//
// System.IO.StreamReader.cs
//
-// Author:
+// Authors:
// Dietmar Maurer (dietmar@ximian.com)
// Miguel de Icaza (miguel@ximian.com)
// Marek Safar (marek.safar@gmail.com)
//
// (C) Ximian, Inc. http://www.ximian.com
// Copyright (C) 2004 Novell (http://www.novell.com)
-// Copyright 2011 Xamarin Inc.
+// Copyright 2011, 2013 Xamarin Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
using System;
using System.Text;
using System.Runtime.InteropServices;
+#if NET_4_5
+using System.Threading.Tasks;
+#endif
namespace System.IO {
[Serializable]
[ComVisible (true)]
- public class StreamReader : TextReader {
+ public class StreamReader : TextReader
+ {
+ sealed class NullStreamReader : StreamReader
+ {
+ internal NullStreamReader ()
+ {
+ base_stream = Stream.Null;
+ }
+
+ public override int Peek ()
+ {
+ return -1;
+ }
+
+ public override int Read ()
+ {
+ return -1;
+ }
+
+ public override int Read ([In, Out] char[] buffer, int index, int count)
+ {
+ return 0;
+ }
+
+ public override string ReadLine ()
+ {
+ return null;
+ }
+
+ public override string ReadToEnd ()
+ {
+ return String.Empty;
+ }
+
+ public override Stream BaseStream {
+ get { return Stream.Null; }
+ }
+
+ public override Encoding CurrentEncoding {
+ get { return Encoding.Unicode; }
+ }
+ }
const int DefaultBufferSize = 1024;
const int DefaultFileBufferSize = 4096;
bool mayBlock;
- private class NullStreamReader : StreamReader {
- public override int Peek ()
- {
- return -1;
- }
-
- public override int Read ()
- {
- return -1;
- }
-
- public override int Read ([In, Out] char[] buffer, int index, int count)
- {
- return 0;
- }
-
- public override string ReadLine ()
- {
- return null;
- }
-
- public override string ReadToEnd ()
- {
- return String.Empty;
- }
-
- public override Stream BaseStream
- {
- get { return Stream.Null; }
- }
-
- public override Encoding CurrentEncoding
- {
- get { return Encoding.Unicode; }
- }
- }
+#if NET_4_5
+ IDecoupledTask async_task;
+ readonly bool leave_open;
+#endif
public new static readonly StreamReader Null = new NullStreamReader ();
- internal StreamReader() {}
+ private StreamReader() {}
public StreamReader(Stream stream)
- : this (stream, Encoding.UTF8Unmarked, true, DefaultBufferSize) { }
+ : this (stream, Encoding.UTF8, true, DefaultBufferSize) { }
public StreamReader(Stream stream, bool detectEncodingFromByteOrderMarks)
- : this (stream, Encoding.UTF8Unmarked, detectEncodingFromByteOrderMarks, DefaultBufferSize) { }
+ : this (stream, Encoding.UTF8, detectEncodingFromByteOrderMarks, DefaultBufferSize) { }
public StreamReader(Stream stream, Encoding encoding)
: this (stream, encoding, true, DefaultBufferSize) { }
: this (stream, encoding, detectEncodingFromByteOrderMarks, DefaultBufferSize) { }
#if NET_4_5
- readonly bool leave_open;
-
public StreamReader(Stream stream, Encoding encoding, bool detectEncodingFromByteOrderMarks, int bufferSize)
: this (stream, encoding, detectEncodingFromByteOrderMarks, bufferSize, false)
{
}
public StreamReader(string path)
- : this (path, Encoding.UTF8Unmarked, true, DefaultFileBufferSize) { }
+ : this (path, Encoding.UTF8, true, DefaultFileBufferSize) { }
public StreamReader(string path, bool detectEncodingFromByteOrderMarks)
- : this (path, Encoding.UTF8Unmarked, detectEncodingFromByteOrderMarks, DefaultFileBufferSize) { }
+ : this (path, Encoding.UTF8, detectEncodingFromByteOrderMarks, DefaultFileBufferSize) { }
public StreamReader(string path, Encoding encoding)
: this (path, encoding, true, DefaultFileBufferSize) { }
pos = 0;
}
- public virtual Stream BaseStream
- {
+ public virtual Stream BaseStream {
get {
return base_stream;
}
}
- public virtual Encoding CurrentEncoding
- {
+ public virtual Encoding CurrentEncoding {
get {
- if (encoding == null)
- throw new Exception ();
return encoding;
}
}
public void DiscardBufferedData ()
{
+ CheckState ();
+
pos = decoded_count = 0;
mayBlock = false;
// Discard internal state of the decoder too.
