update vendor/

vendor/github.com/marcsauter/single/single.go

@@ -0,0 +1,41 @@
+// package single provides a mechanism to ensure, that only one instance of a program is running
+
+package single
+
+import (
+	"errors"
+	"log"
+	"os"
+)
+
+var (
+	// ErrAlreadyRunning -- the instance is already running
+	ErrAlreadyRunning = errors.New("the program is already running")
+	// Lockfile -- the lock file to check
+	Lockfile string
+)
+
+// Single represents the name and the open file descriptor
+type Single struct {
+	name string
+	file *os.File
+}
+
+// New creates a Single instance
+func New(name string) *Single {
+	return &Single{name: name}
+}
+
+// Lock tries to obtain an exclude lock on a lockfile and exits the program if an error occurs
+func (s *Single) Lock() {
+	if err := s.CheckLock(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// Unlock releases the lock, closes and removes the lockfile. All errors will be reported directly.
+func (s *Single) Unlock() {
+	if err := s.TryUnlock(); err != nil {
+		log.Print(err)
+	}
+}