ProjectedFSLib.cs

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;

namespace ProjectedFSLib
{
    static class Native
    {
        public static T? PtrToStructure<T>(IntPtr ptr) where T : struct
            => ptr == IntPtr.Zero ? default : Marshal.PtrToStructure<T>(ptr);
    }
    public enum HResult : int
    {
        Ok = 0,
        Pending = -2147023899,
        OutOfMemory = -2147024882,
        InsufficientBuffer = -2147024774,
        FileNotFound = -2147024894,
        VirtualizationUnavaliable = -2147024527,
        InternalError = -2147023537,
        AlreadyInitialized = -2147023649,
        AccessDenied = -2147024891,
        CannotDelete = -805306079,
        Directory = -2147024629,
        DirNotEmpty = -2147024751,
        Handle = -2147024890,
        InvalidArg = -2147024809,
        PathNotFound = -2147024893,
        ReparsePointEncountered = -2147020501,
        VirtualizationInvalidOp = -2147024511
    }
    #region Common structures
    /// <summary>
    /// PRJ_NOTIFY_TYPES
    /// </summary>
    [Flags]
    public enum PRJ_NOTIFY_TYPES : uint
    {
        NONE = 0x00000000,
        SUPPRESS_NOTIFICATIONS = 0x00000001,
        FILE_OPENED = 0x00000002,
        NEW_FILE_CREATED = 0x00000004,
        FILE_OVERWRITTEN = 0x00000008,
        PRE_DELETE = 0x00000010,
        PRE_RENAME = 0x00000020,
        PRE_SET_HARDLINK = 0x00000040,
        FILE_RENAMED = 0x00000080,
        HARDLINK_CREATED = 0x00000100,
        FILE_HANDLE_CLOSED_NO_MODIFICATION = 0x00000200,
        FILE_HANDLE_CLOSED_FILE_MODIFIED = 0x00000400,
        FILE_HANDLE_CLOSED_FILE_DELETED = 0x00000800,
        FILE_PRE_CONVERT_TO_FULL = 0x00001000,
        USE_EXISTING_MASK = 0xFFFFFFFF,
    }
    /// <summary>
    /// PRJ_NOTIFICATION
    /// </summary>
    [Flags]
    public enum PRJ_NOTIFICATION
    {
        FILE_OPENED = 0x00000002,
        NEW_FILE_CREATED = 0x00000004,
        FILE_OVERWRITTEN = 0x00000008,
        PRE_DELETE = 0x00000010,
        PRE_RENAME = 0x00000020,
        PRE_SET_HARDLINK = 0x00000040,
        FILE_RENAMED = 0x00000080,
        HARDLINK_CREATED = 0x00000100,
        FILE_HANDLE_CLOSED_NO_MODIFICATION = 0x00000200,
        FILE_HANDLE_CLOSED_FILE_MODIFIED = 0x00000400,
        FILE_HANDLE_CLOSED_FILE_DELETED = 0x00000800,
        FILE_PRE_CONVERT_TO_FULL = 0x00001000,
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT
    {
        public IntPtr Pointer;
    }
    public struct PRJ_DIR_ENTRY_BUFFER_HANDLE
    {
        public IntPtr Pointer;
    }
    #endregion
    #region Virtualization instance APIs
    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_NOTIFICATION_MAPPING
    {
        public PRJ_NOTIFY_TYPES NotificationBitMask;
        //[MarshalAs(UnmanagedType.LPWStr)]
        public IntPtr NotificationRoot;
    }
    public enum StartvirtualizingFlags
    {
        NONE = 0x00000000,
        USE_NEGATIVE_PATH_CACHE = 0x00000001,
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_STARTVIRTUALIZING_OPTIONS
    {
        public StartvirtualizingFlags Flags;
        public uint PoolThreadCount;
        public uint ConcurrentThreadCount;
        //PRJ_NOTIFICATION_MAPPING
        public IntPtr NotificationMappings;
        [MarshalAs(UnmanagedType.U4)]
        public int NotificationMappingsCount;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_VIRTUALIZATION_INSTANCE_INFO
    {
        public Guid InstanceID;
        public uint WriteAlignment;
    }
    internal static partial class ProjectedFSLib
    {
        private const string dllName = "projectedfslib.dll";

