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//
// MemoryMappedViewStream.cs
//
// Authors:
// Zoltan Varga (vargaz@gmail.com)
//
// Copyright (C) 2009, Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#if NET_4_0
using System;
using System.IO;
namespace System.IO.MemoryMappedFiles
{
public sealed class MemoryMappedViewStream : UnmanagedMemoryStream {
IntPtr mmap_addr;
ulong mmap_size;
object monitor;
internal MemoryMappedViewStream (FileStream file, long offset, long size, MemoryMappedFileAccess access) {
monitor = new Object ();
if (Environment.OSVersion.Platform < PlatformID.Unix)
throw new NotImplementedException ("Not implemented on windows.");
else
CreateStreamPosix (file, offset, size, access);
}
unsafe void CreateStreamPosix (FileStream file, long offset, long size, MemoryMappedFileAccess access) {
long fsize = file.Length;
if (size == 0 || size > fsize)
size = fsize;
int offset_diff;
MemoryMappedFile.MapPosix (file, offset, size, access, out mmap_addr, out offset_diff, out mmap_size);
FileAccess faccess;
switch (access) {
case MemoryMappedFileAccess.ReadWrite:
faccess = FileAccess.ReadWrite;
break;
case MemoryMappedFileAccess.Read:
faccess = FileAccess.Read;
break;
case MemoryMappedFileAccess.Write:
faccess = FileAccess.Write;
break;
default:
throw new NotImplementedException ("access mode " + access + " not supported.");
}
Initialize ((byte*)mmap_addr + offset_diff, size, size, faccess);
}
protected override void Dispose (bool disposing)
{
base.Dispose (disposing);
lock (monitor) {
if (mmap_addr != (IntPtr)(-1)) {
MemoryMappedFile.UnmapPosix (mmap_addr, mmap_size);
mmap_addr = (IntPtr)(-1);
}
}
}
}
}
#endif
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