//
// System.IO.UnmanagedMemoryStream.cs
//
// Copyright (C) 2006 Sridhar Kulkarni, All Rights Reserved
//
// Authors:
// Sridhar Kulkarni (sridharkulkarni@gmail.com)
// Gert Driesen (drieseng@users.sourceforge.net)
// Sebastien Pouliot <sebastien@ximian.com>
//
// Copyright (C) 2005-2006, 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.
//
using System;
using System.IO;
using System.Runtime.InteropServices;
namespace System.IO{
public class UnmanagedMemoryStream : Stream
{
long length;
bool closed;
long capacity;
FileAccess fileaccess;
IntPtr initial_pointer;
long initial_position;
long current_position;
#if NET_4_0
SafeBuffer safebuffer;
#endif
internal event EventHandler Closed;
#region Constructor
protected UnmanagedMemoryStream()
{
closed = true;
}
[CLSCompliantAttribute(false)]
public unsafe UnmanagedMemoryStream (byte *pointer, long length) :
this (pointer, length, length, FileAccess.Read)
{
}
[CLSCompliantAttribute(false)]
public unsafe UnmanagedMemoryStream (byte *pointer, long length, long capacity, FileAccess access)
{
closed = true;
Initialize (pointer, length, capacity, access);
}
#if NET_4_0
public UnmanagedMemoryStream (SafeBuffer buffer, long offset, long length) :
this (buffer, offset, length, FileAccess.Read)
{
}
public UnmanagedMemoryStream (SafeBuffer buffer, long offset, long length, FileAccess access)
{
closed = true;
Initialize (buffer, offset, length, access);
}
#endif
#endregion
#region Properties
public override bool CanRead {
get {
return (!closed && (fileaccess != FileAccess.Write));
}
}
public override bool CanSeek {
get {
return !closed;
}
}
public override bool CanWrite {
get {
return (!closed && (fileaccess != FileAccess.Read));
}
}
public long Capacity {
get {
if (closed)
throw new ObjectDisposedException("The stream is closed");
else
return (capacity);
}
}
public override long Length {
get {
if (closed)
throw new ObjectDisposedException("The stream is closed");
else
return (length);
}
}
public override long Position {
get {
if (closed)
throw new ObjectDisposedException("The stream is closed");
return (current_position);
}
set {
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (value < 0)
throw new ArgumentOutOfRangeException("value", "Non-negative number required.");
if (value > (long)Int32.MaxValue)
throw new ArgumentOutOfRangeException("value", "The position is larger than Int32.MaxValue.");
current_position = value;
}
}
[CLSCompliantAttribute (false)]
public unsafe byte* PositionPointer {
get {
#if NET_4_0
if (safebuffer != null)
throw new NotSupportedException ("Not supported when using SafeBuffer");
#endif
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (current_position >= length)
throw new IndexOutOfRangeException ("value");
return (byte *) initial_pointer + current_position;
}
set {
#if NET_4_0
if (safebuffer != null)
throw new NotSupportedException ("Not supported when using SafeBuffer");
#endif
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (value < (byte *)initial_pointer)
throw new IOException ("Address is below the inital address");
Position = value - (byte*) initial_pointer;
}
}
#endregion
#region Methods
public override int Read ([InAttribute] [OutAttribute] byte[] buffer, int offset, int count)
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (buffer == null)
throw new ArgumentNullException("buffer");
if (offset < 0)
throw new ArgumentOutOfRangeException("offset", "Non-negative number required.");
if (count < 0)
throw new ArgumentOutOfRangeException("count", "Non-negative number required.");
if ((buffer.Length - offset) < count)
throw new ArgumentException("The length of the buffer array minus the offset parameter is less than the count parameter");
if (fileaccess == FileAccess.Write)
throw new NotSupportedException("Stream does not support reading");
if (current_position >= length)
return 0;
int progress = current_position + count < length ? count : (int) (length - current_position);
#if NET_4_0
if (safebuffer != null) {
unsafe {
byte *ptr = null;
try {
safebuffer.AcquirePointer (ref ptr);
Marshal.Copy (new IntPtr (ptr + current_position), buffer, offset, progress);
} finally {
if (ptr != null)
safebuffer.ReleasePointer ();
}
}
} else
#endif
{
Marshal.Copy (new IntPtr (initial_pointer.ToInt64 () + current_position), buffer, offset, progress);
}
current_position += progress;
return progress;
}
public override int ReadByte ()
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (fileaccess== FileAccess.Write)
throw new NotSupportedException("Stream does not support reading");
if (current_position >= length)
return (-1);
#if NET_4_0
if (safebuffer != null) {
unsafe {
byte *ptr = null;
try {
safebuffer.AcquirePointer (ref ptr);
return (int) Marshal.ReadByte (new IntPtr (ptr), (int) current_position++);
} finally {
if (ptr != null)
safebuffer.ReleasePointer ();
}
}
} else
#endif
{
return (int) Marshal.ReadByte(initial_pointer, (int) current_position++);
}
}
public override long Seek (long offset, SeekOrigin loc)
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
long refpoint;
switch(loc) {
case SeekOrigin.Begin:
if (offset < 0)
throw new IOException("An attempt was made to seek before the beginning of the stream");
refpoint = initial_position;
