Add lock file

src/utils/lock_file.hpp

@@ -0,0 +1,19 @@
+#pragma once
+#include <string>
+
+namespace utils::filesystem {
+class LockFile {
+ public:
+  LockFile(std::string path) : path_(std::move(path) + ".lock") {}
+
+  void Lock();
+  void lock() { Lock(); }
+
+  void Unlock();
+  void unlock() { Unlock(); }
+
+ private:
+  std::string path_;
+  int fd_ = -1;
+};
+}  // namespace utils::filesystem