//
// System.IO.StreamWriter.cs
//
// Authors:
// Dietmar Maurer (dietmar@ximian.com)
// Paolo Molaro (lupus@ximian.com)
//
// (C) Ximian, Inc. http://www.ximian.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.Text;
using System;
using System.Runtime.InteropServices;
namespace System.IO{
[Serializable]
[ComVisible (true)]
public class StreamWriter : TextWriter {
private Encoding internalEncoding;
private Stream internalStream;
private bool iflush;
private const int DefaultBufferSize = 1024;
private const int DefaultFileBufferSize = 4096;
private const int MinimumBufferSize = 256;
private byte[] byte_buf;
private int byte_pos;
private char[] decode_buf;
private int decode_pos;
private bool DisposedAlready;
private bool preamble_done;
public new static readonly StreamWriter Null = new StreamWriter (Stream.Null, Encoding.UTF8Unmarked, 1);
public StreamWriter (Stream stream)
: this (stream, Encoding.UTF8Unmarked, DefaultBufferSize) {}
public StreamWriter (Stream stream, Encoding encoding)
: this (stream, encoding, DefaultBufferSize) {}
internal void Initialize(Encoding encoding, int bufferSize) {
internalEncoding = encoding;
decode_pos = byte_pos = 0;
int BufferSize = Math.Max(bufferSize, MinimumBufferSize);
decode_buf = new char [BufferSize];
byte_buf = new byte [encoding.GetMaxByteCount (BufferSize)];
// Fixes bug http://bugzilla.ximian.com/show_bug.cgi?id=74513
if (internalStream.CanSeek && internalStream.Position > 0)
preamble_done = true;
}
public StreamWriter (Stream stream, Encoding encoding, int bufferSize) {
if (null == stream)
throw new ArgumentNullException("stream");
if (null == encoding)
throw new ArgumentNullException("encoding");
if (bufferSize <= 0)
throw new ArgumentOutOfRangeException("bufferSize");
if (!stream.CanWrite)
throw new ArgumentException ("Can not write to stream");
internalStream = stream;
Initialize(encoding, bufferSize);
}
public StreamWriter (string path)
: this (path, false, Encoding.UTF8Unmarked, DefaultFileBufferSize) {}
public StreamWriter (string path, bool append)
: this (path, append, Encoding.UTF8Unmarked, DefaultFileBufferSize) {}
public StreamWriter (string path, bool append, Encoding encoding)
: this (path, append, encoding, DefaultFileBufferSize) {}
public StreamWriter (string path, bool append, Encoding encoding, int bufferSize) {
if (null == encoding)
throw new ArgumentNullException("encoding");
if (bufferSize <= 0)
throw new ArgumentOutOfRangeException("bufferSize");
FileMode mode;
if (append)
mode = FileMode.Append;
else
mode = FileMode.Create;
internalStream = new FileStream (path, mode, FileAccess.Write, FileShare.Read);
if (append)
internalStream.Position = internalStream.Length;
else
internalStream.SetLength (0);
Initialize(encoding, bufferSize);
}
public virtual bool AutoFlush {
get {
return iflush;
}
set {
iflush = value;
if (iflush)
Flush ();
}
}
public virtual Stream BaseStream {
get {
return internalStream;
}
}
public override Encoding Encoding {
get {
return internalEncoding;
}
}
protected override void Dispose (bool disposing)
{
Exception exc = null;
if (!DisposedAlready && disposing && internalStream != null) {
try {
Flush();
} catch (Exception e) {
exc = e;
}
DisposedAlready = true;
try {
internalStream.Close ();
} catch (Exception e) {
if (exc == null)
exc = e;
}
}
internalStream = null;
byte_buf = null;
internalEncoding = null;
decode_buf = null;
if (exc != null)
throw exc;
}
public override void Flush ()
{
if (DisposedAlready)
throw new ObjectDisposedException("StreamWriter");
Decode ();
if (byte_pos > 0) {
FlushBytes ();
internalStream.Flush ();
}
}
// how the speedup works:
// the Write () methods simply copy the characters in a buffer of chars (decode_buf)
// Decode () is called when the buffer is full or we need to flash.
// Decode () will use the encoding to get the bytes and but them inside
// byte_buf. From byte_buf the data is finally outputted to the stream.
void FlushBytes ()
{
// write the encoding preamble only at the start of the stream
if (!preamble_done && byte_pos > 0) {
byte[] preamble = internalEncoding.GetPreamble ();
if (preamble.Length > 0)
internalStream.Write (preamble, 0, preamble.Length);
preamble_done = true;
}
internalStream.Write (byte_buf, 0, byte_pos);
byte_pos = 0;
}
void Decode ()
{
if (byte_pos > 0)
FlushBytes ();
if (decode_pos > 0) {
int len = internalEncoding.GetBytes (decode_buf, 0, decode_pos, byte_buf, byte_pos);
byte_pos += len;
decode_pos = 0;
}
}
public override void Write (char[] buffer, int index, int count)
{
if (DisposedAlready)
throw new ObjectDisposedException("StreamWriter");
if (buffer == null)
throw new ArgumentNullException ("buffer");
if (index < 0)
throw new ArgumentOutOfRangeException ("index", "< 0");
if (count < 0)
throw new ArgumentOutOfRangeException ("count", "< 0");
// re-ordered to avoid possible integer overflow
if (index > buffer.Length - count)
throw new ArgumentException ("index + count > buffer.Length");
LowLevelWrite (buffer, index, count);
if (iflush)
Flush();
}
void LowLevelWrite (char[] buffer, int index, int count)
{
while (count > 0) {
int todo = decode_buf.Length - decode_pos;
if (todo == 0) {
Decode ();
todo = decode_buf.Length;
}
if (todo > count)
todo = count;
Buffer.BlockCopy (buffer, index * 2, decode_buf, decode_pos * 2, todo * 2);
count -= todo;
index += todo;
decode_pos += todo;
}
}
void LowLevelWrite (string s)
{
int count = s.Length;
int index = 0;
while (count > 0) {
int todo = decode_buf.Length - decode_pos;
if (todo == 0) {
Decode ();
todo = decode_buf.Length;
}
if (todo > count)
todo = count;
for (int i = 0; i < todo; i ++)
decode_buf [i + decode_pos] = s [i + index];
count -= todo;
index += todo;
decode_pos += todo;
}
}
public override void Write (char value)
{
if (DisposedAlready)
throw new ObjectDisposedException("StreamWriter");
// the size of decode_buf is always > 0 and
// we check for overflow right away
if (decode_pos >= decode_buf.Length)
Decode ();
decode_buf [decode_pos++] = value;
if (iflush)
Flush ();
}
public override void Write (char[] buffer)
{
if (DisposedAlready)
throw new ObjectDisposedException ("StreamWriter");
if (buffer != null)
LowLevelWrite (buffer, 0, buffer.Length);
if (iflush)
Flush ();
}
public override void Write (string value)
{
if (DisposedAlready)
throw new ObjectDisposedException("StreamWriter");
if (value != null)
LowLevelWrite (value);
if (iflush)
Flush ();
}
public override void Close()
{
Dispose (true);
}
~StreamWriter ()
{
Dispose(false);
}
}
}
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