//
// Author:
// Matt Kimball (matt@kimball.net)
+// Ville Palo <vi64pa@kolumbus.fi>
//
+// Copyright (C) 2004 Novell (http://www.novell.com)
+//
+
+using System.Globalization;
+using System.Runtime.InteropServices;
namespace System.IO {
public sealed class BufferedStream : Stream {
int m_buffer_pos;
int m_buffer_read_ahead;
bool m_buffer_reading;
+ private bool disposed = false;
- public BufferedStream(Stream stream) : this(stream, 4096) {
+ public BufferedStream (Stream stream) : this (stream, 4096)
+ {
}
- public BufferedStream(Stream stream, int buffer_size) {
+ public BufferedStream (Stream stream, int buffer_size)
+ {
+ if (stream == null)
+ throw new ArgumentNullException ("stream");
+ // LAMESPEC: documented as < 0
+ if (buffer_size <= 0)
+ throw new ArgumentOutOfRangeException ("buffer_size", "<= 0");
+ if (!stream.CanRead && !stream.CanWrite) {
+ throw new ObjectDisposedException (
+ Locale.GetText ("Cannot access a closed Stream."));
+ }
+
m_stream = stream;
- m_buffer = new byte[buffer_size];
+ m_buffer = new byte [buffer_size];
}
public override bool CanRead {
}
public override long Length {
- get {
+ get {
+ Flush ();
return m_stream.Length;
}
}
public override long Position {
get {
+ CheckObjectDisposedException ();
return m_stream.Position - m_buffer_read_ahead + m_buffer_pos;
}
set {
- Flush();
- m_stream.Position = value;
+ if (value < Position && (Position - value <= m_buffer_pos) && m_buffer_reading) {
+ m_buffer_pos -= (int) (Position - value);
+ }
+ else if (value > Position && (value - Position < m_buffer_read_ahead - m_buffer_pos) && m_buffer_reading) {
+ m_buffer_pos += (int) (value - Position);
+ }
+ else {
+ Flush();
+ m_stream.Position = value;
+ }
}
}
- public override void Close() {
- Flush();
+ public override void Close ()
+ {
+ if (m_buffer != null)
+ Flush();
+
m_stream.Close();
- m_stream = null;
m_buffer = null;
+ disposed = true;
}
- public override void Flush() {
+ public override void Flush ()
+ {
+ CheckObjectDisposedException ();
+
if (m_buffer_reading) {
if (CanSeek)
m_stream.Position = Position;
- } else {
+ } else if (m_buffer_pos > 0) {
m_stream.Write(m_buffer, 0, m_buffer_pos);
}
m_buffer_pos = 0;
}
- public override long Seek(long offset, SeekOrigin origin) {
- Flush();
- return m_stream.Seek(offset, origin);
+ public override long Seek (long offset, SeekOrigin origin)
+ {
+ CheckObjectDisposedException ();
+ if (!CanSeek) {
+ throw new NotSupportedException (
+ Locale.GetText ("Non seekable stream."));
+ }
+ Flush ();
+ return m_stream.Seek (offset, origin);
}
- public override void SetLength(long value) {
+ public override void SetLength (long value)
+ {
+ CheckObjectDisposedException ();
m_stream.SetLength(value);
+ if (Position > value)
+ Position = value;
}
- public override int ReadByte() {
+ public override int ReadByte ()
+ {
+ CheckObjectDisposedException ();
+
byte[] b = new byte[1];
if (Read(b, 0, 1) == 1) {
}
}
- public override void WriteByte(byte value) {
+ public override void WriteByte (byte value)
+ {
+ CheckObjectDisposedException ();
byte[] b = new byte[1];
b[0] = value;
Write(b, 0, 1);
}
- public override int Read(byte[] array, int offset, int count) {
+ public override int Read ([In,Out] byte[] array, int offset, int count)
+ {
+ if (array == null)
+ throw new ArgumentNullException ("array");
+ CheckObjectDisposedException ();
+ if (!m_stream.CanRead) {
+ throw new NotSupportedException (
+ Locale.GetText ("Cannot read from stream"));
+ }
+ if (offset < 0)
+ throw new ArgumentOutOfRangeException ("offset", "< 0");
+ if (count < 0)
+ throw new ArgumentOutOfRangeException ("count", "< 0");
+ // re-ordered to avoid possible integer overflow
+ if (array.Length - offset < count)
+ throw new ArgumentException ("array.Length - offset < count");
+
if (!m_buffer_reading) {
Flush();
m_buffer_reading = true;
return ret;
}
- public override void Write(byte[] array, int offset, int count) {
+ public override void Write (byte[] array, int offset, int count)
+ {
+ if (array == null)
+ throw new ArgumentNullException ("array");
+ CheckObjectDisposedException ();
+ if (!m_stream.CanWrite) {
+ throw new NotSupportedException (
+ Locale.GetText ("Cannot write to stream"));
+ }
+ if (offset < 0)
+ throw new ArgumentOutOfRangeException ("offset", "< 0");
+ if (count < 0)
+ throw new ArgumentOutOfRangeException ("count", "< 0");
+ // avoid possible integer overflow
+ if (array.Length - offset < count)
+ throw new ArgumentException ("array.Length - offset < count");
+
if (m_buffer_reading) {
Flush();
m_buffer_reading = false;
}
- if (m_buffer_pos + count >= m_buffer.Length) {
- Flush();
- m_stream.Write(array, offset, count);
- } else {
- Array.Copy(array, offset, m_buffer, m_buffer_pos, count);
+ // reordered to avoid possible integer overflow
+ if (m_buffer_pos >= m_buffer.Length - count) {
+ Flush ();
+ m_stream.Write (array, offset, count);
+ }
+ else {
+ Array.Copy (array, offset, m_buffer, m_buffer_pos, count);
m_buffer_pos += count;
}
}
+
+ private void CheckObjectDisposedException ()
+ {
+ if (disposed) {
+ throw new ObjectDisposedException ("BufferedStream",
+ Locale.GetText ("Stream is closed"));
+ }
+ }
}
}