move zen vfs implementation to zenstore (#549)

* move zen vfs implementation to zenstore

1 files changed, 103 insertions, 0 deletions

diff --git a/src/zenstore/include/zenstore/vfsimpl.h b/src/zenstore/include/zenstore/vfsimpl.h
new file mode 100644
index 000000000..22ca07a27
--- /dev/null
+++ b/src/zenstore/include/zenstore/vfsimpl.h
@@ -0,0 +1,103 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/logging.h>
+#include <zenvfs/vfs.h>
+
+#include <memory>
+#include <unordered_map>
+
+namespace zen {
+
+#if ZEN_WITH_VFS
+
+class ProjectStore;
+class ZenCacheStore;
+struct VfsServiceImpl;
+
+struct VfsOplogDataSource : public VfsTreeDataSource
+{
+	VfsOplogDataSource(std::string_view ProjectId, std::string_view OplogId, Ref<ProjectStore> InProjectStore);
+
+	virtual void ReadNamedData(std::string_view Path, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void ReadChunkData(const Oid& ChunkId, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void PopulateDirectory(std::string NodePath, VfsTreeNode& DirNode) override;
+
+private:
+	std::string		  m_ProjectId;
+	std::string		  m_OplogId;
+	Ref<ProjectStore> m_ProjectStore;
+};
+
+struct VfsCacheDataSource : public VfsTreeDataSource
+{
+	VfsCacheDataSource(std::string_view NamespaceId, std::string_view BucketId, Ref<ZenCacheStore> InCacheStore);
+	~VfsCacheDataSource();
+
+	virtual void ReadNamedData(std::string_view Path, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void ReadChunkData(const Oid& ChunkId, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void PopulateDirectory(std::string NodePath, VfsTreeNode& DirNode) override;
+
+private:
+	std::string		   m_NamespaceId;
+	std::string		   m_BucketId;
+	Ref<ZenCacheStore> m_CacheStore;
+};
+
+struct VfsServiceDataSource : public VfsTreeDataSource
+{
+	VfsServiceDataSource(VfsServiceImpl* VfsImpl) : m_VfsImpl(VfsImpl) {}
+
+	virtual void ReadNamedData(std::string_view Path, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void ReadChunkData(const Oid& ChunkId, void* Buffer, uint64_t ByteOffset, uint64_t ByteCount) override;
+	virtual void PopulateDirectory(std::string NodePath, VfsTreeNode& DirNode) override;
+
+private:
+	VfsServiceImpl* m_VfsImpl = nullptr;
+
+	RwLock													 m_Lock;
+	std::unordered_map<std::string, Ref<VfsOplogDataSource>> m_OplogSourceMap;
+	std::unordered_map<std::string, Ref<VfsCacheDataSource>> m_CacheSourceMap;
+
+	Ref<VfsOplogDataSource> GetOplogDataSource(std::string_view ProjectId, std::string_view OplogId);
+	Ref<VfsCacheDataSource> GetCacheDataSource(std::string_view NamespaceId, std::string_view BucketId);
+};
+
+#endif	// ZEN_WITH_VFS
+
+//////////////////////////////////////////////////////////////////////////
+
+struct VfsServiceImpl
+{
+#if ZEN_WITH_VFS
+	VfsServiceImpl();
+	~VfsServiceImpl();
+
+	void Mount(std::string_view MountPoint);
+	void Unmount();
+	void AddService(Ref<ProjectStore>&&);
+	void AddService(Ref<ZenCacheStore>&&);
+
+	inline std::string GetMountpointPath() { return m_MountpointPath; }
+	inline bool		   IsVfsRunning() const { return !!m_VfsHost.get(); }
+
+private:
+	Ref<ProjectStore>		  m_ProjectStore;
+	Ref<ZenCacheStore>		  m_ZenCacheStore;
+	Ref<VfsServiceDataSource> m_VfsDataSource;
+	std::string				  m_MountpointPath;
+
+	std::unique_ptr<VfsHost> m_VfsHost;
+	std::thread				 m_VfsThread;
+	Event					 m_VfsThreadRunning;
+	std::exception_ptr		 m_VfsThreadException;
+
+	void RefreshVfs();
+	void VfsThread();
+
+	friend struct VfsServiceDataSource;
+#endif	// ZEN_WITH_VFS
+};
+
+}  // namespace zen