2 // MemoryMappedViewStream.cs
5 // Zoltan Varga (vargaz@gmail.com)
7 // Copyright (C) 2009, Novell, Inc (http://www.novell.com)
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
34 namespace System.IO.MemoryMappedFiles
36 public sealed class MemoryMappedViewStream : UnmanagedMemoryStream {
42 internal MemoryMappedViewStream (int fd, long offset, long size, MemoryMappedFileAccess access) {
44 monitor = new Object ();
45 CreateStream (fd, offset, size, access);
48 unsafe void CreateStream (int fd, long offset, long size, MemoryMappedFileAccess access)
51 mmap_size = (ulong) size;
52 MemoryMapImpl.Map (fd, offset, ref size, access, out mmap_addr, out offset_diff);
56 case MemoryMappedFileAccess.ReadWrite:
57 faccess = FileAccess.ReadWrite;
59 case MemoryMappedFileAccess.Read:
60 faccess = FileAccess.Read;
62 case MemoryMappedFileAccess.Write:
63 faccess = FileAccess.Write;
66 throw new NotImplementedException ("access mode " + access + " not supported.");
68 Initialize ((byte*)mmap_addr + offset_diff, size, size, faccess);
71 protected override void Dispose (bool disposing)
73 base.Dispose (disposing);
75 if (mmap_addr != (IntPtr)(-1)) {
76 MemoryMapImpl.Unmap (mmap_addr, mmap_size);
77 mmap_addr = (IntPtr)(-1);
82 public override void Flush ()
84 MemoryMapImpl.Flush (fd);