use write and move in place for safer writing of files (#70)

* use write and move in place for safer writing of files

2 files changed, 22 insertions, 0 deletions

diff --git a/src/zenutil/basicfile.cpp b/src/zenutil/basicfile.cpp
index f553fe5a0..d837c2caf 100644
--- a/src/zenutil/basicfile.cpp
+++ b/src/zenutil/basicfile.cpp
@@ -560,6 +560,26 @@ TemporaryFile::MoveTemporaryIntoPlace(std::filesystem::path FinalFileName, std::
 
 //////////////////////////////////////////////////////////////////////////
 
+void
+TemporaryFile::SafeWriteFile(std::filesystem::path Path, MemoryView Data)
+{
+	TemporaryFile	TempFile;
+	std::error_code Ec;
+	TempFile.CreateTemporary(Path.parent_path(), Ec);
+	if (Ec)
+	{
+		throw std::system_error(Ec, fmt::format("Failed to create temp file for file at '{}'", Path));
+	}
+	TempFile.Write(Data, 0);
+	TempFile.MoveTemporaryIntoPlace(Path, Ec);
+	if (Ec)
+	{
+		throw std::system_error(Ec, fmt::format("Failed to move temp file '{}' to '{}'", TempFile.GetPath(), Path));
+	}
+}
+
+//////////////////////////////////////////////////////////////////////////
+
 LockFile::LockFile()
 {
 }
diff --git a/src/zenutil/include/zenutil/basicfile.h b/src/zenutil/include/zenutil/basicfile.h
index 0e4295ee3..375da20c3 100644
--- a/src/zenutil/include/zenutil/basicfile.h
+++ b/src/zenutil/include/zenutil/basicfile.h
@@ -101,6 +101,8 @@ public:
 	void						 MoveTemporaryIntoPlace(std::filesystem::path FinalFileName, std::error_code& Ec);
 	const std::filesystem::path& GetPath() const { return m_TempPath; }
 
+	static void SafeWriteFile(std::filesystem::path Path, MemoryView Data);
+
 private:
 	std::filesystem::path m_TempPath;