+++ /dev/null
-//
-// System.IO.BufferedStream
-//
-// Author:
-// Matt Kimball (matt@kimball.net)
-// Ville Palo <vi64pa@kolumbus.fi>
-//
-// Copyright (C) 2004 Novell (http://www.novell.com)
-//
-
-//
-// 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.Globalization;
-using System.Runtime.InteropServices;
-
-namespace System.IO {
- [ComVisible (true)]
- public sealed class BufferedStream : Stream {
- Stream m_stream;
- byte[] m_buffer;
- 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, int bufferSize)
- {
- if (stream == null)
- throw new ArgumentNullException ("stream");
- // LAMESPEC: documented as < 0
- if (bufferSize <= 0)
- throw new ArgumentOutOfRangeException ("bufferSize", "<= 0");
- if (!stream.CanRead && !stream.CanWrite) {
- throw new ObjectDisposedException (
- Locale.GetText ("Cannot access a closed Stream."));
- }
-
- m_stream = stream;
- m_buffer = new byte [bufferSize];
- }
-
- public override bool CanRead {
- get {
- return m_stream.CanRead;
- }
- }
-
- public override bool CanWrite {
- get {
- return m_stream.CanWrite;
- }
- }
-
- public override bool CanSeek {
- get {
- return m_stream.CanSeek;
- }
- }
-
- public override long Length {
- get {
- Flush ();
- return m_stream.Length;
- }
- }
-
- public override long Position {
- get {
- CheckObjectDisposedException ();
- return m_stream.Position - m_buffer_read_ahead + m_buffer_pos;
- }
-
- set {
- 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;
- }
- }
- }
-
- protected override void Dispose (bool disposing)
- {
- if (disposed)
- return;
- if (m_buffer != null)
- Flush();
-
- m_stream.Close();
- m_buffer = null;
- disposed = true;
- }
-
- public override void Flush ()
- {
- CheckObjectDisposedException ();
-
- if (m_buffer_reading) {
- if (CanSeek)
- m_stream.Position = Position;
- } else if (m_buffer_pos > 0) {
- m_stream.Write(m_buffer, 0, m_buffer_pos);
- }
-
- m_buffer_read_ahead = 0;
- m_buffer_pos = 0;
- }
-
- 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)
- {
- CheckObjectDisposedException ();
-
- if (value < 0)
- throw new ArgumentOutOfRangeException ("value must be positive");
-
- if (!m_stream.CanWrite && !m_stream.CanSeek)
- throw new NotSupportedException ("the stream cannot seek nor write.");
-
- if ((m_stream == null) || (!m_stream.CanRead && !m_stream.CanWrite))
- throw new IOException ("the stream is not open");
-
- m_stream.SetLength(value);
- if (Position > value)
- Position = value;
- }
-
- public override int ReadByte ()
- {
- CheckObjectDisposedException ();
-
- if (!m_stream.CanRead) {
- throw new NotSupportedException (
- Locale.GetText ("Cannot read from stream"));
- }
-
- if (!m_buffer_reading) {
- Flush ();
- m_buffer_reading = true;
- }
-
- if (1 <= m_buffer_read_ahead - m_buffer_pos) {
- return m_buffer [m_buffer_pos++];
- }
- else
- {
- if (m_buffer_pos >= m_buffer_read_ahead) {
- m_buffer_pos = 0;
- m_buffer_read_ahead = 0;
- }
-
- m_buffer_read_ahead = m_stream.Read (m_buffer, 0, m_buffer.Length);
- if (1 <= m_buffer_read_ahead) {
- return m_buffer [m_buffer_pos++];
- } else {
- return -1;
- }
- }
- }
-
- public override void WriteByte (byte value)
- {
- CheckObjectDisposedException ();
- if (!m_stream.CanWrite) {
- throw new NotSupportedException (
- Locale.GetText ("Cannot write to stream"));
- }
-
- if (m_buffer_reading) {
- Flush ();
- m_buffer_reading = false;
- }
- else
- // reordered to avoid possible integer overflow
- if (m_buffer_pos >= m_buffer.Length - 1) {
- Flush ();
- }
-
- m_buffer [m_buffer_pos++] = value;
- }
-
- 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;
- }
-
- if (count <= m_buffer_read_ahead - m_buffer_pos) {
- Buffer.BlockCopyInternal (m_buffer, m_buffer_pos, array, offset, count);
-
- m_buffer_pos += count;
- if (m_buffer_pos == m_buffer_read_ahead) {
- m_buffer_pos = 0;
- m_buffer_read_ahead = 0;
- }
-
- return count;
- }
-
- int ret = m_buffer_read_ahead - m_buffer_pos;
- Buffer.BlockCopyInternal (m_buffer, m_buffer_pos, array, offset, ret);
- m_buffer_pos = 0;
- m_buffer_read_ahead = 0;
- offset += ret;
- count -= ret;
-
- if (count >= m_buffer.Length) {
- ret += m_stream.Read (array, offset, count);
- } else {
- m_buffer_read_ahead = m_stream.Read (m_buffer, 0, m_buffer.Length);
-
- if (count < m_buffer_read_ahead) {
- Buffer.BlockCopyInternal (m_buffer, 0, array, offset, count);
- m_buffer_pos = count;
- ret += count;
- } else {
- Buffer.BlockCopyInternal (m_buffer, 0, array, offset, m_buffer_read_ahead);
- ret += m_buffer_read_ahead;
- m_buffer_read_ahead = 0;
- }
- }
-
- return ret;
- }
-
- 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;
- }
-
- // reordered to avoid possible integer overflow
- if (m_buffer_pos >= m_buffer.Length - count) {
- Flush ();
- m_stream.Write (array, offset, count);
- }
- else {
- Buffer.BlockCopyInternal (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"));
- }
- }
- }
-}
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