Add a flag to toggle OneDrive delta incrementals

This will help us while this is still in development. We should be
able to add in features without affecting anything else.

Once we have it in a more or less stable state this can be removed
completely.

src/cli/backup/onedrive.go

@@ -81,6 +81,7 @@ func addOneDriveCommands(cmd *cobra.Command) *cobra.Command {
 	case createCommand:
 		c, fs = utils.AddCommand(cmd, oneDriveCreateCmd())
 		options.AddFeatureToggle(cmd, options.EnablePermissionsBackup())
+		options.AddFeatureToggle(cmd, options.EnableOneDriveDeltaIncrementals())
 
 		c.Use = c.Use + " " + oneDriveServiceCommandCreateUseSuffix
 		c.Example = oneDriveServiceCommandCreateExamples

src/cli/options/options.go

@@ -16,6 +16,7 @@ func Control() control.Options {
 	opt.RestorePermissions = restorePermissions
 	opt.ToggleFeatures.DisableIncrementals = disableIncrementals
 	opt.ToggleFeatures.EnablePermissionsBackup = enablePermissionsBackup
+	opt.ToggleFeatures.EnableOneDriveDeltaIncrementals = enableOneDriveDeltaIncrentals
 
 	return opt
 }
@@ -57,8 +58,9 @@ func AddRestorePermissionsFlag(cmd *cobra.Command) {
 // ---------------------------------------------------------------------------
 
 var (
-	disableIncrementals     bool
+	disableIncrementals           bool
-	enablePermissionsBackup bool
+	enablePermissionsBackup       bool
+	enableOneDriveDeltaIncrentals bool
 )
 
 type exposeFeatureFlag func(*pflag.FlagSet)
@@ -97,3 +99,16 @@ func EnablePermissionsBackup() func(*pflag.FlagSet) {
 		cobra.CheckErr(fs.MarkHidden("enable-permissions-backup"))
 	}
 }
+
+// Adds the hidden '--enable-onedrive-delta-incrementals' cli flag which, when
+// set, enables delta incrementals for OneDrive.
+func EnableOneDriveDeltaIncrementals() func(*pflag.FlagSet) {
+	return func(fs *pflag.FlagSet) {
+		fs.BoolVar(
+			&enableOneDriveDeltaIncrentals,
+			"enable-onedrive-delta-incrementals",
+			false,
+			"Enables delta based incrementals for OneDrive")
+		cobra.CheckErr(fs.MarkHidden("enable-onedrive-delta-incrementals"))
+	}
+}

src/internal/operations/backup.go

@@ -289,6 +289,11 @@ func (op *BackupOperation) do(
 // checker to see if conditions are correct for incremental backup behavior such as
 // retrieving metadata like delta tokens and previous paths.
 func useIncrementalBackup(sel selectors.Selector, opts control.Options) bool {
+	// TODO(meain): remove this once we stabilize delta incrementals for OneDrive
+	if sel.Service == selectors.ServiceOneDrive {
+		return opts.ToggleFeatures.EnableOneDriveDeltaIncrementals
+	}
+
 	// Delta-based incrementals currently only supported for Exchange
 	if sel.Service != selectors.ServiceExchange {
 		return false

src/pkg/control/options.go

@@ -80,4 +80,10 @@ type Toggles struct {
 	// permissions. Permission metadata increases graph api call count,
 	// so disabling their retrieval when not needed is advised.
 	EnablePermissionsBackup bool `json:"enablePermissionsBackup,omitempty"`
+
+	// EnableOneDriveDeltaIncrementals is used to enable OneDrive
+	// delta incrementals. It is set to false by default as OneDrive
+	// delta incrementals is still in development. This flag works
+	// independent of DisableIncrementals.
+	EnableOneDriveDeltaIncrementals bool `json:"enableOneDriveDeltaIncrementals,omitempty"`
 }