CORE-POS/IS4C

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

namespace ParallelLayer {

public class ParallelWrapper_Win32 : ParallelWrapper 
{

    protected const uint GENERIC_READ = 0x80000000;
    protected const uint GENERIC_WRITE = 0x40000000;
    protected const uint OPEN_EXISTING = 3;
    public static IntPtr NullHandle = IntPtr.Zero;
    protected static IntPtr InvalidHandleValue = new IntPtr(-1);

    private IntPtr native_handle;
    private SafeFileHandle safe_handle;

    [DllImport("kernel32.dll", SetLastError = true)] protected static extern IntPtr CreateFile([MarshalAs(UnmanagedType.LPStr)] string strName, uint nAccess, uint nShareMode, IntPtr lpSecurity, uint nCreationFlags, uint nAttributes, IntPtr lpTemplate);
    /** alt; use safehandles?
    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)] 
        static extern SafeFileHandle CreateFile(
            string fileName,
            [MarshalAs(UnmanagedType.U4)] FileAccess fileAccess,
            [MarshalAs(UnmanagedType.U4)] FileShare fileShare,
            IntPtr securityAttributes,
            [MarshalAs(UnmanagedType.U4)] FileMode creationDisposition,
            [MarshalAs(UnmanagedType.U4)] FileAttributes flags,
            IntPtr template
    ); */
    [DllImport("kernel32.dll", SetLastError = true)] protected static extern int CloseHandle(IntPtr hFile);

    public override FileStream GetLpHandle(string filename)
    {
        native_handle = CreateFile(filename, GENERIC_WRITE, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
        if (native_handle != InvalidHandleValue) {
            safe_handle = new SafeFileHandle(native_handle, true);
            return new FileStream(safe_handle, FileAccess.Write);
        }

        return null;
    }

    public override void CloseLpHandle(){
        try {
            safe_handle.Close();
            CloseHandle(native_handle);
        }
        catch(Exception){}
    }

} // end class

} // end namespace