}
// the buffer is empty, fill it again
- private int ReadBuffer ()
+ // Keep in sync with ReadBufferAsync
+ int ReadBuffer ()
{
pos = 0;
- int cbEncoded = 0;
// keep looping until the decoder gives us some chars
decoded_count = 0;
- int parse_start = 0;
- do
- {
- cbEncoded = base_stream.Read (input_buffer, 0, buffer_size);
-
+ do {
+ var cbEncoded = base_stream.Read (input_buffer, 0, buffer_size);
if (cbEncoded <= 0)
return 0;
- mayBlock = (cbEncoded < buffer_size);
- if (do_checks > 0){
- Encoding old = encoding;
- parse_start = DoChecks (cbEncoded);
- if (old != encoding){
- int old_decoded_size = old.GetMaxCharCount (buffer_size) + 1;
- int new_decoded_size = encoding.GetMaxCharCount (buffer_size) + 1;
- if (old_decoded_size != new_decoded_size)
- decoded_buffer = new char [new_decoded_size];
- decoder = encoding.GetDecoder ();
- }
- do_checks = 0;
- cbEncoded -= parse_start;
- }
-
- decoded_count += decoder.GetChars (input_buffer, parse_start, cbEncoded, decoded_buffer, 0);
- parse_start = 0;
+ decoded_count = ReadBufferCore (cbEncoded);
} while (decoded_count == 0);
return decoded_count;
}
+ int ReadBufferCore (int cbEncoded)
+ {
+ int parse_start;
+
+ mayBlock = cbEncoded < buffer_size;
+ if (do_checks > 0){
+ Encoding old = encoding;
+ parse_start = DoChecks (cbEncoded);
+ if (old != encoding){
+ int old_decoded_size = old.GetMaxCharCount (buffer_size) + 1;
+ int new_decoded_size = encoding.GetMaxCharCount (buffer_size) + 1;
+ if (old_decoded_size != new_decoded_size)
+ decoded_buffer = new char [new_decoded_size];
+ decoder = encoding.GetDecoder ();
+ }
+ do_checks = 0;
+ cbEncoded -= parse_start;
+ } else {
+ parse_start = 0;
+ }
+
+ return decoder.GetChars (input_buffer, parse_start, cbEncoded, decoded_buffer, 0);
+ }
+
//
// Peek can block:
// http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=96484
//
public override int Peek ()
{
- if (base_stream == null)
- throw new ObjectDisposedException ("StreamReader", "Cannot read from a closed StreamReader");
+ CheckState ();
+
if (pos >= decoded_count && ReadBuffer () == 0)
return -1;
public override int Read ()
{
- if (base_stream == null)
- throw new ObjectDisposedException ("StreamReader", "Cannot read from a closed StreamReader");
+ CheckState ();
+
if (pos >= decoded_count && ReadBuffer () == 0)
return -1;
return decoded_buffer [pos++];
}
+ // Keep in sync with ReadAsync
public override int Read ([In, Out] char[] buffer, int index, int count)
{
- if (base_stream == null)
- throw new ObjectDisposedException ("StreamReader", "Cannot read from a closed StreamReader");
if (buffer == null)
throw new ArgumentNullException ("buffer");
if (index < 0)
if (index > buffer.Length - count)
throw new ArgumentException ("index + count > buffer.Length");
+ CheckState ();
+
int chars_read = 0;
- while (count > 0)
- {
+ while (count > 0) {
if (pos >= decoded_count && ReadBuffer () == 0)
return chars_read > 0 ? chars_read : 0;
return -1;
}
+ // Keep in sync with ReadLineAsync
public override string ReadLine()
{
- if (base_stream == null)
- throw new ObjectDisposedException ("StreamReader", "Cannot read from a closed StreamReader");
+ CheckState ();
if (pos >= decoded_count && ReadBuffer () == 0)
return null;
int end = FindNextEOL ();
if (end < decoded_count && end >= begin)
return new string (decoded_buffer, begin, end - begin);
- else if (end == -2)
+ if (end == -2)
return line_builder.ToString (0, line_builder.Length);
if (line_builder == null)
return sb.ToString (0, sb.Length);
}
return line_builder.ToString (0, line_builder.Length);
- } else if (end == -2)
+ }
+
+ if (end == -2)
return line_builder.ToString (0, line_builder.Length);
}
}
+ // Keep in sync with ReadToEndAsync
public override string ReadToEnd()
+ {
+ CheckState ();
+
+ StringBuilder text = new StringBuilder ();
+
+ do {
+ text.Append (decoded_buffer, pos, decoded_count - pos);
+ } while (ReadBuffer () != 0);
+
+ return text.ToString ();
+ }
+
+ void CheckState ()
{
if (base_stream == null)
