internal static IntPtr ConvertToNative(int flags, string strManaged)
{
if (strManaged == null)
{
return(IntPtr.Zero);
}
int length = strManaged.Length;
System.StubHelpers.StubHelpers.CheckStringLength(length);
byte[] str = (byte[])null;
int cbLength = 0;
int num = 0;
if (length > num)
{
str = AnsiCharMarshaler.DoAnsiConversion(strManaged, (uint)(flags & (int)byte.MaxValue) > 0U, (uint)(flags >> 8) > 0U, out cbLength);
}
return(Win32Native.SysAllocStringByteLen(str, (uint)cbLength));
}
internal static unsafe IntPtr ConvertToNative(int flags, string strManaged, IntPtr pNativeBuffer)
{
int num;
if (strManaged == null)
{
return(IntPtr.Zero);
}
System.StubHelpers.StubHelpers.CheckStringLength(strManaged.Length);
byte[] src = AnsiCharMarshaler.DoAnsiConversion(strManaged, 0 != (flags & 0xff), 0 != (flags >> 8), out num);
byte * pDest = (byte *)pNativeBuffer;
if (pDest == null)
{
pDest = (byte *)Marshal.AllocCoTaskMem(num + 2);
}
Buffer.memcpy(src, 0, pDest, 0, num);
pDest[num] = 0;
pDest[num + 1] = 0;
return((IntPtr)pDest);
}
internal static unsafe IntPtr ConvertToNative(string strManaged, bool fBestFit, bool fThrowOnUnmappableChar, ref int cch)
{
if (null == strManaged)
{
return(IntPtr.Zero);
}
byte *pNative;
cch = strManaged.Length;
// length field at negative offset + (# of characters incl. the terminator) * max ANSI char size
int nbytes = checked (sizeof(uint) + ((cch + 1) * Marshal.SystemMaxDBCSCharSize));
pNative = (byte *)Marshal.AllocCoTaskMem(nbytes);
int *pLength = (int *)pNative;
pNative += sizeof(uint);
if (0 == cch)
{
*pNative = 0;
*pLength = 0;
}
else
{
byte[] bytes = AnsiCharMarshaler.DoAnsiConversion(strManaged, fBestFit, fThrowOnUnmappableChar, out int nbytesused);
Debug.Assert(nbytesused >= 0 && nbytesused < nbytes, "Insufficient buffer allocated in VBByValStrMarshaler.ConvertToNative");
Buffer.Memmove(ref *pNative, ref MemoryMarshal.GetArrayDataReference(bytes), (nuint)nbytesused);
pNative[nbytesused] = 0;
*pLength = nbytesused;
}
return(new IntPtr(pNative));
}
internal static unsafe IntPtr ConvertToNative(int flags, string strManaged, IntPtr pNativeBuffer)
{
if (null == strManaged)
{
return(IntPtr.Zero);
}
int nb;
byte *pbNativeBuffer = (byte *)pNativeBuffer;
if (pbNativeBuffer != null || Marshal.SystemMaxDBCSCharSize == 1)
{
// If we are marshaling into a stack buffer or we can accurately estimate the size of the required heap
// space, we will use a "1-pass" mode where we convert the string directly into the unmanaged buffer.
// + 1 for the null character from the user. + 1 for the null character we put in.
nb = checked ((strManaged.Length + 1) * Marshal.SystemMaxDBCSCharSize + 1);
bool didAlloc = false;
// Use the pre-allocated buffer (allocated by localloc IL instruction) if not NULL,
// otherwise fallback to AllocCoTaskMem
if (pbNativeBuffer == null)
{
pbNativeBuffer = (byte *)Marshal.AllocCoTaskMem(nb);
didAlloc = true;
}
try
{
nb = Marshal.StringToAnsiString(strManaged, pbNativeBuffer, nb,
bestFit: 0 != (flags & 0xFF), throwOnUnmappableChar: 0 != (flags >> 8));
}
catch (Exception) when(didAlloc)
{
Marshal.FreeCoTaskMem((IntPtr)pbNativeBuffer);
throw;
}
}
else
{
if (strManaged.Length == 0)
{
nb = 0;
pbNativeBuffer = (byte *)Marshal.AllocCoTaskMem(2);
}
else
{
// Otherwise we use a slower "2-pass" mode where we first marshal the string into an intermediate buffer
// (managed byte array) and then allocate exactly the right amount of unmanaged memory. This is to avoid
// wasting memory on systems with multibyte character sets where the buffer we end up with is often much
// smaller than the upper bound for the given managed string.
byte[] bytes = AnsiCharMarshaler.DoAnsiConversion(strManaged,
fBestFit: 0 != (flags & 0xFF), fThrowOnUnmappableChar: 0 != (flags >> 8), out nb);
// + 1 for the null character from the user. + 1 for the null character we put in.
pbNativeBuffer = (byte *)Marshal.AllocCoTaskMem(nb + 2);
Buffer.Memmove(ref *pbNativeBuffer, ref MemoryMarshal.GetArrayDataReference(bytes), (nuint)nb);
}
}
pbNativeBuffer[nb] = 0x00;
pbNativeBuffer[nb + 1] = 0x00;
return((IntPtr)pbNativeBuffer);
}
