2 // System.IO.IntPtrStream: A stream that is backed up by unmanaged memory
5 // Miguel de Icaza (miguel@ximian.com)
7 // Based on the code for MemoryStream.cs:
9 // Authors: Marcin Szczepanski (marcins@zipworld.com.au)
11 // Gonzalo Paniagua Javier (gonzalo@ximian.com)
13 // (c) 2001,2002 Marcin Szczepanski, Patrik Torstensson
14 // (c) 2003 Ximian, Inc. (http://www.ximian.com)
18 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
20 // Permission is hereby granted, free of charge, to any person obtaining
21 // a copy of this software and associated documentation files (the
22 // "Software"), to deal in the Software without restriction, including
23 // without limitation the rights to use, copy, modify, merge, publish,
24 // distribute, sublicense, and/or sell copies of the Software, and to
25 // permit persons to whom the Software is furnished to do so, subject to
26 // the following conditions:
28 // The above copyright notice and this permission notice shall be
29 // included in all copies or substantial portions of the Software.
31 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 using System.Runtime.InteropServices;
43 internal class IntPtrStream : Stream {
44 unsafe byte *base_address;
49 public event EventHandler Closed;
51 public IntPtrStream (IntPtr base_address, int size)
54 this.base_address = (byte*)((void *)base_address);
60 public override bool CanRead {
66 public override bool CanSeek {
72 public override bool CanWrite {
78 public override long Position {
85 throw new ArgumentOutOfRangeException ("Position", "Can not be negative");
87 throw new ArgumentOutOfRangeException ("Position", "Pointer falls out of range");
89 position = (int) value;
93 public override long Length {
99 public override int Read (byte [] buffer, int offset, int count)
102 throw new ArgumentNullException ("buffer");
104 if (offset < 0 || count < 0)
105 throw new ArgumentOutOfRangeException ("offset or count less than zero.");
107 if (buffer.Length - offset < count )
108 throw new ArgumentException ("offset+count",
109 "The size of the buffer is less than offset + count.");
112 throw new ObjectDisposedException ("Stream has been closed");
114 if (position >= size || count == 0)
117 if (position > size - count)
118 count = size - position;
121 Marshal.Copy ((IntPtr) (base_address + position), buffer, offset, count);
127 public override int ReadByte ()
129 if (position >= size)
133 throw new ObjectDisposedException ("Stream has been closed");
136 return base_address [position++];
140 public override long Seek (long offset, SeekOrigin loc)
142 // It's funny that they don't throw this exception for < Int32.MinValue
143 if (offset > (long) Int32.MaxValue)
144 throw new ArgumentOutOfRangeException ("Offset out of range. " + offset);
147 throw new ObjectDisposedException ("Stream has been closed");
151 case SeekOrigin.Begin:
153 throw new IOException ("Attempted to seek before start of MemoryStream.");
156 case SeekOrigin.Current:
157 ref_point = position;
163 throw new ArgumentException ("loc", "Invalid SeekOrigin");
168 ref_point += (int) offset;
170 throw new ArgumentOutOfRangeException ("Too large seek destination");
174 throw new IOException ("Attempted to seek before start of MemoryStream.");
177 position = ref_point;
181 public override void SetLength (long value)
183 throw new NotSupportedException ("This stream can not change its size");
186 public override void Write (byte [] buffer, int offset, int count)
188 throw new NotSupportedException ("This stream can not change its size");
191 public override void WriteByte (byte value)
193 throw new NotSupportedException ("This stream can not change its size");
196 public override void Flush ()
200 public override void Close ()