change file storage, fix #412

lib/file/file.go

@@ -99,16 +99,28 @@ func (s *JsonDb) GetClient(id int) (c *Client, err error) {
  return
 }
 
+var hostLock sync.Mutex
+
 func (s *JsonDb) StoreHostToJsonFile() {
+ hostLock.Lock()
  storeSyncMapToFile(s.Hosts, s.HostFilePath)
+ hostLock.Unlock()
 }
 
+var taskLock sync.Mutex
+
 func (s *JsonDb) StoreTasksToJsonFile() {
+ taskLock.Lock()
  storeSyncMapToFile(s.Tasks, s.TaskFilePath)
+ taskLock.Unlock()
 }
 
+var clientLock sync.Mutex
+
 func (s *JsonDb) StoreClientsToJsonFile() {
+ clientLock.Lock()
  storeSyncMapToFile(s.Clients, s.ClientFilePath)
+ clientLock.Unlock()
 }
 
 func (s *JsonDb) GetClientId() int32 {
@@ -134,7 +146,8 @@ func loadSyncMapFromFile(filePath string, f func(value string)) {
 }
 
 func storeSyncMapToFile(m sync.Map, filePath string) {
- file, err := os.Create(filePath)
+ file, err := os.Create(filePath + ".tmp")
+ // first create a temporary file to store
  if err != nil {
  panic(err)
  }
@@ -177,5 +190,7 @@ func storeSyncMapToFile(m sync.Map, filePath string) {
  }
  return true
  })
- file.Sync()
+ _ = file.Sync()
+ err = os.Rename(filePath+".tmp", filePath)
+ // replace the file, maybe provides atomic operation
 }