BSTRMarshaler.cs

Go to the documentation of this file.

using System.Runtime.InteropServices;
 
namespace System.StubHelpers;
 
internal static class BSTRMarshaler
{
    internal unsafe static IntPtr ConvertToNative(string strManaged, IntPtr pNativeBuffer)
    {
        if (strManaged == null)
        {
            return IntPtr.Zero;
        }
        byte data;
        bool flag = strManaged.TryGetTrailByte(out data);
        uint num = (uint)(strManaged.Length * 2);
        if (flag)
        {
            num++;
        }
        byte* ptr;
        if (pNativeBuffer != IntPtr.Zero)
        {
            *(uint*)(void*)pNativeBuffer = num;
            ptr = (byte*)(void*)pNativeBuffer + 4;
        }
        else
        {
            ptr = (byte*)(void*)Marshal.AllocBSTRByteLen(num);
        }
        Buffer.Memmove(ref *(char*)ptr, ref strManaged.GetRawStringData(), (nuint)strManaged.Length + (nuint)1u);
        if (flag)
        {
            ptr[num - 1] = data;
        }
        return (IntPtr)ptr;
    }
 
    internal unsafe static string ConvertToManaged(IntPtr bstr)
    {
        if (IntPtr.Zero == bstr)
        {
            return null;
        }
        uint num = Marshal.SysStringByteLen(bstr);
        StubHelpers.CheckStringLength(num);
        string text = ((num != 1) ? new string((char*)(void*)bstr, 0, (int)(num / 2)) : string.FastAllocateString(0));
        if ((num & 1) == 1)
        {
            text.SetTrailByte(((byte*)(void*)bstr)[num - 1]);
        }
        return text;
    }
 
    internal static void ClearNative(IntPtr pNative)
    {
        Marshal.FreeBSTR(pNative);
    }
}