//
// Win32APIs.cs
//    
//    Implementation of a library to use Win32 Memory Mapped
//    Files from within .NET applications
//
// COPYRIGHT (C) 2001, Tomas Restrepo (tomasr@mvps.org)
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

using System;
using System.IO;
using System.Runtime.InteropServices;

namespace DTS.Common.Utilities.IO.MemoryMap
{

    /// <summary>Win32 APIs used by the library</summary>
    /// <remarks>
    ///   Defines the PInvoke functions we use
    ///   to access the FileMapping Win32 APIs
    /// </remarks>
    internal class Win32MapApis
    {
        [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]
        public static extern IntPtr CreateFile(
           String lpFileName, int dwDesiredAccess, int dwShareMode,
           IntPtr lpSecurityAttributes, int dwCreationDisposition,
           int dwFlagsAndAttributes, IntPtr hTemplateFile);

        [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]
        public static extern IntPtr CreateFileMapping(
           IntPtr hFile, IntPtr lpAttributes, int flProtect,
           int dwMaximumSizeLow, int dwMaximumSizeHigh,
           String lpName);

        [DllImport("kernel32", SetLastError = true)]
        public static extern bool FlushViewOfFile(
           IntPtr lpBaseAddress, int dwNumBytesToFlush);

        [DllImport("kernel32", SetLastError = true)]
        public static extern IntPtr MapViewOfFile(
           IntPtr hFileMappingObject, int dwDesiredAccess, int dwFileOffsetHigh,
           int dwFileOffsetLow, int dwNumBytesToMap);

        [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]
        public static extern IntPtr OpenFileMapping(
           int dwDesiredAccess, bool bInheritHandle, String lpName);

        [DllImport("kernel32", SetLastError = true)]
        public static extern bool UnmapViewOfFile(IntPtr lpBaseAddress);

        [DllImport("kernel32", SetLastError = true)]
        public static extern bool CloseHandle(IntPtr handle);

        [DllImport("kernel32", SetLastError = false)]
        public static extern int GetLastError();

    } // class Win32MapApis

}