break;
case SeekOrigin.Current:
refpoint = current_position;
break;
case SeekOrigin.End:
refpoint = length;
break;
default:
throw new ArgumentException("Invalid SeekOrigin option");
}
refpoint += offset;
if (refpoint < initial_position)
throw new IOException("An attempt was made to seek before the beginning of the stream");
current_position = refpoint;
return(current_position);
}
public override void SetLength (long value)
{
#if NET_4_0
if (safebuffer != null)
throw new NotSupportedException ("Not supported when using SafeBuffer");
#endif
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (value < 0)
throw new ArgumentOutOfRangeException("length", "Non-negative number required.");
if (value > capacity)
throw new IOException ("Unable to expand length of this stream beyond its capacity.");
if (fileaccess == FileAccess.Read)
throw new NotSupportedException ("Stream does not support writing.");
length = value;
if (length < current_position)
current_position = length;
}
public override void Flush ()
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
//This method performs no action for this class
//but is included as part of the Stream base class
}
protected override void Dispose (bool disposing)
{
if (closed)
return;
closed = true;
if (Closed != null)
Closed (this, null);
}
public override void Write (byte[] buffer, int offset, int count)
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (buffer == null)
throw new ArgumentNullException("The buffer parameter is a null reference");
if (offset < 0)
throw new ArgumentOutOfRangeException("offset", "Non-negative number required.");
if (count < 0)
throw new ArgumentOutOfRangeException("count", "Non-negative number required.");
if ((buffer.Length - offset) < count)
throw new ArgumentException("The length of the buffer array minus the offset parameter is less than the count parameter");
if (current_position > capacity - count)
throw new NotSupportedException ("Unable to expand length of this stream beyond its capacity.");
if (fileaccess == FileAccess.Read)
throw new NotSupportedException ("Stream does not support writing.");
#if NET_4_0
if (safebuffer != null) {
unsafe {
byte *dest = null;
try {
safebuffer.AcquirePointer (ref dest);
fixed (byte *src = buffer) {
dest += current_position;
String.memcpy (dest, src + offset, count);
}
} finally {
if (dest != null)
safebuffer.ReleasePointer ();
}
}
} else
#endif
{
unsafe {
fixed (byte *src = buffer) {
byte *dest = (byte *) initial_pointer + current_position;
String.memcpy (dest, src + offset, count);
}
}
}
current_position += count;
if (current_position > length)
length = current_position;
}
public override void WriteByte (byte value)
{
if (closed)
throw new ObjectDisposedException("The stream is closed");
if (current_position == capacity)
throw new NotSupportedException("The current position is at the end of the capacity of the stream");
if (fileaccess == FileAccess.Read)
throw new NotSupportedException("Stream does not support writing.");
#if NET_4_0
if (safebuffer != null) {
unsafe {
byte *dest = null;
try {
safebuffer.AcquirePointer (ref dest);
dest += current_position++;
*dest = value;
} finally {
if (dest != null)
safebuffer.ReleasePointer ();
}
}
} else
#endif
{
unsafe {
byte *dest = (byte *) initial_pointer + (int) current_position++;
*dest = value;
}
}
if (current_position > length)
length = current_position;
}
[CLSCompliant (false)]
protected unsafe void Initialize (byte* pointer, long length,
long capacity,
FileAccess access)
{
if (pointer == null)
throw new ArgumentNullException("pointer");
if (length < 0)
throw new ArgumentOutOfRangeException("length", "Non-negative number required.");
if (capacity < 0)
throw new ArgumentOutOfRangeException("capacity", "Non-negative number required.");
if (length > capacity)
throw new ArgumentOutOfRangeException("length", "The length cannot be greater than the capacity.");
if ((access < FileAccess.Read) || (access > FileAccess.ReadWrite))
throw new ArgumentOutOfRangeException ("access", "Enum value was out of legal range.");
if (!closed)
throw new InvalidOperationException ("Called Initialize twice");
fileaccess = access;
this.length = length;
this.capacity = capacity;
initial_position = 0;
current_position = initial_position;
initial_pointer = new IntPtr ((void*)pointer);
closed = false;
}
#if NET_4_0
protected void Initialize (SafeBuffer buffer, long offset, long length, FileAccess access)
{
if (buffer == null)
throw new ArgumentNullException ("buffer");
if (offset < 0)
throw new ArgumentOutOfRangeException ("offset");
if (length < 0)
throw new ArgumentOutOfRangeException ("length");
ulong blength = buffer.ByteLength;
if ((blength - (ulong) length) < (ulong) offset)
throw new ArgumentException ("Invalid offset and/or length");
if (access < FileAccess.Read || access > FileAccess.ReadWrite)
throw new ArgumentOutOfRangeException ("access");
if (!closed)
throw new InvalidOperationException ("Called Initialize twice");
this.length = length;
this.capacity = length;
this.fileaccess = access;
this.safebuffer = buffer;
initial_position = offset;
current_position = offset;
closed = false;
}
#endif
#endregion
}
}
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