Update localfs.go

backends/localfs/localfs.go

@@ -2,6 +2,7 @@ package localfs
 
 import (
 	"encoding/json"
+	"errors"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -16,6 +17,7 @@ import (
 type LocalfsBackend struct {
 	metaPath  string
 	filesPath string
+	locksPath string
 }
 
 type MetadataJSON struct {
@@ -127,6 +129,41 @@ func (b LocalfsBackend) writeMetadata(key string, metadata backends.Metadata) er
 	return nil
 }
 
+func (b LocalfsBackend) Lock(filename string) (err error) {
+	lockPath := path.Join(b.locksPath, filename)
+
+	lock, err := os.Create(lockPath)
+	if err != nil {
+		return err
+	}
+
+	lock.Close()
+	return
+}
+
+func (b LocalfsBackend) Unlock(filename string) (err error) {
+	lockPath := path.Join(b.locksPath, filename)
+
+	err = os.Remove(lockPath)
+	if err != nil {
+		return err
+	}
+
+	return
+}
+
+func (b LocalfsBackend) CheckLock(filename string) (locked bool, err error) {
+	lockPath := path.Join(b.locksPath, filename)
+
+	if _, err := os.Stat(lockPath); errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	} else {
+		return true, nil
+	}
+
+	return false, err
+}
+
 func (b LocalfsBackend) Put(key string, r io.Reader, expiry time.Time, deleteKey, accessKey string, srcIp string) (m backends.Metadata, err error) {
 	filePath := path.Join(b.filesPath, key)
 
@@ -201,9 +238,10 @@ func (b LocalfsBackend) List() ([]string, error) {
 	return output, nil
 }
 
-func NewLocalfsBackend(metaPath string, filesPath string) LocalfsBackend {
+func NewLocalfsBackend(metaPath string, filesPath string, locksPath string) LocalfsBackend {
 	return LocalfsBackend{
 		metaPath:  metaPath,
 		filesPath: filesPath,
+		locksPath: locksPath,
 	}
 }