示例#1
0
        public Stream MapView(MapAccess access, long offset, IntPtr size)
        {
            if (!IsOpen)
            {
                throw new ObjectDisposedException("MMF already closed");
            }

            IntPtr baseAddress = IntPtr.Zero;

            baseAddress = Win32MapApis.MapViewOfFile(
                _hMap, (int)access,
                (int)((offset >> 32) & 0xFFFFFFFF),
                (int)(offset & 0xFFFFFFFF), size
                );

            if (baseAddress == IntPtr.Zero)
            {
                throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
            }

            // Find out what MapProtection to use
            // based on the MapAccess flags...
            MapProtection protection;

            if (access == MapAccess.FileMapRead)
            {
                protection = MapProtection.PageReadOnly;
            }
            else
            {
                protection = MapProtection.PageReadWrite;
            }

            return(new MapViewStream(baseAddress, size.ToInt64(), protection));
        }
示例#2
0
 public override void Flush()
 {
     if (!IsOpen)
     {
         throw new ObjectDisposedException("Stream is closed");
     }
     // flush the view but leave the buffer intact
     // FIX: get rid of cast
     Win32MapApis.FlushViewOfFile(_base, (int)_length);
 }
示例#3
0
        /// <summary>
        ///   Open an existing named File Mapping object
        /// </summary>
        /// <param name="access">desired access to the map</param>
        /// <param name="name">name of object</param>
        /// <returns>The memory mapped file instance</returns>
        public static MemoryMappedFile Open(MapAccess access, String name)
        {
            MemoryMappedFile map = new MemoryMappedFile();

            map._hMap = Win32MapApis.OpenFileMapping((int)access, false, name);
            if (map._hMap == NULL_HANDLE)
            {
                throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
            }

            return(map);
        }
示例#4
0
        protected virtual void Dispose(bool disposing)
        {
            if (IsOpen)
            {
                Win32MapApis.CloseHandle(_hMap);
            }
            _hMap = NULL_HANDLE;

            if (disposing)
            {
                GC.SuppressFinalize(this);
            }
        }
示例#5
0
        Create(string fileName, MapProtection protection,
               long maxSize, String name)
        {
            MemoryMappedFile map = new MemoryMappedFile();

            // open file first
            IntPtr hFile = INVALID_HANDLE_VALUE;

            if (fileName != null)
            {
                // determine file access needed
                // we'll always need generic read access
                int desiredAccess = GENERIC_READ;
                if ((protection == MapProtection.PageReadWrite) ||
                    (protection == MapProtection.PageWriteCopy))
                {
                    desiredAccess |= GENERIC_WRITE;
                }

                // open or create the file
                // if it doesn't exist, it gets created
                hFile = Win32MapApis.CreateFile(
                    fileName, desiredAccess, 0,
                    IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
                    );
                if (hFile == INVALID_HANDLE_VALUE)
                {
                    throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
                }

                // FIX: Is support neede for zero-length files!?!
            }

            map._hMap = Win32MapApis.CreateFileMapping(
                hFile, IntPtr.Zero, (int)protection,
                (int)((maxSize >> 32) & 0xFFFFFFFF),
                (int)(maxSize & 0xFFFFFFFF), name
                );

            // close file handle, we don't need it
            if (hFile != INVALID_HANDLE_VALUE)
            {
                Win32MapApis.CloseHandle(hFile);
            }
            if (map._hMap == NULL_HANDLE)
            {
                throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
            }

            return(map);
        }
示例#6
0
        protected virtual void Dispose(bool disposing)
        {
            if (IsOpen)
            {
                Flush();
                // FIX: eliminate cast
                Win32MapApis.UnmapViewOfFile(_base);
                IsOpen = false;
            }

            if (disposing)
            {
                GC.SuppressFinalize(this);
            }
        }