/// <summary>
/// Writes a structure of type T into a slice of bytes.
/// </summary>
public static void Write <[Primitive] T>(this Span <byte> slice, T value)
where T : struct
{
Contract.Requires(slice.Length >= PtrUtils.SizeOf <T>());
var cast = slice.Cast <byte, T>();
cast[0] = value;
}
// Some handy byte manipulation helpers:
/// <summary>
/// Casts a Slice of one primitive type (T) to another primitive type (U).
/// These types may not contain managed objects, in order to preserve type
/// safety. This is checked statically by a Roslyn analyzer.
/// </summary>
/// <param name="slice">The source slice, of type T.</param>
public static Span <U> Cast <[Primitive] T, [Primitive] U>(this Span <T> slice)
where T : struct
where U : struct
{
int countOfU = slice.Length * PtrUtils.SizeOf <T>() / PtrUtils.SizeOf <U>();
if (countOfU == 0)
{
return(default(Span <U>));
}
return(new Span <U>(slice.Object, slice.Offset, countOfU));
}
public static bool ScsiMiniportIdentify(this IoControl IoControl, byte TargetId, out IdentifyDevice IdentifyDevice)
{
const byte ID_CMD = 0xEC;
var SrbIoControl = new SrbIoControl(
Signagure: "SCSIDISK",
ControlCode: IOControlCode.ScsiMiniportIdentify,
Timeout: 2
);
var inparams = new Disk.Sendcmdinparams(
DriveRegs: new Disk.Ideregs(
CommandReg: ID_CMD
),
DriveNumber: TargetId
);
bool Result = IoControl.ScsiMiniport <Disk.Sendcmdinparams, IdentifyDeviceOutData>(ref SrbIoControl, inparams, out var outparams, out var ReturnBytes);
var buffer = new byte[IDENTIFY_BUFFER_SIZE];
using (PtrUtils.CreatePtr(outparams, out var IntPtr, out var Size))
{
IdentifyDevice = (IdentifyDevice)Marshal.PtrToStructure(IntPtr.Add(IntPtr, (int)Marshal.OffsetOf <Disk.Sendcmdoutparams>(nameof(Disk.Sendcmdoutparams._Buffer))), typeof(IdentifyDevice));
return(Result);
}
}
/// <summary>
/// Reads a structure of type T out of a slice of bytes.
/// </summary>
public static T Read <[Primitive] T>(this Span <byte> slice)
where T : struct
{
Contract.Requires(slice.Length >= PtrUtils.SizeOf <T>());
return(slice.Cast <byte, T>()[0]);
}
public static StorageDeviceNumber FromPtr(IntPtr IntPtr, uint Size) => PtrUtils.PtrToStructure <StorageDeviceNumber>(IntPtr, Size);
