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//
// NativeBuffer.cs: class for handling native pointers.
//
// Authors:
// Brian Ritchie (brianlritchie@hotmail.com)
// Sureshkumar T <tsureshkumar@novell.com> 2004.
//
// Copyright (C) Brian Ritchie, 2002
//
//
// Copyright (C) 2004 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.
//
using System;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Runtime.InteropServices;
namespace System.Data.Odbc
{
sealed class NativeBuffer : IDisposable
{
private IntPtr _ptr;
private int _length;
private bool disposed;
public NativeBuffer ()
{
}
public IntPtr Handle
{
get { return _ptr; }
set { _ptr = value; }
}
public int Size
{
get { return _length; }
}
public void AllocBuffer (int length)
{
FreeBuffer ();
_ptr = Marshal.AllocCoTaskMem (length);
_length = length;
}
public void FreeBuffer ()
{
if (_ptr == IntPtr.Zero)
return;
Marshal.FreeCoTaskMem (_ptr);
_length = 0;
_ptr = IntPtr.Zero;
}
public void EnsureAlloc (int length)
{
if (Size == length && _ptr != IntPtr.Zero)
return;
AllocBuffer (length);
}
public void Dispose (bool disposing)
{
if (disposed)
return;
FreeBuffer ();
_ptr = IntPtr.Zero;
disposed = true;
}
public void Dispose ()
{
Dispose (true);
GC.SuppressFinalize (this);
}
~NativeBuffer ()
{
Dispose (false);
}
public static implicit operator IntPtr (NativeBuffer buf)
{
return buf.Handle;
}
}
}
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