1 files changed, 43 insertions, 0 deletions
diff --git a/src/zenutil/include/zenutil/bufferedopenfile.h b/src/zenutil/include/zenutil/bufferedopenfile.h
new file mode 100644
index 000000000..3af7c9991
--- /dev/null
+++ b/src/zenutil/include/zenutil/bufferedopenfile.h
@@ -0,0 +1,43 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/basicfile.h>
+
+namespace zen {
+
+class CompositeBuffer;
+
+class BufferedOpenFile
+{
+public:
+	BufferedOpenFile(const std::filesystem::path Path,
+					 std::atomic<uint64_t>&		 OpenReadCount,
+					 std::atomic<uint64_t>&		 CurrentOpenFileCount,
+					 std::atomic<uint64_t>&		 ReadCount,
+					 std::atomic<uint64_t>&		 ReadByteCount);
+	~BufferedOpenFile();
+	BufferedOpenFile()						  = delete;
+	BufferedOpenFile(const BufferedOpenFile&) = delete;
+	BufferedOpenFile(BufferedOpenFile&&)	  = delete;
+	BufferedOpenFile& operator=(BufferedOpenFile&&) = delete;
+	BufferedOpenFile& operator=(const BufferedOpenFile&) = delete;
+
+	const uint64_t	BlockSize = 256u * 1024u;
+	CompositeBuffer GetRange(uint64_t Offset, uint64_t Size);
+
+public:
+	void* Handle() { return m_Source.Handle(); }
+
+private:
+	BasicFile			   m_Source;
+	const uint64_t		   m_SourceSize;
+	std::atomic<uint64_t>& m_OpenReadCount;
+	std::atomic<uint64_t>& m_CurrentOpenFileCount;
+	std::atomic<uint64_t>& m_ReadCount;
+	std::atomic<uint64_t>& m_ReadByteCount;
+	uint64_t			   m_CacheBlockIndex = (uint64_t)-1;
+	IoBuffer			   m_Cache;
+};
+
+}  // namespace zen