VFS implementation for local storage service (#396)

currently, only Windows (using Projected File System) is supported

1 files changed, 112 insertions, 0 deletions

diff --git a/src/zenvfs/vfsprovider.h b/src/zenvfs/vfsprovider.h
new file mode 100644
index 000000000..8e6896956
--- /dev/null
+++ b/src/zenvfs/vfsprovider.h
@@ -0,0 +1,112 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include "projfsproviderinterface.h"
+
+#if ZEN_WITH_VFS
+
+#	include <zencore/compactbinarybuilder.h>
+#	include <zencore/except.h>
+#	include <zencore/string.h>
+#	include <zencore/thread.h>
+
+ZEN_THIRD_PARTY_INCLUDES_START
+#	if ZEN_PLATFORM_WINDOWS
+#		include <zencore/windows.h>
+#		include <projectedfslib.h>
+#	endif
+ZEN_THIRD_PARTY_INCLUDES_END
+
+#	include <unordered_map>
+#	include <vector>
+
+namespace zen {
+
+class VfsTree
+{
+public:
+	VfsTree();
+	~VfsTree();
+
+	void		 Initialize(VfsTreeDataSource& DataProvider);
+	void		 SetTree(VfsTreeNode&& TreeRoot, VfsTreeDataSource& DataProvider);
+	VfsTreeNode& GetTree();
+	VfsTreeNode* FindNode(std::wstring NodeName);
+	void		 ReadChunkData(Oid ChunkId, void* DataBuffer, uint64_t ByteOffset, uint64_t Length);
+
+private:
+	struct Impl;
+
+	Impl* m_Impl;
+};
+
+//////////////////////////////////////////////////////////////////////////
+
+struct VfsProvider : public ProjFsProviderInterface
+{
+	struct EnumerationState
+	{
+		std::string												  Path;
+		const VfsTreeNode*										  Node = nullptr;
+		std::vector<std::unique_ptr<VfsTreeNode>>::const_iterator Iterator;
+		std::vector<std::unique_ptr<VfsTreeNode>>::const_iterator EndIterator;
+
+		void				 RestartScan();
+		inline bool			 IsCurrentValid() { return Iterator != EndIterator; }
+		bool				 MatchesPattern(PCWSTR SearchExpression);
+		void				 MoveToNext();
+		const WCHAR*		 GetCurrentFileName();
+		PRJ_FILE_BASIC_INFO& GetCurrentBasicInfo();
+
+		PRJ_FILE_BASIC_INFO BasicInfo;
+		std::wstring		CurrentName;
+	};
+
+	//////////////////////////////////////////////////////////////////////////
+
+	VfsProvider(std::string_view RootPath);
+	~VfsProvider();
+
+	void Initialize();
+	void Cleanup();
+
+	void AddMount(std::string_view Mountpoint, Ref<VfsTreeDataSource>&& DataSource);
+	void RequestStop();
+
+	// ProjFsProviderInterface implementation
+
+	virtual void Run() override;
+
+	virtual HRESULT StartDirEnum(_In_ const PRJ_CALLBACK_DATA* CallbackData, _In_ const GUID* EnumerationId) override;
+	virtual HRESULT EndDirEnum(_In_ const PRJ_CALLBACK_DATA* CallbackData, _In_ const GUID* EnumerationId) override;
+	virtual HRESULT GetDirEnum(_In_ const PRJ_CALLBACK_DATA*	CallbackData,
+							   _In_ const GUID*					EnumerationId,
+							   _In_opt_ PCWSTR					SearchExpression,
+							   _In_ PRJ_DIR_ENTRY_BUFFER_HANDLE DirEntryBufferHandle) override;
+	virtual HRESULT GetPlaceholderInfo(_In_ const PRJ_CALLBACK_DATA* CallbackData) override;
+	virtual HRESULT GetFileData(_In_ const PRJ_CALLBACK_DATA* CallbackData, _In_ UINT64 ByteOffset, _In_ UINT32 Length) override;
+	virtual HRESULT Notify(_In_ const PRJ_CALLBACK_DATA*		CallbackData,
+						   _In_ BOOLEAN							IsDirectory,
+						   _In_ PRJ_NOTIFICATION				NotificationType,
+						   _In_opt_ PCWSTR						DestinationFileName,
+						   _Inout_ PRJ_NOTIFICATION_PARAMETERS* NotificationParameters) override;
+	virtual HRESULT QueryFileName(_In_ const PRJ_CALLBACK_DATA* CallbackData) override;
+	virtual void	CancelCommand(_In_ const PRJ_CALLBACK_DATA* CallbackData) override;
+
+private:
+	std::string m_RootPath;
+	Guid		m_RootGuid;
+	VfsTree*	m_Tree = nullptr;
+
+	RwLock											m_EnumerationsLock;
+	std::unordered_map<zen::Guid, EnumerationState> m_ActiveEnumerations;
+
+	Event			 m_StopRunningEvent;
+	std::atomic_flag m_IsRunning;
+	std::atomic_flag m_IsInitialized;
+};
+
+}  // namespace zen
+
+#endif