        /*
            STDAPI
            PrjStartVirtualizing(
            _In_ PCWSTR virtualizationRootPath,
            _In_ const PRJ_CALLBACKS* callbacks,
            _In_opt_ const void* instanceContext,
            _In_opt_ const PRJ_STARTVIRTUALIZING_OPTIONS* options,
            _Outptr_ PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT* namespaceVirtualizationContext
            );
            */
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjStartVirtualizing(
            string virtualizationRootPath,
            in PRJ_CALLBACKS callbacks,
            [Optional] IntPtr instanceContext,
            [Optional] in PRJ_STARTVIRTUALIZING_OPTIONS options,
            out PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext
            );

        [DllImport(dllName, PreserveSig = true)]
        public static extern void PrjStopVirtualizing(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjClearNegativePathCache(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            out uint totalEntryNumber
            );
        /*
        STDAPI
        PrjGetVirtualizationInstanceInfo(
            _In_ PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            _Out_ PRJ_VIRTUALIZATION_INSTANCE_INFO* virtualizationInstanceInfo
            );
         */
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjGetVirtualizationInstanceInfo(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            out PRJ_VIRTUALIZATION_INSTANCE_INFO virtualizationInstanceInfo
            );
    }
    #endregion
    #region region Placeholder and File APIs
    public enum PRJ_PLACEHOLDER_ID
    {
        PRJ_PLACEHOLDER_ID_LENGTH = 128
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_PLACEHOLDER_VERSION_INFO
    {
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = (int)PRJ_PLACEHOLDER_ID.PRJ_PLACEHOLDER_ID_LENGTH)]
        public byte[] ProviderID;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = (int)PRJ_PLACEHOLDER_ID.PRJ_PLACEHOLDER_ID_LENGTH)]
        public byte[] ContentID;
    }
    static partial class ProjectedFSLib
    {
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjMarkDirectoryAsPlaceholder(
            string rootPathName,
            [Optional] string targetPathName,
            [Optional] IntPtr versionInfo,
            in Guid virtualizationInstanceID
            );
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjMarkDirectoryAsPlaceholder(
            string rootPathName,
            [Optional] string targetPathName,
            [Optional] in PRJ_PLACEHOLDER_VERSION_INFO versionInfo,
            in Guid virtualizationInstanceID
            );
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_FILE_BASIC_INFO
    {
        [MarshalAs(UnmanagedType.U1)]
        public bool IsDirectory;
        public long FileSize;
        public long CreationTime;
        public long LastAccessTime;
        public long LastWriteTime;
        public long ChangeTime;
        public uint FileAttributes;
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_PLACEHOLDER_INFO
    {
        public PRJ_FILE_BASIC_INFO FileBasicInfo;
        public struct EaInformation_
        {
            public uint EaBufferSize;
            public uint OffsetToFirstEa;
        }
        public EaInformation_ EaInformation;
        public struct SecurityInformation_
        {
            public uint SecurityBufferSize;
            public uint OffsetToSecurityDescriptor;
        }
        public SecurityInformation_ SecurityInformation;
        public struct StreamsInformation_
        {
            public uint StreamsInfoBufferSize;
            public uint OffsetToFirstStreamInfo;
        }
        public StreamsInformation_ StreamsInformation;
