Add RAII class for atomic overwrites

[libs/core.git] / source / fs / redirectedpath.h

diff --git a/source/fs/redirectedpath.h b/source/fs/redirectedpath.h
new file mode 100644 (file)
index 0000000..50a3609
--- /dev/null
+++ b/source/fs/redirectedpath.h
@@ -0,0 +1,30 @@
+#ifndef MSP_FS_REDIRECTEDPATH_H_
+#define MSP_FS_REDIRECTEDPATH_H_
+
+#include "path.h"
+
+namespace Msp {
+namespace FS {
+
+/**
+Provides a redirected path for the lifetime of the object.  When RedirectedPath
+goes out of scope, it is renamed to the original path.  If destruction happens
+due to an exception, it is unlinked instead.  The primary use for this is to
+atomically overwrite a file with a new version.
+*/
+class RedirectedPath: public Path
+{
+private:
+       Path original;
+
+public:
+       explicit RedirectedPath(const Path &, const char * = ".tmp");
+       RedirectedPath(const Path &, const std::string &);
+       RedirectedPath(const Path &, const Path &);
+       ~RedirectedPath();
+};
+
+} // namespace FS
+} // namespace Msp
+
+#endif