added errors to blacklist

blacklist.go

@@ -6,10 +6,10 @@ import "sync"
 
 // Blacklist is the blacklisting storage interface
 type Blacklist interface {
-	Add(string, int64)
-	Remove(string)
+	Add(string, int64) error
+	Remove(string) error
 	Check(string) bool
-	Map() BlacklistMap
+	Map() (BlacklistMap, error)
 }
 
 // BlacklistMap is the blacklist map structure
@@ -28,17 +28,19 @@ func NewMemBlacklist() *MemBlacklist {
 }
 
 // Add adds a new token signature with expiration time to the blacklist
-func (mb *MemBlacklist) Add(sig string, exp int64) {
+func (mb *MemBlacklist) Add(sig string, exp int64) error {
 	mb.Lock()
 	mb.list[sig] = exp
 	mb.Unlock()
+	return nil
 }
 
 // Remove deletes a token signature from the blacklist
-func (mb *MemBlacklist) Remove(sig string) {
+func (mb *MemBlacklist) Remove(sig string) error {
 	mb.Lock()
 	delete(mb.list, sig)
 	mb.Unlock()
+	return nil
 }
 
 // Check returns true if a token signature is blacklisted and false otherwise
@@ -50,7 +52,7 @@ func (mb *MemBlacklist) Check(sig string) (ok bool) {
 }
 
 // Map returns the blacklist in the form of a iterable map structure for cleanup
-func (mb *MemBlacklist) Map() (list BlacklistMap) {
+func (mb *MemBlacklist) Map() (list BlacklistMap, err error) {
 	list = make(BlacklistMap)
 	mb.RLock()
 	for k, v := range mb.list {