throw new ObjectDisposedException ("StreamReader", "Cannot read from a closed StreamReader");
+#if NET_4_5
+ if (async_task != null && !async_task.IsCompleted)
+ throw new InvalidOperationException ();
+#endif
+ }
+
+#if NET_4_5
+ public override int ReadBlock ([In, Out] char[] buffer, int index, int count)
+ {
+ 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");
+
+ CheckState ();
+
+ return base.ReadBlock (buffer, index, count);
+ }
+
+ public override Task<int> ReadAsync (char[] buffer, int index, int count)
+ {
+ 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");
+
+ CheckState ();
+
+ DecoupledTask<int> res;
+ async_task = res = new DecoupledTask<int> (ReadAsyncCore (buffer, index, count));
+ return res.Task;
+ }
+
+ async Task<int> ReadAsyncCore (char[] buffer, int index, int count)
+ {
+ int chars_read = 0;
+
+ while (count > 0) {
+ if (pos >= decoded_count && await ReadBufferAsync ().ConfigureAwait (false) == 0)
+ return chars_read > 0 ? chars_read : 0;
+
+ int cch = Math.Min (decoded_count - pos, count);
+ Array.Copy (decoded_buffer, pos, buffer, index, cch);
+ pos += cch;
+ index += cch;
+ count -= cch;
+ chars_read += cch;
+ if (mayBlock)
+ break;
+ }
+
+ return chars_read;
+ }
+
+ public override Task<int> ReadBlockAsync (char[] buffer, int index, int count)
+ {
+ 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");
+
+ CheckState ();
+
+ DecoupledTask<int> res;
+ async_task = res = new DecoupledTask<int> (ReadAsyncCore (buffer, index, count));
+ return res.Task;
+ }
+
+ public override Task<string> ReadLineAsync ()
+ {
+ CheckState ();
+
+ DecoupledTask<string> res;
+ async_task = res = new DecoupledTask<string> (ReadLineAsyncCore ());
+ return res.Task;
+ }
+
+ async Task<string> ReadLineAsyncCore ()
+ {
+ if (pos >= decoded_count && await ReadBufferAsync ().ConfigureAwait (false) == 0)
+ return null;
+
+ int begin = pos;
+ int end = FindNextEOL ();
+ if (end < decoded_count && end >= begin)
+ return new string (decoded_buffer, begin, end - begin);
+ if (end == -2)
+ return line_builder.ToString (0, line_builder.Length);
+
+ if (line_builder == null)
+ line_builder = new StringBuilder ();
+ else
+ line_builder.Length = 0;
+
+ while (true) {
+ if (foundCR) // don't include the trailing CR if present
+ decoded_count--;
+
+ line_builder.Append (decoded_buffer, begin, decoded_count - begin);
+ if (await ReadBufferAsync ().ConfigureAwait (false) == 0) {
+ if (line_builder.Capacity > 32768) {
+ StringBuilder sb = line_builder;
+ line_builder = null;
+ return sb.ToString (0, sb.Length);
+ }
+ return line_builder.ToString (0, line_builder.Length);
+ }
+
+ begin = pos;
+ end = FindNextEOL ();
+ if (end < decoded_count && end >= begin) {
+ line_builder.Append (decoded_buffer, begin, end - begin);
+ if (line_builder.Capacity > 32768) {
+ StringBuilder sb = line_builder;
+ line_builder = null;
+ return sb.ToString (0, sb.Length);
+ }
+ return line_builder.ToString (0, line_builder.Length);
+ }
+
+ if (end == -2)
+ return line_builder.ToString (0, line_builder.Length);
+ }
+ }
+
+ public override Task<string> ReadToEndAsync ()
+ {
+ CheckState ();
+
+ DecoupledTask<string> res;
+ async_task = res = new DecoupledTask<string> (ReadToEndAsyncCore ());
+ return res.Task;
+ }
+
+ async Task<string> ReadToEndAsyncCore ()
+ {
StringBuilder text = new StringBuilder ();
- int size = decoded_buffer.Length;
- char [] buffer = new char [size];
- int len;
-
- while ((len = Read (buffer, 0, size)) > 0)
- text.Append (buffer, 0, len);
+ do {
+ text.Append (decoded_buffer, pos, decoded_count - pos);
+ } while (await ReadBufferAsync () != 0);
return text.ToString ();
}
+
+ async Task<int> ReadBufferAsync ()
+ {
+ pos = 0;
+
+ // keep looping until the decoder gives us some chars
+ decoded_count = 0;
+ do {
+ var cbEncoded = await base_stream.ReadAsync (input_buffer, 0, buffer_size).ConfigureAwait (false);
+ if (cbEncoded <= 0)
+ return 0;
+
+ decoded_count = ReadBufferCore (cbEncoded);
+ } while (decoded_count == 0);
+
+ return decoded_count;
+ }
+#endif
}
}