        public PRJ_PLACEHOLDER_VERSION_INFO VersionInfo;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 1)]
        public byte[] VariableData;
    }
    static partial class ProjectedFSLib
    {
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjWritePlaceholderInfo(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            string destinationFileName,
            // PRJ_PLACEHOLDER_INFO
            IntPtr placeholderInfo,
            uint placeholderInfoSize
            );
    }
    [Flags]
    public enum PRJ_UPDATE_TYPES
    {
        NONE = 0x00000000,
        ALLOW_DIRTY_METADATA = 0x00000001,
        ALLOW_DIRTY_DATA = 0x00000002,
        ALLOW_TOMBSTONE = 0x00000004,
        RESERVED1 = 0x00000008,
        RESERVED2 = 0x00000010,
        ALLOW_READ_ONLY = 0x00000020,
        MAX_VAL = (ALLOW_READ_ONLY << 1),
    }
    [Flags]
    public enum PRJ_UPDATE_FAILURE_CAUSES
    {
        NONE = 0x00000000,
        DIRTY_METADATA = 0x00000001,
        DIRTY_DATA = 0x00000002,
        TOMBSTONE = 0x00000004,
        READ_ONLY = 0x00000008,
    }
    static partial class ProjectedFSLib
    {
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjUpdateFileIfNeeded(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            string destinationFileName,
            // PRJ_PLACEHOLDER_INFO
            IntPtr placeholderInfo,
            uint placeholderInfoSize,
            [Optional] PRJ_UPDATE_TYPES updateFlags,
            [Optional] out PRJ_UPDATE_FAILURE_CAUSES failureReason
            );
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjDeleteFile(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            string destinationFileName,
            [Optional] PRJ_UPDATE_TYPES updateFlags,
            [Optional] out PRJ_UPDATE_FAILURE_CAUSES failureReason
            );
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjWriteFileData(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            in Guid dataStreamId,
            IntPtr buffer,
            ulong byteOffset,
            uint length
            );
    }
    [Flags]
    public enum PRJ_FILE_STATE
    {
        PLACEHOLDER = 0x00000001,
        HYDRATED_PLACEHOLDER = 0x00000002,
        DIRTY_PLACEHOLDER = 0x00000004,
        FULL = 0x00000008,
        TOMBSTONE = 0x00000010,
    }
    static partial class ProjectedFSLib
    {
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjGetOnDiskFileState(
            string destinationFileName,
            out PRJ_FILE_STATE fileState
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = true)]
        public static extern SafeAlignedBuffer PrjAllocateAlignedBuffer(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            [MarshalAs(UnmanagedType.SysUInt)]ulong size
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = true)]
        public static extern void PrjFreeAlignedBuffer(
            IntPtr buffer
            );
    }
    #endregion
    #region Callback support
    [Flags]
    public enum PRJ_CALLBACK_DATA_FLAGS
    {
        ENUM_RESTART_SCAN = 0x00000001,
        ENUM_RETURN_SINGLE_ENTRY = 0x00000002
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct PRJ_CALLBACK_DATA
    {
        public uint Size;
        public PRJ_CALLBACK_DATA_FLAGS Flags;
        public PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT NamespaceVirtualizationContext;
        public int CommandId;
        public Guid FileId;
        public Guid DataStreamId;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string FilePathName;
        readonly IntPtr _VersionInfo;
        public PRJ_PLACEHOLDER_VERSION_INFO? VersionInfo
            => Native.PtrToStructure<PRJ_PLACEHOLDER_VERSION_INFO>(_VersionInfo);

