfo, ok := liveMounts[mountPoint]
-	if ok {
-		err := mountInfo.unmountFn()
-		if err != nil {
-			return err
-		}
-		delete(liveMounts, mountPoint)
-	} else {
-		return errors.New("mount not found")
-	}
-	return nil
-}