Cleanup

Dalamud/Utility/TerraFxCom/TerraFxComInterfaceExtensions.cs

@@ -0,0 +1,175 @@
+using System.IO;
+using System.Runtime.InteropServices;
+
+using TerraFX.Interop.Windows;
+
+using static TerraFX.Interop.Windows.Windows;
+
+namespace Dalamud.Utility.TerraFxCom;
+
+/// <summary>Utilities for <see cref="IUnknown"/> and its derivatives.</summary>
+internal static unsafe partial class TerraFxComInterfaceExtensions
+{
+    /// <summary>Creates a new instance of <see cref="IStream"/> from a file path.</summary>
+    /// <param name="path">The file path.</param>
+    /// <param name="mode">The file open mode.</param>
+    /// <param name="access">The file access mode.</param>
+    /// <param name="share">The file share mode.</param>
+    /// <param name="attributes">The file attributes.</param>
+    /// <returns>The new instance of <see cref="IStream"/>.</returns>
+    public static ComPtr<IStream> CreateIStreamFromFile(
+        string path,
+        FileMode mode,
+        FileAccess access,
+        FileShare share,
+        FileAttributes attributes = FileAttributes.Normal)
+    {
+        var grfMode = 0u;
+        bool fCreate;
+        switch (mode)
+        {
+            case FileMode.CreateNew:
+                fCreate = true;
+                grfMode |= STGM.STGM_FAILIFTHERE;
+                break;
+            case FileMode.Create:
+                fCreate = true;
+                grfMode |= STGM.STGM_CREATE;
+                break;
+            case FileMode.Open:
+                fCreate = false;
+                grfMode |= STGM.STGM_FAILIFTHERE; // yes
+                break;
+            case FileMode.OpenOrCreate:
+                throw new NotSupportedException(
+                    $"${FileMode.OpenOrCreate} is not supported. It might be, but it needs testing.");
+            case FileMode.Append:
+                throw new NotSupportedException($"${FileMode.Append} is not supported.");
+            case FileMode.Truncate:
+                throw new NotSupportedException($"${FileMode.Truncate} is not supported.");
+            default:
+                throw new ArgumentOutOfRangeException(nameof(mode), mode, null);
+        }
+
+        switch (access)
+        {
+            case FileAccess.Read:
+                grfMode |= STGM.STGM_READ;
+                break;
+            case FileAccess.Write:
+                grfMode |= STGM.STGM_WRITE;
+                break;
+            case FileAccess.ReadWrite:
+                grfMode |= STGM.STGM_READWRITE;
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(access), access, null);
+        }
+
+        switch (share)
+        {
+            case FileShare.None:
+                grfMode |= STGM.STGM_SHARE_EXCLUSIVE;
+                break;
+            case FileShare.Read:
+                grfMode |= STGM.STGM_SHARE_DENY_WRITE;
+                break;
+            case FileShare.Write:
+                grfMode |= STGM.STGM_SHARE_DENY_READ;
+                break;
+            case FileShare.ReadWrite:
+                grfMode |= STGM.STGM_SHARE_DENY_NONE;
+                break;
+            default:
+                throw new NotSupportedException($"Only ${FileShare.Read} and ${FileShare.Write} are supported.");
+        }
+
+        using var stream = default(ComPtr<IStream>);
+        fixed (char* pPath = path)
+        {
+            SHCreateStreamOnFileEx(
+                (ushort*)pPath,
+                grfMode,
+                (uint)attributes,
+                fCreate,
+                null,
+                stream.GetAddressOf()).ThrowOnError();
+        }
+
+        var res = default(ComPtr<IStream>);
+        stream.As(ref res).ThrowOnError();
+        return res;
+    }
+
+    /// <summary>Calls <see cref="IPropertyBag2.Write"/>.</summary>
+    /// <param name="obj">The property bag.</param>
+    /// <param name="name">The name of the item to be interpreted as a VARIANT.</param>
+    /// <param name="value">The new value, to be interpreted as a <see cref="VARIANT"/>.</param>
+    /// <returns>Return value from <inheritdoc cref="IPropertyBag2.Write"/>.</returns>
+    public static HRESULT Write(ref this IPropertyBag2 obj, string name, object? value)
+    {
+        VARIANT varValue;
+        // Marshal calls VariantInit.
+        Marshal.GetNativeVariantForObject(value, (nint)(&varValue));
+        try
+        {
+            fixed (char* pName = name)
+            {
+                var option = new PROPBAG2 { pstrName = (ushort*)pName };
+                return obj.Write(1, &option, &varValue);
+            }
+        }
+        finally
+        {
+            VariantClear(&varValue);
+        }
+    }
+
+    /// <summary>Calls <inheritdoc cref="IWICMetadataQueryWriter.SetMetadataByName"/>.</summary>
+    /// <param name="obj">The object.</param>
+    /// <param name="name">The name of the metadata.</param>
+    /// <param name="value">The new value, to be interpreted as a <see cref="PROPVARIANT"/>.</param>
+    /// <returns>Return value from <inheritdoc cref="IWICMetadataQueryWriter.SetMetadataByName"/>.</returns>
+    public static HRESULT SetMetadataByName(ref this IWICMetadataQueryWriter obj, string name, object? value)
+    {
+        VARIANT varValue;
+        // Marshal calls VariantInit.
+        Marshal.GetNativeVariantForObject(value, (nint)(&varValue));
+        try
+        {
+            PROPVARIANT propVarValue;
+            var propVarRes = VariantToPropVariant(&varValue, &propVarValue);
+            if (propVarRes < 0)
+                return propVarRes;
+
+            try
+            {
+                fixed (char* pName = name)
+                    return obj.SetMetadataByName((ushort*)pName, &propVarValue);
+            }
+            finally
+            {
+                _ = PropVariantClear(&propVarValue);
+            }
+        }
+        finally
+        {
+            _ = VariantClear(&varValue);
+        }
+    }
+
+    /// <summary>Calls <inheritdoc cref="IWICMetadataQueryWriter.SetMetadataByName"/>.</summary>
+    /// <param name="obj">The object.</param>
+    /// <param name="name">The name of the metadata.</param>
+    /// <returns>Return value from <inheritdoc cref="IWICMetadataQueryWriter.SetMetadataByName"/>.</returns>
+    public static HRESULT RemoveMetadataByName(ref this IWICMetadataQueryWriter obj, string name)
+    {
+        fixed (char* pName = name)
+            return obj.RemoveMetadataByName((ushort*)pName);
+    }
+
+    [LibraryImport("propsys.dll")]
+    private static partial int VariantToPropVariant(
+        void* pVarIn,
+        void* pPropVarOut);
+}