block reference couting copy support windows (#564)

- Improvement: On Windows file systems that allow block reference counting we use it where possible to speed up copy of data during `zen builds download` operations
  - Enabled by default, disable with `--allow-file-clone=false`

1 files changed, 23 insertions, 0 deletions

diff --git a/src/zencore/include/zencore/filesystem.h b/src/zencore/include/zencore/filesystem.h
index 36d4d1b68..92b249cec 100644
--- a/src/zencore/include/zencore/filesystem.h
+++ b/src/zencore/include/zencore/filesystem.h
@@ -179,6 +179,29 @@ ZENCORE_API void WriteFile(void*			NativeHandle,
 						   std::error_code& Ec);
 ZENCORE_API void ReadFile(void* NativeHandle, void* Data, uint64_t Size, uint64_t FileOffset, uint64_t ChunkSize, std::error_code& Ec);
 
+class CloneQueryInterface
+{
+public:
+	virtual ~CloneQueryInterface() {}
+
+	virtual bool	 CanClone(void* SourceNativeHandle)		  = 0;
+	virtual uint64_t GetClonableRange(uint64_t	SourceOffset,
+									  uint64_t	TargetOffset,
+									  uint64_t	Size,
+									  uint64_t& OutPreBytes,
+									  uint64_t& OutPostBytes) = 0;
+	virtual bool	 TryClone(void*	   SourceNativeHandle,
+							  void*	   TargetNativeHandle,
+							  uint64_t AlignedSourceOffset,
+							  uint64_t AlignedTargetOffset,
+							  uint64_t AlignedSize,
+							  uint64_t TargetFinalSize)		  = 0;
+};
+
+ZENCORE_API std::unique_ptr<CloneQueryInterface> GetCloneQueryInterface(const std::filesystem::path& TargetDirectory);
+
+ZENCORE_API bool TryCloneFile(const std::filesystem::path& FromPath, const std::filesystem::path& ToPath);
+
 struct CopyFileOptions
 {
 	bool EnableClone = true;