Fix potential data races (#82)

service/audit.go

@@ -42,12 +42,13 @@ func (s *Service) httpAudit(handler string, data *httpData, w http.ResponseWrite
 }
 
 func reqAuditFields(req *http.Request) []mlog.Field {
-	delete(req.Header, "Authorization")
+	hdr := req.Header.Clone()
+	delete(hdr, "Authorization")
 	fields := []mlog.Field{
 		mlog.String("remoteAddr", req.RemoteAddr),
 		mlog.String("method", req.Method),
 		mlog.String("url", req.URL.String()),
-		mlog.Any("header", req.Header),
+		mlog.Any("header", hdr),
 		mlog.String("host", req.Host),
 	}
 	return fields

service/store/bitcask.go

@@ -34,6 +34,9 @@ func (s *bitcaskStore) Set(key, value string) error {
 		return ErrEmptyKey
 	}
 
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
 	err := s.db.Put([]byte(key), []byte(value))
 	if err != nil {
 		return fmt.Errorf("failed to set key: %w", err)
@@ -47,12 +50,13 @@ func (s *bitcaskStore) Set(key, value string) error {
 }
 
 func (s *bitcaskStore) Put(key, value string) error {
-	s.mut.Lock()
-	defer s.mut.Unlock()
 	if key == "" {
 		return ErrEmptyKey
 	}
 
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
 	if s.db.Has([]byte(key)) {
 		return ErrConflict
 	}
@@ -73,6 +77,10 @@ func (s *bitcaskStore) Get(key string) (string, error) {
 	if key == "" {
 		return "", ErrEmptyKey
 	}
+
+	s.mut.RLock()
+	defer s.mut.RUnlock()
+
 	val, err := s.db.Get([]byte(key))
 	if errors.Is(err, bitcask.ErrKeyNotFound) {
 		return "", ErrNotFound
@@ -87,6 +95,9 @@ func (s *bitcaskStore) Delete(key string) error {
 		return ErrEmptyKey
 	}
 
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
 	err := s.db.Delete([]byte(key))
 	if err != nil {
 		return fmt.Errorf("failed to delete key: %w", err)
@@ -100,6 +111,9 @@ func (s *bitcaskStore) Delete(key string) error {
 }
 
 func (s *bitcaskStore) Close() error {
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
 	err := s.db.Close()
 	if err != nil {
 		return fmt.Errorf("failed to close store: %w", err)