Use a map[string]struct{} for validOpts

For consistency with `mandatoryOpts`, and because it is a
tiny-tiny bit more efficient.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

3 files changed, 6 insertions, 6 deletions

diff --git a/volume/local/local.go b/volume/local/local.go
index 1c844cf0e3..6bf2aa9015 100644
--- a/volume/local/local.go
+++ b/volume/local/local.go
@@ -357,7 +357,7 @@ func validateOpts(opts map[string]string) error {
 		return nil
 	}
 	for opt := range opts {
-		if !validOpts[opt] {
+		if _, ok := validOpts[opt]; !ok {
 			return validationError(fmt.Sprintf("invalid option key: %q", opt))
 		}
 	}
diff --git a/volume/local/local_unix.go b/volume/local/local_unix.go
index 1d25c330da..e8f12c9030 100644
--- a/volume/local/local_unix.go
+++ b/volume/local/local_unix.go
@@ -22,10 +22,10 @@ import (
 var (
 	oldVfsDir = filepath.Join("vfs", "dir")
 
-	validOpts = map[string]bool{
-		"type":   true, // specify the filesystem type for mount, e.g. nfs
-		"o":      true, // generic mount options
-		"device": true, // device to mount from
+	validOpts = map[string]struct{}{
+		"type":   {}, // specify the filesystem type for mount, e.g. nfs
+		"o":      {}, // generic mount options
+		"device": {}, // device to mount from
 	}
 	mandatoryOpts = map[string]struct{}{
 		"device": {},
diff --git a/volume/local/local_windows.go b/volume/local/local_windows.go
index 5748681bb0..eb19e79747 100644
--- a/volume/local/local_windows.go
+++ b/volume/local/local_windows.go
@@ -15,7 +15,7 @@ import (
 type optsConfig struct{}
 
 var (
-	validOpts     map[string]bool
+	validOpts     map[string]struct{}
 	mandatoryOpts map[string]struct{}
 )