        public uint TriggeringProcessId;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string TriggeringProcessImageFileName;
        public IntPtr InstanceContext;
    }
    public delegate HResult PRJ_START_DIRECTORY_ENUMERATION_CB(
        in PRJ_CALLBACK_DATA callbackData,
        in Guid enumerationId
        );
    public delegate HResult PRJ_GET_DIRECTORY_ENUMERATION_CB(
        in PRJ_CALLBACK_DATA callbackData,
        in Guid enumerationId,
        [Optional] string searchExpression,
        PRJ_DIR_ENTRY_BUFFER_HANDLE dirEntryBufferHandle
        );
    public delegate HResult PRJ_END_DIRECTORY_ENUMERATION_CB(
        in PRJ_CALLBACK_DATA callbackData,
        in Guid enumerationId
        );
    public delegate HResult PRJ_GET_PLACEHOLDER_INFO_CB(
        in PRJ_CALLBACK_DATA callbackData
        );
    public delegate HResult PRJ_GET_FILE_DATA_CB(
        in PRJ_CALLBACK_DATA callbackData,
        ulong byteOffset,
        uint length
        );
    public delegate HResult PRJ_QUERY_FILE_NAME_CB(
        in PRJ_CALLBACK_DATA callbackData
        );

    [StructLayout(LayoutKind.Explicit)]
    public struct PRJ_NOTIFICATION_PARAMETERS
    {
        public struct PostCreate_
        {
            public PRJ_NOTIFY_TYPES NotificationMask;
        }
        [FieldOffset(0)]
        public PostCreate_ PostCreate;
        public struct FileRenamed_
        {
            public PRJ_NOTIFY_TYPES NotificationMask;
        }
        [FieldOffset(0)]
        public FileRenamed_ FileRenamed;
        public struct FileDeletedOnHandleClose_
        {
            [MarshalAs(UnmanagedType.U1)]
            public bool IsFileModified;
        }
        [FieldOffset(0)]
        public FileDeletedOnHandleClose_ FileDeletedOnHandleClose;
    }
    public delegate HResult PRJ_NOTIFICATION_CB(
        in PRJ_CALLBACK_DATA callbackData,
        [MarshalAs(UnmanagedType.U1)] bool isDirectory,
        PRJ_NOTIFICATION notification,
        [Optional] string destinationFileName,
        [Optional] in PRJ_NOTIFICATION_PARAMETERS operationParameters
        );
    public delegate void PRJ_CANCEL_COMMAND_CB(
        in PRJ_CALLBACK_DATA callbackData
        );

    public struct PRJ_CALLBACKS
    {
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_START_DIRECTORY_ENUMERATION_CB StartDirectoryEnumerationCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_END_DIRECTORY_ENUMERATION_CB EndDirectoryEnumerationCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_GET_DIRECTORY_ENUMERATION_CB GetDirectoryEnumerationCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_GET_PLACEHOLDER_INFO_CB GetPlaceholderInfoCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_GET_FILE_DATA_CB GetFileDataCallback;

        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_QUERY_FILE_NAME_CB QueryFileNameCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_NOTIFICATION_CB NotificationCallback;
        [MarshalAs(UnmanagedType.FunctionPtr)]
        public PRJ_CANCEL_COMMAND_CB CancelCommandCallback;
    }
    public enum PRJ_COMPLETE_COMMAND_TYPE
    {
        NOTIFICATION = 1,
        ENUMERATION = 2
    }
    [StructLayout(LayoutKind.Explicit)]
    public struct PRJ_COMPLETE_COMMAND_EXTENDED_PARAMETERS
    {
        [FieldOffset(0)]
        public PRJ_COMPLETE_COMMAND_TYPE CommandType;

        public struct Notification_
        {
            public PRJ_NOTIFY_TYPES NotificationMask;
        }
        [FieldOffset(4)]
        public Notification_ Notification;

        public struct Enumeration_
        {
            public PRJ_DIR_ENTRY_BUFFER_HANDLE DirEntryBufferHandle;
        }
        [FieldOffset(4)]
        public Enumeration_ Enumeration;
    }

    static partial class ProjectedFSLib
    {
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjCompleteCommand(
            PRJ_NAMESPACE_VIRTUALIZATION_CONTEXT namespaceVirtualizationContext,
            int commandId,
            HResult completionResult,
            [Optional] in PRJ_COMPLETE_COMMAND_EXTENDED_PARAMETERS extendedParameters
            );

    #endregion
    #region Enumeration APIs
        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = false)]
        public static extern void PrjFillDirEntryBuffer(
            string fileName,
            [Optional] in PRJ_FILE_BASIC_INFO fileBasicInfo,
            PRJ_DIR_ENTRY_BUFFER_HANDLE dirEntryBufferHandle
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = true)]
        [return: MarshalAs(UnmanagedType.U1)]
        public static extern bool PrjFileNameMatch(
            string fileNameToCheck,
            string pattern
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = true)]
        public static extern int PrjFileNameCompare(
            string fileName1,
            string fileName2
            );

        [DllImport(dllName, CharSet = CharSet.Unicode, PreserveSig = true)]
        [return: MarshalAs(UnmanagedType.U1)]
        public static extern bool PrjDoesNameContainWildCards(
            string fileName
            );
    }
    #endregion

    public class SafeAlignedBuffer : SafeBuffer
    {
        protected SafeAlignedBuffer(bool ownsHandle) : base(ownsHandle)
        {
        }

        protected override bool ReleaseHandle()
        {
            if(handle != IntPtr.Zero)
                ProjectedFSLib.PrjFreeAlignedBuffer(handle);
            return true;
        }
    }
}